HEL
1
cHSii
^'^ : -'
THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
LOS ANGELES
ULYSSES S. GRANT
COLLECTION
lie RALPH D. REED UBRAtT
UNIVERSE '. ,,f
tos AMGELES. CAUB-,
/ f 3 /
Frederick Warne Gf Co's Publications
THE LIBRARY OF NATURAL HISTORY
ROMANCE.
The Romance of Wild Flowers. A
Companion to the British Flora. By Edward Step,
F.L.S., author of " Favourite Flowers of Garden and
Greenhouse," " Wayside and Woodland Blossoms,"- &c.
In crown 8vo, cloth gilt, gilt top, price 6s.
This volume (No. i) contains upwards of 200
Original Illustrations by M. E. Step, T. Carreras, and
the Author, of which 32 are full-page plates, finely
printed in tints from photographs taken from Nature
expressly for the work.
Love of the country, which steadily grows upon our
ever-increasing town populations since they have taken to
cycling, is largely mixed up with an interest in the animal
and vegetable life of moorland, wood, and seashore. To
aid irl the identification of these creatures there are
numerous admirable Floras and Text-books, which give
the structural details with brevity and technical precision.
Unfortunately, such literature only encourages .the
enthusiast, whilst it repels all others.
The Library of Natural History Romance is projected,
not for the enthusiastic specialist, but for the others^the
readers who do not want to be told that a certain organ
or creature is of such a shape, but why it is so formed.
Structure will be indicated plainly, but the reason for that
structure and its relation to the creature's habits and mode
of life will be brought out strongly. The volumes will
really aim at imparting the most interesting facts of Natural
History in the most interesting manner, to which end the
pencil and the camera will be freely used to assist the pen.
" No one is better qualified to write a popular book on the British flora
than Mr. Edward Step. He is the guide, counsellor, and friend of eveiy
field club, and his knowledge, gained as it is from Nature herself rather than
from the library or the class-room, is placed before the unscientific reader in
just such a form as he or she can easily comprehend. Print, illustrations, and
text are alike excellent, and this library should appeal to every lover of the
country." Pall Mall Gazette.
Chandos House, Bedford Street, Strand, London
Frederick Warm & Co.'s Publications
HOW TO KNOW AND WHERE TO FIND
THE WILD FLOWERS.
Wayside and Woodland Blossoms.
First and Second Series. Pocket Guides to the British
Wild Flowers for the Country Rambler. By Edward
Step, author of "Favourite Flowers of Garden and
Greenhouse," &c. In pocket-book form, size 6 by
4 ins., in neat art linen gilt, limp binding, round
corners, price ys. 6d. each ; or in best French morocco
tuck, gilt edges, with expanding Pocket for Notes,
Specimens, &c., price los. 6d. each.
The purpose of these volumes is to assist a very large
and increasing class of persons who possess a strong love
of flowers, but to whom the ordinary " Floras " are as
books written in an unknown tongue. The author's aim
has been to write a work that, whilst it satisfied the
rambler who merely wishes to identify the flowers of his
path, might also serve as a stepping-stone to the " Floras "
of Hooker, Bentham, and Boswell-Syme.
Each volume contains over 120 coloured plates, por-
trayingabout 156 species, drawn direct from nature; among
them representatives of all the best-known genera will be
found. There are also several black and white plates, and
upwards of 400 species are clearly described in the text.
Mr. Britten, writing of the First Series in Nature Notes, said" Mr. Step
has condensed the best observations into a small compass, and his little
volume is greatly in advance of every previous undertaking. It will add
very slightly to the bulk of the most restricted arrangement of luggage, and
forms an admirable pocket companion for the lover of wild flowers. . . .
In it the reader will find much to learn and very little to unlearn, and we
know of no other that can be so unreservedly recommended to the tyro in
British Botany."
"This is just the little book which every true lover of that particular
phase of natural beauty namely, wild flowers delights to find in his
pocket when rambling along country lanes. The delicately-tinted illustra-
tions are absolutely true to their growing counterparts." Liverpool Mercury.
" It is an excellent book, which will be welcomed alike by the more
learned in flower lore and by the beginner who would be more fully versed
in the evolutions of woodland and wayside life." Sheffield Daily Telegraph.
Ghandos House, Bedford Street, Strand, London
, . . . The Library
of Natural History
. . . Romance
SHELL LIFE
i 4
i TO 7 BANDED SNAIL; 8 TO 10 WRINKLED SNAIL; n, 12 HEATH SNAIL:
13 TO 15 POINTED SNAIL.
SHELL LIFE
AN INTRODUCTION TO THE
BRITISH MOLLUSCA
EDWARD STEP, F.L.S.
AUTHOR OF
'FAVOURITE FLOWERS OF GARDEN AND GREENHOUSE'
"WAYSIDE AND WOODLAND BLOSSOMS"
"THE ROMANCE OF WILD FLOWERS" ETC. ETC.
WITH UPWARDS OF
SIX HUNDRED ILLUSTRATIONS
LONDON
FREDERICK WARNE & CO.
AND NEW YORK
1901
[All Rights Rese>-ued\
Geology
Librar
Q1L
PREFACE
rilHE object of this work is much the same as that
-* which led to the writing of its companion volume
The Romance of Wild Flowers to awaken an interest
in, and lead to a closer study of, the creatures de-
scribed. Shells and their makers, of course, necessi-
tated a different kind of treatment from that accorded
to the wild flowers ; but the author's plan of making
his readers first acquainted with the outstanding
characteristics of the prevailing types of structure
as embodied in such familiar forms as the snail, the
mussel, and the cuttle, will enable them to follow
him throughout the further chapters.
It is not pretended that this volume will enable the
reader to determine the exact species of all the native
mollusks that may come under his notice ; but it is
hoped he may get from it an intelligent idea of the
sub - kingdom so far as it is represented in these
islands, and may be assisted in discriminating between
most of those commonly encountered in the woods and
lanes, by the pond and stream, or along the seashore.
Of the seven hundred and fifty species of Mollusca in-
digenous in the British Islands and the adjacent seas,
no less than six hundred and fifty species have been
briefly described in these pages. But it is not as a
6
6 Treface
shell - collector's handbook that the volume is .sent
forth ; rather to suggest the consideration of these
creatures as living organisms, whose diversity of
form and structure has intimate relation to their
mode of life, the persecution of enemies, and other
factors in the struggle for existence though some of
us are at times too apt to regard such differences as
being dictated by the needs of the classifying
naturalist. In accordance with this intention, so
far as was compatible with the necessity for pro-
ducing a volume of handy size, attention has been
directed to those habits and external influences that
may reasonably be considered to have brought about
modifications of form and colour, protective resem-
blances, and so forth.
A few words may be added as to the system upon
which the Genera, Families, and Orders have been
grouped (see Appendix). In this matter I have
mainly followed the plan adopted by the Rev. A. H.
Cooke, M.A., in his admirable "Molluscs" (Cambridge
Natural History, vol. iii.), which is likely to long
remain the standard text-book. The reader who
desires to enter upon the wider and deeper study of
this branch of Nature will thus experience no diffi-
culty in expanding his elementary acquaintance with
our local fauna into a fuller knowledge of the
Mollusca of the world.
CONTENTS
I. INTRODUCTORY
Materials for the study of Mollusks close at hand
Garden Snail and its shell Swan Mussel and Common
Mussel Common Sepia or Cuttle Types of three principal
classes of Shell-life ...... 21
II. THE SHELL AND ITS FORMATION
Shell/?sA a misnomer Some Mollusks without shells
The primitive shell Importance of the conical form to
shore - dwellers Form of shell determined by habit of
Mollusk Comparisons between the shells of shallow and
deep water, rock and sand The door of the shell The
Oyster a degenerate Thin shells of pelagic species Thin-
ness of fresh-water shells Land-snails Shells of Slugs and
Cuttles undeveloped or absent . . . .32
III. FEEDING AND BREATHING
Oyster, though headless, has a mouth Bivalves all
tongueless Cuttles' bird-like beak The Snail's wonderful
tooth-ribbon, and thousands of teeth Powerful gizzards
Lungs and gills Air-breathers and water-breathers The
molluscan heart and circulation Blood mostly colourless . 40
IV. SEEING, HEARING AND SMELLING
Sense organs of Mollusks differ from those of higher
animals Decentralisation of sense impressions Local
brains Nerve-threads, commissures, and ganglia Eyes and
eye-spots Stalked-eyes, internal eyes, and vanished eyes
Evolution of the molluscan eye The Argus-eyed Scallops
The Saddle-oyster's sense of hearing Otocysts and
Otoliths Sense of smell more important than sight or
hearing Whelk's keen scent Slug's sense of locality A
strange form of nose Sense of touch acute . . .48
Contents
V. NUT-SHELLS AND MUSSELS
PAGE
Bivalve shells Nut-shells The "foot" of a burrower in
gravel How the valves are kept closed Hinges, locking-
teeth, and bands of muscle Leda-shells Long siphons
denote a deep burrower Microscopic food of bivalves
Saddle-oysters and their attachment-plug Noah's Ark
Dog-Cockle Eared Limopsis Common Mussel Its value
for food and bait Gregarious Its byssus, or mooring-
ropes Mussels as foreshore conservators The legend of
Bicleford Bridge Horse Mussels and their crab companion
. Crenellas ....... 54
VI. OYSTERS AND SCALLOPS
Fan Mussels and Pea-crab The Oyster : its personality
The parent of millions Their infantile activity and
later laziness " Natives " and " Green Oysters "Enemies
of the Oyster Scallops Their flight through the sea-
Purpose of the ribs and " ears " The Quiii as butterfly of
the sea File- shells , . . . . .75
VII. HEART-COCKLE AND FRESH-WATER
COCKLES
Astarte-shells Hinge-teeth and their relation to habit
of Mollusk Another reason for ribs Burrowing feet
Iceland Cyprina Heart - Cockle Lucina and Hatchet-
shells Double-tooth Urchin-shell A strange attachment
Kelly-shells Shell-collecting from fish stomachs : a big
haul Coin -shells and Crustaceans A bivalve scavenger
The Weasel's-eye : its strange use of shell Fresh-water
Cockles and their climbing ropes Pea-shells Fresh-water
Mussels: their probable origin British pearls and pearl
fishery Swan Mussels The Zebra Mussel and its strange
history . . . . . . . .92
VIII. WEDGE-SHELLS, VENUS-SHELLS, AND
COCKLES
Tellins Mud burrowers Furrow-shells Wedge-shells
with milled edges Trough-shells Circe and Artemis-
Smooth Venus, our most massive native Toothed edges
Contents 9
PAGE
not requisite The Clam Food and money Carpet-shells
The Pullet Kock Venus Rock-borers Red Nose A
molluscan hedgehog Various Cockles Common Cockle . 118
IX. GAPERS, PIDDOCKS, AND SHIPWORMS
Shells that will not shut Sunset-shells Old Maid, a
mud dweller Its remarkable siphons, always extended
Basket-shells Otter-shells or " Clumps "Eaten in Herm
Razors of sorts Why the hinge is not central Razors
not so sharp as mussels Saxicava Flask-shell Piddocks
How rocks are broken up Multivalve shells Paper
Piddocks -Wood Piddock Ship-worms How wreckage is
disposed of Pandora Lantern-shells Skye Gaper . 144
X. TUSK-SHELLS, MAIL-SHELLS, AND LIMPETS
Elephant's - tusk A connecting link Mail-shells A
shell of plates Tortoiseshell Limpets Other Limpets-
Common Limpet and its stronghold How it adheres Its
excavating powers Its homing habit Blue-rayed Limpet :
its two forms Slit-limpets and Keyhole-limpets Ormer
or Sea Ear Its perforated shell . . . .178
XI. TOP-SHELLS AND PHEASANT-SHELL
Dolphin -shells Umbilicus and operculum Top-shells
Pheasant-shell A tiny gem Fresh- water Nerite Prob-
able origin from a marine form . . . 199
XII. NECKLACE-SHELLS AND WINKLES
Violet Sea-snail and its egg-raft Eyeless derelicts
Wentletraps or Staircase-shells A forty-guinea shell
Aclis-shells Necklace-shells and their strange egg-bands
How shells are reduced Marsenia : a snail that is seen
through Protective resemblance Velvet-shell Bonnet
Limpets Hungarian Cap Cup - and - Saucer Limpet
A quaint interior Winkles Dwarf Winkle and its
resemblance to bladders of Fucus Rough Winkle Is it
becoming a land-snail ? An object-lesson in evolution
Periwinkle Chink-shells 210
i o Contents
XIII. SPIRE-SHELLS AND MARSH-SNAILS
PAGE
Round-mouthed Snail A sea-snail that has left the sea
Evidences of its origin Its shell door Its enemy, Drilus
Point-shell Spire-shells Rissoas and Hydrobias Small
and numerous Fresh-water Winkles Sentinel-shells
Belted shell Marsh Snails or River Snails Viviparous
Valve-shells ... . 228
XIV. COWRY AND PYRAMID-SHELLS
Small Needle-whelk " Shillifillies "Horn-shells The
Reversed Horn Obelisk-shell Screw-shell or Auger A
snail that deliberately breaks its shell Strange history of
the Blind-shell Pelican's-foot Cowries Another object-
lesson in s 1 .. ell-evolution Margin - shell Poached Egg
Protective ornamentation European Cowry Atlanta . 238
XV. WHELKS AND CONELETS
Some toothless sea-snails Polished Eulima Of para-
sitic descent Urchin Snail A strange habitat Pyramid-
shells by the score The teeth of the Whelk family
Spindle-shells Why a siphon is needed Sting-winkles
Varices or growth lines : what they indicate Why oysters
are scarce The Purple and its dye How it clings to wave-
washed rocks Its stony shell How the Star-fish eats it
out of house and home Its singular egg-capsules Dog-
whelks Despoilers of bait Spindle-shells Red Whelk or
Buckie White Whelk Common Whelk Varieties and
monsters Egg capsules Keen scent Money value of a
Whelk " fishery "Least Whelk Conelets . . .248
XVI. SEA-SLUGS
Darwin's mistake about Sea-slugs How shells have
been discarded Actajon and Bubble-shells Snail crushers
Canoe - shells Blind burrowers Shells hidden and
thinned Lobe - shell Sea Hare A reputed depilatory-
Its colour changes Its purple clouds The true Sea-slugs
Pleurobranchus How enemies are discouraged The
origin of foot-lobes Crowned Runcina Cerata and their
functions Sea Lemons Resemblance to sponges Sense-
Contents
1 1
organs and gill - leaves Venus Slug mimics anemone
Crested Slug Declined by fishes Homberg's Triton
Devoted to Deadman's Fingers Gulf- weed Slug Carrying
one's liver outside Bushy - backed Slug Disguise a
necessity Crowned Sea-nymph Marbled Slug Plumed
^Eolis Mimics Sagartia Alder's ^Eolis Green ^Eolis
Despised /Eolis : a spectral slug Embleton's ^Eolis A
variety that has taken to fresh water Other ^Eolids
Crowned yEolis : an anemone eater Hermans, Crimson and
Green Food and .shelter combined Alder's Slug Green
Elysia Falmouth Slug Pteropods .... 267
XVII. POND-SNAILS
Lung breathers Stalked -eyes and sessile eyes Herma-
phrodites Herald-shell Mouse-eared Alexia Little Ear-
shell Fresh-water Limpets Great Pond-snail A general
feeder Its development affected by size of pond Marsh
Limnaa Dwarfed Linuuca : a wet - nurse for the Liver
Fluke The evolution of Sheep Rot Tennyson and Nature
Smooth Pond-snail Ear Pond-snail Wandering Pond-
snail Glutinous Snail Involute Snail Flat - coils or
Trumpet-snails The Ram's-horn A small snail in a large
house Twisted Trumpet - snail Other Trumpet-snails
An American visitor Bladder-snails Moss Bladder-snail . 306
XVIII. LAND-SLUGS AND GLASS-SNAILS
Unpopular subjects Not all Slugs are harmful Slugs
with shells and without Carnivorous Slug A foe to earth-
worms Great Grey Slug Its liking for sculleries and
dairies A taste for cream and lamb A taster of books
Tree Slug Yellow Slug Field Slug A destroyer of seed-
lings and (reputed) consumption cure Smooth Slug
Keeled Slug Small Black Slug Glass-snail Simroth's
theory of Slug origins Draparnaud's Snail Cellar Snail
Garlic Snail Other Glass-snails Love darts . . 328
XIX. LAND-SNAILS
More Slugs Large Black Slug Fondness for fruit A
very mixed feeder Dusky Slug Garden Slug Spotted
Kerry Slug Twenty-five Helices Dwarf Snail The
1 2 Contents
reward of patient seeking Rock Snail Hounded Snail
Stone- turning and leaf-sifting Beautiful Snail Prickly
Snail A climber of trees and a parachutist Plated Snail
Cheese Snail A relic of the ancient forests Lapidary Snail
Bristly Snail Ruddy Snail A weakness for strawberries
Silky Snail Green Hairy Snail Dusky Snail Kentish
Snail Carthusian Snail Copse Snail Kne\v the way to
the tap Sandhill Snail A probable alien Banded Snail
Snail - showers The flavour of Down mutton Sheep-
snails Heath Snail Wrinkled Snail Theorising on a
false basis Pointed Snail Brown - lipped Snail Its
wonderful variation White-lipped Snail Common Garden
Snail Comes home to roost Apple Snail or Roman Snail
A reputed alien, biit more probable autochthon Apples or
pot-lids Its winter sleep Its egg-laying A chalky egg-
shellThe Apple-snail's first meal The Good Samaritan
of Shell-life Bulins Molluscan Dirty Dicks Chrysalis-
shells Numerous but minute Barred doors Tree Snail
Door-shells Mimicry of beech-buds How the ridges are
worn away Slippery Moss-snail Agate Snail A blind,
subterrranean ghoul Amber Snails and more flukes A
remarkable seashore slug . ... . . 343
XX. CUTTLES
The most highly-organised mollusks Suckers and Ink-
bags How colour-changes are effected The Common
Octopus The Curled Octopus Eight-armed Cuttles and
ten-armed Cuttles Spirula Fragile shells that cross the
Atlantic -Common Cuttle" Cuttle-bone " Hectocotylus-
arm Derivation of word Cuttle Eggs in bunches Pen-
and-ink mollusks Little Cuttle Ross' Cuttle Common
Squid First-class bait How to catch a Squid Absence of
Squid ' ' pens " on shore Egg-mops Marbled Squid
Flying Squids Architeuthis, a monstrous Squid Oceanic
Cuttles Evolution of the Cuttles' shells 383
APPENDIX
A Classified List of British Mollusks . . . 4U1
Index to Popular Names ..... 413
LIST OF ILLUSTRATIONS
PAGE PLATES
Laiul Snails (Helix) Front
Dog Cockle, \
ispiece
Top-shells and) .
PhLant-shell/^'^ 6204
Green Crenella, \Facingpage 63
Necklace-shells and)
223
etc.
Winkles / '
Great Scallop and Quin ,,
78
Periwinkle and)
226
Scallops, )
84
Chink-shells J
Astarte-shells, etc. J :
Coneletsandj
238
Iceland Cyprina and)
94
Dog-whelks J
Heart-Cockle / '
Sea-slugs . . . ,,
287
Zebra Mussel, )
99
Sea-slugs . . . ,,
294
Montagu-shells, etc. ) '
Sea-slugs . . . ,,
302
Orb-shells and)
106
Fresh-water Snails . ,,
319
Pea-shells /
Land-slugs (Limax) . ,,
334
Tellins and \
190
Slug-shells and)
340
Furrow-shells/
l^U
Glass-snails /
Wedge-shells and)
127
Land-slugs (Arion) . ,,
345
Trough-shells / '
Land-snails (Helix) . ,,
351
Venus-shells and)
130
Brown-lipped Snail . ,,
363
Carpet-shells /
AVhite-lipped Snail . ,,
364
Cockles . . . .,
139
Common Garden Snail )
Of*/
Sunset-shells and\
142
and Apple Snail J "
obo
Piddock / '
Chrysalis Snails and\
374
Mail-shells and \
182
Door-shells J '
Limpets J
Cuttles . . . ,,
383
Ormer and ^
1 ft*}
Cuttles . . . ,,
398
Blue-rayed Limpet)
iy*>
\* The above full - page plates depict about 300 figures of
Mollusks, the individual names of which will be found at the
foot of each plate.
List of Illustrations
TEXT ENGRAVINGS
INTRODUCTORY .
PAGE
21
Hinge-teeth .
PAGE
56
Shell of Garden Snail .
22
Shining Nut-shell .
57
Swan Mussel .
26
Beaked Leda .
58
Edible Mussel
27
Dwarf Leda .
58
Soft parts of Swan Mussel
Interior of Beaked Leda-
(Anodonta) .
28
shell ....
58
Young of Swan Mussel .
29
Saddle-oyster, under-side
59
Sepia .
30
Side view of Saddle-
oyster, showing mode
THE SHELL AND ITS
of attachment
60
FORMATION
32
Right side of Anomia,
Limpet ....
34
with shell removed
61
Common Top .
34
Prickly variety of the
Painted Top .
35
Saddle-oyster
61
Netted Dog-whelk .
35
Noah's Ark .
62
Wentletrap .
36
Milky Ark, interior
63
Sting-winkle .
36
Common Mussel ( My t il us
Pelican's-foot .
36
edulis), closed and
attached by the byssus
66
FEEDING AND BREATHING
40
Common Mussel, opened
Beak of a Cuttle-fish
to show the various
(Sepia)
41
organs.
67
Portions of the tongue of
Common Horse Mussel .
68
a Whelk, with a row
Part of epidermis .
69
of teeth
42
Tulip Horse Mussel
Teeth of raduhe of Lim-
Bean Horse Mussel
nica stagnates, Anci/lus
Cross-cut Crenella .
1
Jluvifttilis,&nd.Sitccinea
Marbled Crenella .
' 2
putris ....
43
Green Crenella, interior.
3
Under surface of Limpet
45
Black Crenella
3
SEEING, HEARING, AND
OYSTERS AND SCALLOPS .
5
SMELLING .
48
Fan Mussel
6
Interior of Fan Mussel,
NUT-SHELLS AND MUSSELS
54
right valve .
7
Common Nut-shell
55
Oyster, with right valve
Interior of Nut-shell
55
removed
8
List of Illustrations
Hunchback Scallop
PAGE
82
PAGE
River Pea-shell . . 109
Variegated Scallop
83
Painter's Mussel . .111
Quin or Queen
84
Pearl Mussels, showing
Seven-rayed Scallop
85
pearl within the shell,
Tiger Scallop .
85
and detached pearls . 113
Mottled Scallop, shell
Swan Mussel, end view . 114
and animal .
86
Duck Mussel . . .115
Gaping File-shell .
88
Zebra Mussel. . .116
Heart File-shell .
88
Fragile File-shell .
89
WEDGE - SHELLS, VENUS -
Gaping File-shell .
89
SHELLS AND COCKLES 118
File-shell in its nest
90
Tellin, with foot and
Gaping File - shell, in-
siphons extended . 119
terior ....
91
Blunt Tellin . . .120
Baltic Tellin . . .120
HEART - COCKLE AND
Thin Tellin . . .120
FRESH-WATER COCKLE
92
Hough Tellin, interior . 121
Furrowed Astarte .
93
White Furrow-shell . 123
Furrowed Astarte, in-
Peppery Furrow-shell . 123
terior ....
93
Hinge-plate of Peppery
Flat Astarte .
94
Furrow-shell . .123
Iceland Cyprina
95
Banded Wedge-shell . 125
Interior of Cyprina
95
Polished Wedge-shell . 125
Heart-Cockle .
96
Elliptical Trough-shell . 126
Beaks of Heart-Cockle .
96
Cut Trough-shell . . 127
Interior of Heart-Cockle
97
Rayed Trough-shell . 127
Northern Lucina .
97
Smooth Venus . .128
Globose Kelly-shell, sus-
Little Circe - shell, ex-
pended by byssus
101
terior . . . .129
Interiorof Globose Kelly-
Little Circe - shell, in-
shell .
102"
terior . . . .129
Minute Kelly-shell
102
Enlarged plan of hinge
Scaly Coin-shell
103
of Little Circe-shell . 129
Shining Coin-shell and
Rayed Artemis . .129
enlarged hinge .
105
InteriorofRayedArtemis 129
Convex Coin-shell .
105
Smooth Artemis . . 130
Turton's Weasel-eye,
Smooth Venus . . 130
open and closed .
106
Interior of Smooth Venus 131
Hinge-teeth, Sphccrium .
107
Banded Venus . .132
Horny Orb- shell
108
Warty Venus . . .132
Nut Orb- shell
108
Warty Venus, interior . 133
Lake Orb-shell
109
Striped Venus . . 133
2
i6
List of Illustrations
PAGE
Wavy Venus, exterior
Wrinkled Rock-borer
PAOK
161
and interior . .134
Arctic Rock-borer .
162
Golden Carpet-shell . 135
Flask-shell, front view .
162
Banded Carpet-shell . 135
Flask-shell, side view
162
Banded Carpet-shell, in-
Flask-shell .
163
terior . . . .136
Case of Flask-shell .
163
Pullet Carpet-shell . . 136
Pholas in its burrow
164
Cross-cut Carpet-shell . 137
Right valve of Common
Rock Venus . . .137
Piddock .
165
Rock -borer (Petricola
Portion of hinge-plate .
165
lithophaga) . . .138
Dorsal shields.
166
Rough Cockle . . 140
Common Piddock in its
Little Cockle . . .140
cell .
166
Banded Cockle . . 141
White Piddock
167
Common Cockle, interior 141
Little Piddock
167
Paper Piddock
168
GAPERS, PIDDOCKS, AND
Wood Piddock
169
SHIP-WORMS . . 144
Ship-worm
170
Blunt Gaper . . .145
Norwegian Ship-worm .
172
Hinge - teeth of Psam-
Pandora-shell .
173
mobia .... 145
Left valve of Pandora .
173
Tellin-like Sunset-shell . 146
Thin Lantern-shell .
175
Faroe Sunset-shell . . 147
Papery Lantern-shell
176
Hinge and cartilage pro-
cess of Gapers . .148
TUSK-SHELLS, MAIL-SHELLS
(
Old Maid . . .149
AND LIMPETS
178
Blunt Gaper . . .150
Elephant's Tusk-shell .
179
Basket-shell . . .151
Grooved Tusk-shell
180
Interior of Basket-shell,
Mail-shells .
181
showing hinge-teeth . 151
Under-side of Chiton and
Pointed Basket-shell . 151
profile of head
182
Sipl'.ons of Necera . . 151
Bristly Mail-shell .
183
Oblong Otter-shell . . 153
Bordered Mail-shell
185
Common Otter-shell . 154
Smooth Mail-shell .
185
Short Razor . . . 155
Marbled Mail-shell
186
Smooth Short Razor . 155
Tortoiseshell Limpet
186
Egg-shell Razor . . 156
Common Limpet .
188
Pod Razor . . .157
Blue-rayed Limpet
193
Pod Razor, interior of
Blue-rayed Limpet, older
left valve . . .158
specimen
193
Sword Razor . . .160
Keyhole Limpet
194
Wrinkled Rock- borer . 161
Punctured Limpet .
194
List of Illustrations
PAGE
Punctured Limpet, from
above . . . .195
Common Slit-limpet . 195
Rosy Slit-limpet . . 195
Ormer . . . .196
TOP-SHELLS AND PHEAS-
ANT-SHELL . . .199
Head of Grey-top . . 201
Operculum . . .201
Common Top-shell . . 201
Grey Top-shell . . 205
Painted Top . . .205
Pheasant-shell . . 207
Head of Phasianclla . 208
Fresh-water Nerite . 208
NECKLACE -SHELLS AND
WINKLES . . .210
Violet Sea-snail with its
float . . . .211
Violet -snail and float,
side view . . . 212
Head of Wentletrap . 213
Common Wentletrap . 213
Glossy Aclis-shell . . 214
Egg -band of Natica
alcleri . . . .215
Large Necklace-shell . 216
Life aspect of N. catena . 216
Common Necklace-shell . 217
Velvet-shell . . .219
Hungarian Cap . . 221
Cup-and-Saucer Limpet,
interior . . .221
Single roAV of teetli from
theradulaof Periwinkle 222
Animal of male Peri-
winkle, with the shell
removed . . .223
Periwinkle . . .224
Eggs of Periwinkle . 225
PAGE
Banded Chink-shell, . 226
Banded Chink-shell, en-
larged . . . .226
Pallid Chink-shell . . 227
Eggs and young of Pallid
Chink-shell . . .227
SPIRE-SHELLS AND MARSH-
SNAILS. . . .228
Round-mouthed Snail . 229
Latticed Spire-shell . 231
Thick-lipped Spire-shell . 231
Laver Spire-shell . . 232
Common Bithynia . . 233
Dun Sentinel . . .233
Dun Sentinel . . .234
White Belted-shell . . 234
River Snails . . .235
Common River Snail . 236
Lister's River Snail . 236
Common Valve-shell . 237
COWRY AND PYRAMID-
SHELLS. . . .238
Small Needle-whelk . 239
Auger-shell . . .240
Blind-shell . . .240
Pelican's foot . . .241
Pelican's foot, from below 242
Margin-shell, from above
and below . . . 243
Margin-shell and animal 243
Poached Egg . . .244
Poached Egg-shell . . 244
Young shell of Cowry . 245
European Cowry, from
above and below . . 245
European Cowry . . 245
Atlanta peroni . . 246
WHELKS AND CONELETS . 248
Polished Eulima , . 249
i8
List of Illustrations
PAGE TAGK
Conical Pyramid-shell . 250 Gulf-weed Slug . . 287
Staircase Pyramid . . 251 Bushy-backed Slug . . 288
Sting-winkle . . .252 Plumed .Eolis . . 291
Ribbed Spindle-shell . 252 Dotted vEolis . . .297
Purple or Dog-winkle . 255 Green Elysia . . . 301
Egg-capsules of the
Black Limapontia . . 302
Purple. . . .257
Clione . . . .303
Netted Dog-whelk . .257 Shell of Limacina . . 304
Netted Dog-whelk . . 258
Clio pymmidata . . 305
Slender Spindle-shell . 260
Common Whelk . . 262
POND-SNAILS . . .306
Row of teeth of Common
Least Herald-shell . . 307
Whelk . . .263
Mouse- eared Alexia . 308
Opercula of Whelk, nor-
Fresh-water Limpet . 309
mal form and double . 263
Part of a row of teeth
Cluster of Egg-capsules . 263
from the radula of
Least Whelk . . .265
Fresh-water Limpet . 310
Seven -ribbed Conelet . 265
Portion of row of teeth
Teeth of Bela . . .265
from radula of Great
Red Conelet . . .266
Pond-snail . . .311
Turreted Conelet . . 266
Great Pond-snail . . 312
Great Pond-snail . . 313
SEA-SLUGS . . . .267
Marsh Limnrca . .314
Actaeon-shell . . .271
Dwarfed Limna>a . . 314
Blunt Bubble-shell . . 271
Smooth Pond-snail . . 316
Canoe-shell . . . 272
Ear Pond-snail . . 317
Cylindrical Bubble-shell 272
Wandering Pond-snail . 317
Cylindrical Bubble-shell 273
Ram's- horn Snail . . 320
Southern Bubble-shell . 273
Ram's-horn . . .321
Soft Bubble-shell . . 274
Whirlpool Trumpet . 322
Gizzard -plates of Accra . 275
Margined Trumpet . 323
Soft Bubble-shell . . 275
Shining Trumpet . . 325
Lobe-shell . . .275
Fountain Bladder-snail . 325
Lobe-shell . . .276
Shell of Fountain
Sea Hare. . . . 276
Bladder-snail . . 325
Shell of Sea Hare . . 276
Moss Bladder-snail . 326
Spawn of Doris . . 282
Young of Doris, with
LAND-SLUGS AND GLASS-
shell . . . .282
SHELLS . . .328
Red Doris . . . 282
Shell-bearingSlug(Testo-
Hairy Sea Lemon . . 283
cclla haliotidea) . . 330
Crested Slug . . .286
Great Slug . . .332
List of Illustrations
Shell of Great Slug-
PAGE
333
Pellucid Glass-snail and
shell .
338
Cellar-snail
340
Tawny Glass-snail .
342
LAND-SNAILS .
343
Black Slug .
344
Lapidary Snail
353
Kentish Snail
356
Carthusian Snail .
357
Sandhill Snail
358
Pointed Snail .
362
Brown-lipped Snail
363
Mountain Bulin
370
Lesser Bulin .
370
Large Chrysalis-snail
371
Pupa an tivertigo
373
Tree Snail
373
Plaited Door-shell .
374
PAGE
Two-lipped Door-shell . 376
Slippery Moss-snail . 378
Three - toothed Moss-
snail . . . .379
Agate Snail . . .379
Amber Snail . . .380
Row of teeth of radula
of Succinea putris . 380
Large Amber Snail . 381
Graceful Amber Snail . 381
CUTTLES . . . .383
Suckers of Cuttle . . 385
Spirula peronii . . 389
Common Cuttle . . 389
Shell of Sepia . . . 390
Pen of Little Cuttle . 391
Little Cuttle, upper-side 392
Common Squid . . 394
Pen of Common Squid . 394
HE materials for beginning an
acquaintance with the shell-
bearing animals lie almost at
every back door. Should there
be an untidy corner of the
^' ( garden where empty flower-pots
are stored, a water-butt, or old wood is stood there,
without search, you may surely find a few examples of
the dingy and too common Garden Snail. Much as we
may object to the presence of this Snail where there are
choice or tender plants, we shall find it a very handy
example if we desire to obtain knowledge respecting
the class to which it belongs. All the Mollusca, it
is true, do not agree in structure with the Snail, any
more than they agree in external appearance, but we
may well adopt it as one of the few general types of
structure under which all the species may be classed.
A description of a species that is accessible to all,
and at least familiar by sight, should prove more
generally acceptable than an illustration drawn from
22 Shell Life
the sea, which to the mass of Britons is not always
get-at-able : therefore we search slightly among the
trailing ivy in the back-garden and pick up a rather
shabby-looking shell.
This is the portable house wherein is lodged the
common Garden Snail, and when the shell has been
washed by contact with the
dripping leaves after a heavy
summer shower, one may get
an idea of its true colours. It
has a yellowish ground, thickly
overlaid with spots and bands
of dark warm brown broken
by irregular lines of lighter
tint. The shell is packed with
a solid jelly of greenish hue
the living creature that formed the hard shell by
excretion from its outer surfaces, but at present it is
without form, a mere jelly in a jelly -mould.
Let us put this specimen into a saucer with a little
tepid water, and see what effect it will have upon
him. Here are just those conditions he likes best,
warmth and moisture, and he immediately begins
to emerge from his shell and assume a definite shape.
His body is elongated, with a flat base and a rounded
upper side, the front ending in a sort of head dis-
tinguished by two pairs of what children designate
"horns." These tentacles, instead of having the
character of horns, are exceedingly soft and mobile,
readily shortened to escape injury, or even completely
withdrawn into the head. The lower of these
appendages are short, and curved towards the ground ;
the upper ones are much longer and carry the eyes
Introductory 2 3
at their extremities they take an upward direction
and are waved backwards and forwards for the
purpose of receiving impressions.
The shell is supported near the middle of this
elongated body, and appears to be rather small for
the accommodation of so large an inmate, though we
have not yet seen the whole of the Snail. What we
can now see extended is generally known as the foot
the locomotive organ of the Snail. Within the
shell is a good deal more the " visceral hump " con-
taining most of the internal organs. By a series of
muscular contractions the Snail glides along upon the
sole of its foot, slime being poured out for the
necessary lubrication of its path the glistening
silvery trail that often enables the irate gardener
swiftly to avenge the loss of his choicest seedlings.
The mouth of the creature, as will have been seen,
is situated just below the smaller pair of tentacles,
and is bounded by lips. Behind the upper lip is the
horny, arched, and ribbed jaw which bites off and
breaks down the food, which is then passed over a
ribbon-like tongue, set in regular order with thousands
of hook-like teeth, which rasp it into minute frag-
ments. It then, of course, finds its way to the crop
and the stomach by way of the gullet, for, in spite of
the Snail's jelly-like, structureless appearance, it can
boast of heart, liver, kidney, reproductive organs, and
both nervous and muscular systems. With these
items we have no immediate concern, for in this
volume I do not propose to enter deeply into the
anatomy of my subjects; but there is one point to
which I must call attention. If we look at the mouth
of the shell when the Snail is extended, we shall see
24 Shell Life
that it is closely lined with a very soft material called
the mantle. The name suggests that this organ
invests the whole body of the Snail when it is with-
drawn into the shell; it does this and more the
mantle is the immediate producer of the shell.
The porcelain of our Snail's shell is composed mainly
of carbonate of lime, and a microscopical section
reveals the fact that it is made up of three distinct
layers, each formed separately by different portions
of the mantle. The material is obtained from the
tissues of the plants upon which the Snail feeds, and
has been absorbed from the soil by the roots. It
appears to be separated from the Snail's blood as this
circulates through the mantle, which has the power to
pour it in a fluid state upon its outer surface. By
exposure to the atmosphere the fluid lime mixed with
animal matter hardens into shell. This animal matter
is conchiolin, a substance not differing greatly from
chitin, of which the hard parts of insects are con-
structed. The calcareous particles appear to be held
together by the animal matter, and the whole sets
into a hard stony formation. When a portion of shell
is soaked in a weak acid, the carbonate of lime is dis-
solved and a very delicate gelatinous film is left. A
similar result is obtained in the case of Whelk and
Top-shells to which certain sea-anemones attach them-
selves. The base of the anemone appears to pour out
some acid which dissolves the lime and leaves only a
soft papery shell-form behind. When the mollusk is
dead and the empty shell is left exposed to the atmo-
sphere, the animal matter soon perishes and leaves the
shell without gloss and exceedingly brittle.
All parts of the mantle have power to excrete one
Introductory 2 5
or other layers of this shell, as is proved by the repair
of breakages. Many an adult shell bears signs of
earlier accidents, the fractures being always evident
from the fact that the colour patterns of the original
are not reproduced. It is only the edge of the mantle
that can produce the colour and pattern, and this is
the part that first makes all the additions to a grow-
ing shell to allow room for the growth of the animal,
whilst the other parts of the mantle merely strengthen
this first layer by backing and thickening it. The
upper layer therefore carries the pattern and colour,
whilst the lowest layer is usually white and highly
polished. Outside all there is a kind of animal
varnish, protecting the shell from many injuries, and
this is known sometimes as the epidermis, but more
correctly as the periostracum. Sometimes the shelly
matter assumes the crystalline condition, the carbonate
of lime having taken the form of calcite or aragonite.
The statement made above that the fluid shell-matter
is poured out and moulded upon the external surface
of the mantle is the modern view generally held, but
some authorities agree with the late Dr. W. B.
Carpenter, who held that it was secreted in the cells
and interstices of the outer membrane of the mantle,
which was afterwards separated.
The Snail breathes air, but its " lung " is merely a
cavity opening directly on the surface of the animal
and closed at will, in a manner corresponding to the
opening and closing of our lips. Its inner walls are
lined with a fine network of vessels through which
the blood courses, absorbing oxygen from the moist
air and giving off carbon. This simple form of lung
is referred to as the Pulmonary Sac, and its external
26 Shell Life
opening may be watched for just below the lip of the
shell on the right-hand side.
Each individual Garden Snail combines the func-
tions of both sexes. When one reflects that every one
of those Snails clustering under the ivy will probably
produce numerous eggs, he ceases to wonder at the
enormous number that contrives to survive in spite of
the depredations of birds and gardeners. One hundred
may be taken as the average number of its eggs, and
these are deposited in cup-shaped hollows among
herbage, and covered with a little loose earth. The
young come forth with the same shape as their parents,
carrying a tiny, glassy shell on their backs, and differ-
ing only in size. They become adult in about a year,
and live until about five years old. Late in autumn
they retire in companies to dry nooks and corners,
there to spend the winter, many of them attaching
their shells to those of their neighbours, all closed by
tough films which keep in some degree of warmth.
The Snail is not the stupid senseless creature he
is commonly thought to be.
His entire body is very sensi-
tive, and even when deprived
of his eyes he can distinguish
between light and darkness.
His sense of locality is of a
high order, for he has his
favourite roosting place and
invariably returns to it for
his day's rest after a night's
wanderings in search of food.
As an example of a second class of shells and shell-
makers, let us take either of the large Swan Mussels
Introductory 27
that live in fresh-water ponds and lakes, or the Edible
Mussel of our seashores. These are so much alike
in general structure, that
either will serve our present
purpose. Here the shell is
a bivalve that is, it is
formed in two pieces (valves)
which are hinged together
by their upper edges. Having
., . j. i ., Edible Mussel
seen that the shell of the
Snail was produced by the mantle, we shall not
be surprised to find that the Swan Mussel's mantle
is in two parts corresponding with the valves
of the shell. Within the two lobes of the mantle
there are four plates or leaves of very delicate tissue
the gills in two pairs. Between these again lie the
foot, the visceral mass, and the lips of the mouth.
This creature, though it has a mouth, has no head,
and it does not wander about in search of food, but
lies partly embedded in the mud with the shell gaping
slightly, and waits for its food to come to it.
The gill-plates are covered with delicate filaments
(cilia) like the gossamer of small spiders, and, appar-
ently by the constant rhythmical movement of these,
currents of water are drawn in, passed over and between
the gills, where the blood circulating through their
tissues absorbs the oxygen, whilst the microscopic forms
of animal and plant life with which the waters abound
are filtered out and passed to the lips. This being
the method of their feeding, the bivalves lack the
horny jaws and the tooth-studded ribbon such as we
found in the Garden Snail. Occasionally examples
of the Swan Mussel are found combining the functions
28
Shell Life
of both sexes, but as a rule in bivalves the sexes are
in separate individuals.
We have here several points of difference in struc-
ture and habit be-
tween the Garden
Snail and the Swan
Mussel ; there is
also a want of
uniformity in the
length of their
lives, for our pres-
ent subject attains
a respectable old
age varying from
twenty to thirty
years, and does
not begin to pro-
duce young until
it is five years old.
This difference of
age may be at
,/*' f j least partly ac-
Soft parts of Swan Mussel (Anodonta) COUnted for by the
foot; b, mouth; c, lips; d, c, gills; /, vent; quiet Sedentary
g, mantle; h, siphon ,. .. , , .*
lire lived by the
Swan Mussel, which has also probably brought about
a condition of degeneration from a primitive form ;
whilst the active Snail has no doubt advanced from
that primitive condition. The evidences of this
degeneration are to be found in the loss of head,
eyes, masticatory apparatus, and reduced means of
locomotion.
One other dissimilarity between these two types
Introductory 29
must be noted. We have seen that the Snail lays
eggs, and that when the young escape from these
they resemble their parents in
all respects other than size.
The Swan Mussel retains its
eggs until they hatch, but the
little creatures that emerge in
no wise resemble the parent.
They appear to represent an
early ancestral condition of
the species. They have a temporary two-valved shell
with hooked tips, with which they cling to the fins
and tails of fishes, leading a kind of parasitical
existence for a time ; and then they drop to the
mud where a new and permanent shell grows within
the valves of their cradle. This part of the Swan
Mussel's history may be dealt with more fully later.
Our third type of structure must be sought in the
sea, for it has neither land nor fresh- water repre-
sentative. It is the Common Sepia, one of the
Cuttles. Here there is no sign of an external shell,
and the shape is altogether different from either of
those we have already considered. The Sepia is
quite symmetrical in form, with a distinct head
surmounted by a crown of eight arms and two long
clubbed tentacles. In the centre of this crown is the
mouth, armed with a pair of horny jaws not greatly
unlike the beak of a parrot, which they resemble in
their action. Within the mouth there is a tooth-
ribbon like that of the Snail, but it is comparatively
small, because the principal work of disintegration
of food is done by the jaws, and the Sepia's digestive
powers are of a superior order. The eyes are large
Shell Life
and prominent, placed on the sides of the head below
the arms. There is no external shell, but in the
mantle there is the one
familiarly known as
" C u 1 1 1 e - bo n e," more
especially to bird fanciers.
This consists of a thin
hard shield, filled with
thin soft plates of porous
lime.
The Sepia can walk
head downwards by the
aid of its arms, whose
inner surfaces are covered
with powerful suckers ; it
can also swim rapidly
backwards by violently
ejecting water from the
gill-chamber through a
tube called the funnel.
The opening by which
water is admitted to the pair of gills is in front
below the arms. The sexes are distinct, and the
young are produced from eggs attached in great
clusters to seaweeds.
These three creatures the Garden Snail, the
Swan Mussel, and the Sepia stand as types of
the three principal classes of mollusks with which
we have to deal in the following pages ; and we
have so introduced them on the principle of pro-
ceeding from the most generally known to the less
known. Regarded from the point of view of the
systematic naturalist, the Sepia, as the highest
Sepia
Introductory 3 1
type, should stand first, the Snail next, and the
Swan Mussel last, its structure being more primi-
tive than that of the others, but reversing this
order we propose to deal first with the more simple
forms. For the natural sequence of the British
species, proceeding from the most highly organised
to the lowest groups, the reader is referred to the
Appendix.
HE great group of animals
briefly considered in the fol-
lowing pages has been singu-
larly unfortunate in the names
that have been bestowed upon it. The majority
of the creatures comprised in it have been described
as Shell -fisli by the non - scientific person, and as
such associated with forms so dissimilar as crabs
and lobsters, which resemble oysters and whelks
only in the fact that they are not fishes. On the
other hand, when the great Cuvier was seeking a
name for the entire class in which cuttles, snails,
bivalves, and slugs are included, and wishing to
indicate the soft, boneless character of their bodies,
he selected the word Mollusca, derived from the
Latin mollis, soft. But it is not a very distinctive
name, for there are many soft boneless creatures not
included in the group, and moreover the Romans
used the name for a kind of nut with a soft shell.
32
The Shell and its Formation 3 3
We are, therefore, in the position of having no well-
known name that will apply with anything approach-
ing accuracy or distinctness, in the way, for example,
that we denote beasts, birds, reptiles, and fishes ; and
there does not appear to be any prospect of getting
what we want. The naturalist is so used to the
term mollusk that he is not likely to seek or adopt
another, and the layman is too conservative to give
up so well-known and so inaccurate a name as Shell-
fish. The reader will understand why the word
" Shells " occupies a more important position in the
title of this volume than the makers and wearers of
those shells, and will not regard it as being due to
sympathy with the early collectors and writers who
regarded the shell as of chief importance, and the
animal that secreted and lived in it as quite a
secondary matter.
In such a case accuracy is out of the question, for
many of the creatures described in these pages have
no apparent shell ; a greater number have absolutely
none when full-grown, though some of them begin
life with a rudimentary shell which does not develop.
But though the shell is not everything, it is so
characteristic of the Mollusca as a class, that we are
justified in giving some consideration to it at the start.
There is every reason for supposing that the
primitive molluscan shell was not much unlike that
which covers the Limpets to-day. Such a form gives
great strength with but a small expenditure of
material, and it is susceptible of modification in many
directions. A number of species whose anatomy
shows they are not intimately related, have retained
this form of shell to the present day. In proof of this
34 Shell Life
we need only refer to the native species of Acmcca,
Haliotis, Calyptrcea, and Ancylus. For creatures
living in shallow water along the
seashores, exposed to frequent hammer-
ing by the waves, such a form would
be highly protective, as may be proved
by watching the Limpets (Patella) on
the rocks. Adhering tightly with the
base of their bodies to the rock, and
drawing down the edges of the shell
by muscular contraction, the wave
breaks upon the shell without harming or shifting it.
In the case of the Limpet the shell is enlarged
equally all round its edge, so that it fits accurately
to the spot of rock the Limpet has chosen for a
permanent resting-place.
Even where the simple uncoiled form of shell has
been departed from, there has in innumerable in-
stances been a retention of the general external
shape, that the minimum of resistance shall be offered
to the waves. Take either of the common species of
Top-shells that frequent the same situations as the
Limpets : although the cone is here coiled several
times upon an axis, the external shape is still
that of a cone with an almost flat
All our univalve shells will be
found to be modifications of this type,
in some making a low pyramid, in
others drawn out to a proportionately
great length. This diversity of form
is, no doubt, determined by the habit of the mollusk
and the situation it inhabits. For example, those
T'he Shell and its Formation 35
species that adhere to rocks in shallow water
(Top, Purple, Winkle, Limpet), and are therefore
subject to the rushing of water and the heavy
beating of breakers, have their shells broad, smooth,
and free from sculpturing that might catch the
water and so result in the mollusk being swept
from its hold. Closely related species that live on
sandy or gravelly bottoms appear in many cases to
find an advantage in angles and knobs ; probably
because, their foothold being precarious, when they
are detached by waves their irregular surface
prevents their being swept far from the spot. This
difference is well illustrated lay comparing the
Common Top
with a closely
allied species,
the Painted Top,
which occurs on
Painted Top Sand > and haS Netted Dog-whelk
the surface of
the shell broken up into a series of little knobs.
The Netted Dog-whelk lives on sandy shores, and
its shell has a similar surface, whilst the upper
surface of the animal is dotted with dark spots that
closely resemble grains of sand. The Common
Wentletrap has a great number of flat plates
standing out edgewise from each coil of the long
shell. The very rugged character of the Sting
Winkle's house is obviously determined by similar
reasons for utility ; and, though much less rugged,
the strong sculpturing of the Pelican's-foot is clearly
of the same order.
How the character of the shell is modified by
Shell Life
changed habits in the creature that makes it, may
be seen clearly in the case of the Blue-rayed Limpet
(Helcion). In its young condition it should
be sought on the broad fronds of the large
tangles and oar - weed.
The form of the thin
shell well suits it for this
situation, the frond float-
sting Winkle
Wentletrap
ing i 11
currents
and the
shell offering little opposition
to the flow of the water. As
the frond waves iridescent gleams play upon its
purple-brown, and in order that the Blue-rayed
Limpet may not be readily seen it bears upon its
clear brown shell from three to six fine lines of
bright blue radiating from the apex and giving
an effect similar to that seen on the tangles. As
it gets older this Limpet climbs down the stalk,
where there is no iridescence, and finally is to be
found among the root-like suckers by which the
weed is attached to the rock. In such a situation
there is more risk to the shell from the rush of
stones, etc., at the lower level. The shell, in con-
sequence, becomes much thickened, the edges are
modified to fit it for adhering to the cylindrical
stem instead of the plane surface of the frond, and
as the blue lines would be an attraction rather than
a disguise they are gradually obscured. The shell
^The Shell and its Formation 37
has assumed the form known as the Smooth Limpet.
Exotic species of Patella that live entirely upon
floating seaweeds have their transparent shells like
those of Helcion, but those that live upon rocks
require thick shells to withstand the breakers.
All the species to which we have just referred
with the exception of the Limpets have the mouth
of the shell accurately closed by a thin plate of
shell or chitin. It is seen closing the orifice of the
Wentletrap figured opposite, and on the end of the
foot of the Sting Winkle beside it. It is known as
the opercidum, or cover, and at one time was con-
sidered to be the other valve, bringing the univalves
into close agreement with the bivalves. But a little
consideration serves to show that the operculum is
not part of the true shell, for it is not a product of
the mantle, but of the foot.
And this brings us to the consideration of the
enormous difference between the shells of, say, the
Oyster and the Whelk. In spite of the very high
value, commercial and epicurean, that is set upon
the Oyster, present-day knowledge all seems to point
to the probability that he is a degenerate from the
form of the ancestral mollusk, which almost
certainly had a head and something approaching a
masticatory apparatus. Whilst some of its de-
scendants in successive generations went on im-
proving the simple tent-like form of their shells,
by twisting them into spirals, and developing their
organs to fit them for lives of varied activity ;
others, finding that the sea was well provided with
food, appeared to think that activity involved an
unnecessary strain upon the organism. These simply
38 Shell Life
attached themselves to rocks or weeds, or burrowed
slightly in sand or mud, and lay with their mouths
open to receive such good things as might chance
to fall in. They lay over on one side, the mantle
became divided into two lobes, and consequently
the shell moulded upon its surface was in two
valves hinged together, the head was lost, though
the toothless, tongueless mouth remained, hidden
by the lobes of the mantle.
That the general tendency of development was
in the direction of improving upon the simple
ancestral form is indicated by the fact that of the
enormous number of distinct species known in a
fossil or recent condition, only one-fifth are bi-
valves, whilst three-fourths have a single shell.
To get back to the adaptation of the shell to the
conditions of life : pelagic or floating species have
the shell reduced to a thin glassy consistency, serv-
ing the double purpose of rendering them light and
transparent, the transparency preventing their easy
detection by enemies who are likely to regard them
instead as part of the jelly-fishes upon which such
pelagic mollusks largely subsist. Some species that
dwell in deep water out of the reach of surface
convulsions have very thin shells also. At the
other extreme some deep-water forms that have
evidently been much sought after by the larger
fishes for their food secrete very thick and solid
shells that may be proof against the equally hard
and stony palate-teeth of the fishes. In all the
fresh- water forms it is evident there can be little
need for thick and heavy shells, and as a matter
of fact they are light and thin. Especially is this
The Shell and its Formation 39
the case with the pond-snails, who probably find
carbonate of lime not very plentiful in their little
world, neither is it greatly needed as a protection.
A strong shell is required by those land-snails
whose habitat exposes them to the attacks of birds
like the thrush, but it is essential that the shell
should not be heavy. The carbonate of lime is in
this case obtained from the plants upon which the
snails feed, and it is therefore only to be expected
that on chalky soils the snails should be exceedingly
abundant, whilst in sandy districts they are rare
or entirely absent. But it does not follow that on
chalky soil the shells will be necessarily thick,
Clausilia laminata, for example, plentiful in beech
woods on the chalk, having a thin semi-transparent
shell, apparently with little chalk in it.
In the slugs of our gardens and hedgerows the
shell has been reduced to a little shield covering
the breathing organ, or to a few granules of lime
beneath the mantle ; whilst many of the Sea-slugs
have found it an advantage not to develop the
shell at all, though they are born with the nucleus
of a shell like all other mollusks. A somewhat
similar case to that of the terrestrial slugs, so far
that is as the shell is concerned, will be found
among the Cephalopods : the Sepia produces beneath
its mantle the familiar " cuttle-bone," in the Squid
this is reduced to the long transparent " pen " of
animal matter only, whilst in the Octopus the shell
is represented by two little stylets in the substance
of the mantle.
LTHOUGH it is not a part of my
purpose to enter upon the anatomy
and physiology of the Mollusca
beyond what is necessary for an
understanding of the differences in
form and habit of the various
groups, there are certain points which are so char-
acteristic of the class, or which distinguish the
several orders, that some elementary reference to
them is essential. But the reader whose interest
at present extends only to external forms and
coverings may, an it please him, for the present
skip this chapter and return to it later.
Though, as we have seen, the bivalves have
probably retrograded so far from the prevailing
type as to have lost their heads, these presumed
degenerates have retained a mouth and a digestive
system as being necessary to their continued
existence. But though the mouth remains in these
bivalves, it is little more than an opening to the
Feeding and Breathing 41
gullet and the stomach ; there are neither jaws,
teeth, nor tongue. The absence or presence of a
tongue has been found to be an important item in
classification, and we find that some authors have
divided the Mollusca into two unequal groups,
the Tongue-bearers (Glossophorct) and the Tongue-
less (Afflosaay, the Tongue-bearers including the
Cuttles and the Univalves, the Bivalves constituting
the Tongueless.
It is in the Cuttles that we find the highest
development of jaws for the purpose of biting off
portions of food. These
are composed of chitin,
formed much like the
beak of a parrot, and
working much in the
same fashion except that
in the case of the Cuttle Uppe ' , (a > an . d ' w ^ <';> P. rt j1'. of the
beak of a Cuttle-fish (Sepia)
the upper jaw works
within the lower. The more ordinary type of jaws
may be observed by watching any of our common
snails feeding. The Land-snails (Helix) have the jaw
only in one portion, and this is placed behind the
upper lip ; but in the Pond-snails (Limncea) there
is an accessory plate on either side of the mouth,
and these act with the upper plate. If a pond-
snail be watched as it glides up the glass of an
aquarium and cleans off the minute vegetation, the
mechanism of the jaws will be understood better
than from a description.
The food having been cut off by the jaws is
not yet in a condition to be readily digested; it
has first to be masticated. This work is performed
42 Shell Life
by a very remarkable organ peculiar to the
Mollusca. It is an almost transparent ribbon of
chitin, whose upper surface bears a large number
of minute teeth, of varying forms, number, and
arrangement, set in transverse rows, and each row
symmetrically divided into central, lateral, and
marginal teeth. The organ is variously known as
the tongue, the radula, the lingual ribbon, or the
odontophore. Only a small portion
is brought into action, the remainder
xX <^^"^ being coiled away at the back of the
^^ mouth, ready for use when the teeth
Portions of the tongue J
of a wheik, with on the torepart shall have been worn
a row of teeth ^ These teeth as a rule are few
(greatly enlarged) .
and large in those species ot car-
nivorous habit, whilst those of herbivorous tendency
have them small and numerous. Many of the
carnivorous mollusks make their tongues serve a
double office, for they have no jaws, and the whole
of the cutting and breaking up of their food has
to be done by the teeth; this, no doubt, explains
their larger size.
The number of these teeth to one tongue or radula
varies to a remarkable extent : thus, one of the Sea-
slugs (jEolis coronata) of our own coasts has only
about 17, whilst the large brown Sprinkled-snail
(Helix aspersa) of our gardens and hedges has 105
teeth in each transverse row, and no less than 135
rows that is, a total of 14,175 teeth in one mouth.
There are, of course, many species with numbers
intermediate between JZolis and Helix; the large
Pond-snail (Limncea stagnalis), whose teeth are
shown in the figure a below, has 111 such teeth in
Feeding and Breathing
43
a row and about 110 rows = 12,210; the little Fresh-
water Limpet (Ancylus fluviatilis) I has 120 rows
of 75 = 9000; and the Amber Shell (Succinea putris)
c of our watersides has 50 rows of 65 teeth = 3250.
A Mexican species of Helix is said to have 40,000
teeth, whilst Umbrella, a Mediterranean mollusk,
has so many it is impossible to count them, but they
have been estimated to number somewhere about
750,000 ! Every one of these minute teeth has
Teeth of radula of a, Limncea stagnalis; 6, Ancylus fluviatilis;
c, Sttccinea putris (greatly magnified)
muscular attachment to the radula, and can be
erected or depressed at the will of the mollusk.
These remarkable organs extracted from the
mouth of any of the common mollusks of our
hedges or seashores, make beautiful objects for the
microscope ; but their preparation requires a good
deal of care and nice manipulation. They are first
boiled in caustic potash to get rid of the animal
matter, and after washing in clean water are
mounted in glycerine jelly.
Most of the mollusks that bear these radulae are
also provided with salivary glands, and in some of
the species that habitually bore through the shells
44 Shell Life
of others in order to feed upon the occupant, the
saliva is found to contain an appreciable proportion
of free sulphuric acid, which evidently softens the
spot of shell upon which the radula is then brought
to bear.
The molluscan stomach, with which we have not
space to deal, varies with the habit and food of the
mollusk. Some species have it lined with knife-like
plates, or with knobs and teeth. The Canoe-shell
(Scaphander lignarius) has a gizzard in which the
Tusk-shell (Dentalium), its favourite food, is crushed
up prior to digestion.
Having glanced at the mechanism by which the
mollusks prepare their food for assimilation, let us
take a similarly brief and superficial view of the
means whereby the blood is aerated in the principal
groups. It is evident that one system of respiration
will not serve for the whole of the Mollusca, seeing
that whilst some spend their lives submerged in fresh
or salt water, others live as constantly surrounded
by the atmosphere. Many of the fresh- water species,
however, breathe air only, and cannot therefore
venture far from the surface, their air-chamber
requiring to be frequently recharged. On the other
hand, marine species like the Limpet and Periwinkle,
provided with gills for breathing water, have to
spend hours on the dry rocks, and can only do so
by storing sufficient moisture to keep their gills
damp.
It is probable that the ancestral mollusk had no
special organs for respiration, but simply absorbed
oxygen through his surface tissues, beneath which
the blood flowed and took up the vital gas. Then
Feeding and Breathing
45
probably the production of a shell closely covered
so much of the surface that a simple comb-like
organ was developed to carry on this function
constantly. Such an organ exists in what we may
regard as little different from the primitive form in
certain species of Mail-shells (Chiton). Into this
comb-like organ (ctenidium) the blood flows, and
through the tissues of the branches absorbs the
oxygen from the surrounding waters. In other
species these simple ctenidia have degenerated until
no longer functional, and their place is taken more
efficiently by a series
of plate - like gills
encircling the body
Such a form of res-
piratory apparatus
may be seen in the
Limpet, of which a
figure is here given.
Here the letters c c c
show the position of
the encircling series
of gill-plates, whilst
the true but aborted
ctenidia must be
sought in a pair of
very small yellow
bodies situated on
the sides of the neck.
External branchiae a, foot; 6,
are also developed in
many of the Sea-slugs, taking the form of cerata, whip-
like, plume-like, or foliage-like processes from the back,
face of Limpet
antle ; c, gills ; d, mouth ;
e, tentacles
46 Shell Life
through which the blood flows and takes up oxygen
through their tissues. In the bivalves, as will be
more fully described later, the gills vary greatly in
the degree of complexity. They are usually placed
on either side of the body between it and the mantle
which thus form the branchial cavity. In most cases a
couple of tubes or siphons lead to this chamber from
the exterior, one admitting fresh supplies of water,
the other carrying off that which has passed over the
gills and been robbed of its oxygen.
In the land and fresh-water snails (excepting the
few whose shells are closed by an operculum) respira-
tion is effected in a " lung-chamber," though there is
no lung in the sense of a spongy mass of tubes as we
know it in the higher animals. The chamber, which
opens on the right side of the snail, more or less
towards the front part, is lined with a network of
branching vessels through which the blood circulates.
Air is taken into this cavity frequently when the
mollusk is active, and then the opening is closed
until all the oxygen has been taken up by the blood,
when the chamber is refilled and again closed. The
Pond-snails (Limncea) when living in shallow water
frequently come to the surface to recharge this cavity
with fresh air, but when living at considerable depths
they appear to absorb the oxygen from the water,
whether by filling this lung-chamber or through the
general skin-surface is not quite clear.
In intimate relation with the varied forms of gills
or lungs there is, of course, a heart ; and where there
is only a single gill there will only be one auricle and
one ventricle to the heart, but there may be two or
four auricles if there are as many gills. From the
Feeding and Breathing 47
gills the oxygenated blood flows to the heart, whence
by way of the aorta it is distributed throughout the
body, and returning by veins it is again passed
through the gills. It must not be supposed, however,
that the circulation is as rigidly confined in definite
tubular vessels as in the higher animals. Much of
the blood appears to flow indefinitely in irregular
spaces of the body called lacunce and sinuses, getting
reinforced by that which has passed through the gills
and heart, but perhaps not all of it finding its way
back to these organs. The vital fluid is in most
mollusks colourless, but a few of the more active
species possess the red colouring matter (hcemoglobin)
which distinguishes the blood of vertebrates.
S we have just learned in the cases
of respiration and circulation, we
must not expect to find in the
Mollusca organs of sense similar
to those of the higher animals.
The whole of the body being so
soft is no doubt highly sensitive ; nevertheless there
are special organs for special senses, and these organs
are well furnished with nerves to convey their im-
pressions to the local brain. For there is no grand
centre of the nervous system as furnished by our
brain. Instead of one great trunk-line of nerves and
nerve-bundles, as in the vertebrates, we find in the
mollusks a system of large and small nerve-threads
traversing the length and breadth of the animal,
connected here and there by loops (commissures),
and from certain knots (local brains or ganglia)
sending off a number of short branches. All these
local brains are connected by other nerves, and the
chief of them are known as the cerebral, the pedal, and
Seeing, Hearing, and Smelling 49
the visceral ganglia. In those mollusks that possess
a distinct head nerves go off from the cerebral
ganglion to the tentacles, the eyes, and are connected
with a pair of small ganglia (the buccal ganglia) that
command all the mouth parts, the pedal ganglia
supplies the foot, the visceral or pleural ganglia send
nerves to the mantle, the heart, the gills, the stomach,
and the other internal organs.
The eyes of the Mollusca are alike different from
those of higher animals, and from one another. The
highest development of the molluscan eye is found
among the Cuttle-fishes and their allies, but a pair
of well-developed eyes is the possession of nearly all
the mollusks that are furnished with heads. Yet the
presence of a head is not absolutely essential for the
acquirement of eyes, for some of the bivalves, such
as the Scallops and Ark-shells, have eyes on the
fringes of the mantle, and some foreign species of
Mail-shells (Chiton) have been found to have certain
parts of their shell-plates closely studded with minute
pigmented dots which serve the office of eyes. In
the land-snails the eyes are carried at the top of the
longer pair of tentacles, a position which allows the
snail to see in all directions ; in the water-snails the
eyes are at the base of the tentacles. Species that
live underground have the eyes more or less aborted.
Our own little Needle-shell (Ccccilianella acicula),
which lives an entirely subterranean life, has lost
them altogether ; so also have several of our marine-
snails that are always seeking their food under the
sand. Others of similar habit have eyes, but they
are covered by thick skin that can allow very little
impression of light to reach them.
So Shell Life
From a consideration of a series of molluscan eyes
it is not Difficult to surmise the developmental history
of the most perfect among them. Thus, in the
Limpet to which we have already referred as being
probably much like the ancestral mollusk there is
little more than a fold of the skin forming a depres-
sion lined with rod-shaped cells containing pigment
and forming a retina, which is connected \vith the
optic nerve. In the Tops (Troclms) the depression
of the epidermis is greater, so that it encloses a
spherical space lined with retinal cells and filled
with fluid (vitreous humour), but open in front so
that the face of the eye is bathed in water. In the
Sting Winkles (Murex) there is an advance upon this
form, for the opening of the eye has become quite
closed and there is a lens before the vitreous humour.
Now the eyes of these three species present a very
close resemblance to three stages in the development
of the eye in the embryo of the Squid (Loligo), which
shows an advance upon Murex by producing an iris
round the fore-part of the lens, an optical chamber in
front of the lens, and a transparent cornea before that
again.
It must be apparent that eyes are of the greatest
value to the most active species of Mollusca the
Cuttles. These have, consequently, developed their
eyes to a greater degree of efficiency than other
orders. The inactive, often fixed, bivalves have been
found in many cases to have a pair of eyes on what
may be regarded as the head during their larval
condition, thus indicating that in the early history
of the Pelecypoda they had eyes in the adult state.
Those bivalves that lead a more active life, such as
Seeing, Hearing, and Smelling 5 i
the Scallops (Pecten), have a considerable develop-
ment of eyes upon the fringes of the mantle, and it
has been reasonably surmised that these eyes enable
them to guide themselves in their vigorous zigzag
flights through the waters. But it may be regarded
as tolerably certain that these eye-substitutes, or
pigment spots, that are crowded upon certain parts
of the mantle in many bivalves are merely sensitive
to varying qualities of light and are useless for
observation. The casting of a shadow upon such
species affects these pigment spots, and from them
the intelligence is conveyed along the nerves to the
various ganglia, with the result that as a precaution-
ary measure, the foot and siphons are withdrawn
and the valves are shut with a snap. The Land-
snails (Helix) being crepuscular or nocturnal in their
habits can see farther in twilight than at midday,
but their visual powers are very limited at the
best, and extend only to a distance of about six
millimetres. The Round - mouthed Snail (Cyclo-
stoma elegans), however, whose eyes are not
mounted on tentacles, can see to a distance of about
a foot.
The sense of hearing has not been very extensively
investigated, at least little but negative results have
been obtained from experiments made with a view
to testing its extent. One experiment of the kind
made by Mr. W. Bateson in the Plymouth Laboratory
of the Marine Biological Association, a few years
ago, showed that a Saddle-oyster (Anomia) sus-
pended in the water to be free from any chance
of jarring of the solidly -framed tank, closed its
valves on Mr. Bateson making a creaking sound
52 Shell Life
of a particular pitch by rubbing his finger along the
glass.
The seat of hearing resides in a pair of closed cells
called otocysts filled with a clear fluid in which are
suspended one or more grains of chalky material
called otolitks, and lined with cilia. These otoliths
may be very numerous, and they are agitated by
sounds in the immediate neighbourhood of the
animal. These vibrations act upon the cilia which
convey impressions by the acoustic nerve to the
cerebral or the pedal ganglia.
The most important of the senses to the Mollusca
is apparently that of smell. It is quite certain that
it is much farther-reaching than either vision or
hearing, and more constantly in use. Great numbers
of carnivorous mollusks, such as whelks, dog-whelks,
and naticas, are found in lobster-pots baited with
" high " fish which they have smelled through the
waters. Slugs appear to be highly endowed with
this sense. Apples and bean-pods dropped in the
centre of a road will draw slugs from the hedges on
either side. As soon as certain species of Agaric
come up in the woods slugs bear down upon them
and commence feeding upon them. They are also
able to locate a dish of milk in a dairy and proceed
to drink from it. Of course, this sense is more highly
developed in the active univalves than in the more
or less sedentary bivalves, but the agile Pea-shells
(Pisidium) are not deficient in it, as shown by the
numbers that swarm over any dead animal that has
been thrown into a ditch or pond inhabited by them.
Some of the Sea-slugs have a special pair of antennae
furnished with projecting plates which are believed
Seeing, Hearing, and Smelling 5 3
to collect sensations of smell from the surrounding-
waters. They are therefore known as rhinophwes or
nose-bearers.
The sense of touch is acute, as must be obvious
to anyone who has handled almost any species of
mollusk. Creatures of such soft substance must
necessarily be very sensitive in this direction or they
would meet with many injuries. To touch a snail,
however lightly, is to cause it to shrink into its shell
at once. A slug has no shell that it can crawl into
on being molested, but it instantly draws in its eyes
and antennae and hunches the body up into a thick,
short heap that exposes the minimum, of surface to
attack. In many of the shelled species the margin
of the mantle is cut up into lobes and filaments
which are all very sensitive to touch, and in some
there is in addition a pair of protruding palps near
the mouth that serve as tactile organs. These palps
are also present in the bivalves but there, except in
special cases, most of the tactile work is performed
by the foot and the siphons.
ANY different systems have
been adopted at various
times for the intelligent and
orderly arrangement of the
bivalve mollusks (Pelecy-
poda). That followed in
these pages is based upon the character of the
breathing organs, and, all things considered, this
appears to afford the most natural basis. In the
sketch of the Swan Mussel in the opening chapter
the position and structure of these organs were briefly
indicated, but in that species the gills have reached
a high stage of development. Starting from the
simplest form of such organs we find examples in
the little Nut-shells that burrow in the mud and
sand of our seashores.
The most plentiful of these is the Common Nut-
shell (Nucula nucleus), whose empty shells may be
found along our beaches washed in from deeper
3\ut-shells and Mussels 5 5
water, its living range being between 3 and 145
fathoms of water. The shell, as shown in the figure,
is bluntly triangular in shape, coloured
outside with yellowish green marked with
darker growth-lines running parallel with
the lower margin, whilst many very fine
grooves radiate from the rather prominent
beak to the lower margin. The little creature
that produces this shell is cream coloured ; its mantle
has plain margins, and its oval foot is toothed all round
the edge. The mouth and lips are small, but the
lips have long appendages which are protruded from
the shell at the same time as the foot, and used as
sense-organs in the search for food. The small brown
gills are simple and plume-like.
The maker of the Nut-shell burrows among sand
and gravel, the '' foot " being extended to its utmost
length and worked between the fragments ; each tip
of the tooth-like edges then catches hold of a particle
of gravel, the foot as a whole is shortened, and so the
shell is hauled along by the contraction of the foot.
At the same time the appendages of the lips feel
about for food. When the dredge has scraped up
one of these little mollusks from the bottom there is
no foot visible ; it has been withdrawn into the shell,
and the valves now fit closely together.
Only the insertion of a knife to sever the
muscles, or to break them by leverage, can
effect the opening of the shell. The
examination of an odd empty valve,
picked up on the shore, or of the accom-
panying figure, will help us to understand how this
firm closure is maintained. It is a left-hand valve,
56 Shell Life
so that the figure shows it in its natural position,
with the concave side towards us. In the com-
plete shell the upper margin of this valve is
connected with its fellow by a kind of hinge
(ligament), resembling those primitive leather hinges
by which boys attach lids to boxes and doors to
rabbit-hutches. This shell hinge, however, is more
horny than leathery, and is, so to speak, fixed on the
stretch, and this explains why when a bivalve
mollusk dies its shell gapes open : the hinge-ligament
exerts a pulling action which tends to separate the
lower edges.
Just beneath the beak inside each valve there is a
little spoon-shaped projection containing a bulging
bit of elastic cartilage, which also serves the
purpose of forcing the valves apart. On
either side of this cartilage is a row of low
Hinge-teeth ridges like the teeth of a comb, and into
(enlarged)
the spaces between similar teeth on the
right valve fit; the lower margin of each valve is
also faintly marked in a like manner. The number
of the hinge-teeth varies in different species ; in the
present one there are about 15 teeth in front of the
beak and about 25 behind it. The object of all these
interlocking teeth is to ensure the accurate closing of
the valves when they are brought together, and to
prevent any lateral movement that would enable an
enemy to destroy the hinge. But the mechanism by
which the two valves are closed and held tightly
together, in spite of the opening action of the hinge-
ligament, consists of a couple of bands of muscle, one
towards each end of the shell. On the pearly inner
surface of the valve we can see slight oval impres-
S^ut-shells and Mussels 57
sions of the ends of these muscles; these are the
points to which they were attached. The hinge- teeth
on the valves of the Nut-shells are simple in character,
but we shall find in other species that they gradually
became more complex.
There are three other native species of Nut-shells
whose peculiarities may be briefly noted in contrast
with those of the common species. The Furrowed
Nut-shell (N. sulcata) has a larger, more triangular
shell, with five ridges parallel with the lower margin ;
dull olive. Found locally in from 3 to 50 fathoms
where the bottom is of sandy mud or clay. The
Shining Nut-shell (N. nitida) is more acutely tri-
angular, yellowish brown, and very glossy; mantle
fringed. Sand and gravel from extreme
low water to 86 fathoms, but not very
common. The Thin Nut-shell (N. tenuis),
though still triangular, has a tendency
to roundness of outline, but flattened
from side to side; brownish yellow, thin, and glossy.
Found locally, in sand and mud from 25 to 100
fathoms, chiefly along the Scottish coasts, the north-
east of England, and east and south of Ireland. The
external colours given above are those of the living
epidermis or periostracum, which invests and protects
the shell from the action of gases dissolved in the
water. Beneath this covering the actual surface of
the shell may be entirely different in hue, but where
the epidermis is permanent it will be more convenient
to indicate its colour rather than that of the shell.
Closely allied to the Nut-shells are the four native
species of Leda, but they are readily distinguished
by several differences in form and structure. One
58 Shell Life
important advance in development consists in the
production of the hinder part of the mantle into two
long tubes or siphons, which are
thrust out beyond the shell and
reach up to the water above the
rnud and sand in which the creature
burrows. The purpose of these
DwJfLeda siphons is to enable the Leda to
remain safely buried whilst it gets
a constant fresh current of water over its gills, and
to bring microscopic food to its mouth. Through the
lower of these tubes the fresh supplies pour in, whilst
the vitiated current carrying off waste passes out
through the upper tube. With a view to the better
protection of these siphons the shell has been elon-
gated backwards. In the Dwarf Leda (L. pygmcea)
the siphons are not very long, and they are united
throughout their length, showing that though the
mollusk affects deep water (20 to 86 fathoms) it does
not burrow much below the surface of the mud, or
indeed remain entirely covered by it. Its tubes may
be entirely withdrawn into the shell, which closes all
round as do the Nut-shells. The shell is scarcely
a quarter of an inch long. The Beaked Leda (L.
minuta) is a much larger species, and the great
change in the shape of the shell shows
that the creature is given to burrowing
more deeply and to remain buried.
The siphons, which are united only for
half their length, have become much interior of Beaked
Ueda-stiell
longer in order to reach the water
above, and the shell has become greatly lengthened
behind for their partial protection, there being
and Mussels 59
insufficient room in a shell shaped like that of
L. pygmcva to withdraw the whole of the long
siphons. The valves at this point do not fit closely.
There is a slight gape, and this indicates that owing
to the constant protrusion of the siphons the mantle
is never able to extend the edges of the shell so
that they will meet. In some other bivalves we shall
see that the foot also is kept so constantly distended
that the shell gapes at the front end also. The
hinge-teeth are in this species less simple in their
shapes, as will be seen in the figure of the interior
of a left valve. It is found in muddy gravel and sand
between 20 and 100 fathoms deep, on our northern
coasts.
The two genera Nucula and Leda constitute the
sole British representatives of the order Pro-
tobranchiata, the bivalves in which the branchia3
or respiratory organs have the simplest character.
They consist of parallel, unbranched, independent
filaments arranged in two rows on each side of
the central body-mass. In the next lowest group,
the order Filibranchiata,
the filaments have become
so long that they are
folded back upon them-
selves and show signs of
lateral adhesion. The
order includes the Saddle-
oysters (Anomioi), the
Ark-shells (Area), and the
TIT i / ~MT i *7 \ Saddle-oyster under
Mussels (Mytilus).
The Saddle-oyster (Anortiia ephippiuni) is a thin,
flat, little pearly shell found on old oyster-shells, crabs,
60 Shell Life
rocks, and other submerged objects, and is not un-
reasonably though quite inaccurately regarded by
the 'long-shore folk as the young of the true Oyster
(Ostrea). It is not even closely related to the true
Oyster, nor is it edible. It is by no means an easy
task to persuade fishermen that these are not young
oysters, but the quickest method of convincing them
is to prise off the Saddle-oyster and exhibit its under-
side as shown in our figure. It is then seen that
there is a pear-shaped orifice in the lower valve
through which an attachment plug passes and fixes
the Saddle-oyster to its chosen support. No genuine
Oyster is attached in this way, nor has it a hole in
its shell. The Common Saddle-
oyster is about 2 inches across
when full - grown, variable in
outline, but more or less circular.
It is never very thick, but varies
Side view of Saddle-oyster, *
showing mode of attach- in this respect according to age.
Outside it is dull white in colour,
or tinged with yellow, pink, or brown ; within it
is polished and opalescent. The lower valve in its
growth follows the modelling of the surface to
which it is attached, whether that be the smooth
rounded stem of a huge seaweed, the rough sur-
face of the rock, or the ribbed shell of a scallop.
The upper valve, of course to a less degree, follows
the shape of the lower. Normally the lower valve
is flat and the upper one convex. There are no
hinge-teeth as in the Nut-shells, though there is
a half - moon shaped pad of cartilage to keep the
valves apart when the single muscle is relaxed.
The plug by which the shell is fixed to its support is
^{ut-shells and Mussels 61
attached to the upper valve and passes through the
lower one. It appears to represent the byssus-threads
of the Mussel and
Scallop united into
a solid mass. The
expanded end evi-
dently corrodes the
living surfaces to
which it attaches,
for it is frequently
found to be lodged
in a little pit.
The animal varies
in colour from yel- Ri ht side of Anomia, with sheii -removed
loW tO red and fl, opening for hinge; m, adductor muscle;
, T . n, calcified byssus
brown. Its mouth
is large, and furnished with a pair of long slender
lips. As the animal does not burrow, and is usually
found solitary, it can develop its shell pretty equally
in all directions ; the mantle is therefore more or
less circular like the shell, its margin fringed with
two or three rows of yellowish filaments. Again,
because it is not a burrowing or otherwise
active animal, the white cylindrical foot is
very small. There is a variety (aculeata)
in which prickly scales are developed on the
upper valve.
The only other British species is the
Ribbed Saddle - oyster (A. patelliformis),
smaller than the last, and attaining to little
more than half its dimensions. From 20
to 30 waved ribs radiate from the beak to the
margin, and the shell is often ornamented with
62 Shell Life
streaks or spots of red-brown, and by a number of
fine overlapping scales. It is a common but little-
known species, its range being only between the
depths of 10 and 86 fathoms. Both these species
appear to owe their security alike from storm and
enemy to the thin flat form that sits so tightly
on its chosen base, and affords little opening to the
predatory fish or bird that might consider its thin
body worth prising off.
The Ark-shells (Area} present an appearance very
different from the exceedingly thin Saddle-oysters.
The Common Noah's Ark (A. tetragona} is a
quaint little yellow and brown box - like shell of
distorted aspect that loves to spend its time in the
crevices of rocks, or attached by
its byssus to the empty shells of
other bivalves. A perfect specimen
is covered all over with ridges
which radiate from the beaks to
the lower margins, whilst other but less prominent
ridges cross these at right angles ; but owing to
its habit of grubbing in crannies and among rubbish,
the greater portion of this ornamentation gets rubbed
off, as shown in the illustration, and consequently it
is not easy to obtain a good example. The beaks are
wide apart, and the 40 to 50 hinge-teeth are of simple
form. Towards the hinder margin of the whitish
mantle there is a number of closely grouped ocelli
dark spots that are not true eyes but which are so
sensitive to changes in the intensity of light that
they serve the same purpose. They consist of cells
filled with a dark pigment and covered with a
cuticle of high refractive power. Real eyes are
DOG COCKLE EXTERIOR ; 2 DITTO, INTERIOR ; 3 GREEN CRENELLA.
3{ut-shells and Mussels 63
seen in the larval condition of many species, and
this is part of the evidence that the bivalves have
degenerated from a higher primitive type. The
conical white foot has a deep central groove, through
which a dark green byssus is spun. The porcelain-
lined interior of the shell bears large oval impressions
of the muscles, and the inner margin is marked with
a series of indentations, those of one valve fitting into
those of its companion. The Noah's Ark occurs on
all our coasts, at all depths.
There are four other native species : one, the
Hebridean Ark (A. pectunculoides), with thinner
shell, finer sculpture, and the left valve larger than
the right, is found chiefly in deep water (35 to 100
fathoms) round Shetland and the Hebrides.
Another, the Milky Ark (A. lactea), has
valves of equal size, their white colour
partially hidden by the brown velvety
epidermis. The animal is not much given
to burrowing, but chiefly attaches its short horny
byssus-threads to the inside of old shells and to
rock-crevices between 15 and 25 fathoms, on all our
shores.
The Dog - Cockle or Comb - shell (Pectunculus
glycimeris) has an appearance quite distinct from
any other native species, and requires very little
description to enable one to identify it. The shell
is nearly circular, of a dull yellowish - white colour,
irregularly marked with zigzag lines and conical
patches of dark red. The epidermis forms a thick
dark brown velvet, but from most specimens that
are washed up the beach this is all rubbed off. On
specimens dredged up from the deeper water it
5
64 Shell Life
affects (7 to 90 fathoms), a band of epidermis will
usually be found bordering the lower margin. Large
examples measure 2| inches across. It would appear
that many fishes not strong enough to crush this
solid shell yet make attempts to wrest its valves
apart, for great preparations have been made to
keep off such enemies. The valves are united by a
number of bundles of ligament, attached to long
triangular cavities sunk in the shell between the
beak and the broad hinge-plate. The hinge-teeth
are thick, and in adults number about six on each
end of this plate, which is plain in the centre, though
young individuals exhibit a few minute teeth here.
The impressions of the mantle and muscles are very
deep on the interior, and the flat, lower margin is
impressed with about 50 teeth, in appearance like
the edge of a coarse comb. Those of the two valves
interlock, and so prevent the slightest shifting by the
most powerful assailant when the shell is closed.
In spite of this, it has one enemy that it cannot defy.
This is the Cat-fish, which cracks the stony shells with
its long powerful teeth as though they were nuts.
The animal is of sluggish habit, and lives on the
surface of gravel and among "nullipore," all round
our coasts. It does not burrow, and therefore has
no siphons, but the edge of the mantle is somewhat
contracted and protruded at the hinder side of the
shell ; at this part, too, it is studded with a great
number of black eye-spots.
The Eared Limopsis (Limopsis auritcc) somewhat
resembles the Dog - Cockle internally, though the
shell is less round and owes its name to a fancied
likeness to Lima, the File-shell. Although common
S\ut-shells and Mussels 65
as a Tertiary fossil, in a living or recent state it is
rare. A few specimens have been taken in deep
water (85 fathoms) off the Shetlands. It is a very
small, glossy white shell, marked with fine lines
radiating from the beak, and crossed by irregular
ridges. The yellow-brown epidermis takes the form
of a fringe of long hairs. The margins of the shell
are rounded except behind the hinge, where its
straightness gives the eared appearance to the shell.
Like those of the Dog-Cockle, the strong teeth of
this species are in a continuous line, but confined to
the hinge - plate. The lower margins are devoid of
teeth. It has a long thin foot, by means of which it-
creeps and climbs, and spins an almost transparent
thread.
The Common Mussel (Mytilus edulis) is one of the
most useful of the Mollusca to mankind, for in
addition to its wide use as a food, it is of great value
as a bait in the long-line fishing. Strongly gregarious
in its habits, it attaches itself to rocks, timbers, and
masonry by its tough byssus spun by the short dark-
brown foot. This habit of associating in closely
packed masses has doubtless led to the contracted
wedgelike form of the shell, and to the absence
of in this case unnecessary hinge or marginal
teeth. Occasionally a few small hinge - teeth are
developed, but as the species indulges in very little
locomotion after early life these are. not much needed.
The mantle has a double margin, the outer one plain,
whilst the inner is at different parts fringed or
toothed, and on the hinder part formed into an im-
perfect siphon.
Though the Mussel is always found hung up by its
66 Shell Life
byssus, it is by no means a prisoner. It possesses the
Common Mussel (Mytilus edulis), closed and attached by the byssus
(nat. size)
power of separating itself from these threads. In an
aquarium when a Mussel has attached itself and then
S^ut-shells and Mussels
67
grown dissatisfied with its position, you will see the
broken and discarded byssus-ends in patches all over
the tank. Mussel-beds on some parts of our coasts
have been jealously watched because of their power
to hold the mud and sand, and prevent the foreshore
shifting away
with the tides and
currents. The
story of Bideford
Bridge is founded
upon the know-
ledge of the bind-
ing power of the
byssus. Most
books mentioning
Mussels repeat the
legend that Mus-
sels instead of
mortar bind the
stones of the
bridge together,
and that, there-
fore, the town
authorities forbid
the removal of
the mollusks that
throng its piers.
It is true that a prohibition of this sort exists,
but it is due to a conviction that the Mussels
keep off the wear and tear of the tide. Mussels at
times give rise to very unpleasant symptoms in
those who have eaten them, occasionally even causing
death. All kinds of theories have been invented
(nat. size)
lantle edge; 6, foot; c, byssus; d, e, muscles of the foot;
/, mouth; g, lips; h, lobe of mantle; i, j, gill plates
68 Shell Life
to account for this unwholesome condition, but it
would appear to be due to their growth in the com-
paratively stagnant waters of harbours, or to their
being laden with spawn. In various parts of the
coasts of Europe, Mussels are in a sense cultivated by
placing boughs of trees on the mud, which become
covered thickly with Mussels. The boughs are
taken up after a few years and sold by weight.
The accompanying woodcut showing the various
parts of the animal will help to make clear further
descriptions of the bivalves.
The large Horse Mussels are by most authors
separated from the genus Mytilus and known by the
name of Modiola. Of these we have several distinct
species. Their shells are more oblong than wedge-
shaped, quite without teeth, and the byssus though
much finer is also more ample. Instead of hanging
themselves up, they burrow, and some spin a kind of
byssal nest around themselves in which gravel and
other marine rubbish is mixed up. The affix
" Horse " signifies that these Mussels are coarse and
unfit for food.
The Common Horse Mussel (M. modi-
olus) may be distinguished readily from
the Mussel by the fact that the beaks
instead of being at the extreme pointed
end of the shell are at a slight distance
from it. The thick solid shell is purplish
yellow in hue, but its true colour is dis-
Common Horse *
Mussel (re- guised by the dark brown epidermis
which, in young specimens, becomes
drawn out into long fringing processes. As in the
Mussel, the impressions of the mantle and muscles are
and Mussels 69
well marked. The animal, too, may be at once identi-
fied by its difference in colour from the true Mussel.
The latter has a creamy white tint, but this is dark
orange ; the foot red, whitish towards the thick and
wrinkled base. Both margins of the mantle are
without fringe or toothing, though covered with
delicate cilia.
Its habitat is a muddy gravel at various depths
between low water and 80 fathoms, most plentifully
on our northern coasts. Its usual size is about 5
inches long, but it has been found over 9 inches in
length. Its roomy interior is a favourite resort of
the Pea-crab, which appears to live on the most
friendly terms with it, and to avoid all risk of
injuring its host has got rid of every one of those
angles and sharp edges that characterise most crabs,
and is now as smooth and glossy as glass, with every
edge rounded.
There are several other British species described,
of which one or two are possibly only juvenile
forms. The Bearded Horse Mussel (M. barbatus) is
little more than 1 inch long, with an orange or
scarlet shell, mostly hidden by a thick yellow-brown
epidermis, which on the back and front of the shell
is so split up as to form a fringe of thorns. Each of
these thorns is bearded along one side only, as
shown in the figure of a small portion. It
occurs on the south and west coasts of
England and Wales ; rarely on the east ;
also on the south and west of Ireland. Its
habitat is on rough ground from low water
to 18 fathoms. The Tulip Horse Mussel (M. adri-
atica) has a broad convex shell, slightly smaller than
Shell Life
the last, thin and glossy, of a yellowish hue, the
hinder portion being also usually marked with rosy
or purple streaks after the manner of
a tulip. The thin polished epidermis
is almost transparent. It occurs very
locally in Scotland, more frequently in
the south of England, around Ireland,
and along the Welsh coast, preferring a
bottom of gravel, or sandy mud, at depths ranging
from 7 to 40 fathoms ; but it cannot be reckoned as
at all a common shell in British waters. The
general aspect of the Bean Horse Mussel (M. phase-
olinus) is similar to that of the Bearded Horse
Mussel, owing to the manner in which the epidermis
is split up into slender processes. But the difference
may be seen at once if one of these filaments be
examined, for neither of its edges is bearded as in M.
barbatus. Stripped of this shaggy coating the
shell would be seen to be very much the shape of a
kidney-bean, as indicated by the name phaseolinus,
and of a yellow colour tinged with purple. The
hinge-plate is sculptured into a series
of round teeth. It is about three-
fourths of an inch in length. It is
common on all our rocky coasts from
low water to a depth of 86 fathoms.
It often disguises itself by spinning up fragments of
shell and gravel with byssus into an outer envelope.
The " crenulated " or notched hinge and upper
margin of the last species constitutes a connecting
link with the genus Crenella, which has obtained its
name from such ornamentation. The shell resembles
that of Nucula in the fact that it is entirely
Bean Horse Mussel
-s hells and Mussels 71
composed of " mother-o'-pearl." The mantle forms
only one siphon, that for getting rid of waste, and
this is very short, fresh supplies being taken in by
the open front. The foot is of peculiar construction,
consisting of a cylindrical stalk and a tongue-shaped
expansion which is used for crawling. Instead of
spinning an extensive byssus, these content them-
selves with a single thread by means of which they
suspend themselves. The genus is now restricted to
two species, though formerly those now forming the
genus Modiolaria were included in Crenella.
The Glossy Crenella (C. rhombea) has a solid-
looking, glossy white shell, marked by delicate
radiating ribs, and covered by a slight pale yellow
epidermis. The "broad hinge-plate is notched or
creriulated as already noted, and bears a wedge-
shaped tooth with notched edges. The interior edges
are also crenulated, so that the valves securely
interlock all round. It is less than one-quarter of an
inch in length, and occurs on rocky coasts in the
south-west of England and round the Channel Islands
from low water to about 20 fathoms. The Cross-
cut Crenella (C. decussata) is more oval than sa^
the last, of the dimensions shown in the figure. ^^_
It is also glossy, but the number of ribs is cut
smaller, and they are crossed by fine hair- c
like lines. At the points of contact these lines are
slightly raised into minute rounded points. The epi-
dermis is thicker and of a darker hue, so that the
general appearance of the shell's colour is pale olive.
It affects gravelly sand on our northern coasts, from
Yorkshire and Northumberland to the Shetlands,
and ranging from 3 to 70 fathoms in depth ; it
72 Shell Life
also occurs oft' the coast of Antrim, Ireland. It is
very active, and likes to climb and hang suspended
by its thread.
The Modiolarias, though formerly regarded as
Crenellas, which we retain as a popular name,
differ from these in several small but sufficiently
important points. The mantle forms a distinct
incurrent tube in front and an excurrent one behind.
The foot is strap-shaped, and may be extended until
it is a mere thread two or three times the length of
the shell. The shell is rhomb-shaped, but instead of
the ribs on the surface extending equally all over the
shell they are in two series, which leave the centre of
the valves plain. The hinge-plate is notched as in
Crenella, but as a rule the central or cardinal tooth
is wanting. There are four British species. The
Marbled Crenella (M. marmorata) though
somewhat angular is roughly oval in shape,
thin and glossy, pale green marbled with
red- brown. Its byssus is almost trans-
parent, but tolerably strong. It lives
among the root-like suckers of the larger seaweeds,
in the crevices of rocks, the interior of empty shells,
and very commonly embedded in the tough coat of
the simple ascidians. An average specimen of
Ascidia mentula may yield as many as twenty of
these mollusks, which do not appear to cause any
inconvenience to the host. It occurs on all our
coasts, but must be sought below the lowest tide-mark,
in what are known as the Laminarian and Coralline
zones. If not satisfied with its present quarters, it
displays considerable activity in seeking others,
stretching its foot to its greatest extent, and having
^ut-s hells and Mussels 73
taken hold by its tip, pulling itself rapidly along by
contracting its foot again. Having secured a corner
to its taste, it spins its byssus and becomes fixed for
the time. The Ribbed Crenella (M. costulata) is a
much smaller and brighter species, the shell
pi'oportionately narrower, cream coloured marked
with purple-brown streaks, which are often zigzag,
and which show through the pale green epidermis.
Occasionally it attains the length of half an inch.
It is local on the coasts of Devon, Cornwall, Wales,
Donegal, and the Island of Herm, where it may be
found spun up under stones, or on small seaweeds, in
the lowest range of rock-pools, often with shell
fragments and gravel mixed up with its byssus.
The Green Crenella (M. discors) is slightly longer
and much broader than the last, yellowish brown,
with a rather thick green epidermis ; less
angular than the others. The animal sews
together branches of the common coralline
and other small seaweeds that it may dwell
in safety within the nest. It is very
generally distributed, and may be found
abundantly in rock-pools at half -tide and below. The
Black Crenella (M. nigra) is so-called because in
aged specimens the epidermis assumes
a black tint ; more frequently it is
something between a purplish brown
and dark olive when looked at
closely. The colour and the sculp-
ture at once distinguish it from the
others. The two sets of ribs from the beaks are
crossed by a third and coarser transverse set, which
form a network, often with minute knobs at the
74 Shell Life
intersections. It is a purely northern species, being
found round the coasts of Scotland and Shetland,
extending south only as far as Yorkshire and Durham ;
occurring in muddy gravel at depths ranging from
7 to 90 fathoms. Large specimens may measure as
much as 2i inches. It is known to northern fisher-
men as the "Corduroy Mussel."
These are the only genera of Filibranchiata repre-
sented on our coasts.
the Oyster and its allies
we reach the third order of
bivalve moll use a the
Pseudolamellibranchiata a
small order characterised by
a further advance in gill - structure. The united
filaments of the gill are not merely so long as to
require folding back until they practically constitute
four gill-plates on either side of the foot, but the
edges of these plates may be united to the foot and
the mantle respectively. The edges of the mantle
are quite open all the way round, the foot is very
small, arid the foremost of the two muscles for closing
the valves is usually undeveloped. The only native
representatives of this order are the Fan Mussel
(Pinna), the Oyster (Ostrea), the Scallops (Pecten),
and the File Shells (Lima).
The Fan Mussel (Pinna rudis) has the distinction
of being our largest native mollusk, adult specimens
76 Shell Life
varying from 10 to 15 inches in length, with a
greatest breadth of more than half that measurement.
The shell is wedge-shaped, the beaks at the extreme
front, the broad end gaping and closure impossible.
For two-thirds of their upper margins the valves are
connected by a narrow, horny, elastic ligament, set
in a fold of the toothless hinge-plate. The glossy,
horn-coloured, thin shell is marked by lines radiating
from the beaks to the hinder margin, and lines of
growth crossing these. The animal, which varies in
colour from yellow to red-brown, uses its foot chiefly
for spinning the strong and abundant byssus by
which it moors itself to the bottom. The connection
between form and habit is at once seen in all the
members of this order : they are inactive creatures, so
the foot, which is primarily a locomotive organ, has
dwindled to small proportions. The byssus shown
Oysters and Scallops 77
in the figure has been worked up, as an object of
curiosity chiefly, into muffs and other articles, and
when mixed with silk has been woven into gloves.
Although the Fan Mussel occurs all round our
islands, in muddy gravel or sand, from low water to
a depth of 80 fathoms, it cannot be regarded as a
common species. Where it does occur it will be
found in some numbers, for it is gregarious in habit,
like all the species mentioned in this chapter. The
pointed forepart of the shell is inserted in the ground,
so that the broad open end is uppermost. The fisher-
men avoid the ground where the Fan Mussels are
Interior of Fan Mussel right valve
from fear of having their nets destroyed by the sharp
knife-like edges of these broad ends. I have already
referred briefly to the little Pea-crab (Pinnoteres) as
lodging permanently in the shell of the Mussels and
Horse Mussels; still more does it affect the Fan
Mussel, in which retreat it came under the notice of
Pliny and other ancient writers, who called it Pinna's
Friend, and invented many marvellous fables of the
doings of these strange partners. Except on the
supposition that the crab acts as a housemaid or
scavenger it is not easy to understand what advantage
the mollusk derives from the partnership. Crab
Shell Life
architecture is rich in angles, sharp edges, and spines,
to serve various purposes in their lives ; but the Pea-
crab has given itself up so whole-heartedly to the
comfort of its friend that it has got rid of every
angle, every sharp edge, every spine and stiff hair.
All its parts are rounded, and polished with a surface
like glass, so that the movements of this strange
little crustacean between the gills of the Pinna
cannot cause injury to the very delicate tissues of the
mollusk.
The Oysters are represented in our fauna by the
solitary species which has from the earliest human
period been regarded as a luxury, because the demand
appears always to have exceeded the supply ; and
concerning whose structure, growth, artificial cultiva-
tion, and commercial value very much has been
written.
The Common Oyster (Ostrea edulis) needs little
description, its shell being at least as familiar in the
streets of inland cities as
it is on the seashore.
Attention may be called
to the fact, however, that
the valves are not equal
in size or form, the lower
(left) being larger and
convex, and the upper
(right) is flat or slightly
concave. Whilst the left
is frequently marked by
overlapping plaits, folds,
and flat spines, the right is usually plain. The shell
of the very young Oyster is round in outline, but
Oyster, with right valve removec
GREAT SCALLOP ; 2 QUIN (WITH TUBES OF SERPULA) ; 3 QUIN, WHITE VARIETY.
Oysters and Scallops 79
its succeeding growth will in all probability greatly
modify this form. At an early stage of existence
the left valve becomes cemented to a stone, an older
shell, or to some other object on the bottom, and
thenceforward remains a fixture. It has, therefore,
no need of a foot either for locomotion or for spinning
a byssus, and the foot is absent. The mantle has a
double margin with a fine fringe ; the lips are large
and nearly triangular. In the adjoining figure it
will be seen that the solitary muscle for closing the
valves is placed nearly in the centre of the shell. In
the species considered in the previous chapter there
were two such muscles, one at each end of the shell
but away from the beaks. In Pinna, though these
muscles appear to have changed their positions, it is
really the beaks that have moved to the extreme
front of the shell. In Ostrea, one muscle has entirely
gone, but the remaining one is much enlarged. There
is a thick, strong, curved pad of cartilage between the
beaks to keep the valves open, and a short ligament
on either side of it. The hinge-plate is thick, but not
furnished with teeth.
Having regard to the number of natural foes,
apart from man, the most rapacious of them all, it
is not surprising to learn that the progeny " spat "
of one Oyster may be anything from a few hundred
thousands to sixty millions. When discharged by
the parent these are furnished with delicate cilia, and
by lashing these they float through the water during
the first two days. They then settle on some suitable
foundation, to which they become permanently attached
or they perish. The character of the weather at
this period is of the utmost importance to the future
6
8o Shell Life
Oyster supply; and the Oysters have selected the
summer months as affording the greatest chance of
success. A warm day and a quiet sea are the
favourable conditions required ; with a low temper-
ature and troubled waters there is every probability
of the spat being destroyed, or, what is almost as bad,
carried far out to sea.
Left on their natural banks Oysters are full-grown
in about four years, but when dredged and laid down
again in the culture beds they take several years
longer. " Natives " are those supposed to have passed
the whole of their lives in the beds about the mouth
of the Thames and Medway, but many of them no
doubt are those that have been dredged in distant
parts of the coast, purchased by the Kent and Essex
merchants, and relaid for a year or so. Oyster-
dredging is regulated by local fishery bylaws, which
fix the minimum limit of size at which dredging is
legal ; 2| inches, for instance, being the minimum at
Falmouth, the Oyster then being about 2| years old.
They are considered to live about ten years, but to
be at their best at five years, when the shell measures
as many inches across. The " Green Oysters," or
huitres de Marennes, of Normandy have been
specially fattened on a green diatom (Navicula
ostrearia) in ponds rich in this particular form of
microscopic plant -life. In the course of several
years of this diet the Oyster in turn becomes green,
and acquires a special flavour.
Both on the natural sea-banks and the estuarine
beds to which they are transplanted, Oysters have a
number of enemies to contend with. Starfishes and
crabs are the best known of these, and they can be
Oysters and Scallops 8 1
captured and destroyed ; but a more insidious foe is
not evident until its mischief is done. This is a small
orange sponge (Cliona) that bores a network of
tunnels ramifying completely throughout the shell,
rendering it rotten, and compelling the Oyster con-
stantly to deposit new layers of shelly matter within
to keep the intruder out. Whelks and other mollusks
with drilling power bore through the shells and eat
out the Oyster ; whilst the octopus with his parrot-
like beak, and the skate with its powerful teeth, also
add to the destruction. The Oyster occurs naturally
on all our coasts ranging in depth from low water to
about 45 fathoms.
The Scallops (Pecteri) are not only the near
allies of the Oyster, but some of them share the
same beds with their more valuable relatives.
Though the Oyster is more highly esteemed on
account of its commercial and gastronomic import-
ance, the Scallops must be pronounced at once more
beautiful and more interesting. The shell is more
nearly symmetrical, though the valves are usually
unequal, and the strong even ribs with which the
surfaces are ornamented has made the shell familiar
in decoration of many kinds. This shell though
strong is thin, though hard is light. The strength
is largely due to the hollow ribs, which make
possible the lightness necessary for submarine flight,
small Scallops and Quins being remarkable for
their power of rapidly flitting with a zigzag course
through the water by the opening and rapid closing
of their valves. A glance at the interior even of
an empty shell will show that the muscle for
closing the valves is very large, and must conse-
82 Shell Life
quently be very powerful. The ribs of the Scallop
shell serve another important purpose besides that
of combining strength with lightness : at the lower
margin the ribs and intervening spaces of the two
valves so accurately fit together that with the
almost central muscle holding the valves together
any shifting of them to right or left is impossible.
The development of the "ears" at each side of the
beak gives similar strength to the upper margin,
and allows of the employment of a long though
narrow ligament. The foot is developed as a finger-
like organ, occupied in the spinning of byssal threads,
and space is left between the ears for the passage
of these, the two valves being kept slightly apart
at this place by a little boss. Ordinarily the shell
is kept slightly open by the pad of elastic cartilage
between the beaks, and then the mantle is seen to
great advantage. Its margin is double, the inner
finely fringed and the outer edged with long
tentacles, and at their base gleam a row of large
and brilliant opalescent " eyes," whose optical powers
appear to be of a relatively high order. All the
British species are unattached
with the exception of
The Hunchback Scallop (P.
pusio), which in the adult state
becomes attached like an Oyster
by its lower valve. Though it
begins life with as symmetrical a
Hunchback Scallop She11 RS the therS > & llaS & likhl g
for contracted quarters, such as the
interior of vacated shells, clusters of certain corallines
(Escliara), etc. After attaching the newest portion
Oysters and Scallops 83
of its right valve to its support, its further growth
proceeds unequally ; so that the distorted appearance
ensues which has suggested the title of Hunchback
as a fitting one, though Linnaeus called it piisio (a
youngster), from what he evidently regarded as its
immature or unexpanded appearance. In its early
and regular condition the shell is longer from back
to front, like the other species, but as maturity
comes to it the distance from beaks to lower
margin becomes greater than the length. The
valves, too, that had formerly been equal in size,
now become unequal, the upper often larger and
more convex than the lower. The sculpture consists
of larger and smaller sharp ribs, which alternate,
and in an adult number about 70, here and there
rising into prickly scales. It ranges through all
shades of colour, from white through yellow
and red to brown, streaked and blotched with
other tints of the same series. The posterior ear
is larger than the other; and the ocelli are few
in number. It may be found where the coast
is rocky, ranging from 5 to 85 fathoms.
The Variegated Scallop (P. varius)
has only from 25 to 30 ribs of equal
thickness, often bearing blunt thorn-
like plates on their upper sides.
The ears are unequal, the hinder one
being the larger. Its colour and
markings are much like those of the
Hunchback, but its ocelli of which
there are about 30 are smaller than
in that species. It is well distributed all along our
coasts, from extreme low water to a depth of 40 fathoms.
84 Shell Life
The Quin or Queen (P. opercularis) is more
nearly circular in shape, thin and smooth, marked
by 18 or 20 broad, rounded ribs, sometimes with
scales upon them. The ears are almost equal.
The colour varies from white to yellow, orange,
pink, red, brown, or purple, often marked with
streaks or spots of other colours. The animal is
as varied in colour as its shell. The 35 to 40
black ocelli have a pupil-like spot of greenish grey.
Full-grown specimens measure from 2| to 3 inches
across. The Quin is more partial to sandy than to
rocky shores, and that is probably
the reason why it is less given
to fixing itself, and more addicted
to flitting like a submarine
butterfly. It is strange that this
power of flight should be so little
known to fishermen : I have
caused the most profound as-
tonishment in some experienced
members of this class by showing
them Quins in full activity in an aquarium-tank.
This species is much used for food on some of our
coasts, the oyster-dredgers obtaining great numbers
from the oyster-banks and selling them for a few
pence per hundred.
The Seven-rayed Scallop (P. pes-lutrce) is also
almost circular in outline, but at once distinguished
from the others by the very different sculpture,
the seven ribs being widely distant from each
other. Between these strong ribs the somewhat
glossy shell is very finely grooved. In the upper
valve the ears are almost equal, but in the lower
i VARIEGATED SCALLOP ; 2 SEVEN-RAYED SCALLOP ; 5 TIGER So
6 MOTTLED SCALLOP; 3 HEART FILE-SHELL; 4 TRIANCJUI.A
ASTARTE-SHELL J 7, 8 FURROWED AsTARTE-SHELL.
Oysters and Scallops 85
one the right ear is distinctly larger. The shell
is ruddy brown in colour, marked with white,
and measures \\ inch across. It is
entirely a northern form, North-
umberland marking its most southern
range on our coasts ; it has a prefer-
ence for rough ground and deep
water, what is termed its bathy- .
Seven-rayed Scallop
metrical range lying between 20 (one-fourth nat.
and 90 fathoms. size)
The Tiger Scallop (P. tigrinus) has a smaller and
proportionately thicker shell, covered with fine even
corrugations but with only a few distinct ribs. The
ears are very unequal, that to the left of the beak
being three or four times larger than its fellow. It
ranges from yellow (occasionally white) to purple,
with the streaks and spots of other hues that have
suggested its names. The animal varies from creamy
white to red, and its 10 brown ocelli
have pupils of gold. It is fairly plentiful
wherever the bottom is sandy or gravelly,
and is fond of hiding in the interstices
of masses of coral or clinker, whence it
flits at pleasure. Almost any stony mass
from the bottom will be found to harbour a number
of living examples of this species, providing its
surface is at all broken up into minute caverns,
where the little Porcelain-crab and many another
marine animal will also be found. Testa's Scallop
(P. incomparabilis) is very similar, but with a broader,
flatter, and thinner shell, less prominent beaks, and
more equal ears. Its colouring is brighter, and as
a rule the inside of the shell is without the crenu-
86 Shell Life
lations which enable the valves to interlock. It is
recorded from deep water (18 to 80 fathoms) at
Shetland, Skye, Antrim, Galway, Exmouth, and
Guernsey
The Mottled Scallop (P. striatus) differs but
slightly at first sight from Testa's Scallop, but it
is " larger, thinner, and more fragile," the ribs are
thickly covered along their
ridges with projecting
scales, and crossed by
minute and irregular raised
lines. The colouring, though
similar, is less bright. The
whitish animal has 25
crimson pupilled, blue-black ocelli, of unequal size
and irregular disposition. It is found on hard
ground in from 12 to 90 fathoms of water round
Shetland, Scotland, north-east England, Ireland, Man,
and Scilly.
The Pygmy Scallop (P. similis) is a minute
and exceedingly fragile species, of almost circular
form. The lower valve is much smaller than the
upper, and looked at from above the right ear is
larger than the left. The sculpturing takes the
form of fine concentric lines instead of the usual
radiating ribs ; the colour white or yellowish,
streaked or mottled with brown or white. The
animal has about 20 unequal ocelli in two series,
black with a pearly centre. It prefers sandy
bottoms of a muddy quality, and ranges from 2
to 80 fathoms, all round our islands, but is nowhere
very plentiful.
The Great Scallop or Clam (P. maximus) differs
Oysters and Scallops 87
from all the other species in the inequality of its
valves, the lower being very convex outside, whilst
the upper is flat with a slight concavity towards the
beak. This upper valve is also smaller than the
lower, so that the lower margins do not meet. The
shell is thick and solid, ornamented and strengthened
by about 15 broad ribs, which are themselves corru-
gated. The lower valve is white suffused with pink
and pale yellow, but the upper valve has the ribs
dark red, and the intervening channels brown, the
whole colour paling away to the beak. The animal
is pink or red, the mantle marbled with brown and
white. There are from 30 to 35 large unequal
ocelli in two series, greenish or dark blue. The
young ones spin a byssus and suspend themselves by
it, but before they have become adult they appear to
have lost this power, or to have learned that their
shells have acquired sufficient weight and solidity to
resist movements of the lower waters. It occurs
generally around our islands in water of from 7 to
80 fathoms. The saucer-like lower valve has long
done duty as a drinking vessel.
Closely related to the Scallops are the File-shells
(Lima), so-called on account of the rasp-like character
of the shell sculpture. The valves of the shell are
uniform and always white, and the mantle is not
ornamented with prominent ocelli at the margins.
But though not well developed and conspicuous they
are there, and to make up for their deficiency the
tentacles which fringe the mantle are exceedingly
long and numerous, and wave about like the tentacles
of the sea-anemones. During early life the File-
shells flit through the water like the Scallops. The
88 Shell Life
foot of the animal is finger-shaped and grooved ; and
its lips are furnished with tentacles like those of the
mantle. Like the Scallops the File-
shells spin a byssus, which may be
an easily detachable cord whereby
they temporarily attach themselves, or
may be an enveloping tissue like that
of the Horse Mussel, only in this case
it would be plastered over with excre-
ment, gravel, shell fragments, and sea-
weeds, forming a nest in which are
several youngsters or one adult. The
native species are four in number.
The Elliptical File-shell (L. elliptica)
is a small species confined to the waters of the west
coast of Scotland and Shetland. Its shell is oval
or elliptica], thin and glossy in spite of the 30 or
40 fine ribs with toothed crests which radiate from
the prominent beaks. The valves have small tri-
angular ears, and are connected by a slight ligament.
The body and foot of the animal are pale orange,
whilst the tentacles are more pink in hue. It inhabits
sandy mud in water from 15 to 85 fathoms deep.
The Heart File-shell (L. subauriculata) is smaller
than the last, more oblong, more convex, and with
only 24 ribs, of which the middle one is the
largest. The beaks projecting beyond the
hinge are very prominent. The animal agrees
in colour with the white shell, and uses its
white foot for crawling. It is generally dis-
tributed round our coasts where there is a
sandy or gravelly bottom at a depth from 18 to 90
fathoms.
Oysters and Scallops 89
The Fragile File-shell (L. loscombii) differs from
the preceding in the fact that the valves of the
shell are not equal sided. The ribs number
from 40 to 60, and are very fine and
sharp. The upper side of the shell gapes
slightly. The animal is coloured bright
orange, and the tentacles of the same hue
curling back over the white shell present a
striking contrast. It is generally distributed where
there is mud or gravel between 5 and 100 fathoms.
It is one of the species that weave nests, though not
invariably. If the bottom is soft it sinks chambers
in it, but where the ground is hard some protection is
needed against members of the Cod-family who have
a weakness for Lima-flesh ; then it spins a nest, and
decorates the exterior with shells or fragments of
shell of other mollusks and of crustaceans.
The Gaping File-shell (L. hians), our largest
species, is more solid and less glossy than the others ;
its ribs stronger and rougher. The triangular ears
are unequal, and the pure white colour which distin-
guishes it in early life afterwards becomes more or less
discoloured. The valves gape along
the front margin, and discover the
red animal. The orange mantle is
fringed with a thousand or more
filaments which, curling over the shell,
are in constant movement. Like the
tentacles of the anemones, these have
the power of taking hold ; and by
Gaping File-shell . . r , .,.,..
placing one s finger among this living
fringe the Lima may be drawn to a considerable
distance. It affects harder ground than its con-
90 Shell Life
geners, in water from 12 to 40 fathoms. Here
it builds its nest under large stones, mingling
with the byssus - threads bits of nullipore and
File-shell in its nest (nat size)
fragments of shell, lined within with excrement.
The young ones often associate, several in one nest,
but the adults are quite solitary. They frequently,
however, accommodate guests, who in all probability
Oysters and Scallops
act as scavengers. Among these are the little
Porcelain-crab (Porcellana longicornis) and a marine
worm (Polynoe). The Hermit - crab
who lives in cast-off whelk-shells has
similar messmates who do their best
to keep the house clean for their
host.
This family also contains the Wing-
shell (Avicula kirundd), one of the
Pearl - oysters, and closely allied to
Pinna. It is like a small Pecten
whose hinder " ear " has grown to an
inordinate length, so that it resembles a wing rather
than an ear. Its home is in the Mediterranean, but
it is occasionally taken on our southern shores,
perhaps being brought hither by currents in its earlier
stages. Several fishes, crabs, and jelly-fishes also
make their way from the Mediterranean to the coasts
of Cornwall and Devon.
Gaping File-shell-
interior
HE creatures to be described
in this and some following
chapters differ from the fore-
going in the higher develop-
ment of their respiratory
organs. In the Mussel family
we showed that the gill-filaments had got so long
that they had to be folded over so that the gills
appeared to be fourfold on each side of the visceral
mass. In the Oyster and Scallop family advance
had been made upon tin's development by the ends
of the turned-over gills uniting with the foot and
the mantle respectively. The present chapter deals
with mollusks in which the two folds of each gill-
plate have been partially united by trusses which
leave internal spaces and increase the respiratory
capacity. There are usually two muscles for closing
the shell, and the mantle-edges are united at one or
more points. The group includes both marine and
Heart-Cockle and Fresh-water Cockle 93
fresh-water species, so we must at times turn from
the seashore to the river and pond.
The animal in the first genus A starte has an
almost round body, flattened from the sides. The
lips are large ; the mantle thick, not fringed with
tentacles, but part of it forms a short excretory
siphon behind. The foot is conical and small, though
tolerably powerful. The shell is more or less tri-
angular and thick, somewhat flattened, with concentric
furrows. It is covered by a thick yellow or brown
epidermis, and has prominent beaks. In front of the
beaks will be found a dark depression called the
lunule, found in many other genera of bivalves, and
here heart-shaped or lance-shaped. Internally the
valves are furnished with three central teeth
(cardinals) below the beak, and a ridge-like tooth
(lateral) on either side. There are
three native species.
The Furrowed Astarte-shell (A. sul-
cata) has from 24 to 40 thick ridges,
and is white beneath the brown epi-
dermis. The broad hinge-plate bears Furrowed Astai
three cardinal teeth, one small and indistinct, two
large ; laterals indistinct. The margin is thick and
notched within. It partially embeds
itself in sand and mud all round our
islands in water from 7 to 145
fathoms deep. It is by no means
active, getting its microscopic food in
plenty without the necessity for pur-
suing it. The Flat Astarte-shell (A.
compressa) is only about one-half the length and
breadth of the last named, and may be distinguished
94 Shell Life
from younger examples of that species by its flatter,
more equilateral valves, and the slight depressions
between the ridges. The interior margin
has a plain bevelled edge, not notched. This
is a local species of northern range. It has
been found in sand and mud off the coasts
of Yorkshire, Mull, and Antrim, in from 20
to 40 fathoms of water. The Triangular Astarte-
shell (A. triangularis) is the smallest of the trio, and,
as its names indicate, has three almost equal sides.
It is thick in proportion to its size, and the valves
are almost without the thick ridges of the two
foregoing species. Where these are present they
are few and not very prominent. The yellow or
brow r n epidermis, which is streaked with darker tints,
disguises the white of the shell. The margin may be
either toothed, or plain and bevelled. It occurs
locally in from 3 to 60 fathoms of water. A
fourth species (A. crenata) has been dredged
between the Hebrides and Faroes, but can scarcely
be regarded as British.
Attention should be called in connection with the
Astartes to the development of the hinge-teeth. We
shall gradually come upon species that are more or
less advanced in this respect, and we wish our
readers to consider these teeth in relation to the
habits of the animal. A deep-burrowing species that
is provided with long siphons, rendering frequent
visits to clean water unnecessary, is also in little need
of very powerful hinge-teeth. As a matter of fact
the shell will be rarely closed ; and powerful locks
would be thrown away on an open house. But
the Astartes only partially embed themselves in the
ICELAND CYPUINA ; 2 HEART COCKLE.
Heart-Cockle and Fresh-water Cockle 95
mud so little that they need no long siphons;
sufficiently, however, to make the presence of ribs
upon the shell an advantage these helping to keep
them firmly in place when they have withdrawn the
foot and closed the valves.
In the Iceland Cyprina (Cyprina islandica) we
have an example of a single species constituting the
sole living representative
of its genus, though of
the fossil species of that
genus we know nearly a
hundred. The shape of
the valves is shown in the
figure, but if the complete
shell be looked at from
behind it will be seen that
in that aspect it is
heart - shaped. It is a
thick and slightly glossy shell, with numerous
irregular concentric raised lines, which are stronger
towards the margins than in the middle. The colour
is white tinged with yellow and pink, but the brown
epidermis hides this. The beaks are prominent and
considerably curved. Along the
upper edge of each valve there
is a groove which holds one side
of the ligament. The hinge-plate
is broad and bears three strong
cardinal teeth. The laterals are
also strong in the left valve, but
ior of Cyprina . . &
in the right they are very slight.
It measures between 4 and 5 inches in length,
and almost as much from the beak to the lower
7
96 Shell Life
margin. The animal is of a creamy tint, and the
mantle forms two short tubes behind, whose mouths
are fringed with delicate tentacles. The long foot is
broad at the base, but runs to a sharp point. By the
aid of this powerful instrument the Cyprina burrows
in the muddy sand, but not deeply, as may be gathered
from the shortness of the tubes and the sculpture of
the shell, slight as that is. It is found on all our
coasts, at all depths from low water to 100 fathoms.
The Heart-Cockle (Isocardia cor) when viewed
from the side appears almost round, but from either
end it is seen to be more com-
pletely heart-shaped than Cyprina.
The beaks are curved spirally
towards the front, and from this
point they present the appearance
of the illustration. The thick
shell is yellowish white in colour,
but this is quite hidden beneath
the red -brown epidermis, which bears stiff short
hairs set in numerous lines radiating from the beaks.
The thick, broad hinge-plate bears two cardinal teeth
and two laterals. All these interlock and form a
powerful safeguard against the shifting of the valves.
The animal is whitish, the borders of the mantle
orange, and the strong tri-
angular foot of the same
colour. The siphons are very
short, with _ broad, fringed Beaks of Heart . Cockle
openings which are at the
centre of the lower margin. Full-grown specimens
average 4 inches across the longer axis of the shell,
and almost as much at right angles to it. The
Heart-Cockle and Fresh-water Cockle 97
strange situation of the siphons is explained by the
habit of the Heart-Cockle : by means of the foot the
shell is embedded, beaks first, in
the slope of a muddy bank, so
that only the lower margin of
the shell with siphons is ex-
posed. It is a local shell, and
its distribution is almost con-
fined to Devon, Cornwall, the
west coast of Scotland, and the
Interior of Heart-Cockle
south and east coasts of Ireland.
The Northern Lucina (Lucina, borealis) is also an
almost round shell viewed from the side, but from
either end it is seen to be a much
flatter shell than the preceding. Its
whiteness is hidden by a yellow-brown
epidermis, and its surface is relieved
by a series of low but sharply cut
concentric ridges. The pointed beaks.
Northern Luctna * A
in spite of their small size, are tolerably
distinct. The hinge-teeth are two strong cardinals
with a long lateral on each side of the beak. The
interior margins are smooth and bevelled. The
animal is white, with short thick lips and extremely
short siphons. The long slender foot emerges from
the shell at about the centre of the lower margin, and
serves chiefly as an anchor to moor it to the gravel
and sand upon which it lies all round these islands,
from extreme low water to upwards of 100 fathoms.
There is a second species the Prickly Lucina (L.
spinifera) which is of more local occurrence. The
shell is more triangular than the last named, the
epidermis of a much paler tint, the beaks less
98 Shell Life
prominent, and the ridges somewhat overlapping,
their terminations giving a spiny character to the
upper margin. There is but one cardinal tooth in the
right valve, but in the left there is a small additional
one. It is more plentiful on our northern shores than
in the south, and especially on the west coast of
Scotland.
In the next genus, the Hatchet-shells (Axinus), the
smooth shell is more globular, though with a triangular
outline, the hinder portion furrowed. The beaks are
considerably recurved, but the hinge-teeth are entirely
wanting, though an excavation in the right valve and
a corresponding eminence in the left have somewhat
the appearance of teeth. The margins of the shell
are not toothed. The thickened margin of the mantle
is open all round and not prolonged into siphons.
The long slender foot is almost cylindrical. There
are five British species, all small and all living on
muddy - sandy shores. The Rusty Hatchet - shell
(A. ferruginosus) is the most plentiful of these,
and gets its name from a rust-like deposit over the
epidermis which protects the thin, white, almost
globular, shell. It occurs between 30 and 100 fathoms,
chiefly off Skye, Shetland, and the west of Ireland.
The Wavy Hatchet-shell (A. flexuosus) has a more
oval and less glossy shell. The terms "wavy" and
"flexuosus" apply to the upper margin behind the
beaks. The hinder margin of the mantle is con-
tracted so as to form some approach to a siphon or
the aperture of one. This species is widely distri-
buted, and ranges between 3 and 90 fathoms. The
Skye Hatchet - shell (A. croulinensis) is obliquely
oval, swollen, more solid, and longer than the last
ZEBRA MUSSEL ; 3 ROUND DOUBLE-TOOTH ; 4 RUSTY MONTAGU-SHELL :
5 WAVY HATCHET-SHELL ; 6 PRICKLY LUCINA ; 7 MONTAGU'S
URCHIN-SHELL ; 8 TWO-TOOTHED URCHIN-SHELL
Heart-Cockle and Fresh-water Cockle 99
named. The white shell shows through the thin
epidermis. The tooth-like folds of the hinge-plate
are stronger than in either of the other species. It is
a rare species, and appears to be restricted (in Britain)
to Skye and Shetland, where it occurs in deep water,
between 45 and 85 fathoms.
The Round Double-tooth (Diplodonta rotundata) is
almost round in outline, somewhat glossy, with
irregular concentric ridges; white, but covered in
front by the yellowish epidermis. There are two car-
dinals and two laterals in each valve, one of the
cardinals in each being cleft in order to receive the
undivided one of the opposite valve. The animal is
white, with large free lips, and the mantle edges are
united, save for the large aperture on the lower margin
where the foot emerges, and for the incurrent and
excurrent orifices on the lower margin. The shell is
about 1 inch long, and almost as deep from the beak
to the lower margin. It is found on the surface of
sandy mud in from 12 to 20 fathoms, chiefly on our
southern shores, but also locally on the west, as at
Lundy, Anglesea, and Fishguard.
There are six little bivalves of local occurrence
that have been named after Colonel Montagu, who
first discovered and described them. His name in
the Latinised form of Montacuta stands for that of
the genus. As they have no popular name, we think
it fitting to call them Montagu-shells. Montagu's
Urchin-shell (M, substriata) is a small, yellowish,
oval, semi-transparent shell, about a quarter of an
inch in length. Its valves are marked by about a
dozen faint ribs radiating from the beaks, but not
reaching to the front margin. The animal spins a
TOO Shell Life
byssus, and on the lower margin there is an indentation
whence this issues. There is a long tooth on each
side of the hinge-line, those of one valve interlocking
with those of the other. The animal agrees with its
shell in being almost transparent. The rear portion
of the fringed mantle forms a brief tube for the out-
ward current of water, and the foot is large- and
powerful. From 8 to 100 fathoms deep is the range
of this species on all our shores, but not on the sand
or mud affected by its allies. It has a more remark-
able habitat, being found only on living Sea Urchins,
and chiefly on the spines of the Heart-Urchins, such
as Spotangus purpureus, Ecldnocardium cordatum,
and Bryssus lyrifer. To these spines it is attached
by the coarse byssus-threads, and no doubt it selects
this strange position in order to share the food of the
Urchin. The Heart - Urchins, it may be mentioned,
bury themselves in the sand, and appear to exist by
continually swallowing it and digesting out the
organic matter mixed with it. The Urchin's mouth is
a shovel-shaped aperture on the lower surface, and
Montagu's-shell is attached to a spine in front of it
where the indraught of sand is likely to bring minute
food - particles to the mollusk. The two - toothed
Montagu - shell (M. bidentata) is less oval than
the last, approaching nearer to square ; flatter,
and much less transparent ; whiter in colour. The
teeth in the right valve are shorter and broader than
those in the left. The mantle has its margin fringed
with bright silvery teeth, and forms a very brief tube
behind. The large broad foot is somewhat triangular
in outline. It may commonly be found on all our
coasts, in water from 10 to 70 fathoms, nestling in
Heart-Cockle and Fresh-water Cockle 101
the crevices of old bivalves, sometimes in the burrows
of the Boring- sponge (Cliona) in old oyster- valves.
Its greatest length is only a couple of lines. The
rusty Montagu-shell (M. ferruginosa) is more oblong,
greyish white in hue, but this is hidden by a
rusty-looking incrustation that covers the epidermis,
and is no doubt due to the peculiar habitat of the
creature. The front teeth differ from the back, and
the opposite front pair differ somewhat from each
other in order that they may interlock. It affects the
burrows of the Heart-Urchin (Ecliinocardium cor-
datum), and often is attached by its byssus to the
bristle-like spines of the Urchin, and is dragged about
with every movement of the Urchin.
We have now to briefly describe four small genera,
two of them each represented by a solitary species.
They are all small, and consequently little known to
the average seaside visitor, and have no popular
names. We must therefore utilise their scientific
names as far as possible. The Globose Kelly-shell
(Kellia suborbicularis) is more or less
globular, equal-sided, thin, glossy, with
faint lines running across from the beaks,
and others parallel with the lower margin.
The thin and iridescent epidermis gives a
greenish hue to the white of the shell. In
the right valve the two strong teeth are
laterals ; they are repeated in the left valve with the
addition of a cardinal. Both shell and animal are
nearly transparent. As shown in the first figure, the
mantle extends considerably beyond the shell margin,
and its edges are united all round. There is a large
opening on the lower margin to allow passage for
102 Shell Life
the strap-shaped foot ; it is greatly extended in front
to form an incurrent tube, and a small opening
behind serves as an excurrent siphon. The
longer diameter of the shell is from one-
third to a half -inch. The small creature
interior of moves freely by means of its foot, and
Ke'iy b h S Iii attaches itself by an almost invisible thread,
hanging in the position shown in the figure.
It is fond of taking refuge in muddy discarded shells
in rock-crevices, and about the tangled suckers of
the larger seaweeds. Its vertical range is from
extreme low water downwards. The Minute Kelly-
shell (K. minuta} is much smaller, its longest measure-
ment being only one-twelfth of an inch. It has a
thin, semi-transparent, glossy shell of a purple-brown
tint, darker at the beaks and paler in front.
Its principal markings are the irregular lines
of growth. There is but one siphon in this
species. The foot is comparatively large, J^nu^ed
very flexible, and much used by the
animal for climbing seaweeds. It is found in great
abundance all round our coasts at low water and a
little beyond. It has sometimes been called the
Mullet-shell because of the fondness of that fish for it.
Mr. Hyndman took about 35,000 of these shells from
the stomach of a single mullet. This certainly showed
praiseworthy industry on the part of the fish in the
collection of food, as well as testifying to the good
qualities of the mollusk as a fish-food and to its
astonishing fecundity.
In the matter of size the Ruddy Lassea (Lascea
rubra) comes between the two Kelly-shells, being
about the tenth of an inch in length. The shell is
Heart-Cockle and Fresh-water Cockle 103
oval, unequal-sided, white, deeply tinged with red
towards the upper margin, and covered by a yellowish
epidermis. There are two lateral teeth in each valve,
but in the left valve there is in addition a small
cardinal. The mantle does not extend so much be-
yond the shell as in Kellia, but in front it forms a
protuberant incurrent tube. The excurrent orifice is
not seen beyond the shell margin. The long, tongue-
shaped foot is used for similar purposes as in the
last-named species, and a byssus of less simple
character moors it to rock-crevices, to corallines and
other seaweeds, chiefly between tide-marks, all round
our coasts. It is a species that retains its eggs until
they are hatched. These are produced in batches of
from 12 to 20, and when sufficiently developed the
fry are shot into the world of waters through what
ordinarily serves as the incurrent siphon.
The Coin - shells (Leptori), so - called from their
resemblance to a small coin (lepton), are represented
by five native species. They differ in several respects
from the creatures just described. The shell is more
liberally provided with hinge-teeth, there being a
cardinal and two laterals in each valve. The mantle,
which is fringed with long tentacles, protrudes nearly
all round, and the foot can be flattened in such manner
that it resembles the foot of a snail, and is
used in similar fashion. The Scaly Coin-
shell (L. squamosurn) is almost square and
flat, its substance thin almost to transpar-
ency, glossy, and white. It is finely ribbed
in two directions, the spaces left between
the network thus formed giving the surface the ap-
pearance of being minutely pitted. Inside the shell is
104 Shell Life
iridescent, marked with fine irregular grooves which
run from the beak to the lower margin. The cardinal
tooth is small and erect, whilst the laterals are long
and plate -like. The white animal has a short
excurrent siphon, and a bluish foot streaked with
white. The fringe of tentacles around the mantle
is shown in the figure, where will also be seen one
tentacle above the foot developed abnormally as
compared with the others. When the creature
crawls along it waves this tentacle about, appar-
ently using it as a sense-organ, feeling its way and
ascertaining the presence of food. It is a southern
species, its distribution here being restricted to
Dorset, Devon, Cornwall, the Channel Islands, and
the south and west of Ireland. Like the Montagu-
shells previously described, it has a preference for
the company of a creature belonging to an entirely
different class of animal life. In this case the mess-
mate is a singular crustacean, known as Gebia stellata,
that burrows in muddy sand. No doubt the Lepton
acts, to some extent at least, as a scavenger, feeding
upon the excretions and surplus food of Gebia, whilst
the flatness of its shell enables it to keep out of
the way as the Gebia scuttles up and down his
burrow.
The Shining Coin-shell (L. nitidum) is a much
smaller species, as will be seen on reference to the
figures, which are of the natural size. It differs from
squamosum by the shell being less flat, less thin,
with the beaks more prominent, and the animal
appearing to be more gelatinous. The lower edge
of the shell is less straight, and the fine rib-marks
run only in one direction that is concentrically.
Heart-Cockle and Fresh-water Cockle 105
The shell is white with a tendency towards a
yellowish tint, which is the hue of the opalescent
epidermis. An enlarged figure of the
hinge-teeth is given ; they are more
highly developed than in squamosum.
The foot is more distinctly blue, necked shining co
with white, and the siphon is placed in and enlarged hinge
front instead of behind. It occurs sparingly on
all our coasts where there is coarse sand, between
10 and 90 fathoms. The form sometimes described
^^ as a separate species under the name of the
|^Jp Convex Coin-shell (L. convexum) appears to
convex be a variety (convexa) of L. nitidwm. It is
Coin - distinguished by the shell being slightly
more convex, and marked all over with coarser
pits than those found only round the beaks in the
type.
The Furrowed Coin-shell (L. sulcatulum) is almost
circular in outline and flattened; its substance thin
and almost transparent, like that of L. squamosum,
but instead of the pit marks we have here a numerous
series of broad concentric ribs covering the surface.
The cardinal tooth in the left valve is strong and
erect, whilst the corresponding one in the right is
very small. The length of the shell is only about
one-twentieth of an inch. It appears to be a southern
form, and has been found in the Channel Islands
among corallines below the lowest tide-marks. . Clark's
Coin-shell (L. clarkice) is another minute species, but
of more yellow tint than the last, streaked with fine
white lines that radiate from the beak. Instead of
the ribs of L. sulcatulum, the sculpture here consists
of numerous fine concentric grooves. The outline is
io6 Shell Life
triangular-oval ; and the cardinal tooth in the left
valve though strong is more oblique than erect. It
has been found on gravelly sand on various parts of
our coasts, both north and south, ranging in depth
from 18 to 80 fathoms.
Turton's Weasel-eye (Galeomma turtoni) is the
sole British representative of its family and genus.
The thin oval shell is equal-sided, with minute beaks,
and gapes widely in front. The hinge is without
teeth, and there is no epidermis. The animal has a
long foot flattened to form a narrow sole, upon which
it glides after the manner of a snail. The edges of
the mantle are joined, but at the
front there is an orifice for protrud-
ing the foot, and there is a siphon at
either end. Contrary to the habit of
most bivalves, which keep their shells
as nearly closed as possible, the
weasei-eye Weasel-eye spreads open its valves
to the fullest extent, and so flattened
out, as in our first figure, it glides over the weeds
and corallines, in water between 5 and 20 fathoms,
on our southern coasts. It attaches itself by a
byssus, but when it wishes to move away the
byssus is thrown off from the foot. It will be at
once seen in the light of previous remarks that there
is distinct relation here between the habits of the
creature and the absence of hinge-teeth. A mollusk
that uses its widely expanded valves to protect it
has little need of the teeth with which many other
species lock their valves together so the teeth are
not developed.
Leaving the seashore for a time, we must repair to
NUT OKH-SHKI.L ; 2 HOUNY ORIJ-SHKI.I. ; 3 OVAL OKU-SHELI. ; 4 LAKE OUB-SHELI
8 SHINING PEA-SHELL; 9 Rosy PEA-SHEM..
Heart-Cockle and Fresh-water Cockle 107
the fresh- water pond or stream, in order that we may
consider some of its inhabitants in their proper order.
There on the mud or climbing the weeds we shall find
a number of little bivalves, to which the popular name
of Fresh-water Cockle has been applied. The nine
species found in this country belong to two genera
of one family the Sphseridse and are not at all
related to the true Cockles (Cardium). Their thin
shells are more or less globular, the valves being of
equal size but not equal-sided. The hinge is provided
with both cardinal and lateral teeth, and their general
character may be gathered from this figure of the
hinge of Sphcerium corneum. The animals are very
active, and by means of the mobile foot can riot only
climb weeds, but by spreading it out on
the surface of the water can float with
their shells inverted after the manner of Hinge-teeth
the pond-snails. From such a position SjJuartom
they often descend gradually to the bottom by spin-
ning a thread of mucus, the end of which remains at
the surface or attached to a floating weed. By means
of these threads they can reascend to the surface or
remain suspended half-way. They hibernate in the
fine soft mud at the bottom, becoming active again
when the warmth of spring has penetrated to those
depths. The eggs are retained in a brood-pouch
within the gills until they hatch, and the young
remain there for a time, finally being shot out
through the siphon when developed sufficiently
to take care of themselves. The four species of
Sphcvrium have each two siphons, a character which
serves to separate them from the five species of
Pisidium. which have one siphon only.
io8 Shell Life
The Horny Orb-shell (S. corneum) is common in
most ponds and streams throughout the country.
The beaks are placed almost in the centre
of the upper margin of this almost globular
shell, which is covered with a thin glossy
epidermis. The colour is that of horn with
some lighter bands running parallel with
the lower margins. The teeth are well developed.
The length is about half an inch, and the animal's
span of life is about two years. The Nut Orb-shell
(8. rivicola) is a much larger, more oval, and more
solid-looking shell, and its colour is yellowish brown.
It is covered by a thick brown epidermis, and has
strong concentric ribs. The hinge-teeth
are similar to those of S. corneum, but
much stronger. The interior of the shell
has a pearly coating. The animal, like
8. corneum, is greyish, but the broader
foot is less pointed, and the shorter siphons are
nearly of the same length and whiter. Though not
found in stagnant water, it is not partial to rapid
streams ; but may be sought in the gently flowing
rivers, brooks, and canals of England, from north
Somerset and Surrey to south Northumberland. The
Oval Orb - shell (S. pallidum) is a local shell of
oblong form, much flatter than the foregoing, thin
and semi-transparent, with fine concentric grooving.
The animal is white, with a long tongue-shaped foot,
and the long siphons are connected almost throughout
their length. It occurs only in England, and there
its range is limited to Surrey, Middlesex, Warwick-
shire, Lancashire, and Yorkshire, where it is found
in ponds and canals. The last of the quartette, the
Heart-Cockle and Fresh-water Cockle 109
Lake Orb-shell (8. lacustre), when looked at from the
side is much like S. corneum, but from either end it
is seen to be somewhat compressed, the beaks central,
and usually capped by the nucleus of the shell ; very
thin, semi-transparent, and glossy, of a
greyish-brown hue. The white animal has
a foot twice the length of its shell. The
siphons of this mud-loving species are long,
and exhibit a marked difference between
the respiratory and excretory tubes : the former being
cylindrical with a wide mouth, whilst the latter is
slightly conical with a small mouth. It is well
distributed over England and Wales in still waters,
but is only found locally.
As already indicated, the five species of Pea-shells
(Pisidium) may be recognised as such at a glance by
their possession of one siphon instead of two. Their
shells are also much smaller and less equal-sided than
those of the Orb-shells. The River Pea-shell (P.
amnicum) is solid, glossy, somewhat tri-
angular, and swollen ; deeply grooved,
greyish brown in colour, with a thick epi-
dermis, and a quarter of an inch in length.
The greyish animal is almost transparent,
with a long broad foot and a short siphon. It is
generally distributed in running waters. The Foun-
tain Pea-shell (P. fontinale) is similar in shape to the
last, but smaller, less solid, faintly grooved, of a paler
grey colour, with more prominent beaks, and a thin
epidermis. It is widely distributed in similar situa-
tions to those affected by the last named. The Small
Pea-shell (P. pusillum) is oval and thin, with little
gloss, finely but irregularly grooved ; of a brownish-
no Shell Life
grey colour, with very thin epidermis, and the beaks
nearly central. The animal is pale pinkish, with a
long slender foot, and short conical siphon. It is the
only native Pisidium of an oval form, so it will be
readily identified by this feature, and by the almost
central position of the beaks. It is generally dis-
tributed in pools, ditches, and marshy places. The
Shining Pea-shell (P. nitidum) is nearly round, very
glossy and iridescent, pale yellow or pale brown,
more strongly grooved than in the other species.
The interior is whitish. The animal is also whitish,
with a long, finely-pointed foot, and short, funnel-
shaped siphon with a notched margin. It is found
in lakes and ponds throughout the country. The
Rosy Pea-shell (P. milium), though very glossy like
the shell of P. nitidum, and grooved in a similar
manner, is more nearly oblong than round, and the
lower margin is straight instead of curved. In colour
it is yellowish or pale brown, the interior pearly and
white. The animal varies in hue from white through
yellow to rosy red, and has a long, slender, some-
what conical foot. Like the other species, this is
generally distributed throughout the country in still
waters.
All these Orb- shells and Pea-shells are but tiny
representatives of the marine Cockles, and, of course,
are cockles only by popular courtesy. The Fresh-
water Mussels are even more widely separated from
their salt-water namesakes, though our native species
are not of the insignificant sizes of the Fresh- water
Cockles. It has been suggested that all of these
fresh-water bivalves have originated in marine, or
at least estuarine, species which have become
Heart-Cockle and Fresh-water Cockle 1 1 1
accustomed to a certain admixture of fresh water,
and have gradually wandered farther up the rivers
and their feeders until they have finally become used
to water that is absolutely fresh. As they have got
into quieter waters, where, too, enemies are less
abundant, their shells have become thinner and less
solid, with modifications of the animal to match.
The Pearl Mussels (Unio) are represented in our
waters by three species, of which the best known is
the Painter's Mussel (U. pictorum), so called be-
cause the valves were formerly used to hold artist's
colours, just as they are used to-day to hold the gold
and silver for illum-
inating. The oblong
compressed shell is
covered by a thin
epidermis through
which show the yel-
low ground-tint, the Painter , s Musse|
parallel lines of
brown, and the rays of green on the hinder part.
The beaks are considerably forward from the centre ;
the lower margin is almost straight. The interior
is pearly, and the muscular impressions are distinct.
A notched tooth on the front of the left valve fits
into a groove formed by the margin of the shell and
a strong tooth on the right valve ; whilst a long
plate-like tooth on the back of the right valve fits
into the groove of a similar plate on the left valve.
The animal has a large, broad, tongue-shaped foot of
a reddish or yellow colour, with which it burrows into
the mud of ponds and slow rivers. Owing to the
thinness of the epidermis on the beaks these being
1 1 2 Shell Life
the oldest portions of the shell the shelly matter at
this part frequently becomes eaten away by the
action of gases dissolved in the water. It is about
3 inches long. The animal is coloured light red
tinged with grey, and the mantle is bordered with
brown. The siphons of Sphcerium and Pisidium are
represented in Unio by a couple of orifices on the
hinder margin of the mantle, of which the dark
brown upper (excurrent) is somewhat more elongated
than the lower grey (incurrent). This may be
regarded as an English, rather than a British, species,
for it occurs only in the rivers and ponds of England
and Wales, and does not extend north of Northumber-
land, or occur in Ireland.
The Swollen River Mussel ( U. tumidus) is a slightly
more solid shell than the last, and viewed endwise
presents a much greater thickness hence its name.
In colour it is a glossy brown, the lines of growth
often tinged with green. The interior is bluish and
pearly, with strongly marked impressions of both
mantle and muscles. The hinge -teeth, though similar
to those of the last named, are of a stronger character.
The animal differs in colour from V. pictorum in
being greyish instead of red. Its distribution is
nearly the same as that of U. pictorum, except that
it does not occur north of Yorkshire. Both of these
species produce pearls, but they are very small and of
inferior quality. The Pearl Mussel is U. margaritifer,
which has a shell of more oblong shape, much
flattened, though of solid material. There is no
gloss upon its rough, blackish-brown surface. Its
length is about 5t inches. The interior is pearly,
but in this case the tint is flesh-colour, varied with
Heart-Cockle and Fresh-water Cockle 1 1 3
stains of dull green. The animal is usually greyish
with a tinge of red. It is a northern species, not
occurring south of Pembrokeshire and Yorkshire.
This is the species which produces the British pearls,
at one time a somewhat important article of jewellery.
The so - called " fishery " appears to have been
abandoned, probably on the ground that " the game
is not worth the candle." We are told that in the
Pearl Mussels, showing pearl within the shell, and
detached pearls (1-8)
middle of the eighteenth century the Perthshire Tay
in three years contributed to London pearls valued
at 10,000. These varied in hue from white, through
pink and green to brown and black, the white pre-
dominating, and the pink most in demand. The
peasants used to collect the mussels from the
mountain streams just before the corn-harvest, and
in the oldest and most deformed specimens they were
most likely to find the pearls. Yet it is said that not
n 4 Shell Life
one per cent, of the shells contained a pearl, and that
only one pearl in a hundred had any great value.
The best of these, very regular in form, clear in
colour, and the size of a pea, would be worth 3
or 4.
The Swan Mussels (Anodonta), of which we have
two forms, are less regular in outline than the Pearl
Mussels, and are, as their scientific name indicates,
practically toothless, though the hinge - teeth are
represented by sharp ridges on the valves. I have
already described their structure in the Introductory
Chapter. They occur in similar situations to those
affected by the Pearl Mussels, but are more generally
distributed throughout Great Britain. The large
Swan Mussel (A. cygnea) has an oval shell, but
with a straight hinge-line, and with the beaks
placed well away from the centre, forward. The
Heart-Cockle and Fresh-water Cockle \ i 5
forepart is swollen, and the upper part above the
beaks compressed. Greenish yellow is the colour of
the shell, which is covered by a thin, brown, glossy
epidermis. The lines of growth are strongly marked,
and the interior is white with a pearly iridescence.
The animal is grey, tinged with red or yellow ; the
large foot yellow or orange ; the edges of the mantle
tinged with brown and fringed. It occurs in slow
waters and ponds almost throughout Britain, usually
in large colonies. It is calculated that full-grown
specimens are twelve or fourteen years old. The
Duck Mussel (A. anatina)
is considered by many
conchologists to be merely
a variety of A. cygnea.
There can be no doubt that
it is very closely related
to it, and probably arose
quite recently as a variety,
but it appears to be now a
permanent form, and per-
haps would be more cor-
rectly described as a sub-species of A. cygnea.
The shell is proportionately longer, and less swollen,
of thicker material, olive or brown in colour, with
darker concentric bands, and with green rays from
the beaks. The hinge-line is slightly curved, and
higher than in A. cygnea. The animal differs from
its congener chiefly in the larger size of the lower
siphon, which is also fringed with more numerous
and more delicate tentacles. It is found in similar
situations to the last, but is not so widely distributed,
and does not appear to occur in Ireland.
u6 Shell Life
The only remaining fresh - water bivalve to be
described represents a distinct family the
Driessensiidae. It is the Zebra Mussel {Driessensia
polymorpha), which is very similar in appearance to
the Common Mussel (Mytilus) of the sea-coasts, but
differs from it in having a partition extending across
the tip of each valve and thus dividing this portion
of the interior into two. The shell is sharply keeled
along each valve, and is dull brown in colour. The
hinge is without teeth, and the pearly interior is but
faintly marked by the muscular impressions. The
animal is dark hued, with a paler, clearer, slender
and cylindrical foot which spins a strong byssus.
From all this it will be seen that
Driessensia approaches much more
nearly to the marine species than to
other fresh-water bivalves. All the
latter retain their eggs until they
hatch; Driessensia, like the marine
bivalves, discharges her eggs into the waters, and
the young larvae that come from them are free
swimmers. They appear in the middle of the summer
on the surface of the water in great numbers. After
apparently feeding on the microscopic plant-life of the
surface for about eight days, they sink to the bottom.
By this time the foot has formed and become very
long and narrow, and the shell round, much like that
of Sphcerium. The swimming organ the velum
has disappeared, and in future the creature must use
its foot and its byssus for locomotive purposes.
Another point connecting this species with those of
the sea is the fact that the edges of the mantle are
united almost throughout their length.
Heart-Cockle and Fresh-water Cockle 1 1 7
The history of Driessensia in this country is very
singular. Geological evidence shows that in later
Tertiary times this species was abundant, not only
in Britain but over a good portion of Continental
Europe also. Then it vanished without leaving any
evidence why, but held its ground in the Aralo-
Caspian rivers, whence during the last one hundred
and fifty years it has been spreading once more over
Europe. In 1824 Mr. J. Sowerby discovered that it
had reached London. It was found in the Thames and
the Surrey Commercial Docks, and the very natural
conclusion was reached that it had come over from
the Baltic attached by its byssus to some of the
timber - laden vessels. It has since spread very
considerably about the country, and we have even
heard it whispered that a certain London water
company has occasionally supplied it to their
customers, who had only bargained for water.
HE members of the Tellin
family (Tellinacea) are dis-
tinctly deep burrowers in
sand or mud, and this habit
has had effect in developing
the foot to be a powerful organ, and in lengthening
and separating the siphons to give them greater
power and mobility that they may reach up above
the sand to the clear water. The lips also are large,
the gills unequal in size, and the mantle fringed with
tentacles. The general appearance may be gathered
from the figure opposite. The name Tellina was
applied by Dioscorides and other of the ancients
to certain species of marine mollusks, not neces-
sarily those for which the word is now used. There
are seven British genera in the group, with over a
score of native species.
The Pomegranate Tellin (T. balaustina) had
its name suggested to Linnaeus by the resemblance
Wedge-shells^ Venus-shells, and Cockles 1 1 9
between its colouring and that of the pomegranate-
flower. It is a thin almost transparent shell, some-
what swollen and of a triangular-oval outline. The
surface is slightly polished, marked by exceedingly
fine lines and slightly raised concentric plates, which,
however, have in many specimens been rubbed off.
The colour is white, delicately tinged with yellow,
whilst from the
beaks to the
lower margin
faint streaks of
pink radiate.
The beaks are
small, incurved,
and almost
touch. The epi-
dermis is thin
and iridescent. The interior, which is tinged with
orange, is polished. It is about 1 inch in length.
The animal is semi-transparent, greyish white, with
transparent tubes. It is an inhabitant of fine sand
in deep water (18 to 80 fathoms); but although
generally distributed in the Mediterranean, and found
in many parts of the North Atlantic, it does not
appear to be plentiful anywhere on our shores. It
has been found at Falmouth, in the Moray Firth, at
Stornoway, Skye, Shetland, and in Birterbury Bay,
County Galway.
The Blunt Tellin (T. crassa) has a yellowish-white
shell with faint pink rays from the beaks to the lower
margin, and marked by numerous strong concentric
ribs. The left valve is much natter than the right.
In young specimens the shell may be found covered
Tellin, with foot an
extended
120 Shell Life
with a fibrous yellow-brown epidermis, but this soon
gets completely cleaned off as the mollusk burrows in
the sand. The Baltic Tellin
(T. balthica) has a glossy shell,
somewhat triangular when
viewed from the side, but
rather globular as seen from
the end. In colour it varies
from white to crimson, occa-
sionally with bands of a deeper
tint; and the surface finely
grooved. The animal is yellowish, tinged with
brown ; the upper siphon larger than the lower.
Its habitat is in sandy gravel and
mud, between tide-marks, all round
our coasts. The Thin Tellin (T. tennis)
is triangular-oval, flattened, thin, and
semi-transparent, varying in colour tic Te||in
from white, through yellow to rose;
the right valve larger than the left. The animal is
yellowish white, its siphons nearly equal in length.
It frequents sandy beaches about
low-water mark, but it does not
burrow deeply. The Bean - like
Tellin (T. fabula) has a triangular-
oval, thin, and semi-transparent
shell, glossy, pearl - white tinged
with yellow. The animal is similar to that of
the Thin Tellin, of a clear white colour and with
slightly longer siphons. It is common in sandy bays
from low water to 15 fathoms.
The Rough Tellin (T. squalida) is flattened and
thin, the valves slightly unequal, opaque, satiny, of
JEAN-LIKE TELLIN ; 2 ROUGH TELLIN ; 3 DONAX-LIKE TELLIN ; 4 LITTLE TELLIN
5 BRITTLE TELLIN; 6 THIN FURROW-SHELL; 7 WHITE FURROW-SHELL;
8 PEPPERY FURROW-SHELL.
Wedge-shells^ Venus-shells, and Cockles 1 2 1
a pale orange tint, reddish near the beaks. The
animal is whitish tinged with flesh - colour; the
tubes speckled and the mantle-
edges strongly fringed ; foot large.
It is not a common species, but
it may be found on sandy shores
on the south and west of these
islands, at depths between 7 and
15 fathoms. The Donax-like Tellin (T. donacina)
is triangular-oblong, compressed, somewhat glossy,
of a yellowish - white colour with pink rays. The
animal is white, with the edges of the mantle finely
toothed, and the long slender tubes marked with
white along their sides. It burrows in shell-sand
and nullipore, between 4 and 25 fathoms. The
Little Tellin (T. pusilla) is very like the last
mentioned, but smaller, more convex, and more
solid. Its colours, too, are brighter, and may be
white, yellow, pink, or rose, with rays of deeper
tint. The animal is transparent white, the edges of
the mantle quite plain, and the siphons nearly con-
tiguous and equal in size, the excurrent being four
or five times the length of the incurrent. The foot
is toothed along the sides. It occurs on sandy shores
at depths from 3 to 85 fathoms.
The Brittle Tellin (Gastrana fragilis) has been
separated by Schumacher from the genus Tellina,
because of its more wedge-shaped and swollen shell,
and because the lateral teeth of the hinge are want-
ing and the cardinal teeth of the left valve are very
unequal in size. This,, the only British species so
separated, has a rather thin, but opaque, shell of
triangular form and pale yellow hue, with fine
122 Shell Life
concentric ridges. The animal is yellowish white,
with a large foot, and tubes nearly twice the length
of the shell. It is a local species, found burrowing
in sand between low water and a depth of 12
fathoms.
The Furrow-shells (Scrobicularia) are so-called on
account of the shape of the cartilage-pit, which is in
this genus a narrow chink under the beak. The
shell differs from that of Tellina in the fact that
while the right valve has two cardinal teeth, the left
has but one. The shells are white, with concentric
grooving, and gape behind for the extrusion of
the siphons. The Prismatic Furrow - shell (S.
prismatica) is almost flat, of an oblong wedge-
shape, thin, fragile, and semi - transparent, highly
polished but minutely striated. The prismatic
effects are due to the thinness of the epidermis.
The animal, which is very active, is pearly white ;
its foot large and pointed, its siphons slender, and
the mantle edges finely fringed. It is not a common
species, though generally distributed on sandy ground
in from 3 to 90 fathoms of water. It may be obtained
most easily from the stomachs of flat - fishes and
haddocks. The Glossy Furrow-shell (S. nitida) is
more oval than the last, and the valves gape more
widely. The animal is clear white, with a large
foot and very long siphons; the mantle is fringed
with short cilia. It is a more local species than
prismatica, and occurs in muddy sand between 3
and 100 fathoms.
The White Furrow-shell (Syndosmya alba) is oval,
thin, opaque white, polished, but with minute con-
centric grooves. The animal is whitish tinged with
Wedge-shells > Venus-shells, and Cockles i 2 3
blue and spotted with pure white ; the siphons are
as long as the shell, and the mantle is edged with
several rows of minute fleshy points. It
is a mud - lover and social, and may be
found in quantity in bays and estuaries
from extreme low water to 40 fathoms.
In spite of its dirty surroundings, the shell
is always remarkably clean. The siphon-
tubes are protected from the mud by a light-
brown epidermis. The Peppery Furrow - shell (8.
piperata) is triangular - oval, nearly equal - sided,
thin, opaque, flattened, without gloss; the colour
is greyish white,
stained with yel-
low or black from
contact with the
mud ; the epi-
dermis glistening.
The accompanying
figure of the
hinge-plate in this species will give a good idea of
the character prevailing in this group, where the
lateral teeth are greatly reduced or wanting. The
hinge-plate it will be seen is thick, broad in the
centre. There are two cardinal teeth in the right
valve, thin, plate-like, and parallel ;
in the left valve there is one car-
dinal, but often this is double.
There are no laterals, but their
purpose is served by the ridged
sides of the hinge-plate, which keeps the valves from
shifting. The animal has a pale yellowish body, the
mantle - edge scalloped irregularly and minutely
Hinge-plate of
Peppery Furrow-shel
124 Shell Lift
fringed. On some parts of our coast this mollusk
.is known as the Mud Hen. It has a fondness for
stiff mud and clay beds at the mouth of rivers, a
little below low-water mark. It burrows to a depth
of about 6 inches, keeping open cornmunciation
with the water above by means of its long tubes.
The Thin Furrow-shell (S. tennis) is a much smaller
and more triangular species than the last ; more con-
vex, thin, opaque, iridescent; greyish white, often
stained by burrowing in clay. The animal is white,
with a delicate fringe to the mantle. The inhalent
tube is twice the length of the shell, the exhalent
tube one - third less. It appears to be fond of
brackish water, for it is found chiefly in mud at
low water along the estuaries of the south coast
from Kent to Devon.
The Wedge - shells (Donax) are more triangular
than the Furrow-shells, the valves glossy though
partially scored by crossing grooves. The beaks
are a good deal behind the middle line. The valves
do not gape behind, and their inner margins are
usually " milled," so that the closed valves interlock.
There are two cardinals in the left valve, a double
central one in the right, and a lateral fore and aft in
each. The animal has a fringed mantle, short thick
diverging siphons, and a very large and pointed
sharp -edged foot. They are found in sand from
low-water mark to about 8 fathoms, but as they
burrow only an inch or so below the surface there
is no necessity for long siphons. The Banded Wedge-
shell (D. vittatus) is the best - known species. It
is variously coloured yellow, brown, olive, or purple,
often with three white rays from the beaks, and with
Wedge-shells* Venus-shells, and Cockles 125
concentric bands of deeper tint than the ground colour.
The animal is very agile, of a purplish red or yellow
colour ; the siphons are pale ^^^
orange, and not more than ^^^ : ^jjj^ -"^
half an inch in length. It
is plentiful at low water in
most sandy bays. The
Polished Wedge - shell (1).
politics) may be at once distinguished from the
preceding by the absence of the milling along the
inner margin of the valves. The
colour is chestnut-brown varying
towards olive, with a broad cream-
coloured ray and some marbling
Polished Wedge-shell 11 j i -r, -t
of the same tint. It burrows in
sand at extreme low water and a few fathoms
below it, chiefly on the coasts of Devon, Corn-
wall, and the Channel Islands. The Abrupt
Wedge-shell (D. trunculus) has been taken occasion-
ally on our southern shores. It is larger than the
Banded Wedge-shell, and may be distinguished from
it by being more acutely triangular, the striations
more delicate, and the inner edge not milled beneath
the hinge-ligament. Further, the hinder part of the
shell does not slope gradually to a point, but abruptly
as though cut off.
The Trough - shells (Mactra) are represented by
five or six species. The shells are triangular-oval,
swollen, with a slight gape behind. There are two
erect diverging cardinals, and large plate-like laterals
on each side of them two in the right, one in the
left valve. These lateral teeth have their edges
milled in M. elliptica, M. solida, and M. sub-
126 Shell Life
truncata. The animal has a thick mantle with
fringed edges. The siphons are united throughout
their length, but the exhalent tube is fitted with a
tubular valve. The foot is large, tongue-shaped, and
very extensible, used for burrowing and leaping as in
the Cockles. They inhabit sandy coasts, burrowing
but slightly below the surface, and ranging from low-
water mark to about 35 fathoms.
The Thick Trough-shell (M. solida) is, as its names
indicate, both thick and solid. In shape it is very
nearly an equal -sided triangle, only the angles are
rounded. Its colour is yellowish white, and it is
marked with slight concentric grooves, but in spite of
these the surface is quite smooth. The measurement
from end to end is less than that from the beaks to
the lower margin. The animal is white or yellow
tinged with brown. The siphons are short, their
mouths fringed with yellow or red filaments. It is
common in coarse sand at low water and a few
fathoms below it, all round our islands. The
Elliptical Trough - shell (M. elliptica) is by some
authors regarded as a mere variety of M. solida.
The shell is smaller, thinner,
more elliptical than triangular,
the greater measurement being
from back to front, instead of
from beak to lower margin. It
. , /-,/x ,
occurs m deeper water (10 to
100 fathoms) than M. solida.
The Cut Trough-shell (M. suUruncata) has the
ends of the shell much contracted, so that the beaks
are very prominent, and the general aspect is
hatchet-shaped. There is a heart-shaped depression
i ABRUPT WEDGE-SHELL; 2 BANDED WEDGE-SHELL; 3 GLAUCOUS T H
4 THICK TROUGH-SHELL ; 5 ELLIPTICAL TROUGH-SHELL
Wedge-shells, Venus-shells, and Cockles 127
both before and behind the beaks. The animal has
the mouth of its siphon-tubes fringed with two rows
of yellow or red filaments. The
foot is yellowish and slender; the
mantle with a toothed edge. It
lives in coarse sand from low water
to 27 fathoms. In the north of
Ireland it is known as Lady Cockle ; Cut Trough . sheM
in the Clyde district it is the "Aikens."
The Rayed Trough-shell (M. stultorum) is of the
same general shape as M. solida, but thin and glossy,
and the yellowish ground is
largely covered by broken
rays of brown from the
beaks to the margin. The
animal is white, tinged with
blue ; the mantle fringed
with white filaments ; the
Rayed Trough-shell f ot white > thick. It is
common on all our shores,
the animal burrowing in sand between extreme low
water out to 18 fathoms. The Glaucous Trough-shell
(M. ylauca) is triangular-oval, rather thin and glossy ;
yellowish white, with rays of yellow-brown or fawn
colour, and the upper margins marked with brown.
It is covered with a brown, satiny epidermis. The
animal is white, its mantle fringed with white fila-
ments ; the siphon-tubes short and conical, tinged
with yellow and streaked with red-brown. It is a
rare species, but it occurs on the Cornish coast,
where it ranges over the sand in shallow water,
quickly burying itself to a depth of two or three
inches when the tide goes out.
9
128 Shell Life
The general characters of the mollusks comprising
the sub-order Veneracea are an almost round or
oblong shell of equal valves, whose hinge has three
diverging cardinal teeth, the muscular impressions
oval and polished, and the mantle impression showing
a deep sinus into which the siphons are retracted
when not in use. The animal has unequal gills
which are slightly folded ; the foot is large, tongue-
shaped, and adapted for burrowing in sand, gravel, or
mud, in which the species live. The siphons are
unequal, cylindrical, and in general short, showing
that the mollusk does
not go far below the
surface, and in most
cases they are
speckled in a way
that makes them har-
monise with the sand.
The deep sinus of the
mantle-impression is
a character serving
to distinguish any member of the family from related
genera. A good example of the family may be found
in the Smooth Venus (Venus chione), whose massive
shell may be found after gales thrown up on sandy
beaches of the Cornish coast. But our enumeration
of the species must begin with one that is not so
typical, because, its tubes being so very short their
withdrawal has not produced a deep sinus in the
impression of the mantle within.
The Little Circe-shell (Circe minima) is the only
native representative of its genus. It has a nearly
round, flattened shell, with broad, flattened, plate-
Wedge-shells, Venus-shells, and Cockles 129
Enlarged plan of hinge
Little Circe-shell
like ridges with slight furrows between. It is of
various tints, white, yellow, red, brown, purple,
sometimes streaked, rayed, or
spotted with deeper shades. The
animal is transparent greyish in
colour, the mantle spotted with
brown and fringed with short
cylindrical points. The tubes are
unequal in length. Its habit is to
burrow slightly among sand and
nullipore in from 5 to 85 fathoms
of water.
The Rayed Artemis (Dosinia exoleta) has an
almost circular shell thick, solid, flattened, and
covered with ridges, but, unlike
those of Circe, these are finer, much
more numerous, and overlap. It is
cream coloured, marked with several
faint rays of red-brown, and some
irregular spots of the same colour
scattered over the rays. Owing
probably to the epidermis being
worn away in early life, this shell has the appear-
ance of having been tossed about
a good deal on the shore, and it
was this aspect, no doubt, that
struck Linnaeus when he named it
exoleta worn away. The animal
is pale yellowish, the mantle
fringed with white lashes, and the
siphons short and united. The
large foot is white and axe-shaped. All around
these islands it may be found in sandy bays at a
Rayed Artemis
Interior of Rayed
130
Shell Life
depth of a few fathoms. The Smooth Artemis
(D. lupina} is similar to the Rayed Artemis, but
smaller, smoother, and less round
in outline. The sides and lower
margin may be, indeed, in Jeffreys'
words "an arc of three-fifths of a
circle." The animal is greyish
white in colour, the mantle-margins
fringed with short tentacles. The
siphons are united except at the
mouths, and are capable of extension to three times
the length of the shell, showing that this species is in
the habit of burrowing more deeply than the previous
one. It is equally common, and may be found as
near as low-water mark on sandy ground.
The Smooth Venus (Venus chione) is one of the
finest of our native species ; its thick, heavy shells
Smooth Artemis
being nearly 4 inches in longest diameter. Its shape
is described as triangular-oval. In colour it is a light
pinkish brown, with a varying number of narrow
rays of darker hue from the beaks to the lower
5 PULLET CARPET-SHELL.
Pledge-shells^ Venus-shells, and Cockles i 3 i
margins, which are round - edged, and perfectly
smooth. The concentric lines are so slight that they
at first sight appear to be more due to colour than to
sculpture ; and the character of the epidermis is such
that it resembles a coat of varnish. The animal is
flesh-coloured with a tendency towards orange. The
mantle is slightly scalloped along the lower margin,
and has a few tentacles at the front. The orange
tubes of this species are not united all the way, and
their mouths are fringed with black-tipped tentacles.
The large, thick foot is dark flesh-tinted. It is not
generally distributed, its range in our waters being
confined to the south and west,
where it dwells in sand at
depths between 12 and 25
fathoms. It is a good edible
species, not only for man, but
is also appreciated by fish and
bird ; hence its thick hard
valves, which probably are | nterior of smooth Venus
needed not only to resist the
jaws and palate teeth of big fishes, but to prevent
injury from rolling about in great commotions of the
lower waters. We have seen it washed up on Cornish
beaches after continued heavy gales, and have seen
the Razor-bills and Puffins attack it with their
powerful bills, nipping off a little of the shell at one
end to admit the point of their beak in order to
sever the adductor muscle which keeps the valves
closed. It is to these muscles and the exceedingly
powerful hinge-teeth that the inviolability of the
shell is due, for there are no cogs along the margins
by which the valves may interlock.
132
Shell Life
with white.
The Banded Venus ( V. fasciata) has a solid shell
with sharp-edged concentric ribs, variable in colour
through yellow, pink, red, to brown,
marked by several rays of darker tints.
The margins of the shell inside are
beautifully milled, except just below
the ligament. The animal has its
mantle bordered with red and fringed
The short yellow tubes are united, save
at the tips, where they are fringed with white. The
thick, white foot is lance-shaped. It is a generally
distributed species, occurring on all our coasts, at all
depths, among gravel, sand, and nullipore. The Pale
Venus (F. casino) is very similar to the last, but
much larger (If inches across), the ribs on the shell
more plate-like, and less robust, more strongly scored
between the ribs, more unicolorous and pale. Of
wide distribution, but only local occurrence, on sandy
ground, from 5 to 90 fathoms.
The Warty Venus ( F". verrucosa) is still larger than
the Pale Venus, and an advance is made in the
passage of the ribs to concentric ridges which are, in
this species, broken into wart-like
irregularities, especially towards
the hinder margin. From the
beaks to the lower margin, crossing
as it were beneath the concentric
ridges, run a great number of
evenly and closely set ribs, which
are more evident in the older
portion of the valves where the ridges are less
prominent. The lower margin is milled inside, as
shown by the figure of the interior of a left valve.
Wedge-shells i Venus-shells, and Cockles 133
It is a dull, rough-looking shell of drab or pale brown
colour, sometimes with a few darker rays, and its
distribution is restricted to the
south and west coasts, where
it occurs in fine gravel and
sand at depths between 7 and
20 fathoms; in the Channel
Islands it may be found at
low water. The Oval Venus
(K ovata) has a dull shell of
triangular-oval shape, whose
longest diameter is little more than half an inch.
From 40 to 50 ribs radiate from the beaks, and are
crossed by half that number of concentric thread-like
ribs, a scale or wart arising where the lines cross.
The colour is yelldw tinged with pink or red, and
occasionally blotched or spotted with red -brown.
The inner margin is milled all round. The short
siphons are of equal length, and connected almost to
the mouths. It lives among sand and nullipores
from extreme low water to deep water.
The Striped Venus (V. gallina) is of somewhat
triangular form, the shell solid, of a pale yellow hue,
with three obscure rays of red-brown spots. Its
sculpture consists of overlapping con-
centric ribs. The inner margins are
milled. The animal is white, and the
white filaments which fringe the
mantle are disposed in tufts. The
long slender siphons are united
almost throughout. It is generally distributed and
common in sand, from low water to 85 fathoms.
The Clam (V. mercenaries), an American species, has
34
Shell Life
become naturalised in the Humber, where it was first
observed in 1864, from which date it appears to have
gone on increasing in numbers. As it is an edible
species highly appreciated in the United States its
continued increase will probably bring joy to local
epicures. It may be noted that the word " niercen-
aria" refers to the former use of these shells in
making " wampum " the strings of beads which
passed as money among the North American tribes.
The Wavy Venus (Lucinopsis undata) is very like
the Round Double-tooth (Diplodonta) described in
the previous chapter, but whereas
that is a strong, glassy- white shell,
this is chalky-white and fragile.
It differs from the other Venus-
shells in being thin and almost
transparent. It is almost circular
in outline, swollen and smooth,
without ribs, but marked by
sunken concentric lines. Its colour
is white tinged with yellow near
the beaks. The impression of the
mantle within is very broad, and
the sinus extends far up towards
the beaks. The mantle-margin is wavy or uneven,
but neither fringed nor toothed. The orange siphons
are widely separate, protruding from the lower rather
than the hinder margin, and the lower tube is longer
than the upper, while both are fringed. It is a
common species everywhere in fine sand, even when
mixed with mud, and ranges between 3 and 100
fathoms. Full - grown specimens measure 1 to
li inch in diameter.
Wedge-shells, Venus-shells, and Cockles i 3 5
The following four species, though belonging to the
same family, form the genus Tapes, and are famil-
iarly known as Carpet-shells from the colour-markings
suggesting the patterns of tapestry. The shells are
solid, more rhornboidal than triangular, and the
beaks are set very near the front extremity. This
character, combined with the shape of the shell, is
sufficient to determine the genus, and the four native
species are so distinct from each other that they may
be readily identified.
The Golden Carpet-shell (T. aureus) is yellowish
white with little gloss. Finely incised, crowded but
shallow lines run from the beaks to
the margins, and are broken by the
very distinct bands marking periods
of growth, and which are often
greyish in tint. The margins of the
shell are quite plain. It is confined *****
chiefly to our south and west coasts
in sandy gravel between 3 and 18 fathoms. The
Banded Carpet-shell (T. virgineus) is more dis-
tinctly oblong than the last. The exterior of this
shell has polish, though it is not very
glossy. The surface scarcely appears
broken by the flattened, close-pressed
ribs, which are slightly rounded only
at the front and back. The ground
colour is P ale yellow, overlaid with
dots, spots, and splashes of purplish
brown, which are arranged in about three wedge-
shaped masses, leaving clear rays between them.
The glossy interior is tinged with yellow, orange,
or purple in its upper half. The margin of the
136
Shell Life
Banded Carpet-shel
interior
mantle is partly toothed and partly waved and scal-
loped. The siphons are separate for only a fourth
of their length, and are pale
yellow, tinged with brown and
purple, and with fringed mouths.
It is a generally distributed
species, and may be found among
sand and nullipores from low
water to over 100 fathoms.
The Pullet Carpet-shell (T. pullastra) is triangular-
oval, yellow, marked especially on the hinder part
with dark purple-brown. The concentric lines are
finer and closer on this shell as compared with the
last, and in addition there are a vast number of
delicate lines radiating from the
beaks. The colouring is in some
specimens very suggestive of the
plumage of a speckled hen, and it is
probably from such individuals that
the mollusk has got the name of
Pullet, which is locally applied to it
on parts of the Devon coast. The animal varies in
colour from white to grey and yellow, and its mantle-
margins may be waved or jagged. It is quite a common
species, and may be found in the muddy sand of the
shore between tide marks, in crevices of the rocks or
in the root-like bases of the larger seaweeds. In these
situations, or in the deserted holes of rock-boring
mollusks, it usually spins a byssus after the manner
of the Mussel. The Cross-cut Carpet -shell (T.
decussata) is decidedly the Carpet-shell, but it is the
back of the tapestry that is shown by its sculpture.
The lines from the beaks break the surface up into
Pullet Carpet-shell
(one-fourth nat size)
Wedge-shells, Venus-shells, and Cockles 137
radiating wavy ribs which are crossed and broken by
concentric lines. There is not the faintest gloss or
polish on the shell. Its colour is a
yellowish drab, stained irregularly
with purple. The animal is cream
coloured or grey, its mantle-edges
scalloped or edged with white ; the
siphons separate throughout their
length and fringed with brown at
the orifices. This species appears to be confined to
the south and west coasts, where it burrows in the
gravel and sand about low- water mark. The Banded,
the Pullet, and the Cross-cut are used in different
parts of the Continent as human food, and the two
last named are eaten in Sussex and probably some
other parts of this country.
In external appearance the Rock Venus ( Venerupis
irus) offers little resemblance to the Carpet-shells,
yet a glance at the interior shows very near relation-
ship. The valves do not fit closely at the hinder end,
showing that the siphons are rarely withdrawn.
There are fifteen or more
concentric ridges, thin and
high, with toothed edges, and
beneath these, running from
the beaks, a crowded series
of fine lines. The animal
is white, tinged with pink, the siphons united
for half their length, and the valve of the lower
protruded beyond the fringe. The foot is rather
small, compressed, and adapted for spinning a byssus.
The favourite habitat of this species is in the holes
of limestone rocks bored by Saxicava, also in the
138 Shell Life
cavernous bulbs or so - called roots of the large
Laminarice. But it is only in parts of the west and
south-west that it need be looked for, such as the
shores of Cornwall, Scilly, Guernsey, Devon, Dorset,
Glamorgan, and Pembroke ; it also occurs round
Ireland, except on the north. Its zone is that of the
big seaweeds a little below extreme low water. The
form varies according to habitat. That figured is
the finest, and it lives either in rock chinks or in the
empty valves of Pholas dactylus.
The Rock -borers (Petricola, lithophaga and P.
plioladiformis) are not British, but they are found
occasionally on our shores. They bore into limestone
and mud. The first named
which is also figured is a
native of the Mediterranean
and the French coasts, but
Rock-borer (Petricola litKopUo,^ the S6COnd COm6S frOU1 N rth
America. This, which has a
more elongated, more strongly ribbed shell than
P. litliophaga, appears to have got established in
recent years about the estuary of the Thames/- and
in the river Crouch, Essex ; it has also been taken
at Hernc Bay just above low water. It is very
probable that it has been introduced among oysters
that have been imported from America and laid
down in these districts.
The Cockles are the British representatives of the
sub-order Cardiacea, which gets its name from the
conventional heart-shape (Karelia) of the closed shell
when viewed endwise. The two valves are exactly
alike, very convex, with prominent beaks, from
which strong ribs radiate. These ribs and the in-
SPINY COCKLE ; 2 PRICKLY COCKLE ; 3 KNOTTED COCKLE ; 4 LEAST COCKLE.
Wedge-shells, Venus-shells, and Cockles 1 39
tervening furrows being continued right to the
margins of the shell, those of the two valves inter-
lock, fitting in a very accurate manner. There are
one or two cardinal teeth in each valve, and a strong
lateral on either side at some distance from the
cardinals. The gills are long and much folded back,
the siphons rather long, the foot large, long, and
cylindrical, the mantle - margins jagged. These
mollusks live in sand and mud, from low water to a
considerable depth, and by means of their foot can
rapidly sink into or rise above it. Pigment spots
serving as visual organs are scattered over the
margins of the mantle and over the tubes.
The Spiny Cockle or Red - nose (Cardium
aculeatum) is the largest of our native species, and
measures as much as 3 inches across. The valves
are somewhat thin and glossy, covered by about
20 strong broad ribs that radiate from the beaks
and bear a number of stout curved spines whose
points are directed backwards. The colour is
yellowish tinged with red. The animal is coloured
bright red, and the red foot, which gives it the
popular name of Red-nose, is long and awl-shaped.
It is found in deep water along sandy shores, chiefly
in South Devon ; at Weymouth, Guernsey, and Dublin
Bay. The Prickly Cockle (0. echinatum) is not so
large as the foregoing, being little more than 2 inches
across ; but the shell is more solid, has a duller surface,
and a less oblique curve to the front margin. The
radiating ribs bear short, stout, triangular spines,
curved backwards. The colour is yellowish white,
stained with red. The animal varies in colour from
white to pink ; the foot is finger shaped, with a flesh-
140 Shell Life
coloured or red skin, twice the length of the shell. It
is common on sandy shores on all our coasts, ranging
from 5 to 100 fathoms. At Jersey very fine specimens
may be taken from muddy sand at low water. The
Rough Cockle (C. tuberculatum) resembles the last
species in general appearance,
but differs from it in having a
larger, more solid, and globular
shell. The ribs are coarser, and
the spines upon them are inter-
rupted by intervening spaces,
whilst in (7. echinatwn the rows
are continuous ; some of the
Rough Cockle
spines (in tuberculatum) are
short and blunt, others flattened. This also is a
southern form, found in sand at extreme low water
to about 12 fathoms on the coasts of Dorset, Devon,
Cornwall, Guernsey, and Bantry. Diameter 3 inches.
The Warty Cockle (C. papillosum) is a small species
whose longest diameter is little more than half an
inch, the shell globular, solid, glossy, with about 25
flat ribs close together. It is coloured yellow and
streaked with reddish brown. It occurs in the
Channels Islands in coarse sand, between 15 and 20
fathoms. At Herm it has been taken at low water.
Fresh valves have also been dredged at Falmouth
(19 fathoms), and Scilly (40 fathoms). The
Little Cockle (6 y . exiguum) has a small, solid,
dull shell, with about 20 compressed ribs,
which are covered in young examples with
white warts ; white or yellowish, sometimes
streaked with brown. It is pretty generally distrib-
uted along our shores, occurring in soft ground a
Wedge-shells, Venus-shells, and Cockles 141
little beyond low-water mark. The Banded Cockle
(C. fasciatum) is another minute species, with about
25 ribs bearing overlapping scales. The shell
is thinner, the valves less swollen. The name
is suggested by the reddish-brown bands,
but these are by no means unfailing marks
of identity, for the species is a very variable
one. The animal is white, with a plain-edged mantle,
and the long, slender, finger-shaped foot is trans-
parent. It is a common shell on all our coasts
where there is gravelly sand, in from 5 to 90 fathoms
of water. The Knotted Cockle (C. nodosum) is
similar to the Banded Cockle, swollen near the
beaks, with from 24 to 28 ribs, covered with little
knobs or oval plates. The colour is white, sometimes
tinged or banded with yellow or brown. The white
animal is somewhat transparent ; the mantle fringed
with white filaments, and the siphons pale yellow ;
foot white. It is generally distributed, and occurs
among sand and shell - gravel at depths between
3 and 86 fathoms.
The Common Cockle
(C. edule) is so thoroughly
well known that it stands
in need of little description.
The shell is somewhat
rhomboidal, solid, and with-
out gloss, traversed by ribs
varying in number from 24
to 28, and by minute lines
crossing each other at right angles. The animal
has a white body, but the mantle is pale yellow,
its edges with a short white fringe. The short
142 Shell Life
siphons are separate throughout, with white fila-
ments along their sides. The white or yellow foot
is proportionately small, thougli long, and ends
in a thin flat point. It occurs in great numbers
on all our sandy shores from low water to about 5
fathoms ; and a smaller, thinner variety extends
up estuaries into brackish water, as, for example,
up the Thames as far as Gravesend. It is said to
occasionally depart from its burrowing habit and to
take to climbing up submerged posts, spinning a
byssus to aid it. The raking in of Cockles for food
and bait forms no inconsiderable item of what is
comprehensively called the fishing industry. The
Least Cockle (G. minimum) might at first sight be
taken for a young example of the last mentioned. It
has a roundish-oval, thin, glossy white shell, crossed
by 28 or 30 flattened, radiating ribs, which bear
minute arched scales. It is subject to little or no
variation, but individuals that have lived in coarse
sand may be found with the ribs cleaned off by
attrition, whereas those found in muddy sand have
the ribs beautifully sharp and fresh. It is not widely
distributed; but it has been found off the west of
Scotland, Shetland, Ireland, Isle of Man, Scilly,
Lundy, the Smalls, and West Orkneys, burrowing in
fine sand at depths between 5 and 100 fathoms.
The Smooth Cockle (0. norvegicum) differs from
all the others in appearance, not only by reason of
its smoothness, but also of its shape. The shell is
distinctly triangular in outline, wedge-shaped when
viewed from the ends, and crossed by about 40 ribs,
which are all but obliterated owing to their lowness
and the shallowness of the intervening grooves. The
i SMOOTH COCKLE
LARGE SUNSET-SHELL ; 3 RIBBED SUNSET-SHELL ;
4 OVAL PIDDOCK
Wedge-shells, Venus-shells, and Cockles 143
colour is whitish, faintly mottled with flesh-tint
where the greenish-yellow epidermis has been worn
off; at the ends of the valves there is no trace of the
ribs. The animal is yellowish white in colour, the
mantle tinged with red and its edges plain. The
siphons are separated throughout their length but
united at the base. It has a large and powerful
rounded foot, with a rough flesh-coloured coat. It is
a local but plentiful shell, dispersed generally along
our shores in from 5 to 80 fathoms, where there is
sand or nullipore.
HE species included in
this chapter form
several sub - orders,
the first of which is
the Myacea, agreeing
pretty closely with Cardiacea in the form of the gills
arid the mantle, the variability of the mantle impres-
sion, and the want of uniformity in the union of the
gills. But the foot instead of being cylindrical is
more or less flattened from the sides, and more
tongue-shaped than finger-shaped. The shells gape
at one end or both, and this, as we have already
pointed out, is due to the fact that the siphons are
almost constantly extended, and consequently when
the shell is enlarged by normal growth these edges
are not permitted to come together. The subjoined
figure, showing the position of the Blunt Gaper
when alive, will help to explain this constant ex-
(papers, Piddocks, and Ship-worms 145
tension of the siphons. The Gaper burrows deeply
into sand and mud, not for its food, but for
safety its flesh being prized by
fishes. At the recess of the tide
they are searched for by gulls, and
if they are too near the surface
they pay the penalty with their
lives. Their siphons are stretched
upward until they reach the water,
when their mouths are opened and
the streams set in motion : one
downward, charged with micro-
scopic life to be filtered out and
used as food ; the other, upward,
discharges the water that has
passed over the gills and been
relieved of its oxygen.
The first genus in this group is
the Sunset-shells (Psammobia), of
which four species are found in
our seas. They have long slender
shells, much compressed and gaping
slightly at each end, the foot being
usually extended as well as the
siphons. These siphons are long, and separate ; the
foot comparatively large; and the mantle -edges
fringed. The popular name is due to
the fact that the yellowish shells are
Hinge-teeth of marked by radiating bands of red,
the notion being that when a valve
is held with the beak below these red bands present
the appearance of beams from a sun that has just sunk
below the horizon. The character of the cardinal
unt Gaper
146 Shell Life
teeth is shown in this figure of a right valve ; in
the left valve the hinder cardinal is much smaller
and not cleft. The beaks are turned slightly to
the hinder end of the shell.
The Tellin-like Sunset-shell (P. tellinella) is thin,
glossy, yellowish white, marked with fine concentric
ribs, the grooves as well as the ribs being polished,
and the radiating bands are of
pink, red, or violet. A streak of
crimson usually runs along the
upper edge of the valves before
i like sunset sheii au< ^ behind the beaks. The in-
terior is highly polished, with
the external colouring repeated. The animal is
white, its mantle with a tooth-like fringe, and the
upper (excurrent) siphon is marked by fine lines of
white from end to end. This brilliant little mollusk
occurs locally all round our coasts, burrowing in
sand between 4 and 85 fathoms, and occasionally
swimming after the manner of the Pectens by
flapping its valves.
The Ribbed Sunset-shell (P. costulata) differs from
the last chiefly in the character of the posterior
slope of the shell, which bears from 12 to 20 slight
but sharp ribs running from the beak to the hinder
margin, which is notched in consequence. In addition
the shell is thinner, the valves unequal, and the less
regular rays are of deeper tints. The animal is
white tinged with pink, the mantle edges thickened
and slightly fringed. This is more local than the
last, and can only be obtained by dredging, as its
habitat is in fine sand in from 15 to 85 fathoms
of water. It is slightly more than 1 inch in length.
(papers, Piddocks, and Ship-worms 147
The Faroe Sunset-shell (P. ferroensis) is larger,
more opaque, and duller, marked with close low
concentric' ridges, which become higher just before
reaching the clearly marked
posterior slope, across which
they are very distinct. In that
particular region they are crossed
by half a dozen (on each valve) Faroe Sunset . she
fine radiating ribs from the beaks.
The shell is more or less covered by a dull greenish
epidermis, but where this is worn away the colour
is seen to be pink with indefinite rays of a deeper
tint and small oval spots of white. The inside is
coloured with some shade of purple, and very highly
polished. This is a common species on all our coasts,
in sand, at depths between 4 and 90 fathoms of
water.
The large Sunset-shell (P. vespertina), which is
the largest of the native species, is of a more oval
form. It is somewhat solid, compressed, and glossy
where the thick olive epidermis has worn off.
Where it is thus bared the shell is seen to be of
a yellowish-white hue with rays of purple-brown
or lilac. The sculpturing of the surface is very
slight, and has the appearance of having been worn
down; it consists of concentric ridges, and more
evident lines of growth, crossed by obscure radiating
lines. Interior coloured yellow or purple. The
animal is yellowish white in colour, with a fringed
mantle, and a broad thick foot. It is a local species,
but found widely distributed, chiefly on the south
and west coasts of both England and Ireland, and
on the west coast of Scotland. Like the others
148 Shell Life
of its genus, it is a sand-dweller, and its range
is from extreme low water to 4 or 5 fathoms. It
attains a maximum breadth of 2i inches, and fairly
large specimens are used for food in the west of
Ireland.
Of the Gapers (My a) we have only three species,
and one of these we have already figured as a type
of the sub-order. The siphons are connected
throughout their length, and though they may be,
and are at times, completely withdrawn into the
shell, they are usually kept fully extended. This
has caused the hinder end of the shell to gape
widely. They are deep burrowers, and therefore
Hinge and cartilage process of Gapers
assume the position shown in our figure, the foot
downwards and the siphons reaching straight up
through sand or mud to the water above, with the
long axis of the shell at right angles with the
surface. Looked at from this point of view it will
be seen that the fore-end of the shell is shaped like
the bows of a boat, that the tongue-shaped foot
may pull it down more easily. These shells are
commonly buried to a depth of eight inches, some-
times a foot. There is a remarkable development of
the hinge-teeth beneath the beak of the left valve in
the shape of a hollow shelf to hold the cartilage,
with corresponding ridges to fit it in the right
valve.
Capers, Piddocks, and Ship-worms
149
The Sand Gaper or Old Maid (IT. arenaria) has
the valves of the shell not quite equal, the right
being a little larger than the left.
The shell is traversed by coarse,
irregular, concentric lines, partially
covered by a wrinkled, papery-
looking epidermis of a muddy grey
colour. The shell gapes at each
end, and the epidermis is continued
back over almost the entire length
of the siphons, as though they
required protection from the ma-
terial through which they have
to push. Where the epidermis is
worn away the shell is a dirty
white, stained with rust near the
beaks. The mouths of the siphons
are coloured with red and fringed.
It is a generally distributed species,
and is found in soft ground from
low water to about 25 fathoms.
It has a preference for estuaries,
and has no objection to brackish
waters. Large numbers are consumed for food,
under the name of " old maids " and " clams," on
some parts of our coasts. The shell is about 4 inches
wide when full-grown.
The Blunt Gaper (M. truncata) is very like the
foregoing species, except that the shell which is
about one-third less in width than that of M.
arenaria ends abruptly behind as though sawn
across, and there is less disparity in the size of
the valves. It is found in similar situations to
Old Maid
(one-fifth nat size)
150
Shell Life
the other, with a marked preference for the open
sea over estuaries.
The Small Gaper (M. bingJiami) has a wedge-shaped
shell, with unequal valves which
gape behind, smooth, and with
fine lines instead of the coarse
ones of the other species. It is
white beneath the epidermis, which
is pale brown. The siphons are
short, especially the incurrent one.
This species does not burrow in
the ground as its congeners do:
instead, it takes possession of
holes that have been made by the
Rock -borers (Saxicava), the empty
tubes of Serpulae, and the crevices
of the so-called roots of the great
Tangles and Wracks, between 5
and 25 fathoms. It attaches itself
by means of a byssus. Individuals
that live this free, out-of-door life,
so to speak, are liable to be mis-
taken for Saxicava or Tkracia.
The Basket - shells (Corbula),
though a large genus, are repre-
sented in this country by a single species, the
Common Basket -shell (C. gibba), in which the
unequal size of the valves noticed in Mya is much
accentuated, so much indeed that the left valve
appears almost like an operculum to the right. The
shell is also drawn out behind to make a cover for
the siphons, which are so short as to be only
slightly protruded. The shell is white tinged with
Blunt Gaper
(one-fifth nat. size)
(papers, Piddocks, and Ship-worms 151
Sasket-
shell, showing
hinge-teeth
yellow and brown, ornamented by concentric ribs
in the right valve, but these become mere raised
lines in the left. The hinge-teeth in
the right valve consist of a thick,
curved cardinal, flanked by a ridge-
like lateral on either side ; in the left
valve the cardinal is hollowed to take
the cartilage, and beside it is a cavity
to fit the cardinal of the right. The animal has a
comparatively large and thick foot, which it uses
for burrowing just below the surface
of sandy and gravelly shores, from
extreme low water to about 70 fathoms.
There are, however, other Basket-
shells beside those of the genus Corbula,
of which the subjoined figure of the
Pointed Basket-shell (Necvra cuspidata)
will serve as a type. In this genus, of which we
have three species, the shells are thin, fig-shaped,
and with unequal valves, though the
disparity is not here so great as in
Corbula. The siphons are longer,
and the hinder part of the shell is
drawn out to partially cover them ;
their orifices are protected by long
tentacles whose ends are divided into
several finger-like points.
The Pointed Basket-shell (N. cuspi-
data) is much drawn out behind,
tolerably solid, more so than in the
other species, much swollen, and the
left valve larger than the right. Its colour beneath
the red-brown epidermis is whitish. The horn-
Pointed Basket-shell
152 Shell Life
coloured cartilage is covered by a chalky band
(ossicle) free from the shell, and a strengthening rib
runs from under the beaks towards the centre of
the siphon-outlet. It has been taken from deep water
(12 to 90 fathoms) in muddy sand, off various parts
of our coast, but chiefly Scotland and north-west
England. The Short Basket-shell (N. abbreviata)
is almost transparent and extremely fragile, of a
triangular-oval shape, swollen, and the valves almost
equal. The surface is slightly glossy, ornamented
by about a dozen concentric folds, and a curved
sharp rib which runs from behind the beak. It
is greyish in colour, covered by a yellow-brown
epidermis. It has been taken chiefly in deep
water (40 to 75 fathoms), off muddy ground, in
Loch Fyne and around Shetland and Skye ; though
in the Kyles of Bute it has been found in 18 fathoms.
The Fine -ribbed Basket - shell (N. costellata) is
similarly semi-transparent and fragile with the
previous species, but is much smaller, less swollen,
the valves less equal, marked with from 20 to 30
fine ribs radiating from the beaks. It has been
taken with the last mentioned, of which it may
be only a variety.
Another small genus of this order is known as the
Otter-shells (Lutraria), of which we have two species.
The shells gape at each end like those of the
Gapers, and the long siphons are similarly covered by
a coarse epidermis ; but there are differences in the
hinge-teeth which separate Lutraria from My, that
of the Otter-shells closely resembling the cardinal
teeth of the Trough-shells (Mactra). There is a
spoon-shaped hollow for receiving the cartilage in
(papers, Piddocks, and Ship-worms 153
each valve ; in the left valve there is a double
cardinal just below the beak which fits into a cavity
of the opposite valve formed by two large diverging
cardinals. The ligament uniting the valves is
exceedingly short, and admits of con-
siderable movement of the ends with-
out opening the shell throughout.
With the valves in their ordinary
positions the shell gapes equally at
each end, but the arrangement of teeth
and ligament is such that the front of
the shell may be entirely closed by
more widely expanding the rear, or
the hinder gape may be nearly closed
by separating the fronts of the valves.
They burrow vertically into deep mud,
the siphons reaching up to the surface,
and the only evidence that Lutraria
lies perhaps a couple of feet below is
an occasional spurt of water from the
excurrent siphon. To dig them out
from this deep retreat is the only way
to obtain living examples ; but as the
situations they frequent are usually beyond the
lowest of tide-marks, this is 110 easy matter. Yet
the people of Herm, one of the Channel Isles, contrive
to get a sufficient number to eat; they know them
under the name of " Clumps." It is an open question
whether the two so-called species are not forms of
the same.
The Common Otter-shell (L. elliptica) is elliptical
in shape, somewhat flattened, solid and heavy
without being very thick. Where the olive
Oblong Otter-shell
(one-fourth nat size)
154 Shell Life
epidermis has been worn off the shell shows a dirty-
white coloration. The growth lines form the
principal surface ornamentation, though there are
finer lines between, but these are quite obscure. In
addition to the cardinal teeth already described, there
are in this species two laterals in the left valve and
one in the right, though only the foremost of those
in the left is at all distinct. Full-grown specimens
measure 5 inches the longest way by 3 inches at
right angles. The animal is white ; the mantle edges
closed for two-thirds of their extent, and fringed
with white. The siphons, connected throughout
their length, are included in a common sheath, which
is 12 or 15 inches in length, covered by an extension
of the shell epidermis. The large thick foot is
capable of considerable extension. It may be found
all round our islands from just below low- water
mark to a depth of 15 fathoms; it has a fondness for
the more muddy ground of estuaries. There is a
variety (intermedia) which is so well named that it
Qapers, Piddocks, and Ship-worms i 5 5
strengthens the doubt as to the specific distinctness
of elliptica and oblonga.
The points by which the Oblong Otter-shell (L.
oblonga} is distinguished from the foregoing are : the
shape of the shell is more slender, with an upward
curve behind, not quite so flat, more solid ; the front
cardinal tooth of the right valve is double, the only
lateral is on the fore-part of the left valve. Its
habits are the same as those of the foregoing, but
it is of more local occurrence, and appears to
be a more strictly southern form. Its longest
measurement rarely exceeds 4 inches, but sometimes
reaches 5 inches. Both species are subject, from
Smooth Short Razor
their attitude, to be annoyed by grains of sand
slipping between the mantle and the shell. These
have to be cemented over and left as evidence by
which the collector may know of their trouble.
We now reach the Razor-shell family, characterised
by having the valves of the shell of equal length,
long and narrow, gaping at both ends. The animal
has a large and powerful foot of a more or less
cylindrical shape.
The Short Razor-shell (Solecurtus scopula) is of
an elliptical shape, convex, with a central depression,
crossed by a large number of overlapping low ribs,
some of which radiate from the beaks to the front
156 Shell Life
end, and the remainder cover the hinder end. The
colour is yellowish white, and the epidermis is
brownish yellow. The hinge is strengthened by a
shelf-like rib on which are in the right valve two
strong curved cardinals, in the left one cardinal and
a short lateral behind it. This is a local species
found in sand in from 20 to 85 fathoms, but some-
times being taken from a little below the extreme
limits of low water.
The Smooth Short Razor (8. antiquatus) has the
shell more compressed, the ribs and lines less
distinct; the colour white, epidermis yellow-brown.
The cardinals are larger, with jagged crests. It is
Egg-shell Ra
found sparingly on all our sandy shores in from 4 to
50 fathoms.
The Egg-shell Razor (Ceratisolen leyumeri) occupies
a position between the Short Razors and the Razor-
shells (Solen), having the beaks almost central as in
the former, but the shell material is similar to that
of Solen, as also are the teeth. The shell is semi-
transparent and glossy, finely grooved in the line of
growth, and yellowish white in colour. Epidermis
pale or deep yellow ; thinner and paler above. There
are two cardinals in the left valve, and one in the
right that fits between them ; the laterals are one in
each valve, a little behind the cardinals. The
interior is pearly white, faintly marked by the
Qapers y Piddocks, and Ship-worms 157
mantle impression. The animal is pale yellowish
the mantle tinged with red, and its edges fringed
where not united. The siphons are distinct for the
greater part of their length, reddish ; and the purple-
red foot is club-shaped when extended
It lives in the sand of extensive bays
on the coasts of Hampshire, Devon,
Wales, and Ireland, at the limits of
low water.
The Pod Razor (S. siliqua) is known
in Scotland as the Spout-fish. The
shell is familiar enough to all who
wander across sandy shores after the
spring tide has receded, though it is
only the empty and mostly broken
valves they see. When full - grown
these shells are 8 inches long and
1| inch broad. A glance at the exterior
of one of these valves is very instruct-
ive, for it shows at once in what
manner the shell is enlarged. In most
of the bivalves we have been considering
the concentric ridges point to the fact
that on three sides of the beaks the
shell-margins have been added to pretty Deduced)""
equally ; or, if the ribs were more closely
crowded at the ends than towards the front margin,
that less material was added to the ends than to the
lower edge. The lines on the shell of the Razor
show us clearly that the chief addition is made to
the hinder end of the valves, next to the lower
margin, very slightly to the upper margin. To the
front end scarcely any addition is made certainly
158 Shell Life
not so much as half an inch during the entire life
of the Razor. This mode of enlargement explains
why the hinge occupies its singular position at the
extreme front of the upper margin. In the left
valve this hinge consists of two stout curved
cardinals, and one or two long hooked laterals behind
them and below the ligament; in the right valve
there is one thin broad cardinal that fits between
the cardinals of the other valve, and behind it a
single lateral fitting under the hook of its fellow in
the left valve. It is remarkable how so one-sided
an arrangement suffices to keep the long and heavy
valves together. That it does suffice is evident on
handling the empty shells ; yet during the life of the
mollusk the power of the hinge-teeth is greatly
reinforced by the adductor muscles, whose positions
are marked by the shaded portions in the above
figure.
The animal is of a pale drab colour, with a
yellowish, tongue-shaped foot. Except at the fore-
end for the passage of the foot, and a minute opening
on the lower surface, the mantle-edges are united
throughout. The siphons are exceedingly short,
united, and their openings fringed. At the base of
these filaments there are grooves in which are
situated pigment spots highly sensitive to light; and
a shadow cast over the sands when the Razors are
(papers, Piddocks, and Ship-worms 159
exposed is sufficient to cause their sudden disappear-
ance. They burrow in the sands about extreme
low-water mark ; not vertically but diagonally.
When the sands are covered with water their shells
are at the surface with the siphons exposed, but
when the sea goes out they retire beneath the sand,
going to the depth of a foot or two. If dug up and
placed upon the surface they bury themselves with
the rapidity of a mole. They can also dart rapidly
through the water, apparently by ejecting water
through the siphons. In many places they are
considered excellent food, and for this purpose they
are caught with a bent or barbed wire thrust through
the open valves. The shells sometimes show at the
hinder end that like Lutraria they have no means
of ejecting sand that gets between the mantle and
shell, so are compelled to cover it over with a coat
of shell - matter. The late Mr. D. Robertson of
Cumbrae relates a singular experience. On the
recess of a spring tide he found three examples of
this Razor, whose shells protruded above the sand to
the extent of an inch and a half, and the mollusks
were unable to pull them down lower. To each
shell was attached several mussels who had attached
their byssus threads before the Razors realised what
it meant; but when the extra-low tide came these
tightly-moored mussels effectually prevented the
withdrawal of the Razors.
The Sword Razor (8. ensis) in most respects
agrees with the Pod Razor, except that the shell is
curved as shown in the figure, and it never attains
the dimensions of the former species 4 inches
being about its maximum length. It is more slender
ii
160 Shell Life
than young Pod Razors of similar length, and it
inhabits deeper water, being found usually between
3 and 20 fathoms, but at Jersey and Herm it occurs
Sword Razor (slightly reduced)
at low water. Linnaeus regarded it as a variety of
S. siliqua, and I think it very likely that he was
right.
The Transparent Razor (S. pellucidus) is similar to
the last named in form, but with thinner though
scarcely transparent shell, and the hinge not quite so
near the end. Length about 1^ inch. It is very
doubtful whether this again is any more than a
juvenile form of S. siliqua.
The Grooved Razor (S. vagina) resembles 8. siliqua
generally, but is more cylindrical, quite straight, of
equal size from end to end, and possessing but
one cardinal in each valve, which is rounded and
stalked. Its English name is due to a constriction
at the fore-end " as if it had been tied while in a soft
and plastic state with a string" (Jeffreys), but this
constriction is frequently found in specimens that
otherwise agree with S. siliqua. I fear there is but
one British species of Solen, with several variations
from the typical form.
The Rock-borers (Saxicava) have the mantle
entirely closed, save for a narrow orifice to allow
the passage of the finger-like foot; the siphons are
long and partially united ; the shell gapes at each
(papers, Piddocks, and Ship-worms 161
end ; the teeth are obsolete or wanting altogether ;
and the mantle impression shows only a shallow
sinus. They bore holes, chiefly in limestone, and
live in these cells with only their red siphons visible
at the entrance.
The Wrinkled Eock- borer (S. rugosa) is a very
common shell, yet it is very seldom seen save
by the conchologist, who knows where to
find it and how to chip it out from its cell
in the rock. The shell has an odd, distorted
appearance, being much stouter in front, and
pinched in the middle of the lower margin,
gaping behind or at each end, and with one
valve often larger than the other. It is
dirty white in colour, with a dull, rough
surface, irregularly wrinkled in concentric
fashion. The teeth, when present, are two small
erect cardinals in the left valve receiving one small
cardinal in the right valve. The animal
is whitish tinged with yellow. The
siphons represented in our figure as
being retracted as far as possible are
capable of great extension, and are
covered almost throughout their length by a brown
sheath, somewhat similar to that of the Gapers;
their extremities are red. Wherever chalk, limestone,
or red sandstone is found on our coast, there this
species may be looked for from a little below ordinary
low-water mark to a depth of about 30 fathoms.
When touched or alarmed it forcibly ejects a stream
of water from its siphons. A small variety, often
distinguished as a separate species (S. arctica), spins
a slight byssus and attaches itself to the so-called
1 62 Shell Life
roots of the larger seaweeds. The shell is more
angular, the wrinkles become ridges, and the teeth
are more evident. Its specific distinction
from S. ruyosa is very doubtful.
Norwegian Rock-borer (8. norvegica). A
much larger species, attaining the dimensions
of 3 inches by 2, has been found in deep water (30
fathoms) between the Dogger Bank and the east coast
of England, where it bores into thick mud. The out-
line of the shell is an irregular oval, the right valve
larger than the left. It gapes at both ends, and is
similar in colour, texture, and ornamentation to its
smaller relative. The teeth are similar to those of
the foregoing. The siphons are protected by a dark
leathery sheath, and the lower tube is larger than the
upper one. From its restricted area in British waters,
and the difficulty of obtaining specimens, it is one
of the most highly priced of native shells in the
catalogues of the dealers, a good example costing
a sovereign.
The Flask-shell (Gastrockcena dubia) bears some
resemblance to a young mussel when viewed from
above ; but below, towards the
foremost end, there is an enormous
oval gape as shown in our figures.
It is very variable, smooth, of the
whitish grey so frequent in the
shells of borers, but covered with
a yellow-brown epidermis. There
is a broad thin hinge-plate, but
no teeth in either valve. The
animal is pale reddish brown, with the mantle lobes
united below and having only sufficient aperture to
(fapers, Piddocks, and Ship-worms 163
allow the foot to protrude. The siphons are long,
semi-transparent, united, and capable of extension to
several times the length of the animal. It
bores into limestone, old shells, and red sand-
stone, but always fashions for itself, when
full-grown, a flask-shaped jacket composed of
shell-fragments and sand cemented together.
It occurs only on the south coast of England,
the Welsh coast, and the south and west of
Ireland, from low water to 20 fathoms. At
Torbay its burrows in the new red sandstone
are beautifully finished off as though lined
with porcelain. Fiask-sh
The Piddocks form the sub-order Phola-
dacea. They are all borers into rock or wood, and
they exhibit a remarkable advance in shell develop-
ment, the typical species being pro-
vided with supplementary valves in
addition to the two that normally
enclose the animal. The white shell
gapes at each end, and though thin
and brittle, is exceedingly hard, the
front part often armed with toothed
Case of Flask-shell
ridges that form a good rasp. There
are no hinge-teeth and no ligament, the valves
being held together by the adductor muscles
only. The hinge-plate is continued outside, and
folds over the upper margin of the shell, where
it is protected by a portion of the mantle. To
protect the mantle, one or more accessory valves
cover it at this part. The front pair of adductor
muscles are attached to the hinge-plates, where their
impressions will be found. The mantle impression
1 64 Shell Life
has a very deep sinus, showing that the siphons are
fully retracted. The animal is somewhat club shaped :
the siphons large, united nearly to the fringed
orifices, and covered by a sheath as in the Gapers ;
the foot also large, but short. They perforate, in
shallow water, rocks, wood, and other substances that
are not so hard as their shells, making vertical
symmetrical burrows. Having made a burrow
whether in limestone or in thick mud the maker
of it remains in it for life. This is very different
from the habits of ordinary burrowing mollusks,
(papers, Piddocks, and Ship-worms 1 6 5
who are constantly changing places. They seldom
interfere with each other by breaking through
their neighbour's party-wall, but as a rule make
their burrows to run parallel. The boring appears
to be effected by the flattened foot, assisted by the
rasp-like forepart of the shell in some species. The
native species are :
The Common Piddock (Pholas dactylus), the largest
by far of those found on our coast, its elongated shell
often measuring 5 inches in length. Each valve is
traversed by from 40 to 50 rows of prickly scales,
Right
which are most developed in the front part. There
is a pale brown epidermis, but it is mostly worn
away except at the edges. The accompanying cut
shows the interior of a right valve of this species.
The hinge-plate, reflected over the beak in a double
fold, is strengthened beneath by a
number of transverse partitions, as
shown in this figure. Within the
shell there runs down from the
hinge-plate a curved shelly band,
called an apophyse, to which the muscles of the body
are attached. Upon the external folds of the hinge-
plate, what are known as the accessory valves are
placed ; but it must be remembered that these are
Portion of hinge-plate
1 66
Shell Life
not of the same character as the two large valves
that enclose the animal, so that it will be better to
speak of them as dorsal shields. In
this species there are four of these
dorsal shields; two in front and side by
side, a third more solid, behind and inter-
locking with these, whilst the fourth is
long and slender, and protects the mantle
and upper mar-gins of the valves. The
animal is whitish like its shell. The
siphons are covered with little fleshy
points, the sheath brown or speckled.
Although chiefly found in the English
and Bristol Channels, it is recorded from
Seacombe, Lancashire, and along the
south, east, and north
coasts of Ireland. It
Dorsal snieids
is not particular m
its choice of material in which
to bore, chalk, slate - rock, red
sandstone, submerged wood, and
even peat, being selected in dif-
ferent localities.
The White Piddock (P. can-
dido) is a smaller species (less
than 3 inches long), and has a
thinner, more convex shell than
the foregoing, the prickles form
from 25 to 30 rows only, the
front gapes less. The reflected
hinge-plate forms but a single fold
externally, which is not partitioned off into cells :
and there is but one dorsal, lance-shaped shield with
Qapers, Piddocks, and Ship-worms 1 67
a central groove. The animal is white, tinged with
brown ; the siphons longer and more slender in pro-
portion than in the Common Piddock,
and longitudinally grooved within. It is
a very sensitive creature, and readily
takes alarm, retiring into its chamber.
It is about 2f inches long.
The Little Piddock (P. parva) has a
more solid, less convex shell than the
last, and is traversed by many rows of
overlapping scales, chiefly on the fore-
part of the valves, gradually getting less
towards the middle, and scarcely evident
behind ; often stained with red from the
clay and red sandstone in which it is found. The
beaks are much nearer the centre than in the other
species. The hinge - plate is fur-
nished with a knob, apparently to
prevent the valves coming too close
together at that part. As in the
White Piddock, there is but one
dorsal shield, and this is of similar
pattern to that of P. Candida. It
is a south coast species, and has
been found also in Guernsey,
Dublin Bay, and near Belfast. Its length is about
2 inches.
The Oval Piddock (P. crispata) has the shell oval
instead of oblong as in the other species ; convex,
solid, coarse-looking, with a broad furrow extending
from the beak to the lower margin almost in the
middle of each valve. In front of this furrow there
are about 20 rows of overlapping sharp scales. The
Little Piddock
1 68 Shell Life
broad hinge-plate folds over and is attached to the
beaks, but there is no knob as in the last species.
The dorsal shield is exceedingly small, and of tri-
angular form. The animal is of a red-brown colour,
with long siphons; these have the orifices fringed
with branched filaments. It is a little more than
2 inches sometimes as much as 4 in length, and
has been found on many parts of our coasts embedded
in mica-schist, shale, oolite, Oxford clay, etc.
The Paper Piddock (Pholadidea papyracea) has a
shell that is exceedingly thin and delicate, oval and
convex, the forepart with transverse
ridges cut into little teeth. The beaks
approach towards the centre of the
upper margin as in the last two species.
The broad hinge-plate is reflected over
the front. In addition to the short
apophyses, there is what may be re-
garded as a triangular cardinal tooth in
each valve. The dorsal shield consists
of two small plates, often united. At
the hinder end of the shell there is a
remarkable horny cup surrounding the
siphons which are entirely connected
throughout their length. This cup,
which is not found in young specimens.
Paper Piddock , , , , , . . ^ , ,,
appears to be the beginning or a sheath
to surround the siphons, but which is not further
developed in this species. It burrows in sandstone,
hard clay, peat, and submerged wood, chiefly along
the coasts of Devon and Cornwall, and at various
places round Ireland ; at low water of spring tides.
The Wood Piddock (Xylophaga dorsalis) is a con-
Gapers, Piddocks, and Ship-worms 169
necting link on one side with the foregoing Picklocks,
and on the other with the destructive Ship-worm
(Teredo), yet to be mentioned. The shell is like that
of a Pholas, but remarkably abbreviated, being in
fact globular in shape. It is glossy and almost
transparent ; crossed near the front end by a furrow
with marginal ridges. There are two dorsal shields,
similar to those of the Paper Piddock, but propor-
tionately larger. The globular animal has long and
slender siphons, connected
throughout the greater part
of their length, and marked
by crested ridges. The foot
is thick and capable of con-
siderable extension. There
can be no doubt, in this case
at least, that the foot is the
boring instrument, for the Wood piddock
epidermis is conspicuous over
the front of the shell, where it would be rapidly
worn off if the shell were used as a rasp. This
species is called the Wood Piddock, because it neglects
the rocks and bores only into submerged or floating
timber, preferring oak, pine, and birch, and evidently
not objecting to other vegetable substances, for it
has been found in the tarred hemp envelope of an
ocean cable. It penetrates only to a sufficient depth
(1^ inch) to bury itself, as shown in our figure.
The remaining genus (Teredo) of this sub-order
includes a few species of insignificant appearance, but
of sufficient power to have made them the despair for
centuries of all who owned wooden ships, timber-built
quays, piers, and stages in salt water. The people of
1 70 Shell Life
Holland have more than once had their welfare
perhaps their existence threatened by the ravages
of the Ship-worms among the piles of their embank-
ments. In the days of "the wooden walls of England,"
prior to the use of copper-sheathing, we also suffered
greatly ; but now that so many of our vessels are of
iron or steel, the Ship- worm's sphere of activity must
be greatly curtailed. The " infallible " remedies in
the shape of washes and paints that have been put
forward to check the ravages of this little sea-monster
must number several hundreds. This, perhaps, is a
matter that, could it be known to the Ship-worm,
might cause it to feel proud, that it had instigated
so much enterprise in others. Most of this, however,
must have been misdirected zeal ; but there is one
case on record of its having inspired a great piece
of engineering. The elder Brunei is said to have
declared that the method adopted in the construction
of the Thames Tunnel was suggested to him by the
Teredo.
The Ship- worms are very like Wood Piddocks, with
an enormous development of the siphons, which may
exceed a couple of feet in length. The shell is even
more gaping than that of the Piddocks, for the valves
touch only at the beaks and at a point on the opposite
margin ; it is helmet-shaped, marked as in Xylophaga,
Gapers, Piddocks, and Ship-worms 171
but without any dorsal shield. Each valve is three-
lobed, and the hinder lobe is usually spoken of as the
auricle or ear. The animal differs from the shell in
its shape, which is worm-like, and for the protection
of this part a chalky tube is secreted of great length
in some foreign species, and extending to a couple of
feet in our own T. norvegica. At the mouth of this
tube the animal has developed a pair of accessory
valves (known as pallets) in the shape of paddles,
the handles of which are attached to the body, and
the blades serve to close up the tube when the
siphons have been withdrawn. They all burrow into
submerged vegetable substances, including all kinds
of timber, and are never found in rocks. They
appear to do all the boring by the action of the
small foot, though it is probable that the valves may
be used to enlarge and round off the cell. The
burrows run with the grain, and consequently
parallel with each other. It is popularly supposed
that the Ship-worms destroy timber in this way to
serve as food, but though the excavated material is
passed out through the exhalent siphon it does not
appear that the animal derives any alimentary benefit
from it, but derives its nutriment from the microscopic
life of the seas, just as the oyster and the cockle do.
The species are:
The Common Ship - worm (T. navalis), usually
about a foot long, sometimes as much again. The
shell is rather thin, and finely ridged. The pallets
have an oval blade, which is indented deeply at its
free end, glossy without, polished and flat within. It
is found in pine, elm, oak, and teak that have been
used for boat-building, piers, piles, etc. This is the
Shell Life
Norwegi
shell; 2, pallets; 3, part of sheath, broken
to show internal plates
species that has caused so much damage and anxiety
to the Dutch. The Norwegian Ship - worm (T.
norvegica) is very similar to the last, but larger in
all respects, the shell
more solid and coarser
in its sculpture. The
large pallets have
oval blades with
squarish ends, con-
cave on the inner
side. Although found
all round our islands,
it is a local species,
and appears to con-
fine its attentions to
fixed timbers, and to
let floating spars and logs pass. The Guernsey
Ship- worm (T. pedicellata) is also very similar to
the Common Ship-worm, but much smaller in every
way ; probably, indeed, it is only the young condition
of a variety. Its chief claim to be considered distinct
lies in the shape of the pallets, which have long
stalks, a square blade, and an oval portion between
the blade and the stalk. It has been found in
submerged timber in several of the Channel Islands.
The Drifting Ship - worm (T. megotara), although
occasionally found in fixed timbers on our shores, is
chiefly known to us as a common inhabitant of the
drifting logs and spars that come no one knows
whence, and get cast on our shores in stormy weather.
Full-grown specimens are intermediate in size between
T. navalis and T. norvegica. There is an expansion
of the hinder margin of each valve known as the ear
Gapers, Piddocks, and Ship-worms 1 7 3
or auricle. In the present species this auricle is very
large, and the hinge-plate is very broad and thick,
with a knob and a tooth in the centre. The sheath,
too, is shorter, and often absent.
Several other species of foreign origin are fre-
quently found in drift-wood on our shores.
The animals comprised in the sub-order Anatinacea
have a single gill on each side, the outer fold of which
is prolonged over the back; the mantle margins
united almost throughout ; the siphons more or less
united and their orifices fringed. The shells are thin,
the valves often unequal, usually coated with nacre
within. The impressions of the mantle and muscles
are not well marked.
The Pandora-shell (Pandora incequivalvis) not only
has the valves unequal, they are inequilateral also.
They gape behind where the short
siphons protrude. It will be seen in
the figure that these siphons are
united almost to their full length,
yet diverge considerably from each
other. The left valve is flat, the right convex and
overlapping the left. They are of variable thickness,
glossy without and of a pearly
white colour. The horn-coloured
cartilage reposes in a groove of
each valve. The hinge-plate of
the left valve bears a rib which
Left valve of Pandora ^ s ^ a corresponding furrow
in the other valve. There is one
cardinal tooth in each valve, that of the right valve
being erect, that of the left horizontal. The Channel
Islands, Weymouth, and Studland are the only British
174 Shell Life
localities for this species, and there it may be found
burrowing slightly in the sand at low water. It has
a trick of squirting water from its siphons when
alarmed, like the Piddocks. There is a variety obtusa
found in deeper water (from 7 to 50 fathoms), and
the difference in habitat has produced a corresponding
difference in the shape of the shell. The normal
shallow-water form has to burrow beneath the sur-
face in order to escape the effects of the surf, and
consequently its shell is extended into a blunt beak
behind to protect the lengthened siphons. In deeper
water there is no fear of such disturbance, and there
is no need for burrowing so deeply ; therefore the
siphons are shorter and the shell less drawn out
behind. This is another object lesson in Nature's
manufacture of species. The Norwegian Lyonsia
(Lyonsia norvegica) is in general shape much like
Pandora, but the upper margin is more horizontal,
and there is less difference in the size of the two
valves. It is very thin, but opaque and yellowish ;
the surface made dull by fine radiating lines crossed
by the lines of growth. The pale brown epidermis
is gelatinous, and has the property of attaching grains
of sand and fragments of shell to itself. The golden
cartilage is contained in grooves as in Pandora, and
the hinge-plates are similarly ribbed and furrowed ;
but the cartilage is covered by a plate, called an
ossicle, that is not attached to the shell but formed
separately. The interior of the shell is iridescent.
The animal is white with a yellowish tinge. The
forepart of the mantle has a slight fringe of a few
projecting points. The siphons are short, fringed at
their orifices, and having a few filaments round the
Qapers, Piddocks^ and Ship-worms 1 7 5
base of each. The white foot is tongue -shaped,
extensible, and grooved for the production of a
byssus. It is not a common shell, but it occurs all
round our islands on sand between 4 and 86 fathoms.
Where these conditions exist it may also be looked
for in the stomach of the Red Gurnard. It is about
If inch in length.
The species of Thracia have nearly oval, more
symmetrical, and somewhat flattened, thin shells,
with a free ossicle as in Lyonsia. The shells gape
behind to allow of the continuous extrusion of the
long separate siphons. The Thin Lantern - shell
(T. prcetenuis) has the right valve less flat and a
trifle larger than the left, which it
slightly overlaps. It is finely
marked with lines parallel to the
edges of the shell, and the hinder
slope is also studded with minute
tubercles. The shell itself is white,
., Thin Lantern-shell
but the epidermis is or a creamy (two-thirds nat. size)
tint. The dark coloured ligament
behind the hinge is so small that it cannot be seen
in dried specimens. Attached to the hinge-plate
is a spoon-like receptacle for the golden cartilage.
The ossicle is sickle-shaped. The animal, includ-
ing the tongue-shaped foot, is white. It occurs in
sand on many parts of our coast from extreme low
water to 60 fathoms. It measures about 1J inch
across. The Papery Lantern-shell (T. papyracea) is
smaller than the last, much thinner, less equivalve,
and more convex. Ligament pale and large; carti-
lage more brown than golden, its pit or spoon more
oblique ; the ossicle shaped like half a ring. The
1 76 Shell Life
animal varies in colour from white to pale brown.
The siphons are short and wide, marked at their
extremities with faint lines.
The foot has a bluish tinge. It
is found in sandy bays a little
below extreme low- water mark.
The Large Lantern - shell (T.
pubescens) is larger, more solid,
Papery Lantern-shell an( I lllOre OVal ; the left Valve
a, ossicle; 6, ditto in position smaller and flatter than the
right. The surface is marked
with fine granulations, and the part near the
hinge is concentrically ribbed. The colour is dull
pale yellow. It is nearly 4 inches across. It is
found only in deep water off the coasts of Dorset,
Devon, and Cornwall. The Convex Lantern-shell
(T. convexa) is swollen, almost four-sided, thinner
than the last - named, but solid and glossy, and
with more delicate ornamentation the granula-
tions in wavy lines. Its colour is pale brown. It
measures a little over 2 inches. It burrows deeply
in muddy sand, in from 4 to 70 fathoms of water, on
all our coasts, but li\ 7 ing specimens are sometimes
washed up the beaches. The Little Lantern-shell
(T. distorta) is the smallest of the British species,
and measures little more than half an inch. It is
very variable in shape, and, owing to its habit of
dwelling in the burrows of Saxicava, and in rock
crevices, it is usually distorted. It is proportionately
of more solid structure than its congeners, of a white
colour and without any gloss. The dingy brown
epidermis gets rubbed off in its favoured haunts, and
can only be detected at the edges of the shell. The
Piddocks, and Ship-worms 177
granulations are arranged in irregular concentric lines.
Ossicle half-moon shaped. It is a local species, but
not confined to any particular stretch of our shores.
It appears to range from a depth of 5 to about 35
fathoms, hiding in old shells and rock, crevices.
Occasionally at extreme low water it may be found
nestling among tufts of Corallina.
The Skye Gaper (Poromya granulata) is a fragile
little pearly shell, with almost equal valves, of
rhomboidal form, gaping behind ; the right valve
overlapping the left. It is ornamented by minute
and rather crowded granulations, and dusky coloured,
with traces of the brown epidermis at the edges only.
Hinge-plate thickened, bearing in the right valve an
erect thick cardinal, in the left a small triangular
cardinal and a plate-like lateral behind. There is no
ossicle. The animal is cream coloured, with a long,
slender, transparent foot. The siphons are short
and thick, encircled at their base by about 20 long
filaments which curve back over the shell. It is
found in mud on rocky shores in Skye, at a depth
of about 40 fathoms. This little mollusk has the
distinction, not only of being the only native repre-
sentative of its genus and family, but also of its
Natural Order, the Septibranchiata, which is dis-
tinguished from the other orders by the gills being
replaced by a muscular partition (septum), which
reaches from the first adductor muscle to the siphons.
E have now left the headless,
toothless bivalves, and are
about to make acquaintance
with higher groups Uni-
valves or Gasteropods, the
mollusks that slide on the lower surface of the foot,
and that have heads, eyes, and jaws. But we make
the transition from one class to the other through
a small intermediate class univalves truly, but with
only a low organisation as compared with that of the
Gasteropoda.
This is the order Scaphopoda or Tusk-shells, so-
called from the curved tubular shell that bears some
resemblance in miniature to the tusk of an elephant,
and is open at each end. The animal is of similar
shape to its shell, with a rudimentary eyeless head,
which is covered by the mantle as in the bivalves.
There is a projection of the pharynx, and on this is
Tusk-shells, Mail-shells > and Limpets 179
situated the mouth. The buccal mass may be found
at the base of the long, pointed, and bilobed foot,
which projects from the large end of the shell.
Within the buccal mass is the tooth-ribbon or radula,
similar to those described in pages 44-46 ; but in this
class it differs somewhat from all the others. It is
broad and oval, with only 5 teeth in a row ; the
central tooth a broad simple plate, the lateral strong,
arched, with two or three points, and the marginal
is a four-sided simple plate. The sexes are separate
in these creatures, the liver is paired and consists of
a number of radiating tubes, but there is neither
special respiratory organ, heart, nor circulatory system.
The nervous
system is similar
to that of the bi-
valves. Around
the mouth are
bunches of fila-
/ , Elephant's Tusk-shell
ments (capta-
cula), which are thrust out for the purpose of catch-
ing the Foraminifera and minute mollusks upon
which the Dentalium feeds. The edges of the
mantle are united, so that it forms a tube open in
front and behind, and the entire surface of this
appears to absorb oxygen for purifying the blood.
It will thus be seen that these mollusks form an
actual link connecting the bivalves with the uni-
valves. In most points they agree with the bivalves ;
in only two respects the shell and the radula do
they agree with the univalves, and even in the
matter of the shell they begin life as bivalves, for in
the embryo this consists of two plates which later
i8o Shell Life
become united to form a tube. There are two native
species :
The Elephant's-tusk Shell (Dentalium entalis)
whose white shell tapers, and curves slightly up-
wards, solid and smooth ; marked by the ti*ansverse
lines of growth, finely scratched longitudinally at
the narrow end, which is cut off obliquely in mature
specimens and furnished with a tubular appendage.
It is also often notched at this end on the lower
(convex) side. The animal is white, the captacula
with oval tips, and the lobes of the foot scalloped
irregularly. It is found buried in sand at all depths
below 3 fathoms, usually in companies ; more plenti-
fully on the north than the south coasts. The
Grooved Tusk-shell (_D. tarenti-
num) differs from the foregoing in
being a little shorter and stouter,
more solid, more curved, and with
Grooved Tusk-shell
a duller surface. The colour, too,
is a cream tint. The lines of growth are less evi-
dent as sculpture, but are sometimes indicated by
brownish coloration. The tubular appendage at the
smaller end is central ; there is no notch in the
shell, but the hinder half is regularly grooved longi-
tudinally as shown in the section above the accom-
panying figure. The animal has a yellowish tinge ;
the captacula are ringed and end in little disks ; and
the foot-lobes have a wavy margin. It occurs in
similar situations to the last, from extreme low water
to a depth of 25 fathoms.
The Mail-shells (Chiton) introduce us to the class
Gasteropoda, to which all the Univalves belong. It
is a vast assemblage of orders, genera, and species.
Tusk-shells ', Mail-shells, and Limpets 181
The orders are only four, but several of these are so
large that they have been divided into sub-orders.
The first of these orders (Amphineura) consists of
the Mail - shells and some worm - like forms. The
Mail-shells alone constitute the sub-order Polyplaco-
phora. They differ from the vast majority of
Gasteropods in not being exactly univalve, for the
shell consists of eight overlapping segments or plates,
the whole series surrounded by a muscular marginal
belt (the girdle) which partly retains them in position.
There is sufficient freedom of movement in these
plates to allow the Chiton, when alarmed, to roll up
after the manner of a Wood-louse. The under portion
of these plates is of the ordinary shelly material, but
the upper layer is chiefly of chitin. This layer is
the sculptured portion, and it is divided off into three
182
Shell Life
triangular areas, known as the median and lateral
areas. The first and last plates are not so divided,
and are generally sculptured in harmony with the
lateral areas of the intermediate plates. Turned over
on its back the Chiton will be seen to have a close
likeness to the underparts of a Limpet. But closer
inspection will show that though it has a head there
are no tentacles and no eyes. The respiratory organs,
too, differ from those of the Limpet. These matters
we have already dealt with in the early chapters. As
the shell-plates are perforated by
numerous pores whose mouths
are occupied by sense organs, it
is probable that the animal can
get on as well without eyes as
the Limpet can with them. The
Mail-shells are provided with a
radula of much more advanced
type than that described in the
Tusk-shells. In that of Chiton
there are 17 teeth in each row.
There are ten or twelve native species of Chiton;
the large figure on the previous page is not British
but a well-known West Indian species (C. squamosus),
selected as a type on account of its superior size.
The British forms are :
The Bristly Mail-shell (G. fascicularis), whose dis-
tinctive feature is the spiny girdle and the series of
tufts of bristles along either side of the shell-plates.
The latter are shield-shaped with a central keel, and
equal to three-fifths of the entire breadth of the animal.
The colour varies a good deal from yellow and orange
to pink, red, or deep brown, marked with lines and
Underside of Chiton, and
a, profile of head
i VELVETY MAIL-SHELL; 2 GREY MAIL-SHELL; 3 WHITE TORTOISESHELL LIMPET ;
4 KEYHOLE LIMPET ; 5 TO 10 COMMON LIMPET AND VARIETIES.
Tusk-shells, Mail-shells, and Limpets 183
blotches of white, green, or brown. The head-plate
has five slight marginal notches, the other plates two
each. The orange-coloured foot is oblong
in shape, broader in front and running off
to a blunt point behind. It may be found
all along our coasts on the under-side of
stones and the face of rocks, stationary and
avoiding the light by day, and ranging in
search of food by night. Its range extends
from low-water mark to about 25 fathoms.
The Velvety Mail-shell (C. discrepant) is
similar in many respects to the former
species, but larger and proportionately more slender.
The girdle is broader, covered with a dense greyish
pile, from which arise tufts of white or reddish
spines as in C. fascicularis. Plates shield-shape,
one half the width of the animal, greyish, mottled
with brown, the keel darker, notches deeper. The
two species have the surface of the plates covered
with granulations like shagreen ; but in Hanley's
Mail-shell (C. hanleyi) the granules become tubercles
arranged in lines. There is no distinct keel, and the
margins are not notched. The colour is ashy brown.
The narrow girdle is clothed with short pale spines,
with a tendency to form tufts behind each plate. This
is a deep-water species, obtained by trawling at depths
between 20 and 80 fathoms. It measures about one-
third of an inch.
The Latticed Mail-shell (C. cancellatus) is very
convex, plates narrow, covered with minute round
granules, arranged in chain-like rows, the links pro-
ducing a lattice-like effect. There is no keel, and the
margin is not notched. The colour is very pale
1 84 Shell Life
yellow. The narrow girdle is fringed with short
spines, and the surface coated with polished yellowish
granules. It is less than a quarter of an inch long ;
and it may be found on stones and about the smaller
seaweeds just beyond low- water mark. The Grey
Mail-shell (C. cinereus) is similar to the last species,
but larger and more compressed ; shell with slight
but distinct keel, the sculpturing not producing the
latticed appearance. The girdle is broader, and more
thickly covered with granules. The colour of the
shell varies from pale yellow to brown, streaked with
dark lines, but the general effect is an ashy grey. It
is one of the most frequent of all our Chitons, and
may be found on rocks, stones, old shells, etc., on all
our shores from low water downwards.
The White Mail-shell (C. albus), which is less than
half an inch in length, is a local northern form. Its
white has a yellow bias, but it is unmarked by lines
or mottling of another tint. It is similar in general
appearance to the Grey Mail-shell, but is more slender
and convex, has a more prominent keel, the granula-
tions finer, more radiating than chain - like. The
margins are slightly notched ; the head-plate having
13 notches, the tail -plate 11, and the intervening
ones 2 each. The brownish girdle is broader and
more regularly beaded, whilst its margin is fringed
with short spines. It occurs in the Isle of Man, and
at various places on the coasts of Scotland, Shetland,
and the Orkneys. The Bordered Mail-shell (C. mar-
ginatus) is similar to C. cinereus, but larger,
narrower, and more convex ; the plates broader, with
a surface like shagreen, mottled or variegated with
yellow, red, and green, and their edges deeply notched.
Tusk-shells, Mail-shells , and Limpets 185
The girdle is evenly covered with minute granules,
vari-coloured, and fringed with short yellow spines.
It is one of our commonest forms, and
may be found everywhere under stones
at various depths, even above ordinary
low- water mark. It is represented of
the natural size in our figure. The Red
Mail-shell (C. ruber) is much like C.
marginatus, but more slender, more
convex, of a reddish-brown tint, and presenting a
smooth appearance. The girdle, too, is broader, and
chequered with small patches of red and white. It
is a species of general distribution on our coasts,
from low water to a depth of 20 fathoms, where it
may be found on rocks, stones, and at the base of
the Laminarias.
The Smooth Mail-shell (G. Icevis) is convex, broad,
and glossy, marked with microscopical scratches and
minute tubercles. It is reddish brown in colour,
veined with white, or variegated with
green or pink. The head-plate has from
16 to 20 deep notches, the tail-plate 15,
and the others 2 each. The broad girdle
is covered with small spine - like scales,
their tips towards the margin, which is
thinly fringed with short pink spines that
readily fall off. The animal is about an
inch long. It is widely distributed, and extends
from extreme low water to about 70 fathoms. The
Marbled Mail - shell (C. marmoreus) is the largest
of the British species. It has a broad glossy shell,
almost smooth to unassisted sight, but under a lens
showing many minute tubercles ; coloured with red-
i 86 Shell Life
brown marked with streaks and specks of white or
yellow. There is a fairly broad girdle of dusky
brown fringed with very short yellowish
spines. The head-plate has 8 notches,
the tail-plate 9, and the intervening
plates 2 each. It occurs among stones
and weeds a little beyond low water,
but not south of Yorkshire.
Through the Limpets we become ac-
quainted with the order Prosobranchiata,
Marbled which includes the great majority of
native Gasteropods. The name signifies
that in this order the plume-like branchiae or re-
spiratory organs are usually placed in front of the
heart. The animals have a distinct head, which is
furnished with a pair of tentacles and a pair of eyes.
They are mostly marine animals, protected by a shell
and mostly by an operculum ; the sexes are separate.
It is divided into two sub-orders, and these again into
sections. The species described in this chapter belong
to the sub-order Diotocardia, most of the animals
comprising it having two auricles to the heart, but
the Limpets are exceptional in that they possess only
one auricle and one ventricle.
The Tortoiseshell Limpet (Acmcua
testudinalis) has a conical but depressed
shell, with growth lines fairly strong,
and with fine scratch - like lines both
radiating and concentric. It is rather
thin, with a dull surface, the ground
colour grey, irregularly marked with
reddish brown, sometimes with white in addition. The
interior is polished, except the broad, bevelled margin,
Tusk-shells, Mail-shells, and Limpets' 187
which is only smooth. Half-way between the margin
and apex is a chocolate mark of horseshoe shape.
The animal is white, with a large head and long awl-
shaped tentacles, with small eyes at their base. Foot
oval and broad. It occurs under stones, from low
water to a depth of 20 fathoms, but comes no farther
south than Northumberland and Durham. One form
of it found on the narrow leaves of Sea Grass (Zostera
tnarina) has the shell compressed so that it becomes
narrow and higher. This form is sometimes dis-
tinguished as A. alvea. The White Tortoiseshell
Limpet (A. virginea) is similar to the last, but only
half the size, rather glossy, pinkish, with brownish
and white rays, rather than white, though a pure
white variety occurs at Scarborough. Its ordinary
length is little more than a quarter of an inch, but
at Guernsey it exceeds half an inch. It is generally
common on stones just below low-water mark. In
Acmcea the apex of the shell is turned forwards; in
Lepeta backwards.
The Fulvous Tortoiseshell Limpet (Lepeta fulva)
is rather smaller than the last ; of a yellow, bright or
dull orange colour, with white rays and fine radiating
ribs ; thinner and semi-transparent, not glossy. The
Blind Limpet (L. cceca) is white, thin, finely grooved
from the beak, about half an inch long. The animal
is whitish, with short tentacles, but no eyes. It is a
Scandinavian species, which has been taken occa-
sionally in a dead state from deep water between
Scotland and Shetland.
The Curled Limpet (Propilidium ancyloides) is
another eyeless species similar to Lepeta, but with
longer tentacles, and the beak of the shell curled
188
Shell Life
backwards into a spiral. Within it has a triangular
shelf-like plate, occupying half of the crown. It is a
deep-water (18 to 100 fathoms) species, plentiful on
nullipores around Ireland, Scotland, and Shetland.
The Common Limpet (Patella vulgata}. So
generally common and well-known a species is in
need of no description, beyond saying that the shell
is conical and solid, with ribs radiating from the
beak. It is variable in colour, some young specimens
being olive-grey, others more yellowish with purple
rays. As it gets older the beak gets completely worn
away, the ribs rubbed down, and
possibly the whole surface made
smooth and almost even. Other old
specimens get covered with nullipore,
or support a forest of delicate weeds.
The inside is very glossy, being coated
with nacre, which exhibits greenish
opalescent gleams. Through this
layer the purple rays may be seen
more or less clearly, though all trace
of them may have gone from the outside. In the
centre there is a large white patch showing the
attachment of the muscle ; it is in the shape of a
broad-mouthed amphora. A less distinct depression
around it marks the attachment of the mantle. The
general appearance of the Limpet from beneath
when detached from the rock is shown in the cut. In
the centre is the broad muscular " foot " by which
adhesion to the rock is effected ; in front of it the
distinct head, with mouth, paired tentacles, and eyes ;
around the whole is the fringed mantle, and between
the mantle and the foot there extends a frill of gill-
Common Limpet
Tusk-shells, Mail-shells, and Limpets 189
plates. There is reason to believe that the primitive
Limpet was not endowed with this extensive frill,
which is a more recent development to fit the species
for changed habits. In the Tortoiseshell Limpets the
breathing organ is a single plume-like gill attached to
the right side of the neck, and protruded when the
creature goes a-walking. It is believed that the
original Limpet had a pair of these plumes, one on
each side ; and if the modern Limpet be taken from its
shell, and the mantle cut away so as to expose the
upper side of the neck, a little yellow body will be
found on each side of it. These are the remains of
the true gills, which have gradually dwindled away
to useless vestiges as the new and from the func-
tional point of view more important frill has
developed. It is probable that, like Acmcea, the
primitive Limpet lived constantly in the water, and
consequently the work of the two small gills ever
exposed to the water was sufficient to keep the blood
oxygenated ; but now the Limpet spends the hours
between the fall and rise of the tide entirely out
of water, and can only manage to keep its gills
sufficiently moist to carry on the process slowly. It
therefore seems probable that, in order to keep the
blood pure, the slower respiration must be maintained
over a much larger surface. The change of habitat
and the development of these pseudo-gills might go
on pari passu: early Limpets with merely the
beginnings of the frill restricting themselves to those
lower rocks that are only uncovered for a short time.
But this is not the only change produced in the
Limpet by its altered habits. As it has learned to
endure fresh water by its exposure to rains and to
190 Shell Life
the, in some places considerable, percolations from
the cliffs, so also the shape of the shell appears to
have been modified. Canon Norman pointed out
years ago that " the nearer high-water mark the
shell is taken, the higher-spired, more strongly ribbed,
and smaller it will be; and that the lower down it
lives, the natter, less ribbed, and larger it becomes."
This result, I should suppose, is due to the action of
natural selection. One of the principal enemies of
the Limpet is the Oyster-catcher, whose bill is admir-
ably adapted for wrenching it from the rock when
its shell is slightly lifted for fresh air or locomotion.
It will be evident that the flatter, smoother, and
larger the shell may be, the more easily it may be
lifted, so that the birds are more likely to select such
specimens in preference to the less easily obtained
small, high-spired, and ridged examples : the former,
therefore, must become scarce on the rocks most
quartered by the larger shore-birds.
The tongue (radula) of the Limpet when uncoiled
is found to exceed the shell in length; it is
furnished with nearly 2000 teeth, with which it
scrapes the surface of the rocks, clearing off the
delicate growths of weeds and leaving a peculiar
zigzag track.
The means by which the Limpet adheres to the
rock has long been a fruitful subject for controversy,
many naturalists appearing unwilling to believe that
it could be held there by the same powers as those
that hold the Winkle the muscles and mucous of
the foot, which by excluding air establish so close a
contact that considerable pulling force is required to
dislodge it. Reaumur experimented with the Limpet's
'Tusk-shells, Mail-shells, and Limpets 191
power in this respect, and says that for several
seconds it supported a quarter of a hundredweight
attached to its shell. Some authors imagined that the
foot contained a number of presumably invisible
suckers ; others, that by drawing up the centre, after
the manner of the street-boy's leathern sucker, it
created a vacuum which held it to the rock. Keaumur
was troubled by some of these notions, but he disposed
of the vacuum theory by cutting a Limpet shell and
all right through, and as the two halves still
adhered to the rock it was clear there could be no
vacuum.
It has long been noticed that the Limpet sinks
pits corresponding exactly to the margin of the shell,
but deep or shallow according to the softness or
hardness of the rock. In this way it overcomes the
difficulty of shutting down its shell closely upon an
irregular surface, by making its own little patch
level. Various agencies have been invoked to explain
how these pits are sunk ; an acid secreted by the
foot, and carbonic acid given off' in respiration, being
among them. No doubt on chalk and other soft
rocks we need look no further than to the pulling
action of muscular contractions of the foot. Even
on the hard slaty rocks of the Cornish coast, I have
frequently noticed that Limpets taken oft' for use as
bait have thin laminae of rock still attached to the
foot. But the most remarkable of the Limpet's
habits is that of returning to the identical spot to
roost after each excursion in search of food. Given
a particular area of rocks it would be almost impossible
to find two pits so exactly alike that they would
equally serve as lodgment for a particular Limpet.
13
192 Shell Life
It was this fact, probably, that led some of the
earlier naturalists to contend that the Limpet never
wandered from the particular spot it had selected in
early life, though Aristotle had recorded its food-
seeking excursions more than two thousand years
before. Not only do they do this whilst still covered
by the sea, but after the tide has receded and whilst
the rocks are still wet. At such times I have often
listened to the noise made by hundreds of Limpets
dragging their shells over the rough acorn barnacles,
and to the rasping sound produced by the radula as
it scraped the minute vegetation off the rock.
There is no need to say anything of the importance
of the Limpet as food and bait, except that on some
parts of our coast this is very great, many tons of the
mollusk being consumed yearly by the poor. Judging
from the contents of the shell-heaps (Kokken-mid-
dings) left near their former rude dwellings by the
aboriginal inhabitants of these islands, the Limpet
had a much greater importance as a food in earlier
days.
There are several well - marked varieties of the
Common Limpet which have distinctive names given
to them, and certain of these have been elevated to
the rank of species by some writers. The var.
elevata has a smaller, rounder, and higher shell ;
var. picta is smaller and thinner, with alternate
blue and reddish rays ; intermedia is smaller, flatter,
and oval, with yellow centre inside and out, the
animal dark - coloured ; depressa, much flatter, more
oblong, ribs finer and sharper, beak nearer front,
centre of interior orange ; ccerulea, flat, roundish oval,
ribs delicate, somewhat irregular, interior dark blue.
Tusk-shells, 'Mail-shells, and Limpets 193
The genus Helcion differs from Patella in the fact
that the frill of gill-plates arising from the left side
of the neck is not continued completely around the
animal, but ends in front of the head. In early life
the shell of the Blue - rayed Limpet (Helcion pcl-
lucidum) is oval, thin, semi-transparent,
rounded above, with the slight beak
above the front extremity. The colour
varies from ochreous to olive, and from B^i'e'-rTyed i_im et
the beak thin broken lines of vivid blue
run to the margins. The number of these lines
varies greatly, but, as a rule, they are about 7,
though they may be 40. The animal is cream
coloured, tinged with brown ; mantle fringed with
long and short filaments ; tentacles slender, eyes
small. I have already alluded to the changed
appearance of the shell when the animal becomes
old (page 36). The young Helcion lives upon the
fronds of the larger seaweeds, where it is not very
conspicuous, but in later life it descends
the rounded stalks, thickening its shell,
compressing the sides and fashioning
the mouth so that it fits the rounded
sur facc accurately. By this time the
blue lines have vanished, as being a
source of danger rather than security in the new
situation, and the shell has no resemblance to its
former self. The animal cuts out a cavity in the
stalk, which it resembles in colour, and there it
remains embedded.
The Slit - limpets (Fissurellidce) form a family
remarkable from the fact that their limpet - like
shells have a slit which serves the purpose of an
194 Shell Life
excretory orifice, corresponding with an oval tube
in the mantle. The animal has two large gills,
placed one on each side. It is probable that from
some such form the bivalves were produced, the
development of these organs into the plate-like gills
producing corresponding changes in the mantle, and
consequently of the shell.
The Keyhole Limpet (Fissurella yrceca) in the
juvenile stage has a distinctly spiral beak and a
slit margin, but as the shell grows, and the em-
bryonic portion becomes the apex, the slit finally
appears like a keyhole at the top
of the shell, and the mantle is
protruded through it. It is a
pale yellowish shell, with rays
of some tint of brown, and about
Keyhole Limpet 50 rugged ribs radiating from
the beak, which are alternately
larger and smaller. The animal is some shade of
yellow ; the mantle extends beyond the margin of
the shell, and is fringed with short stout processes
corresponding with the ribs of the shell which are
produced by them. A similar fringe decorates the
upper part of the foot. The Keyhole Limpet is
found all round the British Islands with
the exception of the east of England
and the east and north of Scotland. It
extends from low water to a depth of
15 fathoms. The Punctured Limpet
(Puncturella noachina) is much smaller than the
last, but agrees with it in having a slit, which does
not, however, take the place of the beak, but is a
little in front of it, as shown in annexed view from
"Tusk-shells, Mail-shells, and Limpets 195
above. The beak remains spiral as in the embryo.
The " Keyhole " of the previous species has a
thickened margin internally, but in the
present species there is a vaulted process
beneath the slit. The shell is white,
ribbed in a mariner similar to that of
F. yrceca, but less rugged. It is a deep-
water (25 to 90 fathoms) species, and a
northern not being found south of Yorkshire.
Common Slit - limpet (Emarginula fissura). In
the genus Emarginula the slit instead of appearing
in very early life and travelling to the crown of the
shell, as in Fissurella and Puncturella,
appears when the animal is nearly
adult and remains at the margin, becom-
ing partially filled up with age. The
mantle protrudes from this slit to form
. . . ,
an excurrent siphon, as in the other
members of this family. The shell is white, and
crossed by ribs much as in the other species, but here
they are less numerous. It is generally distributed,
and may be found on rocks and stones from extreme
low water to a depth of over 100 fathoms. The
Rosy Slit-limpet (E. rosca) is a much smaller species,
with proportionately narrower shell of distinct
Phrygian cap form. The ribs are more equal ^j$^
in thickness, and the pits caused by their Rosy
intersection round, whereas in the preceding | .^ lt " et
species they are more square. The slit is
shorter, the mouth often tinted with bright rose
colour, and the usually white shell sometimes tinged
with pink. It is a southern form, but may be
found commonly in deep water (7 to 25 fathoms)
1 96 Shell Life
on the coasts of Dorset, Devon, Cornwall, and the
Channel Islands. The Large Slit - limpet (E.
crassa) is much larger than the last two species;
the white shell measuring 1| inches in length. It is
a less elevated cone, and the radiating ribs number
between 80 and 100, alternately broad and narrow,
each of the former often divided into three. In
addition to the concentric wrinkles that cross these,
there are radiating rows of minute glistening dots.
The mouth of the shell is oval, and is notched in
agreement with the ends of the ribs. It has
been found under stones at Oban at periods of ex-
tremely low water, but otherwise only by dredging
on rocky ground off' the west coast of Scotland,
Shetland, Antrim, and Dublin, in from 20 to 75
fathoms.
The Ormer or Sea Ear (Haliotis tuberculata).
The claims of this mollusk to be included among
native species are
political rather than
natural, for its only
" station " north of
St. Malo is the shores
of the Channel
Islands, where it is
used for food, after
a t size) being beaten to make
its muscular foot
tender. Flat and shallow as the reddish-brown
shell is, it is distinctly spiral, with the last whorl
very large. Its exterior is rough and shabby-
looking, but it is lined with the iridescent " rnother-
o'-pearl" which makes these shells so valuable to
'Tusk-shells, Mail-shells, and Limpets 197
the manufacturer of fancy articles. Instead of
the 'central or marginal slit, such as we have seen
in the Keyhole and Slit-limpets, the Ormer has a
long spiral series of round holes. As the creature
grows the oldest of these perforations are suc-
cessively filled up, the last remaining open serving
as an anal aperture; whilst the others admit fresh
supplies of water to the pair of branchial plumes,
of which the left plume is the larger. Filaments
from the mantle also pass through these holes, and
doubtless serve as sense organs. The animal has
a broad head, from which a short snout protrudes.
The tentacles are long and thread-like, connected
at their base by a fringed lobe, and at their outer
bases are placed the stalked eyes. The large fleshy
foot is fringed by two rows of delicate filaments, with
green tubercles between. The animal creeps along
after the manner of a Limpet, and, like that species,
rests with the margins of the shell pressed against
the rock, from which, however, rats and birds con-
trive to force it.
Curled Slit - shell (Scissurella crispata). The
minute thin white shell of this mollusk shows an
advance towards the spiral form of the snails. The
last or body-whorl forms the greater part of the
shell, but instead of being spread out and shallow,
as in the Ormer, the sides are contracted, and when
the animal retires within the orifice is closed by a
thin oval operculum. In adult specimens the margin
of the shell is slit in front. The animal has a
rather long foot, a prominent head, and a pair of
long fringed tentacles with the eyes at their base.
Along each side of the foot there are two short
198 Shell Life
pointed lappets, and beyond these two long fringed
feelers. It has been taken on stony ground from
18 to 75 fathoms deep, in Shetland, but the shells
were empty ; also at Orkney, Wick, Caithness, Skye,
Antrim, etc.
TSHfcLL
HE passage from the uncoiled
Limpets to the strictly spiral
cones of the Tops is made
easy by way of the Slit-
limpets and Scissurella, as
shown in the previous chapter. A further advance
in that direction is seen in the tiny Dolphin-shells
(CyclostreiiKi), of which we have three species. They
are more orbicular than Scissurella, and without the
slit margin of the almost circular mouth. The coil-
ing of the shell round an imaginary axis leaves a
deep cavity, known as the umbilicus, which we
shall meet again and again from this chapter in
our story, and shall find that it is often a valuable
clue in the discrimination of species. Another feature
encountered for the first time is the operculum, a
thin horny plate attached to the hinder part of the
mollusk in such manner that when it withdraws into
200 Shell Life
its shell the operculum comes last and accurately
closes the mouth of the shell. In some species this
operculum is composed of hard shell material, but in
the Dolphin-shells it is horny and of spiral structure.
The Shining Dolphin - shell (C. nitens) is thin,
white, glossy, and slightly iridescent, with three
whorls and a thickened lip. The animal has a
bilobed snout, thread-like tentacles from the head,
and tentacle-like appendages to the foot three or
four on each side. It is found in the coralline zone
on the coasts of Devon, Cornwall, Guernsey, all
round Ireland, and the west of Scotland. The other
species is the Flat Dolphin-shell (C. serpuloides).
The specific name of this mollusk was bestowed
because the shell was thought to resemble the shelly
tunnel of the Tube-worm (Serpula). It is almost flat,
the spire being scarcely raised. It occurs between
low water and a depth of 25 fathoms on all our
coasts. It is thought by some that the species
described below as Trockus duminyi should come
here under the name of Circulus striatus, but as
the shell alone is known we think it best to retain
it provisionally where Jeffreys placed it, as the
discovery of the animal will almost certainly lead
to other arrangements.
The Top-shells (Trochus) are closely related to the
Dolphin-shells, as will be evident on comparing the
animals with their ciliated tentacles and side
appendages, although systematists have placed
them in separate families. These differ from the
last in the shells always having a layer of pearl
beneath the outer coat of shell material, and in the
mouth of the shell being oblique and somewhat
Top- shells and Pheasant-shell 201
angular. The umbilicus is not always present, and
is very variable even in the same species. The head
of the animal is furnished with
lobes, as shown in this figure of
the Grey - top's head. At the
" tail " end of the animal an iri-
descent horny disk, showing a
spiral structure, will be seen ; this
is the operculum, which closes the Head of Gre y -to P
shell when the creature has retired.
The Common Top-shell (T. zizyphinus)
is regularly pyramidal with an almost
flattened base, solid, and somewhat glossy.
Ridges of various sizes run spirally from
the sharp apex to the rhomboidal mouth;
the largest ridge being that which
marks the base of each whorl. The
ground colour varies from flesh colour
to purple overlaid with interrupted
or zigzag streaks of dark red. There
are from 10 to 12 whorls in a full-
grown specimen. The animal is
yellowish, variegated with crimson, purple, and
brown. The prominent head has a small bilobed
veil ; tentacles with a brown central streak ; eyes
large, with black pupils, on stout footstalks. The
side appendages are usually four pairs. The oper-
culum has 15 or more whorls. Like all the
members of the genus, the Common Top feeds
upon seaweeds, and it may be found in plenty in
the zone below low - water mark, where the great
wracks and oar-weeds grow. It also extends to
a depth of 85 fathoms, and some of the finest
202 Shell Life
examples have been obtained by trawling in deep
water.
The Western Top - shell (T. occidentalis) is
pyramidal, thin, semi-transparent, glossy, opaline,
with pale golden spiral ridges, and about 7
whorls. Animal like the last species, but witli
usually three pairs of side appendages. The shell is
about half an inch high, and somewhat less across
the base. It has been found on the fishing banks
of Shetland, the Orkneys, and Aberdeenshire, in
deep water 40 to 90 fathoms.
The Granulated Top-shell (T. granulatus) is solid
and opaque; pyramidal, but with the lowest whorl
larger than the other nine put together, ridged
as in the previous species, and tapering abruptly
to a sharp high point. Its colour is pale yellow,
tinged and spotted with reddish brown. The animal
is similar to the foregoing, but the eyes are dark
blue with black pupils, and are mounted on short
white stalks ; side appendages three on each side.
In height and breadth it is about 1| inches. It is a
southern species, and may be sought in the coralline
zone along the coasts of Dorset, Devon, Cornwall,
and the Channel Islands, in the Isle of Man and
on the south and east of Ireland. The name is
suggested by the fact that the larger ridges have
their surface raised into granular points.
The Many-grained Top-shell (T. miliaris) is similar
to the last, but smaller, measuring only about half an
inch either way, arid the ridges broken into granula-
tions by the crossing of numerous oblique grooved
lines. The ground colour is more white than yellow,
but marked with brown and purple as in the last.
Top-shells and Pheasant-shell 203
The animal is covered with short prickly points, and
the tentacles which are marked with three lines
of brown have blunt tips. The eyes are on the
under-side of tubercles at the outer base of each
tentacle. Side appendages three pairs, with a brown
eye-spot just behind each. It occurs chiefly in the
west of Scotland, but has been taken on many other
parts of our coasts, even to Devon, Cornwall, and the
Channel Islands, in from 2 to 70 fathoms.
The Grooved Top-shell (T. striatus) is narrow at
base in proportion to height, flattened beneath, the
whorls 7 in number, of which the lowest 5
are flattened and distinctly keeled. The whole
surface is crossed by innumerable oblique lines
which break up some of the ridges into little knobs.
The ground colour is whitish, streaked obliquely or
speckled with brown. It is about a third of an
inch across at base, and a little more in height.
It occurs along the south coast from Dorset to
Cornwall, in the Channel Islands, and at Cork,
Baltimore, Bantry, and Dublin Bay; its habitat
from low water to a depth of 15 fathoms, and it
appears to be fond of the Crass Wrack (zostera).
Montagu's Top-shell (T. nwntacuti) is similar to
T. striatus, but a little smaller, the whorls not
flattened though somewhat compressed and the
base more convex. It occurs on all our shores
between 7 and 95 fathoms.
In all the foregoing species of Top-shells there
is no umbilicus in the adult, though the fry of
some species show one temporarily. All the species
that follow have this perforation, though in- the
Thick Top it is almost filled up in the adult.
204 Shell Life
The Thick Top-shell (T. lineatus} is not pyramidal
but conical, very thick and dull. Young specimens
exhibit the spiral ridges, but these have disappeared
in the adult. The ground colour is yellowish or
greyish, overlaid by zigzag purple streaks. The
apex of the rather low spire is always eroded by
the time the shell is full-grown. Whorls 6 ; mouth
large and oval, the inner lips bearing a strong tooth-
like tubercle. The large shallow umbilicus is partly
covered by the inner lip. Its measurements are an
inch either way. It is a local shell, but may be
found from Dorset to Cornwall, and up the western
coast to Anglesey ; also in Ireland and the Channel
Islands, between tide-marks.
The Round Top-shell (T. duminyi) is a minute
shell, which is equally convex above and below,
flat spired, and has a very wide and open umbilicus.
It is white, semi-transparent, glossy, and has fine
whorls spirally ridged. The mouth is almost square.
It occurs at Bundoran, Donegal Bay.
The Flat Top-shell (T. umbilicatus) is much larger
(half an inch across) than the last, flat-based and
almost flat-topped, without any approach to the
pyramidal form. The spiral ridges are sharper and
fewer; the colour grey, streaked with red lines or
zigzags ; outer lip bordered with orange and green.
It occurs in numbers, feeding on the Saw-edged
Wrack (Fucus serratus), in the littoral zone along
the south coasts up the Bristol Channel, around
Ireland and the Isle of Man, and along the west
coast of Scotland.
The Grey Top-shell (T. cinerarius) is the most
abundant of all our Top-shells. It varies a good
4
i GROOVED TOP-SHELL ; 2 SMALL PEARLY TOP ; 3 SWOLLEN TOP ; 4 COMMON TOP ;
5 GREY TOP ; 6 FLAT TOP ; 7 THICK TOP ; 10 MANY-GRAINED Top ;
S, g PHEASANT-SHELL; u, 12 FRESHWATER NERITE.
Top-shells and Pheasant-shell
Grey Top-sh
deal in appearance according to its habitat; those
living on the rocks between tide-marks resembling
our figure, but when living upon
oar-weed below the littoral zone it
is much more depressed. There
are 6 or 7 whorls ; the lower ones
flattened and the upper ones
rounded. There are a few thread-
like ridges on the body -whorls.
The ground colour is light grey, overlaid with crowded
oblique streaks of dark purple-brown. The umbilicus
is small and narrow, somewhat one-sided. It is very
widely distributed all along our shores. Its height
is half an inch, and its breadth a little more.
The Swollen Top-shell (T. tumidus) is solid, the
6 or 7 whorls less convex than in the last,
presenting a turreted appearance ; spiral ribs fine
and numerous. Umbilicus large and one-sided. The
colour is white or yellow, overlaid with spiral rows
of red-brown spots. The mouth oblique, with a
slight tubercle in the middle of the inner lip.
About one-third of an inch in height and of similar
breadth. It is rather common and widely distributed,
occurring in the laminarian zone and deeper water
down to 95 fathoms.
The Painted Top-shell (T. magus) is a very
distinct species, the shape of the three
largest of the 8 whorls giving the solid
shell a decidedly turreted appearance.
A number of irregular ridges run
spirally round the shell, and these are
broken up into little knobs. A more
prominent ridge runs round the base of the shell.
Painted Top
206 Shell Life
The ground colour is pale yellow, almost covered by
short streaks of red and purple. Umbilicus wide and
very deep, bordered by a smooth broad ridge. It
is a species of our southern and western shores, to
which may be added Ireland, Man, the Channel
Islands, the Orkneys, and Shetland. It affects a
sandy bottom between low-water mark and 40 fathoms.
Its vacated shell is a favourite cell for Prideaux's
Hermit-crab, which has for companion an anemone,
the Cloaklet, that wraps the shell completely round,
and by secretions from its under-surface dissolves
out the mineral portions and leaves only a soft
mass resembling sodden paper more than shell.
The Pearly Top-shell (T. cinctus); this and the
two following species are characterised by their
pearly lustre, and their possession of an umbilicus.
The shell of the present species is pyramidal, semi-
transparent, pure white with a pearly iridescence.
The largest whorl has two large and several smaller
ridges, some of which are continued along the other
6 whorls. The mouth would be circular but for
its interruption by the spiral ridge which encircles
the deep umbilicus. It is a small species, its height
being one-third of an inch and its breadth a little
less. It was first found by Mr. J. G. Jeffreys in
1861, who dredged it on fine sand and gravel in
85 to 95 fathoms, about 25 miles north-north-west
of Burra Firth Lighthouse, Unst.
The Greenland Top-shell (T. grcenlandicus) is
rather rotund and solid, slightly glossy, with fine
spiral ribs. There are 6 whorls, and the upper
part of each is puckered up irregularly. The colour
is a flesh tint, without streaks or spots. The um-
Top-shells and Pheasant-shell 207
bilicus is narrow, but very deep. It is a quarter
of an inch across and a little less in height. Its
British distribution is limited to the west of
Scotland, Shetland, and the Orkneys, where it occurs
on rocks about the base of the Laminarias, from
low water to a depth of 40 fathoms.
The Small Pearly Top-shell (T. helicinus) is less
conical and shorter than the last, less solid, semi-
transparent, and highly polished. There are no
ribs, and the suture or hollow line that separates
the 5 whorls is less deep than in the last. The
umbilicus is also less deep. The colour is orange
varying to reddish brown, occasionally tinged on the
upper-side of the whorls with blue or purple. It
is a quarter of an inch across the base, which is
almost twice the height. Its habit is similar to
that of the Greenland Top, but its habitat must
be extended by the addition of the east coast
of Scotland and its continuation as far south
as Yorkshire; also Belfast, Dublin Bay, and
Connemara.
The Pheasant-shell (Phasianella pullus) belongs
to a family (Turbinidw) distinct from the Top-
shells, and this is its solitary repre-
sentative in this part of the world.
The home of the genus Phasia-
nella is in Australia, where the
shells are large, P. australis is
2 inches long and 1 inch across,
in the Philippines and India they are much
smaller, whilst in the Mediterranean, the British
seas, and the West Indies they have dwindled to
very small examples. Our own species is no more
14
208 Shell Life
than a third of an inch in length, and a fourtli of
an inch in breadth, but it makes up for its small
size by its exceeding
beauty. The animal is
very like those of the
Top-shells, and like some
d of them it moves one half
~\ the foot at a time in
Head of l^ia^la (enlarged) g lldin g' The OperCUlum,
which we found to be
thin and horny in the Top-shells, is solid and shelly,
ear-shaped, and concave below. The shell, which
is oval, semi-transparent, and highly polished, has
usually a clear yellow or white for its ground
colour, upon which are laid numerous variable
oblique or zigzag streaks and spots of crimson
or purple. There is no umbilicus. It is a common
species on the south and west coasts of England ;
round Ireland; Oban, Mull, Stonehaven, Aberdeen,
Caithness, in Scotland ; and the Channel Isles. It
may be found feeding upon Chondrua crisp us and
the similar Gigartino, mamillosa, a little above and
below low-water mark.
The Fresh- water Nerite (Neritina fluviatilis) is
the sole representative of the family NeritidcK in
this country. It takes us away from the sea for a
brief space, for this is a mollusk, no doubt
descended from the marine Nerites of
warmer climes, that has ascended the
rivers and become modified by the
changed habitat. The shell is obliquely oval,
of a solid character, and with a glossy surface.
The ground colour is yellowish, and is chequered
fop-shells and Pheasant-shell 209
with white, pink, or purple. There are but 3
whorls, and the last of these is equal to at least
two-thirds of the whole shell. The operculum is
half-moon shaped, corresponding with the shape
of the mouth, shelly and solid, coloured yellow or
orange, and spirally grooved ; beneath there is a
sickle-shaped projection which serves to keep it in
position when it closes the shell. The animal
which is yellowish grey spotted with black, and
has a black head shows its relationship to the
Top-shells by its possession of a strong snout. It
has long tentacles, almost transparent, streaked with
black ; and large black eyes on short foot-stalks.
It is found in clear gravel-bottomed rivers, spar-
ingly at the mouth where the water is brackish ;
more frequently in the upper reaches. The globular
egg-capsules are usually deposited on the shell
of another individual, and a singular provision
is made for the welfare of the young though at
seemingly great expense. Each capsule contains
50 or 60 eggs, but only one embryo is permitted
to develop, and this sets to work to demolish its
brothers and sisters.
VERY large number of
species now to be described
constitute the sub - order
Monotocardia the mol-
lusks that have only one auricle to the heart, a
single gill-plume (the left), one kidney, the nervous
system more concentrated, and mostly with a pro-
boscis.
The Violet-snails (lanthina), of which several
species are found washed upon our western shores,
are not natives, but their shells are so frequently
found in a fresh state, if not tenanted by the living
mollusk, that some general reference to them is
necessary. They are what are termed pelagic
species living entirely at the surface of the sea,
where they feed upon the smaller species of jelly-fishes.
The destruction of Velella in this way led to the
supposition in the eighteenth century that lantkina
'^ecklace-sliells and Winkles
21 I
produced the Velellce, which were seen apparently
issuing from its mouth. For such a mode of life
their shell must be thin and light, and to enable
them to float unnoticed by sea-birds and fishes it is
(lantUna) with its float
I, a bubble about to be joined to the float; c, shell; I, float;
p, foot; t, head
coloured violet, the lower whorls, which are most
exposed from above when the creature floats, being
of n darker tint, whilst the upper whorls may be
white. The mouth of the shell floats uppermost, and
212 Shell Life
to steady the creature in this position it fabricates a
kind of raft by the excretion of slime in which it
imprisons bubbles of air. To the under-surface of
this raft the egg-capsules are attached, and on
examination of these it will usually be found that
those nearest to the animal contain eggs, those in the
middle young with fully formed shells, whilst those
near the farther end are broken and empty, the
young ones having departed. When touched, the
Violet-snail exudes a violet fluid which clouds the
water around. They have no power to rise or sink
at will. At least two species / rotundata and /.
Violet-snail and float side view
comiminis drift to our shores. They have no eyes,
and are sometimes termed the " Blind Snails of the
Sea."
The Wentletraps (Scalaria) are well known not by
reason of our several British species, but because of the
high commercial value attached formerly to the Large
Wentletrap (S. pretiosa) from China. Rumphius
records that in 1701 this shell sold for forty guineas;
fifty-two years later the price had fallen 50 per
cent, and since then there has been so continuous a
slump in Wentletraps that a few shillings are now
sufficient to purchase a good specimen. The shells
are distinct from those of any other of our native
Necklace-shells and Winkles
213
Head of Wentletra
mollusks by reason of the ridges that regularly cross
each whorl. The almost round mouth has a flat,
projecting, and continuous lip. As in many other
shells, the stages of growth are indicated by the lips
successively formed standing up as ridges, but in few
cases do they stand out so prominently
as in this genus. The mouth is closed
by a horny ear - shaped operculum.
The head of the animal is short, but
provided with a retractile proboscis of
a cylindrical shape. The tentacles are
awl-shaped, and at the outer side of their bases the
eyes are situated on short stalks. Like lantliina,
the Wentletrap animal ejects a purple fluid when
molested.
Turton's Wentletrap (8. turtonce) is rather glossy,
and consists of about 15 whorls, crossed by slightly
curved and flattened ridges, of which there
are 12 on the largest whorl. The colour
is light yellowish brown with three spiral
bands of purple-brown, the lowest of which
is visible only on the last whorl ; operculum
dark brown. The length of the shell is
an inch and three-quarters, and it is half
an inch across at the base. It is by no
means a common shell, but it may be found
along the coralline zone on many parts of
our coasts. The Common Wentletrap (8.
communis) is similar to the last, but the ridges are
merely folded back, not flattened, and there are only
9 on the body whorl ; they are also connected from
whorl to whorl, so that they form continuous but
oblique lines from the apex to the base. The spiral
214 Shell Life
bands are not continuous as in 8. turtonce, but broken
into short streaks or mottling. Whorls about 15,
separated from each other. Operculum dark brown.
It attains a length of nearly 2 inches, and its habitat
is similar to that of 8. turtonce.
Trevelyan's Wentletrap (8. trevelyana) is fawn
coloured, thinner than in 8. communis, the white
ridges connected as in that species, but narrower and
more flattened, with a short spur on the upper part ;
there are 14 ridges across the lowest of the 14 or
15 whorls, which are not separated. Operculum
pale brown. The shell seldom exceeds 1 inch in
length. A deep-water species 15 to 100 fathoms.
The Small Wentletrap (8. clathratula) is small, semi-
transparent, white, with thin ribs of regular size.
There are only 12 or 13 whorls, and the lowest of
these bears 18 ridges. Operculum yellow-brown.
Length about half an inch. It occurs sparingly in
the coralline zone all round our islands.
The Aclis-shells (Aclis) are much like those of
Scalaria, but without the transverse ridges on the
whorls. The mouth of the shell is oval and slightly
expanded, the outer lips thickened. The animal is
slender, with a long retractile proboscis, long tentacles
with the eyes at their base, and the square-fronted
foot pushed out in front of the head in walking.
. There are only two native species. The
A Glossy Aclis (A. supra-nitida) is about a
T quarter of an inch in length, white, with or
Glossy without spiral ridges, and the oval mouth
inclining strongly to roundness. The Little
Aclis (A. ciscaris) is only about one-tenth of an inch
in length. It is more slender than the Glossy Aclis,
3{ecklace-shelh and Winkles 2 1 5
and has fine strong spiral ridges. Though agreeing in
colour, the form is different, the base being proportion-
ately narrow, and the whorls fewer. They are both
obtained by dredging, and their range extends down
to about 80 fathoms, but empty shells are often to be
picked out of shell-sand on the shore. Two some-
what similar shells formerly included in this genus
are now known respectively as Pherusa yulsonce and
Cioniscus unicus.
The Necklace-shells (Natica) are so-called because
of the peculiar manner in which their eggs are
arranged in strap-shaped bands which coil into the
form of quoits. The capsules
(each containing a dozen or more
eggs) are connected by a gela-
tinous material, at first flaccid
and sticky, but by the adhesion
and incorporation of sand it
becomes firm. These may fre-
quently be picked up on the shores of sandy bays.
The shells are glossy, almost globular, with a low
blunt spire, and a large ear-shaped mouth. The
animal has a long retractile proboscis, which is
usually concealed beneath a flap of the front of the
foot, which is turned up over the creature's head.
The Naticas prey upon other species, chiefly bivalves,
which they hunt in the sand, and whose shells are
drilled by the proboscis. This important organ and
the head are protected from injury in their passage
through the sand by the frontal flap ; but in con-
sequence of this covering the eyes have become very
small or are altogether wanting.
The Large Necklace-shell (N. catena) is a very
216
Shell Life
globose shell of rather handsome appearance, pale buff-
coloured and polished, the upper side of the whorls
ornamented with a series of dark red
or violet zigzag or V-shaped marks.
The epidermis is retained only within
the umbilicus. There are 7 whorls and
a large deep umbilicus. The operculum
Large Neckiace-sheii j s horn-coloured. The shell ordinarily
(one-fourth nat. size)
measures \\ inch each way, but this
is often increased to 2 inches. It is tolerably
common, between extreme low water and a depth
of 10 fathoms, from the south of
England to the north of Scotland.
The Sordid Necklace-shell (N. sor-
dida) is similar to the last named,
but somewhat smaller and more
deeply, less clearly coloured, more
oval longer than broad and
thicker, without the markings. The
whorls are 5 or 6. The horn-
coloured operculum edged with
white. It frequents sandy shores Life aspect of .v. catena
of a somewhat muddy character in
from 7 to 90 fathoms, from Shetland to Scilly, but
is more local than N. catena, and the individuals far
less numerous.
The Greenland Necklace-shell (N. grcenlcmdica) is
thinner, almost semi-transparent, without gloss,
white, with a cream-coloured epidermis ; whorls 4 or 5.
The umbilicus is narrow, and the operculum thin,
lemon coloured. Its measurement is less than 1 inch
either way. It is a deep-water species, and is dredged
from muddy ground in from 40 to 50 fathoms in
^ecklace-shells and Winkles 217
Shetland, and off the coasts of Yorkshire, North-
umberland, and Durham. The Common Necklace-
shell (N. glaucina) is a pretty little species, plentiful
on sandy shores from low
water to great depths. The
shell is thick and solid,
highly polished ; the colour
varies from white to orange, Common Necklace . shel|
and the markings which
are five spiral lines of V's and zigzags vaiy from
orange to chestnut. There are 6 whorls, and the
spire is blunt. The umbilicus is contracted at the
mouth, and the operculum pale horn coloured. The
length is little more than half an inch.
Montagu's Necklace-shell (iV. montacuti) is the
smallest of the native species. It is more globose
than the Common species, the colour usually fawn,
but varying to buff, often with a whitish band along
the upper part of the 5 or 6 whorls, but free
from other markings. The spire, too, is shorter, the
umbilicus rounder and more open, and the operculum
rather more solid. It occurs at depths between
15 and 90 fathoms where there is a sandy or gravelly
bottom mixed with mud ; all round the Scottish, Irish,
and Manx coasts where these conditions exist, also in
the north of England, reappearing in Devonshire and
Cornwall. The Iceland Necklace-shell (N. islandica)
differs from all the others in its less solid and semi-
transparent character, and by having the spire more
elevated. Beneath the dull yellow epidermis the shell
is white, without markings. There are from 5 to
7 whorls. The umbilicus is small, and the
operculum thin and golden yellow in colour. The
2i 8 Shell Life
average length is about 1 inch, but the breadth is
less than seven-tenths. It is a rare shell, restricted
to the north of these islands in from 7 to 80 fathoms,
but most of the specimens have been taken from the
stomachs of haddocks.
We have seen how the various species of Natica
partially envelop the shell in folds of the foot and
mantle ; in the next species the shell is completely
hidden by the mantle.
The Transparent Marsenia (Marsenia perspicua) is
ear-shaped, with a very small spire, but eleven-
twelfths of the whole consists of the body-whorl,
which is almost flat. It is exceedingly thin and
transparent when fresh, but becomes less clear in
dying and loses a little of its form. The animal,
which is much larger than its shell, varies a good deal
in colour from white to yellow or orange, with spots
and blotches which vary to contrast with the
ground colour. There is a pair of long awl-shaped
tentacles, with black eyes at their base only visible
from below, or when the creature swims inverted at
the surface. The ground colour and the markings
are examples of protective coloration, for the
creature feeds upon Compound Ascidians and its colour
assimilates to that of its food, whilst its markings
resemble the common openings of their colonies. Years
ago Mr. Peach devoted a good deal of time to a study
of this creature, and found that it resorted to patches
of Leptoclinum gelatinosum, as he thought for the sole
purpose of excavating a pit in which to deposit its eggs.
Professor Herdman, however, a few years ago called
attention to the fact that Marsenia fed chiefly upon
Lcptoclinum, and that its colouring was protective.
Necklace-shells and Winkles 219
We have had many opportunities for checking
Herdman's observation, and can fully endorse it.
The gelatinous semi-transparent body of the mollusk
so closely matches the ascidian that it is difficult to
see it, and there is no doubt that the likeness protects
it from those creatures that would prey upon it if
they could see it. It is probable that the creature
and its shell have been greatly modified by its mode
of life. It was necessary at first to hide the shell
beneath the spotted mantle, then it would be
gradually flattened out so that the mollusk's back
did not rise so high above the ascidian, and when the
resemblance between the two creatures had become
sufficiently strong the shell would no longer be
necessary as a protecting shield therefore it would
be reduced to its present filmy texture. It is not a
common species, as it occurs chiefly in deep water
down to 90 fathoms but may be found on the
recess of the spring tides on the vertical faces and
under-sicles of rocks and boulders where the
Leptodlnum colonies are.
The Velvet-shell (Velutina hvviyata). There is a
general resemblance between this mollusk and the
last, but though the flaps of the mantle
are turned over the shell the latter is not
hidden. Its name is due to the character
of the thick pale brown epidermis, which
is distinctly velvety. The animal feeds
upon Alcyonium and other zoophytes, and is found
on stony ground in the laminarian and coralline zones
(from 1 to 50 fathoms) all along our coasts.
The Hairy-Keel Shell (Trichotropis borealis) is a
beautiful little shell with a superficial resemblance to
220 Shell Life
the Sting-winkle (Murex). It has an elevated spire
of 7 whorls, with several spiral ribs or keels
upon which the epidermis develops into thorn-like
points or bristles of a pale brown hue. It has a small
curved umbilicus, and the pear-shaped mouth is closed
by a yellow-brown operculum. The animal is white
or cream coloured speckled with yellow, and has a
short bilobed snout separating the long blunt-tipped
tentacles. The small black eyes are stalked. The
animal lurches from side to side as it Avalks. It is a
northern and local species, its range in Britain
embracing the Dogger Bank to the west of
Scotland, Ireland, and the Shetlands. Its habitat
is in the coralline and deep-sea zones.
The Bonnet-limpets (Capulidw) have the muzzle
extended, the eyes situated on the base of the
tentacles, and but one gill-plume, which is finely
and deeply divided. Roughly speaking the shell is
limpet-shaped, but with considerable difference. Two
genera are represented in this country, each by a single
species. They have been considered by various
authors never to move from the spot to which they
have attached themselves in early life, but judging
from my experience with specimens in captivity, I
regard this as no nearer truth than the similar state-
ment formerly made respecting the Common Limpet.
The Hungarian Cap or Cap of Liberty (Capulus
hungaricus) is shaped much like the cap of Liberty,
the beak or apex being spirally curled back ; semi-
transparent, cream coloured, but the greater part of
the shell is hidden by a coarse epidermis of dirty
pale brown hue, which also hides the radiating ribs.
This epidermis is usually rubbed off the upper end of
Necklace-shells and Winkles 221
the shell, and overlaps the edge of the mouth. The
lines of growth are very prominent, but so irregular
that the shell appears to have
been broken several times and
patched up. They are found from
low water to 100 fathoms, at-
tached to rocks and shells ; they
are particularly fond of oyster
and scallop - beds, where they Hungarian c a
attach themselves to the upper
valves. Their food appears to be both animal and
vegetable. Clark and Alder have described this
species and the next as carrying their spawn, till
hatched, between the muzzle and the forepart of the
foot,
Cup-and-Saucer Limpet (Calyptrcva, ckinensis). In
this species the shell is buckler-shaped or conical, with
the beak in the centre ; lines of growth spiral. The
outside dull greenish or with a violet tinge ; the inside
similarly tinted, but highly polished, with a twisted
plate or diaphragm attached to the
hinder part. It is a local species, found
on the south coast from Milford Haven
westward ; also in the Channel Islands.
It occurs from low water to a depth of
L,m P pet-interior 15 fatllOmS attached to shells Ol' pebbles J
in the former situation the cone is very
low almost flat but on small pebbles it becomes
much more elevated. The pebbles selected for resi-
dence often present a surface scarcely larger than
the mouth of the shell, so that increase in the dia-
meter of the latter gives place to vertical enlargement.
Audouin and Milne Edwards declare that the female
222 Shell Life
retains her egg capsules beneath her foot until they
are hatched. The internal plate of the shell appears
to serve for attaching the animal, and obviates the
development of a very powerful muscle such as is
found in the Common Limpet.
The Periwinkle family (LiUorinid(v) have a solid
spiral few-whorled shell, with a round mouth closed
by a horny operculum. The animal
has a broad extended muzzle, and awl-
shaped tentacles with the eyes at their
single row of teeth base. The under-side of the foot is
of periwinkle'" inai 'ked by a central line, and in gliding
the sole on either side of this line is
advanced alternately. Most of the species are
strictly littoral in their habits, and seldom wander
far below extreme low - water mark ; one of our
native species, indeed, is only covered by the sea at
the periods of very high tides, and when heavy seas
throw their big waves far up the shore. Respira-
tion is effected by means of a single gill -plume,
which is contained in a chamber formed by the
mantle. Their principal food at least is of a vege-
table nature, for the rasping of which they are pro-
vided with a very long radula. The sexes are
distinct; the males smaller than the females. The
relative position of the organs will be seen in this
diagram of a partial dissection.
The Dwarf Winkle (Littorina obtusata) is the
yellow, red, brown, purple, or green shell that is so
abundant on all our beaches. In the empty condition
it is piled up at the base of the rocks after a storm ;
in the living state it will be found in profusion on
the Bladder Wrack (F'ucus vesiculosus), where it very
* , *
TCKTON'S WENTLETRAI- ; 2, 3 COMMON NECKLACE-SHELL ; 4 LARGE NECKXACE-
SHEI.L ; 5 CUI'-AND-SAUCEK LlMl'ET ; 6 HUNGARIAN CA1' ', 7 NfiRITE WlNKLE J
8, 9 ROUGH WINKLE.
^(ecklace-shells and Winkles
223
closely resembles the bladders of that seaweed. The
term dwarf applies to the almost suppression of the
spire, a condition
also indicated by
obtusata, blunted.
There are 5
whorls, but the
first four form a
very small part of
the entire shell.
Occasionally pure
white specimens
may be found, and
frequently it is
banded length-
wise with red-
brown. It
measures about
half an inch
either way. The
Nerite-like
Winkle (L. neri-
toicles} has a de-
cidedly conical
shell, and the last
whorl only accounts for two-thirds of the whole.
The colour is a dark red-brown, paler at the base,
where there is sometimes a yellowish zone. In
height it is a little more than a quarter of an inch,
and in breadth a little less than a quarter. It is
usually found clustered on the sides of rocks above
ordinary high-water mark, where during the period
of neap-tides it must remain dry for days in calm
15
Animal of male Periwinkle, with the shell removed
o, mouth; 6, sexual organ; c, reflexed mantle; d, vent;
e, kidney;/, slime-gland; g, gill; A, heart; m, shell-
muscle; p, foot
224 Shell Life
weather; but the gill-chamber holds sufficient
moisture to enable respiration to proceed.
The Rough Winkle (L. rudis) has a less pointed
spire of from 6 to 9 whorls, of which the last whorl
occupies in the male one-half, and in the female
two-thirds of the whole ; the mouth, too, is much
larger in the female than in the male. The colours
range from white, yellow, and orange, to red, brown,
purple, and black, usually with spiral bands of another
tint, and spiral flattened ribs. The female retains her
eggs until they are hatched, and this is said to be the
reason why this species is not used for food, the
minute shells rendering the parent gritty and
dangerous to the teeth of the eater. It is every-
where plentiful where there are rocks and stony
beaches. It is half an inch across, and about five-
eighths in height. Experiments made by Professor
W. A. Herdman with this species show that it is
capable of living out of water for long periods.
Marked specimens upon the rocks were found not to
have moved within thirty-one consecutive days. It
appears to endure life in the water less than life in
air, and to be undergoing the change of habit from
sea to land that must in past
ages have brought about our
land mollusks.
The Periwinkle or Common
Winkle (L. littorea) comes nearest
to the Rough Winkle, but differs
from it in being twice the size,
with flatter whorls, a longer
and sharper spire, a much slighter suture or channel
between the whorls ; the disproportion in size of the
^{ecklace-shells and Winkles
22$
sexes is not so great in the present species, because
the female does not retain her eggs but deposits them
in masses upon
weeds and rocks.
The colour of the
shell is yellow-
brown, greyish
yellow, or olive,
with red - brown
or dark brown
bands, and flat
spiral ridges.
There are 7 or 8
whorls. The cen-
tral pillar round which the spiral is wound is
always white. Winkles are exceedingly common
below ordinary high- water mark all round our coasts,
and thousands of tons are gathered annually and sent
into the towns to be sold as a delicacy among the
poorer classes.
The Chink-shells constitute the genus Lacuna,
which is represented by four native species. They
are chiefly distinguished from the Winkles by the
fact that the lobe to which the operculum is attached
is large, and ends in a pair of long tentacle-like fila-
ments. The head tentacles are flat and smooth, and
the mouth of the umbilicus is a long slit in the pillar,
whence the names Chink-shell and Lacuna (a fissure).
The shell lacks the stony solidity of the Winkle-
shells, though the animal also feeds upon seaweeds,
but not so much about rocks. Loven has observed
that the animals are coloured to harmonise with the
weeds upon which they feed.
226
Shell Life
The Thick Chink-shell (L. crassior) is rather solid,
opaque, brownish yellow, turreted, with thick epider-
mis ; the spire raised, with blunt tip ; whorls 6 or
7, suture deep ; mouth expanded below, with thin
lip. The fissure is not always present. The animal
is very active, and moves along with a jerking of
opposite sides of the foot alternately. Like the
Winkles it is fond of getting out of the water into
the air. It is rather a local species ; but is widely
distributed, and may be found on small weeds below
Banded Chink-shed, Lacuna, divaricata (enlarged)
ordinary low-water mark where the bottom is sandy.
The shell is half an inch long, and less than a third
in breadth. The Banded Chink-shell (L. divaricata)
is conical, thin, semi - transparent, with
slight spiral lines (also present in L. crassior,
but there hidden by the epidermis). The
colour varies from white to pale brown,
usually with four bands of reddish brown ;
whorls 6, suture not deep. Fissure wide.
The animal is shy and restless, and has the
same awkward mode of progression as L. crassior.
*
i TO 7 DWARF Wi
PA u.i n CHINK-
S^ecklace-shells and 'Winkles 227
The shell is about three-quarters of an inch in length
and one-third in breadth. It is quite abundant on
the weeds at low- water mark and below, on all our
shores.
The Globular Chink -shell (L. puteolus) is rather
solid, glossy, and opaque, the whorls not rounded but
rather angular in the centre (periphery) ;
yellowish white, with or without three
reddish bands, sometimes uniformly dull
reddish brown. Spire scarcely raised
chink-sheii above the body whorl, which includes
four-fifths of the entire bulk of the 3
or 4 whorls. Mouth expanded, with a somewhat
angular base ; fissure wide and deep. It may be
found in numbers feeding on small weeds, such as
Carrageen (Chondrus crispus),
about low - water mark. The
Pallid Chink-shell (L. pallidula)
is almost triangular, greatly ex-
panded in front, thin but opaque,
glossy, of a yellow-green colour ;
epidermis somewhat thick ;
mouth very large. The fissure
in this species is exceedingly Eggs an c d j n k u . n s ^ e f Pallid
large and funnel-shaped, exposing
nearly all the hollow spire. Although widely dis-
tributed along our shores, this species is found chiefly
on the south and west, at low water and for a few
fathoms below it. The eggs are deposited in oval
patches on seaweeds, as shown in our figure, where
also are depicted some aspects of the fry.
HE mollusks considered in
the previous chapter were
marine, many of them lit-
toral species, living on the
rocks that are uncovered for hours each day
when the tide has receded. To protect some from
the evaporation of their fluids in such a situation,
and to preserve others from enemies when swept off
the rocks by rough seas, all those that had distinct
whorled shells had the orifice closed by a door or
operculum. It can be clearly seen how such an
adjunct to the open shell made a transition from
marine to terrestrial life easy. Such a form as
Littorina rudis, that spends weeks above high water,
and is believed to be in the process of changing to a
land-snail, was probably the ancestor of the Kound-
mouthed Snail (Cyclostoma elegans), which is clearly
a marine snail that has been so modified that it lives
Spire-shells and Marsh-snails 229
far inland on the dry chalk-downs as well as keeping
up its connections by living along the coast-lands. A
glance at the figure will show that so far as externals
go it makes out a good case for being classified not
very far from the Winkles. There is the long
proboscis, the same contractile tentacles with eyes at
their base, the longitudinal division of the foot, and
an operculum, only this has become shelly instead of
horny. If we inspected the radula we should find
the number and arrangement of the teeth to agree
with that of the Winkles. But there is one great
difference : instead of the gill-plumes of the Winkles,
aeration of the blood in Cyclostoma takes place in a
chamber formed under the mantle
behind the head, the blood circu-
lating about the living tissues of
this chamber and taking up oxygen
from the air. This arrangement
led to th&Cyclostoma being grouped
until lately with the land and fresh-water snails
that have a closed branchial chamber or lung ; but it
is now recognised that there is a great difference in
the two. It is an exceedingly interesting case, for it
gives a distinct clue to the probable origin of other
land-forms that have got much more modified. It
must not be assumed that Cyclostoma originated in
this country from a Littorina. The genus is a
tropical one, and the probability is that C. elegans
had a southern origin, for it is found in the Canaries,
in Portugal, France, Italy, and Central Germany.
It extends no farther north than Yorkshire and
Donegal.
Its habits are rather singular. A vegetable feeder,
230 Shell Life
its favourite resort is on dry hedge-banks, especially
on chalky soil. In dry weather, also in winter, it
partially buries itself, and in excavating a hole it
uses its proboscis for the removal of earth. When
climbing it is said to use this same organ as a hand
to take hold by. It is very shy, and withdraws into
its shell on the slightest alarm, closing its door and
dropping to the ground. This species and the next
are the only native land - snails that possess the
operculum, and its retention in so highly developed
a condition by the present species may be explained
not only by the nature of its breathing apparatus,
but by reference to its enemies. There is a small
beetle known as Drilus flavescens, and its larva or
grub devotes itself to the destruction of the Round-
mouthed Snail. This is how it effects its fell purpose
in spite of the stony door that shuts out most
enemies. The Drilus-larva waits patiently at the
mouth of the snail's shell until the door opens and
the mollusk comes forth ; then it contrives to cut the
muscular attachment of the operculum, so that when
the snail withdraws the door of its fortress will not
close properly. The Drilus can now complete its
work at leisure ; it enters the shell and consumes
the body of the snail, then changes into the pupal
condition and waits within the shell until it has
attained to its final form as a complete beetle.
There is one other native species included in the
same family, though it forms another genus. This
is the Point-shell (Acicula lineata), whose name
indicates, though it does not accurately describe, its
dimensions. Its form is cylindrical, with a slight
tapering to the upper end ; the whorls 6 or 7,
Spire-shells and Marsh-snails 2 3 i
pale brown, glossy, and semi - transparent. The
animal is much like the Round - mouth, but its
tentacles have not the enlarged tips of that species,
the operculum is horny instead of stony, and fits
into an oval mouth. It is an active little creature,
and may be detected by sharp eyes as it ranges over
the moss, dead leaves, and decaying trees in damp
woods or dry ditches.
The Spire-shells (Rissoa) form one of the most
largely represented genera of British shells, something
like a quarter of a hundred native species being in-
cluded in it. Like Acme they have an elongated
shell, but here the shape is distinctly conical, the last
or body-whorl constituting one-
half to two-thirds of the whole. A
The mouth of the shell is more or rajL
less round, fitted with a horny ^^ ^
* Latticed Thick-lipped
operculum ; there is rarely an Spire-sheii Spire-sheii
umbilicus. The animals are very ca ( ^ a) (B ' an
like Winkles ; the body is slender,
the head produced into a bilobed snout, and the
mouth armed with a pair of jaws and a short radula.
The blunt-tipped tentacles are more or less hairy, and
bear the eyes on small prominences near their base.
The foot is divided down the middle as in the Winkles,
but only half-way. From the hinder extremity of
the lobe to which the operculum is attached, an
appendage like a tentacle is given off from each side,
thus showing a relationship with the Chink-shells
(Lacuna). The shells are all very small, but their
forms are beautiful. The Spire-shells may be found
on seaweeds and Zostera at all depths between high
water and 100 fathoms, according to species. The
232 Shell Life
mollusk has the faculty for spinning invisible threads,
and by this means suspending itself from the weeds
or from the surface of the water. It is impossible
here to give descriptions of the numerous species,
whose names will be found in the list at the end of
the work.
The Red Spire-shell (Barleeia rubra) is distinct
from the Rissoce only in that the opercular lobe is
without appendages and the operculum more solid.
The genus Hydrobia, too, is but little removed from
Rissoa, and less so from Barleeia, with which it
agrees in the absence of tails to the operculum lobe.
The shells are smooth, and just beyond the mouth
there is a chink which appears like the
approach to an umbilicus. We have four
species, of which one, the Laver Spire-shell
(H. ulvce), is partially marine. It feeds in
g re at numbers on the Laver or Sea Lettuce
(Ulva latissima), whether this be between
tide-marks on the seashore, in rock-pools, or in
estuaries, and as far up tidal rivers as the salt water
extends. The other species (H. similis, H. ventrosa,
H. jenkinsii) have taken themselves up the rivers
where the fresh water greatly predominates over the
salt, H. similis being found in the muddy ditches of
the Thames marshes between Greenwich and Wool-
wich, where it has for company so distinctly fresh-
water a form as Bithynia tentaculata and the more
marine Assiminia yrayana. In the small genus
Jeffreysia the minute shells are thin and glossy,
and the operculum has a slight projection from
the straight inner side. J. diaphana occurs on
Delesseria and other seaweeds at low water ; /.
S fire-shells and Marsh-snails 233
opalina on Corallina officinalis and Laminaria ;
J. globularis on Laminaria at Croulin Island,
Skye.
In the genus Bithynia again we come upon two
fresh-water species that have obviously been derived
from marine forms. The name is badly chosen, for it
might indicate that the species inhabit deep water,
whereas streams, ponds, and ditches are their usual
habitat. The figure represents the Common Bithynia
(B. tentaculata) of the natural size. The pale brown
shell is a symmetrical spiral of conic-oval outline,
fairly solid ; the oval mouth closed by a thick shelly
operculum ; umbilicus a narrow chink. The animal
is dark brown or black above, paling to a
dirty grey below, with a long deeply cleft
snout, one branchial plume, and thread-like
diverging tentacles. The prominent black
eyes are not stalked. Leach's Bithynia (B.
Icachii) is a much smaller species (a quarter
of an inch long), with a thinner, semi-
transparent shell, swollen whorls, and a more distinct
umbilicus. The mouth of the shell is nearly round,
and the operculum almost circular. Both species
frequent sluggish rivers and still waters, but whereas
the larger form is widely distributed everywhere in
England, Ireland, and Wales, the smaller is more
local and less abundant. They feed
indifferently on animal and vegetable
substances ; and lay their eggs in bands
on stones and water-plants.
The Sentinel-shells (Assiminea) have
been so-called because their eyes are borne upon long
stalks which give them the power of elevation
234 Shell Life
possessed by some of the Crabs, and are therefore
supposed to be able to keep a sharp look-out as a
sentinel should. These eyestalks are of the same
length as the tentacles, to which they are united.
The shell is very like that of Hydrobia. The Dun
Sentinel (A. grayana) lives in brackish water, coming
up the Thames as far as Greenwich. Another
of these small-sized mollusks is the Skenea
planorbis, whose reddish or tawny shell at
first sight looks like one of the small fresh-
water Flat-coiled Shells (Planorbis), whence
its specific name. The spire is flattened, the four
rounded whorls loosely coiled, the mouth round,
and the spiral operculum horny. In habit it is very
like the Winkles, for though it has been dredged
from a depth of 40 fathoms, and may be taken from
Confervce in the rock-pools, it also feeds upon Lichina
pygmcea, which spends half the day submerged and
the other half dried and shrivelled in the air. A
somewhat similar but less depressed shell is the
White Belted-shell (Adeorbis subcarinatus), which
makes up for small dimensions by having a
long scientific name, as many other small
creatures do. There are only 4 whorls, and
these have 6 strong narrow ridges or keels.
The large mouth does not show quite so even
an outline as in our figure, the ridges usually
producing corresponding indentations of the mouth.
The operculum is thin. There is a large umbilicus.
It is a local species, occurring at various places on
the south and west coasts, and at a few places in
Scotland and Ireland.
The obvious natural relationships of the species
Spire-shells and Marsh-snails
235
considered in this chapter causes us to jump fre-
quently from the seashore to the estuary and the
inland waters. So, also, from considering some of
the smallest of our native species we have now to
mention the largest of the fresh-water gill-bearing
River Snails, ViM\po.ro, ; male on left, fe
ght, young (
mollusks the River Snails ( Vivipara). Like many
others that have been under notice the animal has a
prominent snout, the eyes are placed outside the base
of the tentacles (in this case on short stalks), the
shell has a symmetrical spire, and an oval mouth,
closed by a horny concentric operculum. They are
236
Shell Life
Common River Sna
(one-half nat. size)
herbivorous mollusks. The males are smaller than
the females, because the latter retain their eggs until
they are hatched, and, therefore, require more roomy
whorls for their accommodation. The two native
species are much alike superficially, but nature has
been kind to the tyro in giving them marks that
serve to distinguish them readily.
The Common River Snail (F. vivi-
para) has a thicker and longer
shell, a blunter apex, less swollen
whorls, a less circular mouth, arid
the umbilicus is reduced to a small
narrow chink. Lister's River
Snail ( F. contecta) is a little larger
than the other, has a more circular
mouth, and a distinct and deep though small um-
bilicus. It is a much more local species than the
other. They are both fairly active
animals, and tolerably hardy, for
V. contecta ranges from Finland to
the Pyrenees, and V. vivipara has
been known to produce a batch of
young shortly after having been
thawed out from a temperature of
23 F.
The last of these operculate fresh-
water species we have to glance at
are the so-called Valve-shells (Valvata), of which
we have two so distinct in form that there is no
difficulty in identifying them. The animals are
built much on the same plan as the foregoing the
head drawn out into a long snout, and the eyes at
the base of the tentacles, but in this case on the
Lister's River Sna
(one-half nat. size)
Spire-shells and Marsh-snails 237
inner side. When gliding through the waters the
branchial plume is exserted from beneath the mantle,
and with it a long tentacle-like outgrowth from the
mantle, which is regarded as also employed in
respiration, and thought by some as the other
branchial plume aborted. The sexes are united in
each individual, but only one sex is functionally
active at one time. They inhabit slow and still
fresh waters all over these islands. The
Common Valve-shell (F. piscinalis) has a
blunt spire, and the general form of the
shell is globular, brownish yellow in colour, V a h e n ||
and marked with spiral ridges. The um-
bilicus, though round and deep, is not large. The
Flat Valve-shell (V. cristata) differs in the form of
its greyish shell, which is always flat, like that of a
Planorbis, and the animal has a smaller snout and
stouter tentacles. The umbilicus, too, is proportion-
ately larger and more open.
'E are back again upon the
seashore seeking for what
Borlase nearly one hundred
and fifty years ago called
the Small Needle -whelk
(Bittium retwulatuni), a name we believe not
in use among the folks along our coasts, who usually
lump a large number of species together under a
kind of generic title, according to size or habit.
Thus these Horn-shells (Bittium, and Ceritkium),
small Nassas, Pheasant-shells, Necklace-shells, and
others, are all known along the Cornish coast
as " Shillifillies." In the Horn - shells there is a
long pyramidal spire of many whorls ornamented
with little bosses in spiral lines, a small mouth with
a little groove on its lower margin, a horny operculum,
and no umbilicus. The animal is much like those
last described in the previous chapter, but the
branchial siphon is merely a short fold of the mantle,
J i' })
4
4
5
13
J
14
2 EUROPEAN COWRY ; 3 SHALL NEEDLE-WHEI.K ; 4 POLISHED EULIMA ; 5 DISTORTED
EUI.I.MA ; 6 AWL-SHAVED EULIMA; 7 AUGER-SHELL; 8 PRICKLY SPINDLE;
9 LEAST WHELK; 10 RIBBED SPINDLE; n SMALL STING-WINKLE;
12 NETTED DOG-WHELK ; 13, 14 THICK-LIPPED DOG-WHELK.
Cowry and Pyramid-shells 239
the tentacles are awl-shaped, and the eyes are placed
on little prominences at their outer base. The sexes
are distinct. The Common species,
B. reticulatum, figured here, is about
half an inch long, of a reddish-brown
colour. It feeds upon decaying
animal and vegetable matter, and
abounds on all our coasts between
half-tide and about 15 fathoms. The
Reversed Horn-shell (Triforis per-
versa) is a smaller shell with the spiral turned in the
opposite direction. B. reticulatum, like most spiral
shells, has the open mouth on the right hand of the
observer when the shell is held with the spire upwards ;
in T. perversa the mouth is to the left hand. It is
by no means so plentiful as B. reticulatum, and is
found chiefly on our southern and western shores, in
the Channel Islands, and all round Ireland. It is
found sparingly in Scotland, the Orkneys, and Shet-
land. Its range is from low water to about 20
fathoms. The Obelisk-shell (Lovenella metula) is a
third species, of whitish hue, about three-quarters of
an inch long, found rarely on the Shetland fishing
banks in from 45 to 96 fathoms.
Another group of Horn-shells is placed in a separate
genus Cerithiopsis, that is having a likeness to
Cerithium, and these are chiefly distinguished by
the groove at the base of the mouth being developed
into a distinct though short canal, which is lined by
the mantle tube or branchial siphon. The British
species are C. tubercularis, G. barleei, C. pulchella,
G. metaxce, G. concatenata, and G. costnlcAca.
The only example we have of the Screw-shells
16
2 4
Shell Life
Auger-shell
(two-thirds nat :
(Turritella) is the one to which Pennant gave the
name of the Auger (T. communis), on account of its
resemblance to that boring implement. It is a giant
compared with the little Horn-
shells. The whorls are spirally
ridged, the mouth comparatively
small and round, though with a
suggestion of squarishness, and
without a canal or groove. The
operculum is round and horny.
The mantle is fringed with a
triple row of fine filaments. As
the new whorls increase in size to
accommodate the growing animal
the older whorls at the top of the
spire, being too narrow for occupation, are partitioned
off by the deposit of shell internally. It occurs on
all our shores above sand and mud in from 3 to 100
fathoms.
We have just mentioned how the owner of an old
house shuts off the rooms that are no longer large
enough for use, more spacious apartments having
been erected. Some other species having thus
partitioned off the old from the new, deliberately
knock the older portion against stones in order to
break it off; in other cases the making of
the dividing wall appears to cause the older
part to perish. Shells that have undergone
this process are said to be decollated.
Perhaps the case of the Blind-shell (Ccecum
trachea) is still more remarkable, as the entire
appearance of the shell is altered by the conduct
of the animal. It begins life with a shell coiled
Cowry and Pyramid-shells 241
flat (discoid), but after a time the new portions are
added in almost a straight line ; then the animal
constructs a conical division across the interior to
separate the straight portion from the spiral, which
soon falls off. Later another division is made in
order to get rid of a portion that is too narrow. So
that we have here a creature beginning life with a
spiral shell, and arriving at maturity with one of a
cylindrical character like a Tooth-shell (Dentalium},
except that the exterior of this is marked off into
rings whilst that is plain. The ringed appearance
accounts for its specific name trachea as recalling the
structure of the windpipe. The round opening of
the brown shell is closed by a flat brown operculum.
It may be found in fair abundance in water from
15 to 50 fathoms deep on the coasts of Dorset, Devon,
Cornwall, Wales, Guernsey, the Clyde district, Bantry,
and Galway. The animal is extremely active, but
not so agile as that of the minute Smooth Blind-shell
(C. glabrum), which has a thin, smooth transparent
white shell closed by a convex operculum. It is
found all round these islands between the depths of
15 and 50 fathoms.
The Pelican's-foot (Clienopus pes-pelicani) when
fully developed brings to
mind the Strombs and
Wing-shells of the tropics,
and it is interesting to note
how easily this form may
be produced from a shell of
entirely different appear-
ance. In earlier life the shell is shaped like the
Auger-shell (Turritella), but by successive additions
2 4 2
Shell Life
made to the lip the latter expands into a broad
flap with five triangular processes, each grooved
beneath. There are three thick spiral ribs which
are more or less broken into tubercles. The colour
is yellowish - white tinged with brown, and the
mouth is closed by a pointed operculum. The
animal is of similar structure to those we have
been recently considering : the foot continued for-
ward in advance of the head ; the long snout and
awl-shaped tentacles, with the small black eyes on
little footstalks at their base. It is cream coloured,
mottled with purplish brown and flecked with yellow
and white, the whole effect being that of the sand
upon which it glides awkwardly in the coralline zone
(15 to 50 fathoms), as though its shell were an
encumbrance to it. The Shetland Pelican's - foot
Cowry and Pyramid-shells 243
(C. macandreai) is a much smaller and more delicate
species, found only on muddy sand off Shetland in
from 60 to 80 fathoms of water. The five points
from the mouth of the shell are relatively longer and
more distinct, the one that is nearest the spire often
exceeding it in length and running parallel with it.
The colour is paler, so is that of the animal.
A more striking object-lesson in the evolution of
shell - structure is afforded by the three British
members of the Cowry family (Cyprceidce), each of
them representing a separate genus. In all of them
the mantle is furnished with a pair of large side-lobes
which fold over the shell and almost meet above it.
The mouth of the shell is mostly as long as the shell,
and is not closed by an operculum. The animal has
a short muzzle, a broad foot with a squarish front,
and a long siphon. They are carnivorous, feeding
upon zoophytes, etc. Of these three forms the
Smooth Margin-shell (Erato lew is) best illustrates
our meaning. It will be seen that
the body-whorl is three or four times
longer than the remainder of the
shell, and that the mouth is almost
as long as this whorl. The lip of . Ma k rgin -' he "T,
& . * from above and below
this is at first quite thin and sharp-
edged ; then it is turned in a little
but still has a plain edge, but after-
wards it is considerably thickened
and becomes toothed on the inner
margin. Now the animal which
Margin-shell and anima! o
is of a lively disposition does
not permit us to see much of this white shell when
he is on active service, for the mantle-lobes are
244 Shell Life
thrown well up over it, and only a narrow streak of
the shell shows between. The shell is little less than
half an inch in length, and occurs locally all round
our islands on sandy ground in from 12 to 85
fathoms. The white foot is speckled with orange,
pink, and black, to harmonise with this ground, whilst
the mantle-lobes are dotted with purple-brown marks
and studded with pale yellow tubercles in imitation
of the zoophytes on which it feeds.
The Poached Egg (Ovula patula) has a mouth that
is much longer than the shell-proper, and it appears
to be all body-whorl. But
if we look again at the
Margin-shell and imagine
^ the outer lip extended to a
Poached Egg . .,
greater length than the
spire, the result would be spindle-shaped, much like
the shell of the Poached Egg when freed from the
mantle-lobes. This shell is thin, glossy,
and almost transparent, whitish with a
tendency towards yellow. Young speci-
mens exhibit a brief spire within the canal
formed by the extension of the outer lip
above, but the adult shell is of the form
shown in this figure. The animal is yellow-
ish white tinged with brown ; the mantle-
lobes, which sometimes completely cover
the shell, are marked with brown transverse lines
and small spots. It feeds upon the zoophyte Tubu-
laria indivisa, and lives among the colonies of its
victims, the brown stripes of the mantle-lobes helping
to disguise it from its own enemies by assimilation
to the clustered tubes. Its distribution is not general,
Cowry and Pyramid-shells
Young
shell of
Cowry
but restricted to Dorset, Devon, Cornwall, Guernsey,
Sark, and a few places on the Irish coast, in the
coralline zone.
The shell of the beautiful though common European
Cowry (Cyprcea europcea) undergoes a similar change.
At first it is a spired shell, though the spire ^^
is very short ; the outer lip is thin and sharp-
edged, but as it grows this turns in, thickens,
and so reduces the opening considerably. The
difference between the young and the adult
Cowry shells is so great that the naturalists of a few
generations back classed them as belonging to distinct
species. When the identity of the
animals was proved it was believed
that the earlier was abandoned
when it got too small, and a new
one of a different pattern made
to shelter the more adult animal.
The animal varies in colour from
yellow to pink or brown, but most frequently it is
orange. The mantle-lobes, which are covered with
yellow or white raised
points, and red or purple
spots, well cover the shell.
The ground colour of the
shell is white, but in half-
grown individuals this is
crossed by transverse lines of deep flesh tint. In
old specimens the white spaces between these lines
become elevated into ridges which are continuous
with the ribs that protect the mouth. That part of
the shell where the mantle-lobes meet is often marked
with three dark brown spots, of which the central one
European Cowry
from above and belov
European Cowry
246
Shell Life
is the largest and the least sharply defined, but plain
specimens are far more plentiful. The animal is very
active, but also shy, for it rapidly withdraws into its
shell on very slight alarm. The old English form of
the name was Gowry. On some parts of the coast
it is the Nun, in others the Stick-farthing.
Atlanta peroni (magnified)
Between the Cowries and the Naked Tongues
(GymnoglosscC) there comes a group of sea-snails who
have become specially modified for a free-swimming
life in the open ocean. The foot, instead of being
Cowry and Pyramid-shells 247
flat for crawling, as in those that crawl upon rocks
or weeds, is developed into fin -like expansions.
With these they swim in an inverted position at the
surface. The shell is not present, or is very small, in
one family (Pterotrachceidce) ; in another (Atlantidce)
it is spiral, and sufficient to entirely accommodate
the animal, which shuts itself in with an operculum.
Both shell and animal are perfectly translucent, so
that the internal organisation is clear without
dissection. These creatures had not been regarded
as coming within the British area, though they
swarm in the warmer parts of the Atlantic, as
well as in the Indian and Pacific Oceans ; but in
September 1888 Professor M'Intosh took in the waters
of St. Andrews Bay " a small transparent univalve,
like a finely fashioned shell of glass, containing its
inhabitant." It measured about one-twelfth of an
inch, and was probably a young example. It was
evidently a species of Atlanta, nearly allied to that
figured, but having a flat margin instead of the keel
that is present in Atlanta peroni. Such a capture
is of great interest, for hitherto these creatures were
considered to exist only in more genial seaa
EFORE describing the creatures
whose names stand as the title
of this chapter, we must glance
at a couple of orders collectively
known as the Gymnoglossa, or
Naked Tongues, from the fact that the radula (as
well as the jaws) is absent. Their true position in
the systems of classification is still a matter of
contention among the " doctors who differ," but they
appear to be closely allied to forms such as Rissoa
and Hydrobia, and to have lost their teeth owing
to a very distinct change of habit many of them
being parasites. The mouth is developed into a
proboscis, used in the parasitic forms for sucking
the juices of the host.
The Eulima-shells (Eulima) consist of half a dozen
native species with polished awl-shaped semi-trans-
parent shells that taper to a very fine point, but as
the animal in growing has to vacate the older
Whelks and Conelets 249
portion the tip of the spire is frequently broken off.
The mouth of the shell is oval, closed with a horny
operculum, and the outer lip thickened inside. The
animal has a foot whose broad front extends far in
advance of the head, which is kept under shelter
though it shows through the shell, as seen in the
figure. The siphonal fold of the mantle is very
rudimentary, and the eyes are behind the base of the
tentacles, which are united at their origin.
The Polished Eulima (E. polita) has a highly
polished shell resembling ivory, about three-quarters
of an inch in length. The animal is also
white, but streaked and tinged with yellow ;
the snout marked with a golden V, the black
eyes ringed with yellow. Unlike its fellows,
this species is not parasitic, yet it lacks a
radula just as much as they do. This appears
to point to the fact that the original species of
Eulima was a parasite who had no use for
a radula and exchanged it for a proboscis
through which fluids and soft food could be drawn ;
but that E. polita on giving up the parasitic ways of
its ancestors has not found the need for teeth. The
Intermediate Eulima (E. intermedia) is not quite so
large, more spindle-shaped, semi-transparent, and less
distinctly white ; and the animal is without the
V-mark on the snout. The Distorted Eulima (E.
philippi) owes its name to the curved spire of the
slender, nearly transparent shell, which is less than a
quarter-inch in length. The Awl-shaped Eulima (E.
siibulata) has an awl-shaped, semi-transparent thin
shell, half an inch long, with three pairs of spiral
tawny bands. The Two-lined Eulima (E. bilineata)
250 Shell Life
is very similar to the last, but little more than a
quarter of an inch long and with only two of the
spiral bands. Most of these Eulimas attach them-
selves to the shells of bivalves, the opercula of
gasteropods, or to the interior and exterior of the Sea
Cucumbers (Holotliuria).
The Urchin Snail (Stilifer turtoni), of which we
have but one species, agrees with Eulima in having
no teeth. It is, however, housed in a shell of
different shape, the body - whorl being large and
broad, the greater part of the spire above being so
slender and cylindrical that it has suggested the
Greek stylus. It differs from Eulima again in
having no operculum. The head of the animal is
snout-like and ends in a suctorial mouth. The
tentacles are cylindrical, and the mantle-edges turn
up and overlap the margins of the shell. This
creature is found only on and among the spines of
Sea Urchins, where it appears to feed upon the
excreta of the Eckinis.
The Pyramid-shells (Odostomia) are well repre-
sented on our shores by a score of species. The
shells are all small, conical or awl-shaped,
smooth or spirally grooved, with the apex
coiled the reverse way (sinistral) to the
greater part of the shell, and the mouth with
y sh,~ a tooth-like projection on the inner lip hence
the name Odostomia = tooth - mouth. The
animal is very like Eulima. The proboscis is only
protruded for the purpose of feeding, which appears
to be at the expense of the jelly-like polyps and
sponges whose softer slime-like portions they can
obtain by suction. Some of them appear to subsist
Whelks and Conelets 251
upon the excreta of other mollusks, the Pallid
Pyramid (0. pallida) being frequently found on
Pectens near the excretory outlet ; others are found
under clusters of mussels, on the opercula of other
gasteropods, and at the base of- seaweeds. As in
the case of other parasitic mollusks the shell is
white or nearly so. Space will not allow of an
enumeration of the species in the body of the work,
but a list of the British species will be found in the
Appendix. Jeffreys included in the genus the species
often separated to form the genera Turbonilla and
Eulimella. The genus Turbonilla consists of a
dozen species distinguished by having the central
pillar straight (instead of curved as in Odostomia)
and in most cases without the tooth-like
projection. The shell, too, is more elongated,
and the whorls have ribs running across them,'
as shown in the figure of the Staircase
Pyramid (T. scalaris). The six species com-
prised in the genus Eulimella agree with
Turbonilla in the elongated shell with its
straight and seldom-toothed pillar, but it is in this
case free from ribs of any sort and is polished.
The remaining families to be mentioned in this
chapter are grouped together under the name of
Rachiglossa, on account of an agreement in the
disposition of the teeth on the radula. Instead of
there being a large number in each row, there are
here only three ; but each tooth has its front edge
broken into a number of long sharp points, varying
with each family. The proboscis is long, but can be
completely retracted. In the type family, Muircidcv,
the radula is contained in the proboscis, and its
252 Shell Life
central teeth have three or more strong cutting
points, or cusps, whilst the side teeth are plain. It is
to the skilful manipulation of these
central teeth that those neat round
holes in bivalve shells are due, the
members of this family being mostly
carnivorous. A further character of
these mollusks is seen in the shells,
the mouth running off into a spout,
as shown more clearly in the figure
of the Ribbed Spindle-shell (Trophon
truncatus}. This spout is for the
accommodation of the siphonal fold of the mantle,
and is commonly referred to in handbooks as the
anterior canal Through the siphon fresh
supplies of water are drawn into the
branchiae. It is worthy of note that as a
rule (to which there are several notable
exceptions) this form of shell and siphon
indicates carnivorous propensities, and the
reason for its existence may be found in the
habits of the creature. Much of the food
of these mollusks is tainted, often putrid ; and whilst
the mouth is immersed in such a pabulum it would
clearly not serve the purpose of respiration to draw
in water from the immediate neighbourhood. The
long siphon is extended to one side, or over the top
of the shell, and the water taken in from as remote a
point as possible.
The Little Spindle-shells ( Troplto n) are represented
by three species, of whelk-like form, all being about
two-thirds of an inch long. The Prickly Spindle-
shell (T. muricatus) is slender, dull, the whorls
Whelks and Conekts 253
crossed by swollen, sometimes prickly ribs, which are
broken by a series of spiral channels. The colouring
is a flesh tint with touches of reddish brown. The
mouth is small and ends in a long anterior canal.
The operculum is pear-shaped, with the nucleus at
the narrow end. It has been found chiefly on the
shores of Devon, Cornwall, and Guernsey, in the Isle
of Man, Tenby, Dublin Bay, Cork, etc., in soft ground
between 15 and 50 fathoms. The Ribbed Spindle-
shell (T. truncatus) is broader, slightly more glossy,
and paler, the ribs not broken into tubercles by
the spiral grooves. The upper part of the spire is
smooth and polished, the mouth oval and the canal
short. It affects hard ground from 2 to 50 fathoms
deep, on the east coast, around Scotland, south and
east Ireland, and the Isle of Man. The Berwick
Spindle - shell (T. barvicensis) is more like the
Prickly Spindle but broader, much more glossy, the
whorls crossed by fewer but more prominent, almost
toothed, ribs. The cusps on these ridges are stronger
above, so that the top of the whorl appears to be
encircled by spires. The colour is white. This is a
more northern form, occurring on stony ground from
low water to 50 fathoms on our northern coasts,
coming only as far south as Yorkshire and North-
umberland.
The Sting- winkles (Ocinebra) have the same form
of shell, but it is disguised by the ribs and great
thickening of the lip from time to time. What are
known as varices or " growth lines " really represent
periods of comparative rest from shell production.
At least, the shell is not enlarged internally, but only
thickened at its mouth. These are, of course, the
254 Shell Life
same as we have described as ribs crossing the whorls
in the case of Lachesis, Trophon, and others, but
in Ocinebra erinacea they are more varicose. In
addition there are several spiral ridges running from
the mouth to the apex, and in crossing the varices
they produce that rugged appearance so characteristic
of the species. A figure is given on page 252. The
animal is yellowish, mottled with white. It is found
chiefly on the southern and western coasts, including
Wales, and all round Ireland. It inhabits rough
ground from a little below low-water mark to about
30 fathoms. It is one of the great enemies of the
oyster, boring neat round holes in the upper valve of
young oysters and so gaining admittance. It is from
this nefarious practice that the fishermen interested
in oyster-beds have called it the Sting-winkle, its
" sting " being the proboscis with its boring implement.
Like the Murex trunculus so well known to the
ancients, and like Purpura, the Sting- winkle carries
about a small quantity of fluid capable of dying
fabrics violet or purple, and which is probably ejected
in the water for defensive purposes. The shell
attains a length of about 2^ inches. The triangular
egg-capsules, each containing from a dozen to twenty
eggs, are deposited separately but in little groups.
The Small Sting - winkle (0. aciculata) is similar
in appearance, but of a dark red-brown colour,
with more numerous spiral ridges, and only about
half an inch in length. The animal is bright red,
sometimes flecked with yellow. It has been found
only in the Channel Islands, where it is moderately
plentiful.
The Purple (Purpura lapillus), commonly known
Whelks and Conekts 255
as Dog-winkle, and in Ireland as Horse-winkle, is one
of the commonest of marine snails. It may be found
in abundance high and dry on the rocks after the
recess of the tide, where, like the Rough Winkle, it
appears to enjoy a prolonged air-bath. Such a habit
should expose it to grave dangers from shore-birds,
but its shell is thick and stony, and in some places it
appears even to have developed something like pro-
tective coloration, but whether the cases adduced would
be sufficient to deceive birds is open to question. Its
colour is a more or less pure white, spirally banded
with orange, red-brown, or brown ; but the propor-
tions and intensity of these hues, as well
as the sculpturing of the shell, varies
greatly. The Rev. A. H. Cooke, M.A., in
the Cambridge Natural History, remarks
that " in many cases the variations may
be shown to bear a direct relation to the
manner of life. Forms occurring in very
exposed situations, e.q. Land's End, outer Purple '
Dog-winkle
rocks of the Scilly Islands, coasts of north
Devon and Yorkshire, are stunted, with a short spire
and relatively large mouth, the latter being developed
in order to increase the power of adherence to the
rock, and consequently of resistance to wave force.
On the other hand, shells occurring in sheltered
situations, estuaries, narrow straits, or even on open
coasts where there is plenty of shelter from the
waves, are comparatively of great size, with a well-
developed produced spire, and a mouth small in
proportion to the area of shell surface." The same
author also thinks that in some places (Newquay,
Cornwall, for example) the spiral bands of white and
17
256 Shell Life
colour agree with the veined rocks to which the
Purple clings. In this connection it is interesting to
note that Linnaeus must have been struck by the
pebble-like appearance often assumed by this species,
for he called it lapillus (a little stone or pebble).
As in the case of the Periwinkle, already referred to,
this stoniness has relation to the hard knocks littoral
species experience in stormy weather, when they may
be dashed off the rocks and churned up among actual
stones.
The animal is of the pattern usual among the
family, yellowish in colour, more or less tinged with
brown. It attacks limpets in much the same manner
as that adopted by the Sting- winkle ; but its favourite
food is the Mussel, whose shell can be perforated much
more rapidly than that of the Limpet. According to
Spence Bate, a mussel-shell keeps the enterprising
Purple busy for a couple of days, and then it has
the reward of its patience in the succulent flesh of
the bivalve. But it must not be supposed that the
Purple has its own way entirely in this matter of
dainty feeding; it has a Nemesis in the form of a
Starfish who is also fond of Mussel. The Starfish
may be poetically regarded as taking revenge for the
Purple's depredations on the mussel-beds. The Star-
fish has no means of forcing open the Purple shell as
he does with the Oyster, but silently and slowly he
creeps to a spot where several Purples are within
reach of his long fingers, and laying hold of them
with the delicate suckers of his under-side he brings
them all beneath his central mouth. Then his
stomach is turned inside out and envelops the Purples,
which are dissolved out of their shells, in spite of the
Whelks and Conelets 257
protecting operculum, by the powerful digestive fluid
of the Star. The yellow egg-capsules of the Purple
are very common objects on rock-ledges;
each one contains from 20 to 40 embryos.
M. Cailliaud declared not only that these
are hatched by the parent, but that the
father and the mother take turns to pro- <f g fhe a pu U rp!o
tect and incubate them. This, however,
may be dismissed as " embroidery " not warranted by
the observations of others, and in absolute opposition
to all we know of the habits and customs of those
mollusks that deposit eggs.
The Dog-whelks (Nass(t) are almost as well known
as the Purples, though their habits are different. The
animal may be distinguished from those of neighbour-
ing genera by the " tail " of the foot, which, instead of
ending in a blunt point, becomes divided and finishes
like a pair of tentacles, as shown in the figure of the
Netted Dog-whelk (N. reticulata). This species is
common on sandy shores all round our islands,
where it devours the bait on the
" spillers " of the flat-fisher and also
that in the lobster-pots. The animal
is got up to resemble the sand in its
colour and markings; the ground
colour is yellowish, over which is
thickly sprinkled dots of white and
various browns a pepper-and-salt
mixture that assimilates closely to
Netted Dog-whelk ,, . -.. , *
the sand. When at rest, and on the
exposure of the shore by the receding tide, the shell
is half-buried in the sand. It is strongly ribbed in
two directions, so that a network pattern is produced
258 Shell Life
by the depressions, but the prominences are so nearly
equal in height that it does not present the bold
aspect of some allied species. The colour
is a dull buff tinged with brown, except
the inner and outer lips, which are white,
highly polished, the outer lip with 12
or 14 tooth-like elevations. The egg-
capsules in this case are flattened oval
pouches, attached by a short footstalk to
the fronds of the Grass-wrack (Zostera).
Netted Full-sized specimens measure about 11
Dog-whelk
inch.
The Thick-lipped Dog-whelk (N. incrassata) is
little more than half an inch long, entirely different
in appearance from the Netted species, the ridges
across the whorls being stronger than those having a
spiral direction, the colours being brighter, and the
outer lip being greatly swollen, white, with an almost
black spot in the canal. The colour varies from
white or flesh colour to a pale warm brown, the
whitish specimens being more or less striped or
mottled with brown. It is equally common with the
last species all round our islands, but affects stony
ground, at all depths between low water and 145
fathoms. The Dwarf Dog-whelk (N. pygmcea) is a
less solid shell, the spiral ridges fewer and finer,
the colour always yellowish white tinged with
tawny, the outer lip even more swollen, white, but
brown within, and therefore showing no spot in
the canal. It does not attain the length of half an
inch, and it is much more restricted in its range.
It has been found in the coralline zone on the
coasts of Dorset, Devon, and Cornwall, also at
Whelks and Conelets 259
Connemara, Baniry Bay, Dublin Bay, and County
Antrim.
The Spindle-shells (Chrysodomus) are well repre-
sented in our seas by seven species. With the Whelks
(Buccinum) they constitute the British section of the
family Buccinidcv. This family is distinguished by
having the central tooth of the radula armed with
from 5 to 7 stout points, and the lateral teeth
with 2 or 3 cusps. They have a rather long siphon,
eyes at the outer base of the tentacles, a thick
spindle - shaped shell closed by a small horny oper-
culum. The Bed Whelk or Buckie (C. antiqua)
has a solid yellowish or reddish shell with dull sur-
face marked with slight spiral ridges. The thin
epidermis has nearly always worn away. It occurs
nearly all round our islands, in the coralline zone,
but in Shetland it comes into the laminarian zone
and descends into deep water below the coralline.
The animal is largely used as bait in the long-line
fishery, and as human food. Fleming tells us how
the cottagers of Shetland make use of the shell as an
elegant lamp by suspending it horizontally, filling it
with oil, and allowing a wick to lie in the canal,
the lighted portion protruding. It owes its name
antiqua to the fact that it is plentiful as a fossil in
the Crag, where also the " reversed " form with the
left-handed spiral is found. Ordinary specimens are
between 3 and 4 inches in length, with a breadth of
2 inches, but occasionally they may be found as long
as 8 inches. The eggs are deposited enclosed in
pouch-like capsules, flat on the lower, convex on the
upper side, and these are attached one to another
in overlapping clusters. The Wide-mouthed Whelk
260 Shell Life
(0. norvegica) is a paler shell with a larger body-
whorl and mouth, the outer lip expanding outwards,
and the canal short. It is only found on some of our
northern shores, as those of Yorkshire, Durham, and
Northumberland, below the coralline zone. Its
average length is 4|- inches. The egg-capsules are
not clustered, but attached singly by the flat side,
chiefly to the interior of empty bivalves.
Turton's Spindle-shell (C. turtoni), or Long-neck,
is somewhat larger and more solid than the last,
more nearly white, tinged with purple, and further
differing from it in having a longer spire, flatter
whorls, and stronger spiral - ridges ; moreover, the
operculum is a long triangle with rounded base,
whereas in C. norvegica it is more rhomb-shaped,
with three of the corners rounded. The Slender
Spindle - shell (C. gracilis) is more truly spindle-
shaped. Beneath the yellowish epidermis, which is
usually partly gone, the shell is
white or nearly so, with some
approach to a glossy surface ;
and the operculum is rather
solid and triangular-oblong. Its
length is between 3 and 4 inches,
with a breadth of 1| to H
inches. Although found in from
20 to 145 fathoms all round our
islands, it is a rare shell in the
south and a common one in the
north. The capsules are solitary,
Slender Spindle-shell ,., , F , , \
like those of the last named. A
similar but smaller species (C. propinquus) may be
distinguished by its " more delicate texture, finer and
Whelks and Conekts 261
closer sculpture, longer, turreted, and regularly taper-
ing spire, deeper suture, hispid epidermis, less abrupt
curvature of the canal, and especially the symmetrical
apex" (Jeffreys). It occurs on mud and sand in
deep water (15 to 80 fathoms) from Yorkshire to
Shetland. The Northern Spindle - shell (Troschelia
berniciensis) is distinguished by its spiral ridges
which are alternately large and small, being crossed
by striae which produce a network especially notice-
able on the upper whorls. The thick brown epidermis
rises into little points along the spiral ridges, which
give a bristly appearance to the shell. The ear-
shaped operculum is rather thin. The shell, which
is about 3 inches in length, is found on soft ground
in the coralline zone on the coasts of Yorkshire and
Northumberland.
The White Whelk (Liomesus dalei) is a very rare
species in our waters, only a few well-authenticated
captures being on record. The shell is oval, spirally
striated, of ivory-whiteness, covered by a filmy yellow
epidermis ; the spire short and blunt, the canal short
and open, and the operculum triangular with its
nucleus placed on the inner base of the mouth. The
teeth on the radula are without the cusps usual in
the family. It has been recorded from County Cork
and the west coast of Ireland (100 fathoms) ; from the
neighbourhood of the Dogger Bank (40 to 50 fathoms),
Aberdeenshire and Shetland (72 to 87 fathoms).
In the true Whelks (Buccinum) the spindle-shape
is quite lost and the shell is relatively broader in
proportion to its length. The Common Whelk
(B. undatum) is so well known that no detailed
description is necessary. The whorls are crossed by
262 Shell Life
curved broad ribs which are traversed by the spiral
lines. This species is widely and plentifully distri-
buted all round our
islands, on all kinds
of bottoms and at all
depths of water. A
creature found under
so many conditions
should show a great
amount of variation,
if there is anything
in the views already
set forth in these
pages, in which it has
been claimed that the form and substance of the shell
has relation to the habitat. Littoral species, we have
pointed out, like the Winkles and the Purple have
thick solid shells to withstand the hammering of the
waves and the pounding of stones ; and all those
individuals who do not develop a thick shell will be
broken up and destroyed, leaving only those with
thick shells to survive and perpetuate the species.
What is true of the species living under one set of
conditions differing from another species living under
other conditions, applies also to the individuals of a
species that yet live under varying conditions of
depth, climate, and surroundings. The var. litoralis
lives among stones and on mud in the upper part of
the laminarian zone, and consequently is less elongated,
broader, more strongly ribbed than the VBX.flexuosa
that dwells on hard ground in the coralline zone in
the Hebrides, etc. Then the var. paupercula owes
its dwarfed and puny proportions to living in brackish
Whelks and Conelets 263
water, where probably food is not so plentiful. The
var. striata lives in the coralline zone of England,
Ireland, and Wales, where
the waters are quieter and
the rocks less liable to
being: set spinning ; so the
, i i n L i i i Row of teeth of Common Whelk
thick shell is not developed
and the strengthening ribs have to be carefully
looked for. The var. pelayica lives out in the deep
waters of the Dogger Bank, and produces
a thin shell of twice the normal dimen-
sions ; with a longer spire and a smaller
mouth. The Whelk is also given to the
production of abnormal forms to which
the general term monstrosity is ap-
plied. Among these abnormal forms
are included reversed spiral, keeled
whorls, the spire or the body - whorl
greatly lengthened, and the duplication
opercula of wheik or triplication of the operculum. Double
^ddoubie rm OpfeTCula are fairly numerous on the
shores of Kent and Sussex.
The egg -capsules of the Whelk are clustered
together in masses that vary in form according to the
nature of their base. They ap-
pear to have given some trouble
to naturalists, for John Ellis, the
historian of the " Corallines," in-
cluded them in his book as a
species of Alcyonium. Dr. John- c , usier of Egg caps
ston later said they resembled
the nest of a humble-bee, and yet more recently
Dr. J. G. Jeffreys described the cartilaginous pouches
264 Shell Life
as being "of the size and shape of a large split-
pea." The split - pea he had in mind must have
been abnormally large. Each capsule contains
several hundred eggs, but when a few have hatched
they begin to feed on the unhatched and on their
less robust fellow-fry, so that it is computed that
only about a score of young Whelks issue from
each pouch. A common form of the capsule-cluster
is shown in our figure, but sometimes it assumes a
cylindrical form. Besides their extensive use for
bait, Whelks form no inconsiderable item in the food
supplies of the poorer classes, and they are in a sense
trapped for this purpose, carrion being buried under
a heap of stones or in a basket. The Whelks have a
keen scent, and soon finding out the whereabouts of
the bait they swarm over it. They are also caught
by dredging for them. Five-and-thirty years ago
when a Bill for the extension of the Whitstable
Oyster-fishery was before Parliament, it was stated
in evidence before a select committee that the Whelk-
fishery on part of Whitstable Bay yielded a revenue
of 12,000 per annum the Whelks being used partly
for London's food, and partly for baiting the lines of
the cod-fishers.
The Shetland Whelk (B. humphreysianum) is a
small species, with a shell of more oval shape, less
than 2 inches long, thin, somewhat glossy, the
sculpturing not being visible to the unassisted eye,
and the epidermis being absent. It occurs among
the Shetland Isles and the Hebrides; also on the
shores of County Cork and Connemara.
The Least Whelk (Donovania minima) has an oval
operculum with the nucleus at the side. The shell,
Whelks and Conelets 265
which is solid, reddish brown in colour, and rather
glossy, has the whorls crossed by narrow ribs which
are themselves crossed by broad, flattened spiral .
ribs. It occurs at low water and a little below |k
on the rocky parts of the coasts of Dorset, Devon, 1||
Cornwall, and the Channel Isles. It has a trick Least
unusual among the Whelks of swimming on
the surface with the foot uppermost. It is not quite
a quarter of an inch in length.
The Conelets (Conidce) are well represented by
twenty-eight species, none of which exceeds 1 inch
in length, and few of them attain half that
measurement. They are the representatives
of the tropical Cones, carnivorous mollusks
with a remarkable arrangement of teeth
we might almost say absence of teeth,
for the central and lateral ones have dis-
appeared and only the marginal ones are
oneet lef{ . The Bhell ig con i ca j or spindle-shaped,
with a narrow mouth. The Seven-ribbed Coneiet
(Hcedropleura septangularis) is distinguished by
its 7 waved ribs that cross the body - whorl, and
are paler than the red-brown ground colour. The
outer lip has a broad but shallow notch,
and the amber-coloured operculum is pear-
shaped. Its length is little more than half
an inch. The south-western and western
coasts of Britain and the whole of Ireland
between 7 and 25 fathoms, are the habitat
of this species. The Red Coneiet (Bela
rufa}, though similar to the last, has several
points of difference. It quite lacks the slight gloss
of that species, the general outline is less conical, the
266 Shell Life
whorls are turreted, the ribs are narrow, less strong
and more numerous (14 or 15), the operculum ear-
shaped. It has much the same range as
the last named with the addition of the
south and east coasts. It is half an inch
long, and varies in colour from white (var.
lactea) to orange and purple-brown, the latter
being the more usual hue, in spite of the
name. The Turreted Conelet (B. turricula)
is more distinctly turreted than B.
ru/a. The ribs are pretty equal in
height, so that they are not very pro-
minent, and they are crossed by a
number of spiral lines. The colour is
yellowish white or flesh colour (var.
rosea). It is nearly thiee-quarters of
an inch in length, and its habitat is sandy ground at
various depths pretty well all round our shores.
SEA5LUG5
UITE an extensive group of
marine mollusks, well repre-
sented on our coasts, have, like
the slugs of our fields and
gardens, given up the develop-
ment of shells or have restricted their production to
small shields more or less covered by the mantle. They
are included in the order Opisthobranchiata, which
is so-called because the creatures it comprises have
their breathing organs behind the heart (opisthen,
behind). Each individual combines the special
functions of both sexes. The foot often bears side
wings, which fold up over the thin shell and protect
it. In these cases the shell is variously modified, its
solidity and spiral character being reduced in pro-
portion to the amount of protection it acquires. The
comb-like gill is, in some genera, suppressed alto-
gether, or secondary branchiae are substituted for it.
In some groups the liver emerges from the body-
268 Shell Life
mass in a number of little points or long waving
plumes (cerata), which are often coloured by portions
of the creature's food or by the bile. These colours
appear in different instances to have the effect of
disguising the mollusk or of warning its enemies
that it is not good to eat.
Until recently the remarkable forms and colours
of these creatures were not considered to have any
special significance, and it is particularly surprising
that even Darwin failed to note the relation of form
and habit here, so keen as he always was in such
cases. It is true that here he was seeing through
the eyes of others. Had he been addicted to the
study of marine zoology in his later years he would
probably have modified or rewritten certain para-
graphs in the Descent of Man : for example (p. 261) :
" We can in our ignorance of most of the lower
animals only say that their bright tints result either
from the chemical nature or the minute structure of
their tissues, independently of any benefit thus
derived. ... So ... with many animals, especially
the lower ones, the bile is richly coloured ; thus, as
I am informed by Mr. Hancock, the extreme beauty
of the Eolidse (naked Sea-slugs) is chiefly due to the
biliary glands being seen through the translucent
integuments this beauty being probably of no
service to these animals." And again (p. 264) : " That
many of the nudi branch mollusca, or sea-slugs, are as
beautifully coloured as any shells may be seen in
Messrs. Alder and Hancock's magnificent work ; and
from information kindly given me by Mr. Hancock,
it seems extremely doubtful whether these colours
usually serve as a protection. With some species
Sea-slugs 2 69
this may be the case, as with one kind which lives on
the green leaves of the algas and is itself bright green.
But many brightly coloured, white, or otherwise con-
spicuous species, do not seek concealment; whilst
again some equally conspicuous species, as well as
other dull-coloured kinds, live under stones and in
dark recesses. So that with these nudibranch
mollusks colour does not stand in any close relation
to the nature of the places which they inhabit."
Since the reawakening of interest in marine
biological investigations, Professor Herdman, Mr. W.
Garstang, and others, have published observations on
the group which prove that form and colour have a
most important bearing upon the habits of Sea-slugs.
In the case of deep-sea forms observation under
natural conditions is impossible, and even of those
species that may be found along the shore at low
water much remains to be recorded.
A clue to the probable origin of the Sea-slugs may
be found in certain species possessing shells, but
which make a point of constructing them of very
thin material and covering them with the side flaps
from the foot already mentioned. Starting from
Act<xon which has a spiral shell partially covered
in front by lobe-like tentacles from the head to
Pleurobranchus or Aplysia, whose shell is reduced
to a mere flat plate and completely hidden, it is not
difficult to understand how with a tendency to
increase the covering of the shell, the shell itself
would probably be reduced both in size and thickness
as the mantle or the foot-lobes, as the case may be,
more and more effectually protected the breathing
organs. Some species have a spade- like disk, which
2/0 Shell Life
spreads up from the head to cover the base of the
shell and so protect it from destruction by the sand
through which the creature burrows ; others swim in
the open waters by means of their foot-expansions ;
but most of them crawl over seaweeds, sponges, or
corallines, much after the manner of the land-slugs.
Some of them feed upon seaweeds and then agree
with these in colour, whether green, olive, or red ;
but many devour living sponges, sea-squirts, and
zoophytes, and then often reproduce in the decora-
tion of their own bodies the pattern and colour of
the surface upon which they are at once feeding and
being hidden.
The order Opisthobranchiata is divided into three
sub-orders, each divided again into sections, families,
and genera. We cannot go into all these divisions,
but we will glance at representative species from
each of the families found in British waters. The
first sub-order is the Tectibranchiata, or those whose
gill-plume is covered by the folds of the mantle.
They possess a shell, which is more or less enveloped
in folds of the mantle or foot, and is often rudi-
mentary. Some of the families included in the first
section (Bulloidea) appear to have no claim to be
reckoned among Sea-slugs ; but these species, other-
wise closely allied to those whose shells have vanished,
must be included, and they indicate the probable
evolutionary course travelled by the entirely shell-
less kinds. Take the Actseon-shell (Actceon tornatilis)
to begin with. The oval shell is sufficiently solid in
structure for its neatness and regularity to have
suggested to Linnaeus that it had been turned in a
lathe, so he called it tornatilis to express that idea.
Sea-slugs 2 7 1
But the shell is also large enough to accommodate
the entire animal, and it is closed by a horny opercu-
lum that fits its irregular mouth. The
animal presents a strange appearance with
its broad, bilobe-fronted foot, the large broad
head bilobed in front and ending in the pair
of broad leaf-like tentacles which stand erect
or lie back on the shell. The little black
eyes are almost hidden sunk in the skin.
The animal is pale yellow tinged with purple and
flecked with white ; the shell is coloured with flesh
pink, the bands shown in the figure being white. It
is a widely distributed species, and though not common
cannot be considered rare. Its range extends from
extreme low water to about 20 fathoms in sandy
bays. Another species, Actceon exilis, was taken
in 1215 fathoms on the south-east of Rockall, during
the cruise of the Porcupine in 1869.
Many of the species of Bulloidea are known as
Bubble-shells because of their thin, inflated character.
The Blunt Bubble-shell (Tornatina obtusa) is nearly
cylindrical, and looks as though the spire had been
cut off. It is only about a quarter of an
inch long, white, but covered by a brown
epidermis. The animal is white, with a very
short head, erect tentacles at the sides, and
the eyes not perceptible. It is tolerably
common on the sand and mud of estuaries,
where it ranges from low- water mark to about 15
fathoms. There are five other species. They are
provided with powerful gizzards in which they crush
Hydrobice and other small mollusks, for some of
which they have to burrow.
18
2/2
Shell Life
The Canoe-shell (Scaphander lignariius) is a many-
whorled spiral of reddish hue, whose lines and grooves
give it some resemblance to the
grain of fir-wood. The yellowish
animal has a large shield - shaped
head, and the tentacles are united
to form a squarish lobe behind it.
The eyes are not developed owing
to the fact that this mollusk burrows
in the sand for its food. It per-
sistently hunts the little Tusk-shell
(Dentalium entale), crushing the
shell in its powerful gizzard and
digesting its contents. Jeffreys says it "does not
despise any kind of animal food, from minute
Foraminifera to the Sea-mouse or Aphrodita, the
spines of which I found in the gizzard of one
individual. Corbula gibba is evidently a favourite
morsel; and I have observed Dentalium entalis,
Odostoniia rufa, and Ditrupa arietina in other
specimens." It occurs generally in the coralline zone
in from 50 to 90 fathoms. Another species, Scaph-
ander punctostriatus, occurs at Shetland and the
Butt of Lewis in deep water.
The Cylindrical Bubble-shell (Cylichna cylin-
dracea) is distinctly cylindrical, with blunt ends, and
about 1 inch in length,
though the animal is much
longer. Both animal and
shell are white, but the latter
has a dark yellow epidermis.
It presents a singular appearance with its flattened
head and flap, consisting of the united tentacles, ex-
cylindrical
Sea-slugs 273
tending backwards over part of the shell. It is
tolerably plentiful along our sandy bays, between
15 and 50 fathoms, where it grubs, pig-like
in the sand for food with its flat snout.
When irritated it pours out a yellow fluid,
apparently to drive off enemies. A smaller
species, the White Bubble (C. alba), has been
taken in deep water on fine sand off Unst,
Shetland (84 to 95 fathoms) ; Butt of Lewis
(189 to 530 fathoms); West of Ireland (430 to 1366
fathoms).
The Glassy Bubble-shell (Amphisphyra hyalina)
is oval, equal at both ends, of glass-like clearness,
and about a fifth of an inch long. The whitish
animal has a bilobed head, with small eyes, which
are withdrawn into the shell when the animal is at
rest, but show through. It is a native of the lamin-
arian zone. There are three other species, found in
Skye and Shetland.
The typical Bubble-shells (Bulla) are solid, with
the crown perforated and exposing part of the spire.
B. utriculus has an oval glossy shell, fairly solid
yet semi-transparent, with impressed spiral lines. It
is only half an inch in length, and is found in muddy
sand in from 20 to 86 fathoms on various
parts of our coast. B. semilevis was taken
off the south of Ireland in 1000 fathoms
by the Flying Fox expedition, 1889.
The Southern Bubble -shell (Haminea
hydatis) is distinguished from Bulla, with
which formerly it was associated, by being
thin, the crown not perforated, and the outer lip so
expanding as it grows that the spire is completely
274
Shell Life
iSi!: ;.!,:iiL i
Soft Bubble-shell (twice nat.
hidden. It is 1 inch
long, greenish-
yellow, except the
crown and pillar,
which are white.
There are large side
lobes to the foot,
which are turned up
on occasion so as to
partially envelop
the shell. It is a
local southern
species, found on
sandy and muddy
shores from half-tide
down to about 15
fathoms. It some-
times uses the side
lobes of the foot as
swimming organs.
The Soft Bubble-
shell (Acera bul,-
lata) is thin, flexible,
almost transparent,
white tinged with
green. It is almost
entirely covered by
the side lobes of the
foot, and partly by
the mantle. The
animal is grey or
whitish, with minute
dots of lighter and
Sea-slugs
darker tints, and broken lines of purple-brown. The
creature has no tentacles (hence its name, Acera,
without horns), and its small black eyes
are not conspicuous. Its gizzard is not
so powerful as that of the Canoe-shell,
but it is well provided with a number
of triangular horny plates for the tritu-
ration of its food. When alarmed it is
said to eject a purple fluid. Like
Haminea it uses its foot-lobes for swim-
ming purposes. It occurs chiefly on our
southern shores and the coasts of Scotland
and Ireland, in from 3 to 15 fathoms, on
ooze and mud.
The Lobe-shell (Philine aperta) has its
delicate, thin white shell completely
invested by the transparent white
mantle ; but though covered in this
way, so clear is the mantle that both
shell and gizzard may be seen through
it. This pellucid covering is dotted
with opaque white specks which give
a very close resemblance to certain
of the Compound Ascidians. This
likeness, no doubt, serves its purpose
in avoiding destruction. It is said to
be capable of swimming by using its
side lobes. It is common on sandy shores from
extreme low water to about 50 fathoms, all round
these islands. There are seven other native species,
of which the names will be found in the Appendix ;
among them is the Dotted Lobe-shell (P. punctata},
a minute species only about an eighth of an inch in
2 7 6
Shell Life
length, found among zoophytes, etc. The shell is
nearly round, and is marked by an incised pattern
of dots arranged in spirals. It may
be found among shell-sand but is not
common. Another form, P. catena,
somewhat larger, has the ornamenta-
tion in the form of numerous rings
arranged in chain-like series. There
is a broad zone more transparent than
the rest of the shell, and the chain-
uobe-sneii ,., , i -i i ,11
like marks included in that zone are
more strongly defined than elsewhere. An allied
species, Colpodaspis pusilla, of which only two speci-
mens had previously been recorded, was taken a,t
Plymouth in 1894.
In the Sea Hare
(ApLysia punctata)
the shell is reduced
to a more or less
flat shield beneath
the integuments.
It is oblong, almost transparent, and flexible. The
animal is of the remarkable form depicted ; the small
head connected with the humped back by a long neck.
From the foot two ample lobes fold up
over the back, but they may be expanded
and used for swimming. In the middle
of the back is the gill, covered by the
shell and a fold of the mantle which is
continued back to form a siphon. The
head bears two pairs of tentacles, the
hinder pair when erected resembling ears. Viewed
from the front, when this creature is gliding, it
Sea-slugs 277
presents a singular resemblance, in miniature, to a
hare, and this likeness led our forefathers to bestow
the present popular name upon it. But because the
Sea Hare when interfered with pours out a purple
fluid from the edge of its mantle, they said some
unkind things of it that this fluid caused an
indelible stain, and they called it Aplysia (from a
and plus, unwashable). They also averred that this
fluid was a poison, and that contact with the mollusk
would cause all the hair to fall from the head of the
person touching or being touched by it. Specimens
of various sizes are found to differ greatly in colour,
and these have been thought to be different species ;
but there can be little doubt that in their progress
from infancy to maturity they change their depths
along the shore and occupy consecutive zones of
vegetation to which they closely assimilate in colour.
Thus young Sea Hares of a bright crimson colour
spotted with white may be found in an extended
motionless attitude on the crimson fronds of Delesseria,
and then so closely resemble shoots of the weed that
it is difficult to distinguish them. When they become
larger their colour tones down to a brownish red,
then to deep red-brown, much the colour of Dulse
(Iridcea). Purple-brown, olive -brown, and olive-
green are other colour-phases reached by it, in the
course of which it matches with the great tangles
and the smaller wracks. When fully grown and
fully extended the Sea Hare is 6 inches in length.
Sometimes the light spots are entirely absent.
The Sea Hare is a well-protected creature. Not
only does its colour harmonise with the weeds upon
which it glides, but the purple fluid ejected when
278 Shell Life
irritated rapidly creates a cloud under whose shelter
it can escape. It has a nauseous scent, which makes
it objectionable to many creatures; and when it is
contracted it closely resembles the Beadlet Anemone,
which is common in the places it haunts and is also
objected to as food by most fishes. Not only does
the Sea Hare profit by this resemblance to the
anemone, but I have found that the mollusk varies its
seaweed diet by at least occasionally lunching off a
Beadlet. The eggs are deposited in spring among
the weeds. For years much confusion existed respect-
ing the identity of this creature ; it was generally
referred to A. depilans, a Mediterranean species,
which, however, has been taken occasionally on our
south coast. Major A. R. Hunt recorded many
examples taken in Torbay in the years 1875 and
1877, some of which weighed from 1 to 2^ Ibs., and
had shells as much as 2^ inches in length.
The Side-gilled Sea-slug (Pleurobranchus plumula)
belongs to the section Pleurobranchidce, and differs
from the Sea Hare in several respects. Its broader
foot has no side lobes, there is but one pair of broad
tentacles with the eyes at their base, and a large gill-
plume projects from between the right under-side of
the shell and the pointed foot. There is a large
internal, oblong, thin and flexible, almost flat shell,
but whose nucleus shows that it once had a tendency
to spiral growth. The animal is about 1 inch in
length, of a pale yellow colour, and its habitat is
under stones and in empty bivalves. There is
another species, the Rough Side-gilled Sea-slug (P.
membranaceus), whose broad foot has a rounded
extremity and waved margins, whilst the back is
Sea-slugs 279
covered with little conical points. Both the foot and
the flaps of the mantle are used for swimming. The
general colour is red-brown, paler above, and with
blue-grey spots beneath. The shell is a very thin
and flexible transparent plate, similar to that of the
last-mentioned species. The coloration of the animal
makes it a conspicuous object, and no doubt it would
suffer greatly from the attacks of fishes but for the
fact that from its entire surface it can pour out a dis-
tinctly acid secretion so acid, indeed, that blue
litmus paper is turned strongly red by it. Acid is
much objected to by fishes, and the presence of a very
small quantity in otherwise desirable fish - food is
sufficient to disgust the fish. When at rest this
species frequently folds up the sides of its broad foot
over the body, though the foot is not divided into lobes
as in some of those already described. Mr. W. Garstang
thinks we may find in this habit a clue to the origin
of foot-lobes in other species. " In Oscanius [that is
Pleurobranchus] the sides of the foot are frequently
folded over the body of the animal when at rest, and
this habit is still more marked in Haminea. Now the
animals are found to live on muddy bottoms, and a
broad flexible expanse of foot is obviously advan-
tageous for gliding over such surfaces. But the
habits of Aplysia are different. Aplysict lives upon
algse, and for creeping over the narrow stems and
fronds of seaweeds a wide plantar surface would be
not only unnecessary but disadvantageous ; so we
find that the median portion of the originally broad
foot has become specialised for creeping purposes,
while the lateral portions no longer form part of the
plantar surface, but arise from the vertical sides of
2 So Shell Life
the median portion, and retain only their power of
flapping for the purpose of natation. The series of
forms illustrating the evolution of the lateral folds of
Aplysia, is so complete as to leave no doubt about the
truth of this view." 1
The Crowned Runcina (Runcina coronata) is even
more distinctly slug-like, for it has no shell. It is of
a brown colour with a distinct mantle. There are no
tentacles, but there are three slightly plumose gills.
It frequents tide-pools and shallow water, crawling
over mud and brownish weeds, but avoiding those of
green hue upon which its colour would be danger-
ously conspicuous. It is quite small, full - grown
specimens being less than half an inch long.
The foregoing species represent the sub - order
Tectibranchiata, in which the mollusks agree in
possessing a gill on the right side more or less con-
cealed by a fold of the mantle. The following sub-
order though called Nudibranchiata is chiefly charac-
terised by the absence of both gill and shell the
latter, however, being present in the embryo. Many
species are covered with long fleshy points (cerata),
enclosing portions of the liver, and some have the
tentacles ringed with projecting sense-organs (rfiino-
phores). They form two groups, the Holohepatica, in
which the liver is entire and internal, and Cladohepa-
tica, in which the ramifications of that organ are
generally branched or twiggy.
Cerata are frequently present in the Holohepatica,
but they serve the function of gills only, and are
grouped in the middle line of the back ; there are
1 Journal of the Marine Biological Association, vol. i., n.s.,
p. 419.
Sea-slugs 2 8 1
usually no jaws. The most noticeable of this section
are the Sea Lemons, so-called from the resemblance
of one species to the half of a lemon ; at least this
was the likeness that struck the naturalists early
last century. To-day the marine zoologist admires the
remarkable mimicry of sponges in their colours and
markings. They are elliptical in outline, and more or
less flattened. They are completely covered above by
the mantle, which extends even beyond the head and
foot, and is seldom smooth, being usually thrown up
into little tubercles or granules and stiffened by having
calcareous spicules embedded in its substance. The
eyes are mostly hidden by the integument, and can
only be seen by dissection or in the larval stage.
The pair of tentacles on the back come through
apertures in the mantle, and are covered with over-
lapping plates; these are the sense-organs (rhino-
phores). At the other end of the Sea Lemon's back
is a rosette formed by spreading leaf - like organs
arranged round a central cavity. This is the opening
of the anus, and the surrounding leaves are the gills,
all connected at their base and capable of being
retracted into a cavity in some species, though not
in all.
The best-known member of this group, and that to
which the name Sea Lemon was first applied, is the
Rough Sea Lemon (Doris tuberculata), which is
usually about 3 inches in length, though examples
may sometimes be found as long as 5 inches. The
prevailing colour is pale yellow or dull orange, but it
varies from white to orange, and may be marbled or
clouded with grey, pink, and green. The encrusting
sponges of the genus Halichondria, especially Hali-
282
Shell Life
Young of Doris,
with shell
cJwndria panicea, that form large patches on our
rocks at low water and below, and upon which the
Sea Lemon chiefly
feeds, equally vary
in tint. Where
this Halichondria
or Crumb-of-bread
Sponge grows the
Sea Lemon may
also be found, and
when the slug has
moved away from the sponge the former becomes a
very conspicuous object, but when upon or beside it
the slug has every possible chance of escaping notice.
Its back is the same colour as the sponge, and the
numerous little warts help the resemblance. The
circle of gill - plumes resembles the osculum of the
sponge. Not far off in spring we are almost sure to
find the remarkable egg-ribbon, of which each indi-
vidual produces two or three each year.
It is a ribbon 9 or 10 inches long and
1 inch broad, with waved free edge, the
other being glued to the rock as de-
posited and coiled in a spiral. Each
ribbon is estimated to contain on an
average 50,000 ova. There are eight
other members of this genus, differing
in size, colour, and other points. One
of these, the Red Doris (D. coccinea),
is figured. It is only about 1 inch long,
is of a bright scarlet colour, dotted
with black. It occurs on the Cornish coast, feeding
on the sponge Halichondria sanguinea, where it is
Sea-slugs 283
easily overlooked. Johnston's Sea Lemon (D. john-
stoni} is another small species, of a creamy white
colour, which harmonises with the paler form of
Crumb-of-bread Sponge upon which it feeds. There
are dark spots on the back which give the impression
that they are deep pores like those of the sponge.
The Hairy Sea Lemon (Acanthodoris pilosa) varies
in colour from pure white through yellow and brown
to grey and even black. It is covered with soft,
rged three diameters)
conical points which give it a pilose character, and
make it very sponge-like in appearance. It occurs
between tide-marks, but its habits have not yet been
satisfactorily made out; though the very sponge-
like texture of the surface leads one to expect that it
will be found to feed on several of the encrusting
sponges. A second species (A. subquadrata) is
pale and semi-transparent, very squarish at either
extremity.
The Rough Doris (Lamellidoris aspera) is less than
284 Shell Life
half an inch in length, white, and almost transparent,
covered with stalked tubercles that mimic the closed
tentacle-crowns of certain polyps. Most of the twelve
British species of this genus have similar tubercles,
and it is therefore not surprising to find that several
of them have been taken in the act of feeding on
Polyzoa which they resemble in colour and markings.
The Angled Doris (Goniodoris nodosa) is about 1
inch in length, of a transparent white colour tinged
with rose and sprinkled with opaque white or yellow
dots. The mantle has a wavy margin, and at the
rear it is cut into a number of cusps which suggest
the name. A second species, G. castanea, is somewhat
smaller, of a reddish-brown tint usually, covered with
soft tubercles which are blotched with yellowish
white. This species feeds upon colonies of Compound
Ascidians (Botryllus), and when so engaged is very
inconspicuous.
The Venus Slug (Idalina elegans) is obviously got
up to look like a beautiful anemone. It is about
1J inches long, the back much more elevated than
usual, of a delicate pale-rose tint speckled with
a deeper shade. The edge of the mantle is drawn
out into a number of filaments of an orange colour
with yellow tips. The foremost two of these fila-
ments are developed to a large size, and being just
below the tentacles look very like an additional pair.
The true tentacles and the branchial plumes are all
coloured like the mantle filaments, so that they
appear to be the waving tentacles of an anemone. In
spite of its brilliant tinting Idalina does not, like so
many of the Sea-slugs, seek surroundings of similar
colour, but goes where it will be highly conspicuous,
Sea-slugs 285
trusting no doubt to the anemone-likeness, coupled
with the knowledge of anemones that must pervade
the waters it being sufficient to resemble an anemone
in order to discourage would-be destroyers, for the
anemones are known to have stinging powers, a
tenacious hold, great storage capacity, and a bad
taste. Idalina buries itself in the bodies of Simple
Ascidians (Cynthia), protruding its tentacles and
filaments in a very anemone-like manner. Alder
and Hancock, who never suspected the object of the
remarkable forms and colour-ornamentation of the
Sea -slugs, describe the discovery of the species.
They say :
" This valuable addition to our Fauna was dredged
in the summer of 1853, near Castle Cornet, in
Guernsey. From a curious habit, hitherto unknown
in this tribe, of concealing itself in the test of an
Ascidian (Cynthia tuberosa), it escaped observation
on being taken from the dredge, and was put into
our collecting-box as an Actinia [anemone] partially
expanded. On examining the contents of the box in
the evening, we were delighted to find we had got a
beautiful Idalia, which had crept so far out of its
place of concealment as to display its true form. A
second individual was afterwards found amongst the
contents of the box, with only its head and anterior
filaments protruded from the test of another
Cynthia of the same species." There are five other
native species in this genus.
The Crested Slug (Ancula cristata) appears, like
Idalina, to carry a little anemone on its back. It is
not more than 1 inch in length, transparent white
except the sense-organs (rhinophores), and the tips of
286
Shell Life
all other appendages, which are bright orange or deep
yellow. It haunts the neighbourhood of rocks, where
it is not molested by fish, who decline to feed upon it.
Whether it is that the appendages produce a false
impression of its nature, or whether it is dangerous
food and the yellow is a warning colour, is not
altogether clear; but it is certain that for one or
Crested Slug (enlarged four diameters)
both of these reasons the Ancula is a protected
species.
Homberg's Triton (Tritonia hombergi) begins that
section of the Sea-slugs that are ornamented by a
profusion of waving plumes due to their habit of
wearing their gills, or gills and liver combined,
outside. Homberg's Triton is a giant, for it runs to
6 and occasionally 8 inches in length, though ex-
amples of 4 inches are more plentiful. Even these
we shall only obtain by the dredge or from fishermen's
lines. It varies in colour from white to purple-brown ;
its back covered with soft tubercles, and along each
MAKBLEU SLUG ; 2 CROWNED SKA-NYMPH ; 3 HOMBERG'S TRITON ;
4 ROUGH SEA LEMON ; 5 ROUGH DORIS ; 6 ANGLED Doius.
Sea-slugs 287
side from under the edge of the mantle extend many
branched cerata, much like curled and crisped fronds
of one of the smaller seaweeds. The liver does not
extend into the cerata in this genus. The head
is sheltered by a lobed and toothed veil. The
tentacles issue from large sheaths with spreading
mouths, and the rhinophores take the form of a
circlet of fern-like plumes. This slug is never found
away from the Deadman's Fingers (Alcyonium
diyitatwn) whose closed polyps are mimicked by
the tubercles on the Triton's back. The colour
variation in this and some other species appears to
have relation to their food ; for T. kombergi has
been experimentally kept without its favourite food,
when it lost all its colour and became transparent.
There are three other species, of which the best
known is the Common Triton (T. plebeia), a much
smaller species, found in similar situations to the
last named. It is just as variable in colour -just as
the Alcyonium is variable, and in the same tints
and its rhinophores equally mimic the half-extended
crown of tentacles of the polyp. But plebeia is little
more than 1 inch in length, and its head veil, though
divided into seven or eight finger-like appendages,
is not lobed.
The Gulf -weed Slug (Scyl-
hea pelagica) is a quaint
little creature less than 1 inch
long, with rhinophores in long
sheaths, and two pairs of Guif-weed si ug
spreading cerata along the
sides. It is found only on floating seaweeds, and
was at one time thought peculiar to the Gulf-
19
288 Shell Life
weed. It is singular among Sea-slugs in having its
stomach fitted with plates of chitin to break down its
food. In this species the liver branches out into the
cerata, an arrangement that permits of more room
for the stomach, and, as we shall see in some other
species, helps to protect the slug by showing the colour
of the food taken.
Bushy-backed Slug (enlarged)
The Bushy-backed Slug (Dendronotus frondosus)
is obviously adapted for a life among seaweeds and
corallines. The cerata, which form a single series
along each side of the back, are branched and toothed
in a fashion that makes them to closely resemble some
of the small red-brown seaweeds (Callithamnium\
Sea-slugs 289
The sheaths of the rhinophores, and the front of the
head, are cut into similar forms. It is about 1|
inch long. It is said to be highly edible, having
nothing in its flavour to displease the taste of the
most fussy fish ; and therefore its disguise is
absolutely necessary to the species. The colour
varies, but most frequently it is red marbled with
brown and with white or yellow spots. The liver
does not extend to the cerata. It occurs between
tide-marks and in the laminarian zone among sea-
weeds and corallines.
The Crowned Sea-nymph (Doto coronata) feeds
upon Hydroids and Corallines, and consequently
harmonises closely with them in general form and
colour. The body is slender, but from each side
there extends a number of narrow lobes which bear
the bright coloured cerata. The liver is entirely
contained in these cerata, which render the animal
very conspicuous when taken from its habitat, but
this is the under-sides of large stones and rock-ledges
where grows Clava multicornis in abundance, and
its tentacles and sporosacs are closely mimicked by
the cerata and markings of Doto. In deeper water
it will be found to preferably affect the Sea-firs
(Sertularia and Pluinularia). The tentacles are
slender, and issue from long vase-like sheaths. There
are no true branchiae. It is only half an inch in
length. D. fragilis is 1 inch long, more robust
in form, and coloured a dirty yellow, spotted with
white. There are nine pairs of cerata, and these
individually bear a very close resemblance to the
Hydra tuba stage of certain Jelly-fishes. It feeds
upon corallines, especially that named Lobster-horn
290 Shell Life
(Antennularia antennina), at whose base it is fond
of resting, and there, no doubt, its erect cerata mingle
with, and pass as, the Hydra tuba. There are two
other species.
The Marbled Slug (Lomanotus marmoratus) has the
head hidden by a slight veil which appears to be
a modification of the true tentacles. These are
mimicked by prolongations of the foot in front.
The rhinophores are club-shaped, and withdrawn at
pleasure into sheaths. From the back four or five
pairs of rounded and fringed lobes spread out, their
colour varying from fawn to reddish or dark brown,
spotted with white or brown. It attains a length of
2 inches, and feeds upon corallines which it closely
resembles in colour and ornamentation. It swims
with considerable rapidity. Three other species are
included in the British list, but Mr. Garstang con-
siders all four to be but varying forms of one species
which he proposes to call Lomanotus genei.
The Plumed ^Eolis (JEolis papillosa) is very slug-
like, but the back is covered with numerous cylindrical
overlapping cerata, arranged in rows of about ten,
and with two erect slender tentacles such as in many
of the foregoing species bear the organs of smell
(rhinophores), but which are plain in this instance.
There is, in addition, a pair of ordinary tentacles
from near the mouth. The slug attains a length of
nearly 3 inches ordinarily, but examples have been
recorded measuring 4 and 4^ inches. Its colour is
purple-brown, which harmonises with the smaller
wracks growing near low-water mark. The cerata
serve a double nay, a fourfold purpose : first, they
are the breathing organs, oxygenation of the blood
Sea-slugs
291
going on in their outer
layers, but their centres are
filled with isolated portions
of liver directly connected
to the stomach, whence par-
tially digested food is sent.
At the tip each of these
cerata is pierced, and through
the minute channel the ^Eolis
ejects stinging threads for
the annoyance of such
creatures as would essay to
experiment upon the food
value of the slug. A fourth
use of the cerata is found
in their power to mimic the
tentacles of the Cave-dwell-
ing Anemone (Sagartia
troglodytes). Further, when
the ^Eolis is molested it can
throw off some of its cerata
to occupy and probably
disagree with its enemy ;
this appears to entail little
or no injury to the slug, for
the place of the missing
cerata is soon taken by
newly-grown ones. M. Giard
has observed, at Wimereux,
how closely this species re-
sembles the Cave-dwelling
Anemone, but it is difficult
to say w T hich is really the species that profits most by
292 Shell Life
the resemblance, for both are well protected. All the
Sagartias are provided with stinging-threads, which
are shot out from their tentacles with great force
and rapidity and are able to pierce the shells of
shrimps and the scales of small fishes ; in addition
they are mostly unpleasant to the taste and smell.
This would be a good reason why ^Eolis which feeds
upon anemones should mimic Sagartia ; but the case
is complicated by the fact that ^Eolis, as we have
seen, has also stinging cells at the tips of its cerata,
and is known to be otherwise unpalatable to fishes.
The Plumed ^Eolis is among the most active of the
Sea-slugs, gliding and swimming with equal ease.
It is subject to considerable colour variation, and this
is affected to a large extent by the colour of their
food. We have found that the paler, rose-tinted
variety found on the Cornish coast changed in
confinement according to the colour of the anemone
we allowed it to eat.
Alder's Little vEolis (jE. alderi) was first dis-
covered by Mr. W. P. Cocks at Falmouth. It is only
about 1 inch long, and has about fifteen rows of
cerata on each side. These vary from greenish fawn
colour to dark brown with pale yellow tips. Owing
to the small amount of liver in the first two rows of
cerata, these form a white frill behind the head, which
is a very distinct character with this species. On
being touched the head is immediately withdrawn
into the bod}'-, and the cerata are erected, until the
creature bears a striking likeness to a small anemone
often found in its neighbourhood. J glauca is much
larger than the last (nearly 2 inches), and its broad
foot suddenly finishes behind in a sharp point. The
Sea-slugs 293
back is coloured pale red, and the very worm-like
cerata are sage-green tinged with red and spotted
with white.
The Dwarf ^Eolis (Cuthona nana) is only a few
lines in length, pale buff on the back, the head and
tentacles white. The cerata are also white, but the
central tube is red, and a rosy tint shows through ;
they are arranged in eight or ten close rows. Like
other species, it is very sensitive, and when alarmed
brings its head and tail together, and so assumes an
anemone - like aspect. The Orange - tipped ^Eolis
(C. aurantiaca) is similar, but larger, attaining a
length of half an inch. It has a buff coloured back,
and the cerata are in about ten rows. The tips of
the latter are coloured bright orange, below which
there is a white belt, and then the purple-red of the
central tube shows through the transparent re-
mainder. This lower portion is subject to much
variation of tint, probably due to differences of food.
It has been found from Shetland to Cornwall, feeding
on Tubularia, etc.
The Green ^Eolis (Cratena viridis) is entirely
tinged with green, though it is not so distinctly
green as some other species. The long slender body
is white with a yellow - green tinge. The cerata,
which are arranged in nine or ten rows, have pointed
white tips, the central tube being some shade of green
with darker spots. The first four rows of cerata
come close together, the other rows are quite distinct
one from the other. It feeds on Sea-mats (Flustra),
Lobster-horn (Antennularia), etc. We have no less
than thirteen representatives of the genus Cratena.
Of these C. amasna might easily be mistaken for
294 Shell Life
C. viridis, yet by attention to three points it may
as easily be distinguished : the eight rows of cerata
are more distant, except the first three rows which
are close, the head and shoulders are sprinkled with
opaque white raised points, and the back and cerata
are dotted with dark brown. The Olive ^Eolis
(C. olivacea) is also greenish, but, as the names in-
dicate, dull brownish green. The body is yellowish
white, dotted with opaque white, and stained about
the head with rosy streaks and a big blotch of the
same tint.
The Despised ^Eolis (Tergipes despectus) is a minute
creature, only about a third of an inch in length,
but except on this ground in no way deserving its
name. The foot is transparent and colourless, to let
the colour of the Laminaria on which it glides show
through. There are only four cerata on each side,
and these are arranged alternately, not opposite as
is customary in the family. The head and shoulders
are streaked with rose colour, and this extends up the
tentacles, and often along the sides of the foot. The
digestive track is clearly seen through the back,
coloured with pale olive or yellow-brown, taking a
bold zigzag course and sending out a branch at each
angle to one of the cerata. The centre of these is
similarly coloured, but the tip is opaque white, and
the intervening transparent band sometimes red. It
feeds upon the Hydroid Obelia geniculata, or upon
the minute alga? which grow upon its stems. Obelia
is abundant on the fronds of some of the large Oar-
weeds, and as T. despectus crawls about them, and the
colour of the weed shows through it, little but the
digestive track and the connected cerata can be seen ;
I SlDE-GILLED SEA-SLUG ; 2 CRIMSON HERM^A ; 3 ALDER'S SLUG J
4 ORANGE-TIPPED /EOLIS ; 5 GREEN ^EOLIS ; 6 DESPISED ^EOLIS.
Sea-slugs 295
but these almost exactly reproduce the stem and
capsules of the Hydroid.
Embleton's ^Eolis (Embletonia pulckra} is a more
minute example, being only about one-lifth of an
inch. It has only one pair of tentacles the dorsal
but the front of the foot spreads out into lobes ap-
parently to supply the place and functions of the
missing oral pair. The comparatively large oval
cerata are arranged alternately as in Tergipes, but in
this case there are five on the right side and six on
the left. They are transparent, dotted with opaque
white, but the central cavity is bright red, as also is
the digestive track, clearly seen through the back.
There are two other species E. minuta which
is very similar but more slender in all its parts ;
and E. pallida, which has a double series of
cerata along each side, and the tentacles closer
together. There is a variety (var. grayi) which has
adapted itself to fresh, or almost fresh, water, for it
is found in the Victoria Docks, London, where it
feeds upon the Freshwater Sponge (Cordylopkora
lacusiris).
The Minute yEolis (Galvina exiguct) is a somewhat
similar species, with a double row of cerata on each
side and two pairs of tapering tentacles. It is found
upon Halecium and other Hydroids whose capsules
are mimicked by the form and colour of the cerata.
It may be colourless with white cerata, or these and
the tentacles may be banded with olive-green, whilst
patches of the same colour may be present on the
back.. It is only about one-fifth of an inch in length.
There are six other species of this genus found on
our shores, of which the Three-coloured ^Eolis (G. tri-
296 Shell Life
color) attains the length of 1 inch. It is semi-
transparent, white or orange in colour with yellow
tips to the cerata, and the central tube violet fading
to orange-brown towards the base. It feeds upon
Obelia. The Painted ^Eolis (G. picta) has the several
rows of inflated cerata spotted with opaque white
and orange-brown, whilst the centre is pale buff.
Farran's ^Eolis (6r. farrani) is pellucid white, the
tentacles and cerata tipped with orange. The Belted
^Eolis (G. cingulata) is a very beautiful form less
than half an inch in length, white blotched with
rich olive - brown. The cerata are set in eight or
nine distant rows, and have a pale yellow centre
and three olive - brown belts. The tentacles are
banded by red or reddish brown, and behind them
is a patch of olive-brown.
In the genus Coryphella, of which we have six
species, the cerata are not arranged in rows but in
ill-defined clusters.
The Red-gilled ^Eolis (C. rufibranchialis) is about
1 inch long, very slender, and well covered with
slender cerata which are ringed with white near the
tip, and whose irregular central tube is scarlet or
rose coloured. The Slender ^Eolis (C. gracilis) has
large and conspicuous eyes, the tips of the cerata
ringed or patched with opaque white and the centres
reddish yellow. In C. snuiragdina these cerata
centres are emerald green ; in C. landsburghii they
are orange-red. This last-named species, which is,
apart from the cerata tubes, of a beautiful trans-
parent pale violet tint, is found on Hydroids in deep
water.
The White ^Eolis (Favoriniis albus) is nearly half
Sea-slugs 297
an inch long, pellucid white tinged with yellow,
except the dorsal tentacles, which are brown with
white tips. A little below the tips these tentacles
swell out and then contract again. The cerata are
arranged in five or six oblique rows ; in some
specimens these have an olive band near the tip.
F. carneus, the other British species, has the body
and cerata of a pale rose or flesh colour.
The Crowned vEolis (Facelina cor on at a) is about
1 inch in length, transparent - white tinged with
rose, marked on the head, back, and the front of
the cerata with opalescent blue and opaque white.
The dorsal tentacles are fawn coloured adorned with
alternately complete and incomplete olfactory plates
the " crown " of its name. The cerata are grouped
in six or seven clusters or curved rows. This is one
of the most likely species to fall in the way of the
novice, and it is certainly not one of the least
beautiful. It occurs between tide - marks, feeding
upon the Beadlet Anemone, on Lucernaria, various
sponges, and its own kind. The colour of the cerata
tube varies with this
food, but ordinarily
it is some tint of
crimson. There are
three other species,
of which one, the
Dotted ^Eolis (F.
punctatd), is fig-
ured. The dark
flesh-tinted cerata
are in six or seven large clusters, of which the first
and second are separated by a much greater interval
298 Shell Life
than the others. The dorsal tentacles bear about two
dozen oblique plates, one half of which are imperfect.
Both body and cerata are liberally sprinkled with
opaque white dots. An allied species, Calma ylciu-
coides, is said by Hecht (quoted by Cooke 1 ) to imitate
" the ova of certain fishes on which it feeds. Its
elongated and depressed form of body, transparent
integuments, and silvery grey papillae [cerata] combine
to give it a strong resemblance to the spawn of
the fish, which is deposited on stones, the roots of
Laminaria, etc."
The Noble ^Eolis (Fiona marina) is long and
slender, the tentacles all slender, and the sides of
the back irregularly clothed with compressed narrow
cerata of transparent buff with a centre of rich brown
and tips of opaque bluish white. The whole creature
has a lustrous appearance.
The Crested ^Eolis (Antiopa cristata) is a deep-
water species of a transparent pale yellow tint in-
clining to buff. The dorsal tentacles are covered
with oblique plates which meet behind. The " crest "
is found uniting these tentacles, and is arched and
lobed. The transparent cerata show a narrow core
of brown, and pointed tips of white which gradually
changes into ultramarine a little lower. It is 1^
inches long. The other native species (A. hyalina)
is only one - fifth of that size, very transparent,
yellowish with red-brown spots and mottlings. The
cerata are rugged, and lack the white and blue tips.
The genera Proctonotus and Hero each repre-
sented by a single species complete the family
^Eolidiidse so far as it is represented on our shores.
1 Cambridge Natural History, vol. iii. p. 74.
Sea-slugs 299
The remaining families are small, and both genera
and species few.
The Crimson Hermsea (Hermwa bifida) is very
slender in proportion to its inch of length, with a row
of leaf-like cerata down each side. The body is trans-
parent, tinged with pale yellow, or greenish. The
single pair of short tentacles are folded lengthwise,
so that they present the appearance of a tube that
is split down one side. The cerata are transparent
pink, permeated by much - divided branches of the
liver, which take on the colour of the food recently
eaten. This species and the next appear to be
vegetable feeders, and the favourite haunt of the
Crimson Hermasa is among the small crimson weeds
just below low water. It may commonly be found
upon Delesseria, where it is very inconspicuous, for
its cerata are just like small shooting fronds of that
weed. It has large eyes, and it is apparently very
sensitive to changes of light, for a shadow passing
over the creature will at once cause it to contract
itself, draw in its head and erect its cerata, evidently
for the purpose of putting on a fierce aspect. At the
same time it ejects a nauseous fluid. The other
species is the Green Hernwea (H. dendritica), a much
smaller species about one-third of an inch in length
of pale green colour marked with branching lines
of deeper green similar to the veining of a leaf. The
slender cerata are in eight rows along each side ;
transparent, with a sprinkling of opaque white, and
with the central vessel green, the contents lobed, so
that the cerata appear to be banded crosswise. It
feeds upon green weeds such as the delicate Bryopsis
2)lumosa, Codium, Enteromorpha, and Ulva. The
300 Shell Life
foot exudes a very adhesive mucus, and it is conse-
quently difficult to dislodge the slug, which appears
almost to be part of the plant it feeds upon. It is a
remarkable example of the economy of nature when
the food serves at once to nourish a creature and to
provide it with that protective coloration, which
renders it invisible to its enemies. In experiments
made with this species by Mr. W. Garstang, the slugs
refused even to walk over or rest upon red weeds
provided for them, no doubt realising by some sense
that such a contrast made them too conspicuous.
Alder's Slug (Alderia tnodesta) was discovered
nearly sixty years ago by Professor Allman, and
dedicated by him to one of the authors of the
magnificent " Monograph of the British Nudi-
branchiate Mollusca." It is remarkable as being
almost amphibious. Strictly speaking it is not a
Sea-slug, but a salt-marsh slug, as will appear best
by a perusal of Professor Allman's account of its
discovery near Skibbereen, in County Cork, in a salt-
marsh that was only covered by the highest of
spring-tides. He says : " The day was bright and
warm when I met with this curious little animal.
Many had crept out of the water, and were crawling
over the moist fronds of Enteromorpka intestinalis,
and seemed to delight in exposing their slimy bodies
to the influence of the warm autumnal sun. Others
swarmed on the mud in the little shallow pools of
the marsh, when their ova were abundantly de-
posited in the usual gelatinous masses characteristic
of the eggs of the nudibranchiate gasteropods, a
fact which is of itself sufficient to prove that this
strange semi - marine and even semi - aqueous habit
Sea-slugs
301
was quite
natural to our
little nudi-
branch." This
slug is about
half an inch
long, of an oval
shape, variably
coloured pale
yellow, clouded
with clusters
of small dark-
grey spots.
The head is
small, and the
tentacles ap-
pear to be
represented by
mere lobes.
The cerata are
arranged in six
or seven rows
alongeach side.
The Green
Elysia (Elysia
viridis) has its
body depressed
like that of a
leech, but the
head is more
elevated and
adorned with
of the eyes.
It
Green Elysia (enlarged)
pair of ear-like tentacles in front
is little more than half an inch
302 Shell Life
long, and has no cerata ; but the sides of the
body are expanded into wings in which there are
branches of the liver. The foot is narrow, as in
Aplysia, in order to fit it for climbing slender stems,
and the side expansions are sometimes folded up
over the body. Normally this species is green
either a bright green or dull olive but in some
examples the colour varies to reddish brown. These
darker varieties are found along the shore
in shallow water creeping over seaweeds of
similar hue.
The Black Limapontia (Limapontia
capitata) is another leech-like slug, and
although it is less than a quarter of an
inch in length, its dark hue makes it toler-
ably distinct against the bright green of
the finer weeds in the half-tide pools where
it is found. The head looks as though it
had been cut short in front. The eyes are
placed on ridges, and there are no tentacles,
neither are there any cerata. There is one
other British species, the Flat Limapontia
Black (L. depressa}, which is much larger and
Limapontia V ^ " -
more depressed.
The Ridged Acteoii (Actcvonia corruyata) is some-
what similar to the Limapontias, but the head is
adorned by a pair of conical tentacles, behind which
are the eyes, and from which proceed the side ridges
indicated in the names.
The Falmouth Sea-slug (Cenia cocJcsii) is so-called
because it was first discovered at Falmouth by Mr.
W. P. Cocks, and in selecting names for it Messrs.
Alder and Hancock contrived to immortalise both the
E.MHI.ETON'S /Eoi.is ; 2 THREE-COLOUKED /Eons ; 3 REIXJILLED
4 WHITE /EoLis ; 5 VENUS Si.u<; ; 6 CRESTED jEous.
Sea-slugs 303
place (the Cenia of the Romans) and the finder. It
is only about a quarter of an inch in length, and is
distinguished by an elevated back, a somewhat
angular head adorned by a pair of very slender
tentacles before the eyes. The back is black, but
this gradually fades away on either side until it
merges into fawn or yellow.
There is a group of remarkable mollusks scarcely
represented in the British area, and which are there-
fore not of sufficient local import-
ance to have a chapter devoted to / x '
them. They are in no sense slugs, ^____l
but as their natural position appears
to be just after the Nudibranchiata
we deal with them here. We refer
to the Pteropoda, formerly regarded
as a Natural Order, but now con-
sidered as a sub-order of the Opis-
thobranchiata. They are Gasteropods
in which the side expansions of the
foot have been developed into fins, to
fit them for a life at the surface of CWone (somewhat
the ocean. On this account they have
been called the Butterflies of the Sea, but having
regard for their greater activity towards night, it
would perhaps be less incorrect to call them Sea
Moths. In infancy all are provided with shells, but
many dispense with these ere they attain maturity ;
on the presence or absence of a shell in the adult the
primary classification of the group into two sections
is based. Those in which the shell, or a covering of
cartilage, is always present are known as Thecoso-
304 Shell Life
mata ; those which in the adult state have neither
shell nor mantle constitute the Gymnosomata. They
never come near the shore of their own will, for they
are purely pelagic, but many come to land nolens
volens in storms and are destroyed in thousands.
None of them can be said to be truly British, but
the remains of three or four species have been taken
in sufficient numbers and with such frequency that
they must be included in the British list.
Limacina retroversa is one of the shell-bearers.
Its body is more or less tinged with purple, and
the so-called " wings " of the foot are very large,
with a supplementary pair one-third of their size.
The shell is extremely thin and fragile,
almost transparent and clear, but with a
suggestion of yellow when tenanted by
the living mollusk ; there is a tiny
glassy operculurn. It is a common and
abundant species, and its empty shell
may be found in sand on all our shores
where strong currents wash up material from the
deeper waters far out. But the living animal has
been rarely found in our waters. Forbes found it
to the north-west of Skye in 1 850 ; Canon Norman
and J. G. Jeffreys took it in Shetland waters in
1861 and 1867 ; and M' Andrew caught several about
fifteen miles south of Mizen Head, Ireland. Their
position in swimming and floating is reversed the
shell below, the foot expanded above. Their so-called
flight is a movement straight up through the water
by jerks, effected by depressing the wings. By keep-
ing these organs spread they can remain suspended at
the surface or at some distance below it, but on folding
Sea-slugs
305
the lobes they drop to the bottom. A second species
L. helicoides, was found dead at the bottom off the
west coast of Ireland (lat. 56 44' N. ; long. 12 50' W.)
by the Porcupine Expedition, 1869.
Clio pyramidata has a beautiful triangular shell,
of the thinnest crystal, and half an inch in length.
It has been dredged to the north-east
and north-west of Shetland in water
from GO to 84 fathoms, in one case
with the animal in the shell. But in
1869 the Flying Fox off the South of
Ireland, found it in abundance at the
surface.
The only other species that can
urge a slight claim to be regarded
as a Britisher is Clione limacina,
which belongs to the shell-less section and has a
distinct head. It is an Arctic species, and one of the
constituents of the food of whales. Leach captured
a living example on the coast of Mull ninety years
ago ; M'Intosh reported it in considerable numbers
at St. Andrews in 1887, and T. Scott took a specimen
at Inchkeith in 1889.
Clio pyramidata
PONDSHAILS
N spite of the title of this chapter
we are bound by the natural
affinities of the animals to in-
clude in it some species that
have nothing to do with ponds,
one that is an undoubted land-snail, several that
belong to the seashore, and one that is somewhat
amphibious. But all our pond-snails will be included
also, and as these make up the greater part of the
chapter its title will probably be forgiven as the most
appropriate in the circumstance.
The Least Herald-shell (Carychium minimum),
which is found among moss and dead leaves in
woods, will serve to introduce us to the order
Pulmonata, though we shall find the characters of
the order more visibly manifested in following
species. The members of the order are distin-
guished by the possession of two pairs of tentacles,
and by their breathing air by means of a cavity
'Pond-snails 307
formed by the union of the front edge of the mantle
with the neck of the snail. The sexes are united in
each individual ; the shell may be developed
or not ; and there is no operculum. The order ,
is divided into two sub-orders Basommato- ^$
phora, or those that bear their eyes at the Least
base of the upper tentacles; Stylommato- "enlarged")
phora, or those whoso eyes are carried at
the tips of the upper tentacles. There are other
differences : for the moment we will be content with
stating the characters of the first sub-order. The
tentacles cannot be retracted, the teeth arc in many
rows across a radula, there is always a shell and it
is always external. The genus Carychium is in-
cluded in the family Auriculidce, whose members
have conical shells, and as a rule they increase its
roominess not only by adding new matter to the lip,
but also by absorbing the internal partitions, and to
make up for the want of an operculum they develop
the tooth-like processes across the mouth of the shell
shown in the figure above. The breathing organ is
developed into a true lung, for the air-chamber is
lined with delicate vessels through whose tissues the
circulating blood can absorb oxygen.
C. minimum has a shell about one-eighth of an
inch in length; but in spite of its small size both
shell and animal are beautiful. The latter is trans-
parent, with a triangular snout, thick tentacles, and
prominent black eyes. The shell is almost spindle-
shaped, transparent white, glossy, with an ear-shaped
mouth obstructed by two strong teeth. The umbilicus
is represented by an oblique slit. It is fond of damp
places, and must be sought under stones or felled
308 Shell Life
timber, among moss, dead leaves, and grass roots. It
is pretty generally distributed throughout the United
Kingdom and in the Channel Islands, and is fairly
common. According to Moquin - Tandon it can
endure prolonged submersion in water, although
strictly speaking it is a land-shell, but in all prob-
ability its conversion to a terrestrial life is of
comparatively recent date.
The Mouse-eared Alexia (Alexia myosotis), as will
be seen from the figure of the shell, is very close to
Carychium. It is one of a little group that have not
yet lost their fondness for salt water, though this
species has taken to salt-marshes and mud - flats,
where it feeds upon the rotting debris of
seaweeds. The shell measures about a third
of an inch, and varies from yellow to deep
brown in colour; the mouth, which is sup-
posed to resemble a mouse's ear, bears two
teeth on the pillar, with often a tubercle
beside them and a similar projection from the outer
lip. Another species (by some regarded as a variety
only), A. denticulata, lives in rock-crevices and under
stones between tide - marks on the open seacoast.
This form has a much paler, often white, shell, with
a thickened outer lip which is furnished inside with
several tubercles, in addition to those on the pillar.
The Two-toothed Leuconia (Leuconia bidentatus) is
a very similar littoral species, but it is smaller
(one quarter of an inch), and of ivory white colour.
The outer lip has a thin edge but is thickened within,
and the inner lip has two teeth of different size. The
smaller tooth is near the base of the pillar and the
larger a little above it.
Ton d-s nails 309
The Little Ear-shell (Otina otis) is like a copy in
ininature of the shell of Velutina (see page 219),
but the animal is different. When gliding over the
little black lichen that grows abundantly over the
littoral rocks, its shell is evidently several sizes too
small to shelter it, but when the tide goes out, and
the lichen dries up, Otina shrinks and contrives
to get efficient shelter. It is thin, and almost trans-
parent, some shade of red-brown tinged with purple.
Its measurement is only about one-tenth of an inch ;
so it requires to be carefully sought.
We are now done with the seashore for a long
interval, but we may leave it in the pleasantest
manner possible, by way of one of the fresh-water
streams that come down the valley and get lost in
the sandy beach. Here, on the stones in the bed
of the stream, we shall find a tiny limpet-shaped
shell closely adhering in defiance of the strong
current of fresh water for ever rushing over it.
This is the Fresh-water Limpet (Ancylus fluviatilis),
so-called in deference to the shape of the shell re-
gardless of the nature of the mollusk that made it.
The resemblance of the shell is to Hclcion not
Patella, but the animal is widely different from
either of these species, and shows near relation to
the common Limnceids of our ponds. It has a large
head with short cylindrical tentacles,
the eyes at their triangular bases.
The oval foot is almost as large as
the mouth of the shell. The thin
shell is yellowish grey, devoid of gloss, and covered
by a thin epidermis; the spire turned slightly to
the right, whilst the animal is twisted to the left. It
3io Shell Life
is about a third of an inch in length. The animal
feeds upon the minute vegetable growths that cover
the stones, and is especially fond of the aquatic
moss, Fontinalis antipyretica. It does not restrict
itself to the stream, but may often be found on
the wet mossy rocks above. The stomach is said
often to contain fine particles of sand, which are
thought to be taken to aid digestion much as fowls
fill their gizzards with gravel. It has been detected
in the act of getting a free passage to fresh streams
and waters new by clinging to the water-beetle
Acilius sulcatus, which uses its wings for a similar
purpose. The subjoined figure will give an idea
of the character of the te,eth in this species. There
Part of a row of teeth from the radula of Fresh-water Limpet
are 120 rows, and each row contains a central tooth
and 37 lateral teeth on each side of it a total
of 9000. The Fresh-water Limpet is generally
distributed throughout these islands. Its eggs are
deposited in little oval capsules, each containing
eight or ten.
The Lake Limpet (A. lacustris) is a somewhat
smaller and more local species, with a more oblong
shell, the spire of which is distinctly twisted to the
left, whilst the animal is turned to the right. It
inhabits lakes, ponds, canals, and slow rivers, adher-
ing to the under-side of floating and submerged
leaves of water-plants.
The genus Ancylus is included in the family
"Pond-snails 3 1 1
Lhnngeidas, but the more typical characters of that
family are seen in the genus Limncea, where both
animal and shell are twisted to the right. They
are familiarly known as Pond-snails, all the species
being restricted to still, shallow waters. The animal
has a prominent head with short, flattened, triangular
tentacles. From the distant position of the sexual
organs one individual may be united with two
others at the same time, and it is by no means
unusual to see a number of Pond-snails so connected
in one chain. The character of the teeth on the
radula may be gathered from this figure of the middle
portion of a single row ; there is a small central
tooth with 59 laterals on each side, and there are
Portion of row of teeth from radula of Great Pond-snail
110 such rows on the radula, making a total of
12,210.
The Great Pond-snail (L. stagnalis) offers the
advantages of being larger than, and readily dis-
tinguished from, the other members of the genus,
so will serve as a good type. The animal is coloured
yellowish grey ; its head large and adorned by long
tentacles which end in slender points ; the broad
foot edged with yellow. The yellow - brown or
greyish shell is a couple of inches long, and half
as broad ; thin when compared with marine shells,
but tolerably solid for a Pond-snail. It is covered
by a thin epidermis, which frequently decays on
the older portion of the shell and allows the
312
Shell Life
carbonic acid of the pond to attack the lime of
the shell material. It is a general feeder, but with
a distinct bias in favour of animal matter. It will
even attack and kill newts and sticklebacks, whose size
and agility might be considered more than sufficient
to save them from such a fate. It also destroys
the larvae of water-beetles in the same way; but
the mature Dytiscus retaliates by eating stagnates.
It must be confessed, too, that the Great Pond-
snail is, at least
occasionally, a
cannibal, de-
stroying young
individuals of
its own kind.
Its movements
are graceful,
whether it be
ascending or de-
scending aquatic
vegetation or
gliding inverted
along the sur-
face of the water.
They frequently come to the surface to discharge the
effete air in the lung-chamber and take in a fresh
supply. Full-sized specimens of the Great Pond-snail
need be sought only in large ponds ; and it appears to
be a well-established fact that the rate of development
and the ultimate size attained are in direct propor-
tion to the volume of water in which the individuals
have lived. Karl Semper set this point beyond
dispute by separating the fry from a single batch
'Pond-snails
313
of eggs, and rearing them in volumes of water
varying from 100 to" 2000 cubic centimetres, with
a full supply of food in each, and all other condi-
tions equal and as natural as possible. At the end
of sixty-five days those specimens reared in the
maximum amount of water were just three times
the length of those in the minimum volume, and
the intermediate ones in proportion. Its eggs are
deposited in almost cylindrical masses, often curved,
containing from 50 to 120 eggs. Half -grown
specimens are much more slender than the adults,
the shell nearly transparent, and the mouth con-
tracted. The Great Pond-snail may be found in
still or slow waters throughout the country.
The Marsh Limnaea (L. palustris) has a more
solid shell, but its body-whorl is not nearly so
swollen in proportion, so that the length and breadth
measurements are as 5 to 2. The shell is dull
314 Shell Life
yellowish brown in colour, and its oval mouth has
a thickened outer lip. It is usually more or less
coated with mud, owing to its life being
spent in shallow pools, ditches, and bogs.
The animal leads a rather inactive life, and
resents disturbance. The shell measures
1 inch.
The Dwarfed Limnsea (L. truncatula)
might easily be taken on a superficial view
for a young specimen of L. palustris, but
the whorls are turreted (that is, somewhat
flattened above) and with a nearer approach
to glossiness. There is also a distinct umbilical cleft.
Its length is half an inch, and its habitat is on the
mud beside pools and ditches, where it appears
to feed on the low scum-like alycu that grow
in such situations. We have found it near the
base of Cornish cliffs within a foot of high-
water mark, and where it must have been con-
stantly splashed by salt water. Fresh water
trickled through cracks of the limestone and supplied
nourishment for a yellowish-green alga upon which
truncatula appeared to feed, and with which most of
the shells were coated. Viewed from the human
standpoint this species is the most important of the
whole order, for could it but be entirely exterminated
there would be some hope that Rot, that scourge
of the sheep-farmer, could be got rid of. It would
ba foreign to the purpose of this volume to enter
fully into the history of the Liver Fluke (Distoma
hepatica) which causes this diseased condition of
the sheep, from which it is said no less than three
million animals perished in this country during the
Ton d-sn ails 3 i 5
winter of 1879-80 ; but we may briefly explain that
millions of the eggs of this pest are voided with
the excrement of diseased sheep. If such an animal
is turned out on a marshy pasture there will probably
be an abundance of L. truncatula among the grass.
If not, all those eggs will be wasted. They will
hatch, it is true, regardless of the presence or absence
of snail-life, but unless the embryos meet with this
Limncea within eight hours after hatching, they
perish. No other snail not even another species of
Limncea will serve their purpose, but if truncatula
be there the first step in the destruction of a flock of
sheep may be said to have been taken. The Distoma
that is to fulfil its mission enters the branchial
chamber of the mollusk, and there attains a stage
of development that fits it for a different life.
About midsummer, when the grass has all dis-
appeared from the uplands, the sheep are turned
into the marshy bottoms where there is still green
feed. About the roots of the grass there are also
many truncatulas with their branchial chambers
well furnished with Flukes. Sheep are fond of
snails; and this would appear to be a fact well
considered in the Distoma's plan of campaign.
Snails and grass are eaten, and the Flukes, proof
against the action of the digestive fluids, find their
way to the sheep's liver, and begin to set up that
condition of things w r hich the farmer knows as
" Rot." Other species of Distoma that cause similar
trouble to vertebrates, spend their earlier stages in
the bodies of snails. Thus, D. endolabum selects
L. stagnalis as a wet-nurse, and may pass its second
stage in the same species, or may change over to
3 1 6 Shell Life
the fresh-water shrimp, or to a caddis-worm ; finally,
however, it gets into the frog. Another species is
fatal to bats, but works out its destiny in a manner
similar to the progress of D. hepatica. First it
patronises L. stagnalis or Planorbis corneus; its
second stage is passed in certain winged insects
connected with ponds in early life, and these
happen to get snapped up by bats, who thus take
at one gulp the bread of life and the seeds of
death ! Tennyson's well - known line " Nature,
red in tooth and claw," suggestive though it be, is
not adequate to express the fulness of the tragedy.
The Smooth Pond-snail (L. glabra) has also some
resemblance to a small palustris, but though its
length is three-fifths of an inch its breadth
is only one-fifth; the shell has therefore a
more cylindrical appearance, and is thinner
and distinctly glossy. The mouth of the
shell is pear-shaped, and at a little distance
within strengthened by a broad white rib.
There is an umbilical cleft, but it is very
minute. The animal is very shy, and seldom
ventures from the bottom or sides of its ditch or
shallow pool to float along the surface. It is fairly
distributed over England, and occurs in a few places
in Ireland, Wales, and Scotland, but though plenti-
ful where found at all, it is extremely local.
The two remaining species of Limnwa are distinct
from the others by reason of their short spires and
large mouths. The Ear Pond-snail (L. auricularici)
is the larger of these, and its body-whorl is pro-
portionately so enormous that the spire seems
merely a little ornament added to the top. The
'Pond-snails
animal is yellow or brown with a greenish tinge,
dotted with black and white. The tentacles are
broad and diverging, and the eyes
small. The foot is bordered with
yellow. The yellowish shell is semi-
transparent and glossy, bearing in
addition to the distinct lines of growth
delicate spiral ridges. The body-whorl
accounts for quite five-sixths of the
entire shell. The umbilicus is repre-
sented by a slight cleft. It is an inhabitant of
stagnant and sluggish waters, where it usually keeps
near the bottom and exhibits little activity, only
occasionally swimming at the surface. One little
characteristic may help the observer to distinguish
.smaller specimens from some of the varieties of other
species. Limnaeids usually carry their shells with
the spire pointing backwards, but auricularia
carries its shell with the spire at right angles with
the body and the outer lip well covering the VTack
and head, leaving the tentacles above exposed.
The shell is a little more than 1 inch in length,
and a little less than 1 inch in breadth. It is
quite a local species, and though widely
distributed in England and Wales, its
occurrence in Scotland and Ireland is very
limited.
The Wandering Pond-snail (L. peregra)
is the second of those whose shell is nearly
all body-whorl, though here it accounts
for only three-fourths of the whole. The
animal is yellow-grey tinged with green and black
and speckled with whitish and black specks. The
3 1 8 Shell Life
shell is thin, semi-transparent, yellow-brown, with
a large oval mouth. This is the Pond-snail that
everybody knows, because it is ubiquitous wherever
there is slow or stagnant water. Sometimes it
turns up at some distance from the water in damp
meadows, and has even been detected climbing
willow - trees. Like L. stagnalis, the Wandering
Snail is liable to great variation, dependent no doubt
on the area of the pond, the chemical character and
temperature of the water, the quantity and quality
of food available. Some of these varieties differ
considerably from the type. It is a restless creature
when in the water, always on the move, but out of
the water, where it spends a good deal of time, it is
usually very quiet, being then mainly concerned with
the fabrication and hardening of additions to its shell.
Like L. stagnalis it declines to be restricted in its
diet, even practising cannibalism when overcrowded.
It may be seen industriously assisting in the dissolu-
tion of a superfluous dog that has been consigned to
the waters attached to a brick. When drought comes
they protect themselves by burial to a depth of
several inches in the mud whilst it is still soft. A.
thick coating of ice on the pond does not stop their
activity below, and they may even be frozen in solid
ice, apparently, without prejudice to their vitality.
It is very prolific, as may be gathered from its
abundance, and it is estimated that each individual
produces about 1300 eggs in one season. These are
deposited in cylindrical masses of clear jelly. The
shell in the numerous forms varies from half to one
inch in length.
The Glutinous Snail (Amphipeplea glutinosa.) is
*
-
3
m
i TWO-TOOTHED LEUCONIA ; 2 NAUTILUS TRUMPET-SNAIL ; 3 TWISTED TRUMPET-SNAIL ;
4 SHINING TRUMPET-SNAIL ; 5 KEELED TRUMPET-SNAIL ; 6 MARGINED TRUMPET-SNAIL;
7 ROUND-SPIRED TRUMPET-SNAIL ; 8 GLOSSY TRUMPET-SNAIL ; 9 SEGMENTINA I.INEATA ;
10 Moss BLADDER-SNAIL; n FOUNTAIN BLADDER-SNAIL; 12 PHVSA ACUTA.
'Pond-snails 3 1 9
separated from the Limnseids because the mantle has
a contractile expansion, which is usually turned up
until it almost entirely hides the shell. In this con-
dition it presents the appearance of a little dab of
glue, whence the name. As one might expect from
our study of certain marine species that cover up
their shells in this manner, the globular shell is
reduced to the utmost possible thinness, and the spire
is exceedingly abbreviated. It is an active mollusk,
and has a strange habit of disappearing for long
periods from its known localities, and as suddenly
and mysteriously reappearing. Its distribution is very
limited, its headquarters being Kent, Surrey, Berks,
Bucks, Norfolk, north-east Yorks, Westmoreland,
Kings County, and County Down. The Involute Snail
(A. involutcC) is remarkable as being found only in
one station, a small tarn on Cromaglaun Mountain,
in County Kerry. It resembles a glutinosa, in which,
by the growth of the body-whorl and that next to it,
the brief spire is almost hidden in a hollow at the top
of the shell. Owing to its remote habitat the animal
is not well known. The present writer has not seen
it alive ; but some writers say that it agrees with
glutinosa in the mantle expansions enveloping the
shell, whilst others declare that the mantle is entirely
contained within the shell. It has therefore been
variously included as nearly allied to A. glutinosa,
and as being a unique variety of L. peregra \ We
note that Canon Norman in his Revision of the British
Mollusca sets it down as an Amphipeplea, and we
therefore retain it as in his list.
The next section of these Pond-snails comprises
the Flat-coils (Planorbis), made familiar by the
3 20
Shell Life
typical species the Ram's-horn or Trumpet-snail, so
frequently introduced in fresh- water aquaria. Here
it will be seen by reference to the illustration, that
instead of an elevated spire with the whorls one
Rains-horn Snail, PI
above the other they are all in the same plane, and
that the mouth of the shell is to the left instead of
on the right as in Limncea. The spiral is therefore
described as dextral, the shell discoidal. The animals
Tond-snaih 3 2 i
have a short round foot, a short head, and the
tentacles instead of being flat and triangular, as in
LimnoRa, are long and slender, with the eyes at their
inner bases. They are vegetable feeders.
The Ram's-horn (P. corneus), which is the largest
known species, has the whorl rounded, the mouth an
oblique crescent, almost circular. Its colour is reddish
brown approaching to white on the upper surface.
It measures about 1 inch across, and the breadth of
the body-whorl is about one-third. The animal is
dark red-brown, approaching black above and paling
to grey below. It appears to be absurdly small in
proportion to the size of its house, but this enables
it to retreat far in when danger threatens, and also
when active to carry a large supply
of air. When irritated it discharges
from a gland in the neck a quantity
of red fluid, evidently with the object
of making the vicinity unpleasanC.
It is not so prolific as some of the smaller species,
and only produces from 60 to 120 eggs during the
season. These are laid in shield-shaped masses of
firm jelly, each containing from 20 to 40 eggs, which
hatch in fifteen or sixteen days. The epidermis of
young individuals is distinctly downy. Though
occurring in many of the English counties, it is a
very local species ; in Ireland it has been recorded
from Limerick.
The Twisted Trumpet-snail (P. contortus} contrasts
strongly with the Ram's-horn, for though it agrees
with it in having the whorls rounded, it differs so in
size that its greatest diameter is only one-fifth of an
inch. In spite of this diminutive size it has no less
322 Shell Life
than eight coils squeezed together. The upper-side
is flat, with a depression in the centre, the under-side
concave, with a wide and deep umbilicus. The mouth
of the shell is crescent-shaped. The animal is not
very active, though it is fond of floating at the
surface. The egg-capsules of this species only contain
from 6 to 8 eggs, and the total number of eggs laid
during the season is only about 50 per individual.
It is widely distributed throughout the ponds and
ditches of Britain, and occurs in the counties of
Limerick and Tipperary, Ireland.
The following four species resemble each other to
this extent, that their whorls are numerous, angular,
and more or less distinctly keeled. The Round-spired
Trumpet (P. spirorbis) is so named because its keel
is blunt and but little developed. It is little more
than a quarter of an inch across, very thin, one
surface concave, the other almost flat; the mouth
nearly circular. Umbilicus large and shallow. Found
in shallow grassy pools throughout the country. The
Whirlpool Trumpet-snail (P. vortex) is very similar,
but the shell is larger, thinner, flatter, --and
more distinctly keeled towards the lower side.
(jjjjfh The mouth, too, is more oval and angular
7^ than round. It is found in similar situations
Trumpet to the last, but is not so plentiful. The
Keeled Trumpet - snail (P. carinatus) is a
much thicker disk, and measures half an inch
across. The prominent keel is at or near the centre
of the edge. The mouth is an oblique oval, with a
sharp angle above. The flatness of the under-side
makes the umbilicus very indistinct. It is no-
where very plentiful, but is more frequent in the
Tond-snails 323
home and eastern counties. Thence it extends to
Hampshire, Somerset, Dorset, and Gloucester ;
Oxford, Norfolk, Cambridgeshire, Northamptonshire,
Worcester, Warwick, and Staffs. It also occurs in
Ireland, Scotland, and Wales. The Margined Trumpet-
snail (P. umbilicatus), though much like
the last named, is larger, thicker, and
more plentiful. The whorls are narrower,
and the keel instead of being anywhere
near the middle is placed at the lower
edge, so that it forms a very distinct
margin round the disk viewed from below as in the
figure. All these four species are inactive, irritable,
and fond of floating on the surface.
The next group of these Trumpet-snails consists of
three minute species that agree in their shells having
few whorls. Of these the Glossy Trumpet-snail
(P. ylaber) is not so glossy as its name implies, except
in contrast with the following species, but it has
sometimes even an iridescence. It is little more than
one-eighth of an inch across, greyish brown, convex
above with a depressed centre, and concave below
with a large deep umbilicus ; the mouth is almost
round. It occurs in ponds and marshes, but is
very local, though widely distributed. The White
Trumpet-snail (P. albus) is much like it, but the shell
is larger (one-quarter of an inch across), whitish grey in
colour, and all pretensions to gloss are destroyed by
close-set spiral ridges. The upper-side is convex, the
lower concave with a large umbilicus. The mouth
is more oval than round. It occurs in similar situa-
tions to the last, but is not nearly so local. The
strong spiral ridges at once serve to identify it. The
324 Shell Life
Nautilus Trumpet-snail (P. nautileus) is much
smaller that P. glaber, its shell measuring only one-
tenth of an inch across. It is a dull brown, slightly
concave above, slightly convex beneath, bluntly keeled,
and the whorls ridged across, the ridges projecting
on the keel " like the rowels of a spur," as Jeffreys
has it. The rnouth is an oblique oval, arid the
umbilicus is very large. In spite of its minuteness,
its sculpturing makes it a handsome shell. The
animal is very inactive ; it feeds on decaying water-
plants in marshes, ponds, and ditches. A good plan
in collecting it is to carefully pull up some rooted
aquatic plant and wash its base and roots in a jar of
clear water, when if P. nautileus is present in the
pond a large number of specimens will be found at
the bottom.
A species closely allied to P. nautileus was in-
troduced from America, it is believed in cotton-bales,
in the year 1869. In that year Mr. Thomas Rogers
of Manchester noticed it in the refuse water from a
cotton-mill. It was identified as P. dilatatus, an
American species about the same size as P. nautileus,
but with one whorl less, the under-side swollen, the
mouth large and squarish, the outer lip dilated, and
the umbilicus small but deep. Since the year of its
discovery it has largely increased both in numbers
and the area occupied in the Bolton Canal at
Pendleton and Gorton. Its naturalisation illustrates
how easily even minute and delicate aquatic animals
may get carried across thousands of miles of salt
water to new homes.
The remaining species of this interesting genus is
the Shining Trumpet snail (P. complanatus), former]/
'Pond-snails 325
regarded as two species by the separation of some
well-marked individuals as P. lineatus. The shell is
quoit-shaped, convex above, almost flat beneath, with
a central depression on both sides ; semi-transparent,
highly polished, of a reddish or yellowish
horn colour, and bluntly keeled. The body-
whorl clasps the preceding one so exten- shining
sively that only about one-third is visible.
Mouth heart-shaped, umbilicus small. In the form
known as lineatus the body -whorl is partially
divided inside by four or five transverse plates,
which show through the shell as white lines. Some
authors separate this species from Planorbis under
the name of Segmentina nitida. It inhabits small
pools of stagnant water, where it feeds upon decaying
vegetation ; the segmented form being more local
than the other.
The fresh-water snails are brought
to a close with the Bladdei'-snails
(Physci), of which we have two species.
They have very thin and highly
polished shells, with spires turning
from right to left (sinistral). The
animal has two long slender tentacles, with
eyes at their base. The Fountain Bladder-
snail (P. fontinalis) has a shell nearly half
an inch long, much like that of a short-
spired Limncea except that there is no epi-
dermis, and the mouth is to its right instead
of the left. But the characteristic feature of this
species is its mantle, whose sides are expanded so
that they turn up and wrap the shell. The borders
of these mantle-expansions run into finger-like lobes
326 Shell Life
which are shown in our figure. It is a very active
little creature, creeping over the water-plants and
skimming the surface of the water from beneath.
Its home is chiefly in sluggish streams, brooks, and
ditches. The Moss Bladder - snail (P. hypnoru/m)
cannot well be mistaken for its congener, for its
longer shell has a very distinct spire, and it
is not even partially hidden by mantle-lobes.
It appears to delight in basking in the sun as
it glides along the surface of its ditch. It is
very unreliable in its haunts. I have sought
it where a few days previously it had been
abundant, but not a specimen was to be found.
Such sudden appearances and disappearances
can only be explained by supposing the mollusk
spends much of its time out of water; but some
of the stories told of its sudden appearance in dis-
tricts where it had previously been unknown are
in the nature of puzzles. It prefers ditches which
dry up in the summer. It is worth noting that
so far as at present known this is the most
northern of all the Pulmonate mollusks, and has
been found living on the peninsula of Taimyr in
northern Siberia, where the mean annual tempera-
ture is below 10 F. A larger species, P. acuta,
appears to have been introduced to Kew Gardens
with West Indian plants, and now it is thoroughly
acclimatised in the water-lily tank.
The Bladder-snails have a trick of spinning threads
of mucus as they rise to the surface, and by allowing
a short length of it to lie on the water so fix it that
they can use it repeatedly as a direct way up or
down. This mucus thread is not like the byssus of
Tond-snails 327
the bivalves previously described, but simply a secre-
tion from the ordinary slime -gland which most snails
possess. The fresh-water snails that have to glide
over deep impalpable mud require to pour out this
slime to make a safe track for themselves, just as for
quite opposite reasons the land-snail has to use it to
make a smooth path over dry or rough substances.
Some of these slime-ropes of Physa have measured
14 inches. Most of the threads are spun as the snail
ascends, and only rarely (Sphcerium for instance) is
it spun in the descent. Sometimes they are left
for days and used over and over again ; at other
times the descending snail gathers up the thread as
it goes, and probably reassimilates it. Some of the
Planorbids and Limnseids spin these threads, and use
them in the same manner, but the land-slugs, as we
shall see, spin them for different purposes.
.
SSHELLS
F EW living things are probably
so unpopular as slugs, so this
chapter will get skipped by
some of my readers. The
nakedness of their soft bodies,
which necessitates a copious
secretion of mucus, renders them repulsive to us,
and when we think of their ravages among tender
seedlings and succulent strawberries our sensi-
bilities are wounded in a very tender part. And
yet regarding them from this point of view we
may say there are slugs and slugs : w T e may be
a little too indiscriminate in wielding the tar-
brush even where slugs are concerned, and may
condemn as enemies creatures that do us no harm,
though they are related closely to species that work
considerable mischief. In these Land-slugs we find a
tolerably close parallel with the Sea-slugs described in
pages 276-303 : we find closely related to them snails
323
Land-slugs and Glass-shells 329
that are covered with very thin shells, in other
species the shell is reduced until it is only a small
plate acting as a protection to the breathing organs,
and then again it has been reduced to a few discon-
nected grains of shelly material that can serve no
defensive purpose. But, strange as it may appear,
this last section of the Land-slugs will not be dealt
with in this chapter but in the next, their affinities
being rather with the Common Garden Snail.
With the slugs we begin our acquaintance with the
sub-order Stylommatophora, the Pulmonates that
have two pairs of tentacles which can be completely
withdrawn into the head, and that have their eyes
placed at the tips of the upper pair of tentacles. The
sexual organs (with a few exceptions) have a common
opening. The first family of these is the Testacellidce,
the Shelled Slugs, of which three species are found in
this country, but two are believed by some authorities
to be only doubtfully indigenous, and one has certainly
been introduced within the last century, though now
thoroughly naturalised in gardens throughout the
country.
The Carnivorous Slug (Testacella haliotidea) is
about 3 inches in length, and at once strikes the
attention as being of a shape so strongly differing
from that of ordinary slugs. In these the broadest,
thickest part, containing the principal organs, is to-
wards the forepart of the body, which tapers away
behind to a slender tail. All this is reversed in
Testacella, whose stoutest part is to the rear, where
the shell covers the breathing organ. The animal
can elongate itself very considerably in order that
it may pass through the burrows of its special prey
330
Shell Life
the earthworm. It is covered by a tough smooth
skin of yellow-brown, with a slight furrow along
each side from the neck to the shell. The foot
projects a little along each side. The mouth is not
furnished with jaws as in those mollusks that subsist
on vegetation, but its radula is covered with long
sickle-shaped teeth which can make an impression on
the skin of the human hand. Lacking jaws, the car-
nivorous Slug would appear at first sight to be placed
Shell-bearing Slug, Testacclla Tioliotidea (nat sizo)
at great disadvantage in securing such active prey as
the wriggling earthworm ; but it does so by rapidly
extruding its pharynx, and transfixing its victim
with some of the long teeth of the radula, these
organs being then withdrawn and the worm gradually
swallowed.
The average gardener objects to the presence of
worms in his garden, making his lawn unsightly by
their casts, and disturbing the soil in his seed-plots ;
therefore it might be expected he would encourage
Land-slugs and Glass-shells 3 3 i
the efforts of Testacella in keeping down the race.
But to the average gardener all slugs are anathema,
because all are reputed destroyers of seedlings. It
must be admitted on behalf of the gardener that he
has little opportunity for discovering the fact that
Testacella is doing the work that should commend it
to the hater of untidy lawns : for the slug pursues its
prey in the underground burrows of the worm, and
only visits the upper world at night or when the
gi'ound is sodden with moisture. When opposite
conditions prevail, and there is a prospect of drought,
the Testacella will retire to a depth of about three
feet ; or if the conditions preclude so remote a
retreat it will excrete mucus and fashion it into a
tough capsule which hardens and protects the slug
from loss of moisture by evaporation. In like
manner, early in the autumn, after doing their best
to reduce the number of earthworms, they retire into
deep ground and appear no more till the spring-time.
Slugs and snails, as well as worms, contribute to
Testacella's well-being.
Their eggs are not laid in connected heaps, but
separately. They measure about one-sixth of an
inch across which is largo for a slug and are
enclosed in thick tough skin. Cooke says they are
so elastic that they will " if dropped upon any hard
surface, rebound several inches, just like an india-
rubber ball."
The second species of Testacella is T. scutulum,
considered as a variety of T. haliotidea until it was
shown that the so-called variety was more plentiful
and more widely distributed than the type. The
body is yellowish speckled with brown, and the shell
332 Shell Life
is narrower with a longer and more pointed spire.
The third species is T, maugei, believed to have
been introduced from south - west Europe about
1810-12, in earth about the roots of plants, for accord-
ing to Fleming it was first discovered by Drummond,
the botanical explorer, in Messrs. Sweet and Miller's
nursery gardens at Bristol in the year 1812. In a
paper published ten years later Mr. J. S. Miller
expressed the opinion that it had been introduced
with foreign plants, probably from Teneriffe. At
that date it had greatly increased in rich ground, and
in more recent years it began to be discovered in
remote gardens which had been partially
furnished with plants from the Bristol
nurseries. It has now obtained a secure
hold in eight or nine counties, so that
but for existing records it might a few
years hence be regarded as indigenous.
This species is dark brown, and is other-
wise distinguished from its congeners
by its smaller head, and larger, more
cylindrical, shell.
The Slugs proper constitute the genus
Limax, and are represented by eight
native species, of which the best known
is the Great Grey Slug (L. maximus),
which commonly attains a length of 5
or 6 inches. It is by no means restricted
to fields and gardens, but has a decided
liking for sculleries, dairies, etc., where
Slug it can get good food other than that
which is commonly thought to delight slugs. It
keeps its spotted and streaked yellow -grey body fully
Land-slugs and Glass-shells 333
extended when at rest, or with the " tail " curled round
towards the mantle. Close to the tail there is a
slight keel ; otherwise the back is rounded.
The mantle is marked with concentric lines ; (ffi^ll
the upper antennae are long ; and the foot Bbl
is margined with white. Beneath the mantle ^jjjl
is the oblong shell, covering the respiratory She!1 of
cavity whose opening is on the right-
hand border of the mantle towards the back.
All the species in the genus Limax agree generally
with the description above : in addition it may be
said the reproductive orifice opens at the base of the
right upper tentacle, and the mouth is furnished with
a smooth, strongly arched and beaked jaw. They
are often seen in little colonies, and they burrow
slightly beneath the surface for the purpose of
secreting their eggs. Several of them spin threads
of mucus by which they suspend themselves from
trees, rocks, etc. We have already alluded to the
fact that all slugs are not the plant destroyers they
are supposed to be. The Great Slug and the Yellow
Slug (L. flavus) are said actually to decline all foods
containing chlorophyll the green colouring-matter
of most plants. It is therefore highly probable that
the gardener who cannot discriminate between the
various species is wasting much of his valuable time
when he sets out to exterminate slugs. This same
L. maximus is fond of all sorts of kitchen garbage
that is not green, such as fat, bread, meat scraps, milk,
etc. In a passage behind our house in Cornwall we
used to keep meat, milk, " buzzas " of spring- water,
and so forth, until required for use. The cool slate-
floored recess in the wall where stood the water-
334 Shell Life
buzzas was a favourite haunt of L. maximus, and I
was constantly killing them, finding a little later that
other individuals of the same species were feeding on
the remains. This destruction was necessary on my
part, for the slugs, content with the cool niche in the
day,, would ascend at even to a shelf above and make
for the milk-jugs with a view to sipping the cream
from them. The family joint for to-morrow's dinner
hung from a nail in the wall until I observed a couple
of Great Slugs racing up to it. Then I fixed a hook
to the roof for the purpose, for though still accessible
to these creatures it was more remote.
But what Mi\ Cooke x has characterised as " perhaps
the most singular instance of a liking for a particular
food," came within my experience about a quarter of
a century since. In the rear of the publishing house
of Messrs. Isbister on Ludgate Hill, London, there
was an old house used by them for receiving and
storing new books from the binders. During a period
of nearly twelve months one or other of the piles of
new books was constantly found partially damaged
in the morning, though left all right the evening
before. There were slime trails on shelves and
counters, and many of the book - backs exhibited
marks which showed that a slug had been working
at their surfaces with his rough tongue for the sake
of the colouring matter, the glossy finish, or both.
The trouble was laid before me, and a very slight
investigation served to satisfy me that the culprit was
a slug ; but a very long and patient search assisted
by slime-tracks failed to reveal his hiding-place. I
shared the general view of slugs in those days, and
1 Cambridge Natural History : " Molluscs," p. 37.
GREAT GREY SLUG; 2 LI.MAX CINEREO-MGER ; 3 TENDER SLUG; 4 TREE SLUG;
5 YELLOW SLUG ; 6 SMOOTH SLUG.
Land-slugs and Glass-shells 335
directed cabbage and lettuce leaves to be put down in
the hope that the slug would stay upon this choice
food ; but so far as we could determine from an
examination of these leaves the slug never went near
them. I observed that he had either a feeling for
colour or that he found crimson more nourishing, for
his depredations were almost confined to cloth of that
hue. I gave instructions that if caught the slug was
not to be summarily dealt with, but detained until I
could see it and fix its specific identity ; so one day
I received a note to say this molluscan De Wet had
been captured. On arriving on the scene I was
presented with a chip match-box and told the slug
was within. The slug had Leen within, but had
made off again as any sensible slug would have done ;
and he took care never to be caught again, so his
identity could not be established. To-day, however,
with a wider knowledge of the ways of slugs, I do
not feel a shadow of doubt that it was L.
maxim-us turned bibliophile. Had we offered him a
mutton cutlet, or even a slice of bread-and-butter,
instead of cabbage leaves, we might have caught him.
The Tree Slug (L. marginatiis) might be mis-
taken for a half - grown individual of L. maximus
but for the different habitat. Marginatus affects
trees (especially beech and walnut) and lichen-covered
rocks. Its colour is slaty -grey, with a bias either to
blue or green, spotted with yellowish white, and
marked along each side by a darker band. Towards
the tail the back is keeled, and the foot has a whitish
edge all round. The tentacles are much shorter than
in L. maximus ; and the thin glossy shell is almost
flat. It feeds entirely upon lichens, and when seen
22
336 Shell Life
on a tree its colour and markings are so closely in
harmony with its surroundings that it might be
regarded as part of the bark. It frequently descends
from branch to branch by a thread of slime, and the
sexes unite while thus suspended. The Yellow Slug
(L. flavus) is not really as yellow as its names
indicate, the appearance being largely due to its
yellow slime, which is said to stain linen the same
colour. But under the slime the animal is seen to be
yellowish with black spots, of a shape and disposition
to suggest tesselated work. The head and tentacles
which are short are bluish. The foot is white,
margined with yellow. Like L. maximus this
species has no taste for green-meat. It prefers to
haunt cellars, especially if meal, flour, and cream are
anywhere handy. In moist woods it spends the hours
of daylight at rest under stones, coming out at even
and feasting upon any animal remains it can find.
The Field Slug (L. ayrestis) is a much smaller species
about 1| inches long variable in colour, but
usually some ashy - grey tint mottled with dark
brown. The back is keeled near the tail, and the
plentiful slime is distinctly white, tenacious, and
fatty. It is one of the most destructive slugs we have,
viewed from the gardener's standpoint, and is well
worthy of the most zealous attentions at his hands
and feet ! It is not averse to earthworms and insects
as food, but its staple diet is tender vegetables,
seedlings, and ripening fruit in gardens, and crops of
clover, peas, and oats in fields. This is the slug that
is taken alive or boiled in milk as a supposed cure for
consumption.
The Smooth Slug (L. livvis) is an active, glossy,
Land-slugs and Glass-shells 337
little dark brown creature, with a paler mantle, and
exuding a thin colourless slime. Its length is some-
thing between one-half and three-quarters of an inch.
It inhabits marshy meadows, but is very local. The
Tender Slug (L. tenellus) is of similar dimensions,
but in colour it is almost transparent greenish white,
with black head and tentacles. The slime is viscid,
and orange coloured. It is a very local species, the
only places recorded for it being Shetland and
Northumberland.
In all the foregoing species the mantle is wrinkled
in concentric lines as described for L. maximus ; but
in the two following the elevations of the mantle
take the form of little knobs instead of lines, so
that it is said to be shagreened. On this account
they are placed in a sub-genus, Amalia. The
Keeled Slug (L. carinatus) is about 2-|- inches long,
of a yellowish or reddish-brown colour speckled
with black or dark brown, the back with a
prominent keel from mantle to tail of a lighter tint
than the ground colour, and usually amber coloured.
The oblong mantle has a dark line on either side.
The foot has a pale margin, and the thick adhesive
slime is colourless. This is a common species, and of
general distribution. Though it will take earth-
worms, caterpillars, and its younger relations as a
change of diet, it is distinctly a vegetable feeder, and
the author of considerable havoc in gardens and
fields. The Small Black Slug (L. gagates) is of similar
dimensions, but its colour is variable black, slaty,
red, brown, or even yellowish with darker markings.
The head and tentacles slate coloured, and the mantle
larger than in L. carinatus, forming two lobes, with
338 Shell Life
the respiratory opening more forward than in that
species. This also has the prominent keel. The
slime is white or pale yellow. When at rest it
contracts itself into an almost globular shape. It
occurs in hedgerows and gardens, but its distribution
is not nearly so wide as that of L. carinatus, and is of
only local occurrence.
The Pellucid Glass-snail (Vitrina pellucida), which
is frequent under mossy logs and stones in damp
woods, has special -interest for us because of its
intermediate position between snails and slugs.
The animal may be called a slug, but it has a shell
ordinarily of just sufficient dimensions
to accommodate it within, yet of such
exceedingly delicate substance as to
be little protection from enemies.
Si m roth believes that it is the ances-
tral form from which the Slugs have
been evolved by the gradual degenera-
tion of the shell, and its investment
by the mantle. It may also be reasonably supposed
that in the opposite direction by the development of
the shell in size and solidity, such an ancestral form
may have originated the Snails (Helix), the tliin-
shelled Hyalinias marking a stage on the way. Our
only native species is very hardy in spite of its
delicate covering, and it may more commonly be
found in winter crawling over mosses and liverworts
than in summer. This hardiness may be partly due
to the fact that the eggs are not deposited until
autumn, so that the young ones enter upon life at a
time when thick-shelled snails have retreated into
snug quarters for the winter and have plastered up
Land-slugs and Glass-shells 339
their shell to keep out the cold. As shown in our
figure the shell is slightly invested by the mantle,
which has a lobe on the right side, and this is
turned up over the shell when the animal is active.
Such a habit of shell-investment extended, as we
have seen it in many marine species, until the
shell is completely hidden, may have brought
about the conditions existing in Limax where the
shell is reduced to an almost flat plate and is
quite hidden away. The Glass-snail has a quaint
habit, which is no doubt protective, of giving a
vigorous jerk to its tail when alarmed, and so it
throws itself off from the twig or stone it may be
gliding on and drops among the moss below. It is
everywhere plentiful in suitable situations. It ap-
pears to be as much carnivorous as herbivorous,
sometimes attacking in force a sickly earthworm, and
showing a liking for horse-droppings. These traits
are shared by the next genus, Hyalinia, in which
the shell is sufficiently roomy always to accommodate
the entire animal.
Draparnaud's Snail (H. draparnaudi) is the largest
of the genus, of which there are ten native species. This
one is exceedingly local, and has been found only in
Guernsey, Falrnouth, Torquay, Bristol, and Isleworth.
The shell is about three-quarters of an inch across,
glossy, reddish above, whitish beneath. Mouth an
oblique oval ; umbilicus large. A common species
that may be confused with the foregoing is the so-
called Cellar Snail (H. cellaria^, which scarcely
exceeds half an inch across, but it is flatter above,
more yellow than red, whilst below it is distinctly
white, though sometimes with a greenish tinge. As
340 Shell Life
in all the species of the genus, there is an open
umbilicus. The animal is slaty-grey in colour, of a
shy and retiring nature, and evil-
sinelling. It will be found under
brick rubbish in backyards, in cellars,
under logs and stones in woods, and
in mossy hedgerows everywhere. The
Garlic Snail (H.alliaria) is more convex
and darker above, less white beneath,
and only a quarter of an inch across.
The animal is much darker than H. cellaria, and its
tentacles are proportionately shorter ; but the shell
may easily be confused with that of a half-grown Cellar
Snail. Jeffreys' test in such a case is to view the two
shells sideways, when the last whorl of alliaria will
be found to be less deep than in cellaria. It is
more local than the last named, and must be sought
in more open situations, but hidden under stones.
Its name is due to the fact that when irritated it gives
off an odour of garlic which varies in intensity.
Too much importance must not be attached to this
characteristic in arriving at the identity of the species,
for several of its congeners have the same peculiarity,
though perhaps less markedly. It is, no doubt, a
protective endowment, for the odour is not perceptible
until the snail is interfered with, and continued
irritation appears to lessen its pungency.
The Glossy Glass-snail (H. glabra) is a little larger
than the Garlic Snail, whose odour it shares under cer-
tain conditions as when being killed by the boiling-
water method. The animal is bluish grey, with
zebra-like stripes in front and mottled behind ; the
sides marked with a dark line just above the foot.
i CARNIVOROUS Smr, ; 2 TESTACELLA MAUGEI ; 3 FIELD SLUG ; 4 YELLOW SLUG;
5 SMOOTH SLUG ; 6 SMALL BLACK SLUG ; 7 KEELED SLUG ; 8 TAWNY GLASS-
SNAIL ; 9 CRYSTAL SNAIL; 10 HOLLOWED GLASS-SNAIL; u GARLIC SNAIL;
12 DRAPARNAUD'S SNAIL ; 13 GLOSSY GLASS-SNAIL ; 14 SHINING SNAIL ;
15 CELLAR SNAIL.
Land-slugs and Glass-shells 341
The shell is rather convex above, less so beneath,
dark horn coloured, thin, and exceedingly glossy,
clouded with white round the narrow but deep
umbilicus. It inhabits woods and fields, but though
widely distributed it is quite local. The Smooth
Glass-snail (H. nitidula), though about the same
size or slightly larger than the last, is less trans-
parent, and more like the Cellar Snail, but the spire
is more raised than in that species, the surface less
glossy, the mouth less oblique, and the umbilicus is
larger and deeper. It is found under stones, dead
leaves and moss, in woods and hedge banks, where it
frequently buries itself. The Rayed Glass-snail
(H. radiatula} is equally convex above and below,
dark brown, thin, very glossy, marked across the
whorls by well-defined lines, which give the rayed
appearance. The umbilicus is small, but tolerably
deep. The shell only measures about one-seventh of
an inch across, and may be sought in similar but
moister situations than those given for H. nitidula.
The Clear Glass-snail (H. pura) is like H. nitidula,
but differs in being much smaller (one-third inch
across) and the umbilicus much narrower. It is
widely distributed, but somewhat local. It keeps
almost entirely buried under dead leaves and moss
in woods. The Shining Snail (H. nitida) somewhat
resembles H. radiatula, but is larger (one-quarter
inch), has a more prominent spire, and the rays are
much less distinct. It is also less convex below than
above, and is not so thin. It is found at the roots
of grass, under stones and among moss in damp
places. The Hollowed Glass-snail (H. excavatus)
is so-called on account of its wide and deep umbilicus.
342 Shell Life
The shell is more convex above than below, dark
brown, not very glossy, the whorls crossed by deep
lines. It is a local species, occurring chiefly in the
south and west of England, its habitat under logs
and dead leaves in woods. The Crystal Snail
(H. crystallina) is only one-eighth of an inch across,
glossy, thin and translucent, with a greenish tinge.
It has a very narrow umbilicus. The animal is
greyish white, with the upper tentacles deep black.
It occurs about decayed stumps, dead leaves and moss,
and under stones, in woods and meadows. The
Tawny Glass-snail (Conulus fulvci) differs from the
Hyalinias in having a pyramidal shell, the
spire being considerably raised ; there is also
Tawny a me re depression (with occasional perfora-
tion) instead of an umbilicus. The colour is
indicated in the names, and the shell is thin and
glossy. Its height and its breadth are equal about
one-tenth of an inch. Its habitat is similar to that
of H. crystallina. This species from the form of its
shell makes an easy passage to the snails described
in the next chapter.
In another respect two species of Hyalinia show
affinity with the genus Helix, that is in the
development of what has been termed the "love-
dart." The species referred to are H. nitida and H.
excavata. The instrument consists of a delicate
shaft of carbonate of lime, finely-pointed, and con-
tained in a pocket of the female organ, whence it is
discharged just prior to the union of two individuals,
and embedded in the flesh of its mate. It is only to
be found in mature snails, and its office apparently is
to excite the sexual instinct.
UR introduction to the Land-
Snails must be made through
a few species that may appear
to belong to the previous
chapter and to have been forgotten when that
was written. They are slugs it is true, and until
quite recently they were classed with the true
slugs of the genus Limax, but of late they have been
separated as having closer affinity with snails of the
genus Helix they may, indeed, be said to fall in with
the popular and ancient definition of a slug, which
says it is a snail that has cast off or not yet developed
its shell. The slugs of the genus Avion have not
even the debased shell the mere scale that, hidden
by the mantle, protects the respiratory chamber in
Limax ', in Arion it is represented by a few dis-
connected granules of shell-matter covered by the
hinder part of the mantle. They may be distinguished
344
Shell Life
at a glance by noting that the orifice to the res-
piratory chamber is near the forepart of the mantle
instead of to the rear, and the animal has generally
a closer resemblance to a snail minus his house.
Instead of the mantle being marked with concentric
wrinkles it is uniformly shagreened ; and the tail
is furnished with a slime gland. They appear to be
Black Slug
more hardy than the Snails (Helix), and are active
for some time after these have gone into hiber-
nation.
The Large Black Slug (A. ater) is a familiar
object in all parts of the country, in wood, field,
hedgerow, and garden alike, in the last named
doing great damage through its fondness for fruit
damage which the gardener commonly debits
KEELED SLUG ; 2 SMALL BLACK SLUG ; 3 DUSKY SLUG ; 4 GARDEN SLUG ;
5 BOURGUIGNAT'S SLUG ; 6 SPOTTED KERRY SLUG.
Land-snails 345
to the wasp in addition to the share of blame
that rightly belongs to the insect. A full-grown
Black Slug measures about 5 inches, and its upper
surface is covered with coarse long tubercles. The
tentacles are shagreened like the mantle, and their
tips are much swollen. In most cases, but not all,
the sides of the foot are margined with yellow
crossed by dark lines. The Black Slug is by no
means always black it is sometimes white, but
more often yellow, red, brown, or black, and there is
reason to believe that this variation is protective in
character. We have referred to the Black Slug's
fondness for fruit, but it must not be supposed it is
at all exclusive in respect to diet. Fruit is not
always about, so the Black Slug can make a good
meal of table vegetables, of wild plants, a dead mouse
or bird, earthworms, bread, its own kith and kin, or
their slime. It has been known to devour news-
paper after two days' fast. The same specimen
besides eating the dead bodies of five other slugs, a
dead freshwater mussel, some insects, finally ate a little
Pear's soap ! though this, Mr. H. Wallis Kew says,
it took reluctantly, as a person takes physic, no
doubt. It showed the same reluctance respecting the
poisonous berries of the Arum, and the leathery
leaves of Sea Holly and Polypody, though it readily
fed upon the lichens Evernia and Ramalina, and
such biting things as the leaves of buttercups. It
may often be found on Agarics and Boleti, in which it
scoops deep holes, but it may be noted that its evident
enjoyment of this class of food is no guarantee that
the particular fungus attacked is suitable for
human consumption, for the Black Slug will eat the
346 Shell Life
peppery and poisonous Emetic Mushroom (Russula
emeticci). It is a very prolific slug, and during the
breeding season May and June it lays nearly 500
oval and transparent eggs, which are deposited at
the roots of plants, and in other suitable situations,
in batches. The shell is represented by a number of
roundish or oval granules, which were formerly
sought for use in medicine what has not been used
in medicine ? and on this account Ferussac gave
this species the name of A. empiricorum, but the
name used by Linnaeus A. ater has precedence.
The Dusky Slug (A. subfuscus) is more cylindrical
than the Black Slug, of a reddish-brown colour,
marked along the sides with faint black bands. The
back is slightly keeled behind, and the foot is grey
crossed by black lines. The opening to the lung
chamber is almost in the middle of the mantle
margin. It inhabits woods and damp places, and
attains a length of from H to 2-|- inches. The Garden
Slug (A. liortensis) is about the same size as A.
subfuscus, but varying in colour just as A. ater does,
from which it is distinguished by its relatively more
slender proportions and by the back being marked
by a dark stripe down the middle and a narrower
stripe along each side. The mantle is similarly striped.
The shelly granules are in this species united into an
irregular mass. It is not confined to gardens, but is
also common in hedges and woods.
The Spotted Kerry Slug (Geomalacus maeuloBw)
represents a genus generally similar to Anon, but
the animal is capable of far greater extension, so that
it can pass through very minute apertures ; its res-
piratory orifice is near the front of the mantle, and
Land-snails 347
the reproductive opening at the base of the right lower
tentacle. The shell is solid, claw-shaped, with con-
centric lines. All the tentacles are short, and without
eyes. There is a large slime-gland at the tail, as in
Arion. The upper -side is coarsely tuberculated,
black spotted with yellow or white, as well as being
sprinkled with minute specks of black and white.
The thick brown foot is transversely furrowed and
its sides striped ; the under surface has a broad clear
band with a band of light yellow or grey on either
side of it. This mollusk was discovered nearly sixty
years since, by Mr. Win. Andrews, on rocks around
Lough Carrough, in County Kerry, and it has never
been found many miles away from that locality. The
discoverer describes the living slug as a thing of
beauty, and Dr. Scharff has more recently pointed
out that its colouring is of the protective kind,
harmonising so admirably with the lichens that
cover the rocks where it is found that the slug does
not hesitate to lie extended among them even when
exposed to sunshine.
The snail-like slugs are succeeded by the genus
Helix, whose members are understood more par-
ticularly when the word Snail is used. All the
species are provided with a shell sufficiently roomy
to accommodate the entire animal, but it varies
considerably in size, shape, colour, and ornamentation.
It may be disk-shaped, round, or nearly so, or conical.
The lip is frequently strengthened by an internal rib,
and there is usually an umbilicus. The animal has
a thick mantle which lines the shell, and the head
bears a couple of pairs of tentacles, the upper pair
carrying the eyes at their tips. Its mouth is
343 Shell Life
furnished with an arched and ribbed jaw, and the
outer teeth of the well-furnished radula are them-
selves toothed that is, their edges are cut up like
the edge of a saw.
There is no operculum to close the shell in Helix,
but to prevent undue evaporation in summer the
mouth of the shell has a film of mucus spread across
it, and this rapidly hardening keeps the dry air out
and the moisture inside. In winter this epiphragm,
as it is called, is again produced, but then consists
of many layers, because it has to last much longer
and exclude cold. At this period the snails have
usually retired to some sheltered corner among dead
leaves, or in the crevices of walls, where they can sleep
through the inclement season secure against wet and
frost, and from which they emerge with the warm
spring rains. Their eggs are roundish and enclosed
iu tough " shells " in the case of the Roman Snail it
is really a shell containing much lime which are
laid in little heaps, often in burrows excavated by
the foot of the snail. We have already mentioned
the " love darts " of certain species of Zonites, which
connect that genus with Helix, in which the possession
of these singular instruments is characteristic of about
two-thirds of the native species.
Twenty-five British species are included in the
genus Helix by the principal systematists, but from
time to time others have broken off' a few species
here and there to make new genera; and quite
recently there has been a tendency on the part of
some conch ologists to respect all these little genera,
with the result that the important genus Helix, as
moat people know it, is left with only a few species
Land-snails 349
and becomes no more important than Clausilia. In
these pages we have kept the genus intact.
The Dwarf Snail (H. pygmcm) is the least of the
British species, and one that does not fall into the
hands of the collector who has little patience. More-
over, the lens is required for its examination when
obtained, to make sure that the specimen is not the
young of another species (H. rupestris), which is also
very small, but twlae the size of pygincea. The
Dwarf's shell is circular, flattened from above and
below, consisting of four whorls, and measuring one-
sixteenth of an inch across. It is very thin, light
brown, with a silky gloss ; the spire but slightly
raised, the umbilicus large, and exposing the whole
interior of the spire ; mouth horseshoe-shaped, without
an internal rib. The animal is brown or grey,
minutely dotted with black. It chiefly affects woods,
\vhere it lurks under stones and dead leaves during
the daytime. The knowledge that it is found in a
particular wood may be utilised by the collector with
limited time, if he will follow Dr. Turton's plan:
collect a bagful of moist dead leaves, and on reaching
home spread them to dry on an open newspaper ;
the snails can then be sifted out easily. It is a
widely distributed species.
The Rock Snail (H. rtipestris), which resembles the
last somewhat, attains a diameter of one-seventh of
an inch. The shell has five whorls, is of more solid
material than that of H. pygmcea and has a deeper
suture that is, the slight trench separating one
whorl from another. It is also less flattened above,
of a darker brown, and the whorls are crossed by fine
lines. It inhabits the crevices of rocks and walls in
350 Shell Life
elevated positions. It agrees with the Dwarf in
carrying its shell upright when gliding, though most
of the genus carry theirs to one side. The eggs are
retained until they hatch.
The Rounded Snail (H. rotundata) has a general
resemblance to the previous two species, but is much
larger, exceeding a quarter of an inch in diameter.
The shell is more opaque, coloured a yellow-brown
with curved red-brown stripes at regular intervals
across each whorl. The whorls are also adorned with
numerous transverse ribs, except the first. The
periphery or circumference of the shell is bluntly
keeled. The mouth is half-moon shaped, and in old
specimens is strengthened by a white rib inside. The
umbilicus is wide and deep. The animal is very shy.
This very common species may be found almost
anywhere by turning over stones lying on the earth ;
it also affects the shelter of loose bark on decayed
trees, the moss, leaves, and decayed wood that may be
found about old stumps.
The Beautiful Snail (H. pulchella) is another dimin-
utive species, the shell measuring only one-eighth
of an inch across, depressed but convex above, of a
greyish-white colour, transparent and glossy. It is
ornamented with slightly raised curved ridges across
the three and a half whorls, which are separated by a
rather deep suture. The nearly circular and slightly
oblique mouth has a thick and expanded lip. The
umbilicus is rather large, and discloses all the interior
of the spire. It is a widely distributed species, whose
favourite lurking places are under stones and logs, at
the roots of grass and among moss.
The Prickly Snail (H. ucideata), though also small,
i ROUNDED SNAIL; 2 BKAUTIFUI. SNAIL; 3 ROCK SNAIL; 4 PRICKLY SNAIL:
5 CHEESE SNAIL; 6 LAI-IDAKY SNAIL; 7 PLATKD SNAIL; 8 BRISTLY SNAIL;
9 RUDDY SNAIL; 10 SILKY SNAIL; n GREEN HAIRY SNAIL; 12 DUSKY SNAIL ;
13 KENTISH SNAIL; 14 SANDHILL SNAIL; 15 COPSE SNAIL;
16 CARTHUSIAN' SNAIL.
Land-snails 351
is easily distinguished from all its congeners by the
shape and ornamentation of its shell. This is conical,
the spire raised considerably, of a dull brown hue,
and the epidermis forming ridges which in the centre
of each whorl are developed into sharp spines. The
mouth is thickened by a white rib. The shell is
carried erectly when the animal walks. It must be
sought about woods, on the dead leaves of beech,
alder, and holly, and among scale-mosses (Junger-
mannia). It is said to climb trees, but is apparently
too knowing to take the trouble to climb down ; its
method of descent is to attach itself to a nearly falling
leaf and use this as a parachute by which to make
the descent. Small snails that attach themselves to
dead leaves are, no doubt, often distributed widely
from their birthplace by the strong winds of autumn.
The Plated Snail (H. lamellata), of similar propor-
tions to the last named, is less conical and more
globose, more tawny, with a satiny lustre. The
epidermis is produced into close and regular plaits
or folds across the whorls. The half-moon shaped
mouth has a thin lip, and the umbilicus is narrow,
but very deep. Its habitats are similar to those of
the Prickly Snail, bub its range is restricted to
Scotland, Ireland, and the north of England.
The Cheese Snail (H. obvoluta), so called by Dr.
Gray from its resemblance to a flat cheese, is also
quite distinct from all other native species. It is c,
round coil, flat above, not unlike the Ram's-horn
Snail (Planorbis corneus), the spire depressed below
the level of the body-whorl, the periphery rounded.
It is half an inch in breadth, its colour dull ruddy-
brown, and the epidermis is thickly covered with
2 3
352 Shell Life
stiff hairs of the same tint. The mouth is a blunt
triangle, the lip thickened and reddish, with an
internal protuberance near the periphery. There is
a large umbilicus. This mollusk has only been found
in a few places in Hampshire and Sussex, and until
seventy years ago none of our naturalists were
acquainted with British specimens. For years it
was thought that it had been introduced from the
Continent, and that individuals planted out at
Ditcham and Stoner Hill had established colonies at
those places. Later it was found to occur on the
northern escarpment of the South Downs in Sussex,
and in Kew's Dispersal of Shells (1893) Mr. Clement
Reid, F.L.S., has shown that all along that range as
far east as the river Arun, wherever there are patches
of ancient wood the snail may be found. He says :
"The species seems to be very particular as to its
habitat, it must have calcareous soil and plenty of
shade, but the ground must never be sodden. It
seems also to be an exceptionally sedentary species,
for as far as I could see it was confined to ancient
woods, and was never to be found in plantations,
even if the trees were a hundred years old. Almost
the only place where the necessary conditions are
combined is the chalk escarpment, for there we find
slopes too steep ever to have been cultivated, and on
these, consequently, are preserved many patches of
the ancient forest. Nearly all these scattered patches,
as far east as the river Arun, are full of H. obvoluta.
East of the Arun there are few traces of the old
forest, and I have not yet come across this snail. . . .
Everything seems to show that the creature is a relic
of our old woodland fauna, now nearly exterminated
Land-snails 353
through the destruction of the forests." Its shell is
closed in winter by a very thick white epiphragm.
The Lapidary Snail (H. lapicida}, though it has
a depressed shell like the Cheese Snail, has the spire
distinctly raised and the periphery sharply keeled.
The colour is dark ruddy-brown, paling to a dirty
yellow in places. The mouth is oval, with a notch
corresponding to the keel ; the thickened white lip
expanded, and forming a complete peristome. The
umbilicus is large and deep. The epidermis is very
finely granulated, so that through a lens it has the
roughness of a line file. Probably, as Jeffreys
suggests, this appearance may have led to the belief
current in Linnasus' day, that this snail bored into
wood and stone. It was owing to this
belief that Linnaeus called it lapicida
or the Lapidary, but though Jeffreys
terms this an inappropriate name, it La P |dar > Sr
is not so when one regards the shape of the shell with
its sharp keel, much resembling the polishing wheel
of the cutter of precious stones. The Lapidary Snail
has only been found in England and Wales, so far as
these islands are concerned, and it extends no farther
north than Yorks. It is most frequent on soils of a
calcareous nature, though by no means restricted to
them. It is a very difficult snail to find in dry
weather even in places where it is abundant, but
after a heavy summer shower it may be found in
thousands on trees (especially beech) and palings. It
is remarkable how well its form is adapted for con-
cealment in both these situations. When at rest on
beech trunks it is the exact counterfeit of the low-
knobbed excrescences on the smooth grey bark, and
354 Shell Life
along the bottom framing of park palings it as closely
resembles the heads of the iron bolts with which the
framing is put together.
We have now a little group of snails that may well
be considered together, as they agree in the fact that
the epidermis is covered with spreading hairs. The
first of these is the Bristly Snail (H. hispida),
which measures about one-third of an inch across
the low - spired shell. This is thin and semi-trans-
parent, yellowish brown, and thickly covered with
short, recurved white hairs, which are not easily
rubbed off. Sometimes the mouth is furnished with
an internal w T hite rib. Umbilicus of moderate width,
but deep. This species is common everywhere under
stones, logs, and among moss. A variety (concinna)
of this species has been regarded by some writers as
a distinct species. It differs from the type in being
slightly larger, the upper surface of the whorls are
less rounded, the colour light ash - grey occasionally
streaked with reddish brown, frequently with a white
band on the body-whorl, where there is a suspicion of
a blunt keel. The hairs are more scattered, and easily
detached. Umbilicus rather broad. It is found at
the roots of grass in moist places, and under stones
and nettles. It approaches in several of these re-
spects to its larger relative, the Ruddy Snail
(H. rufescens), which has a nearly opaque shell half
an inch broad, of an ash-grey colour suffused with
red, and the whorls closely wrinkled. It is bluntly
keeled, and there is often a white spiral line on the
body- whorl. The umbilicus is fairly large, and deep.
Although not well known to others than conchologists,
owing to its nocturnal habits, it is very plentiful
Land-snails 355
along hedgerows, in gardens and woods. It is partial
to beds of strawberry and violet, and in the former
may do great damage to fruit without its presence
being suspected, the destruction being debited to
birds. If a visit be paid to the strawberry bed
after a heavy summer shower, a different tale may
be told. Thrushes appear to be very fond of this
species as a food. In its young state that is up to
the age of four whorls the shell is covered with
hairs, but these are short and readily fall off.
The Silky Snail (H. granulata) may be mistaken
for the Bristly Snail, but though the diameter of the
shell is about the same in each, that of the Silky
Snail is thinner, and more globular, being more
rounded both above and below. The colour too is
greyish white, with some approach to glossiness. The
thick epidermis is covered with long fine downy
hairs which do not fall off. The spire is considerably
raised, the umbilicus exceedingly narrow and almost
closed. The feel of the shell when handled is quite
distinct, and so numerous are the hairs that it may
be dropped on hard surfaces with impunity. It is a
local species, found on mossy hedgebanks. In Corn-
wall I found it had a great weakness for the Hart's-
tongue fern (Scolopendrium vulgare). The Green
Hairy Snail (H. revelata) is of similar proportions
to the Silky Snail, but is compressed above. The
shell is very thin and semi - transparent (which
granulata is not), coloured yellowish green, and the
four and a half whorls are wrinkled transversely,
which gives the very deep suture the appearance of
being puckered. The thick epidermis is covered with
short white hairs which are easily detached. The
356 Shell Life
mouth is never ribbed. The umbilicus is narrow and
shallow. Its habitat is on the downs along the coasts
of Devon and Cornwall, and in the Channel Islands,
where it buries itself deeply in winter and dry
weather.
The Dusky Snail (H. fusca) in point of size and
shape is much like H. revelata, but the shell is
yellowish brown and it is not hairy. It is so thin as
to be transparent ; it is glossy, and the five and a half
whorls are strongly wrinkled across. The umbilicus is
extremely narrow. Though widely distributed this is
a local species, and its habitat is among nettles and
dog's-mercury, under the leaves of young alders, and
on ferns. It appears to endure a much lower tem-
perature than most of its congeners, and has been
found active in winter when the thermometer
registered several degrees of frost.
The other members of the genus Helix are all
comparatively large. The Kentish Snail (H. can-
tiana) owes its name to the fact that
specimens from Kent were first observed
to be different from H. rufescens, and
it was then thought to be peculiar to
that county. Although most plentiful in
the south of England its range extends
as far north as Northumberland. It has a somewhat
globular shell, thin in texture and semi-transparent ;
the colour yellowish white, tinged with ruddy-brown
towards the mouth and on the under-side, often with
a narrow white band extending half-way or more
round the body-whorl. Adult specimens have a thick
white rib just inside the slightly expanded mouth of
the shell. The umbilicus is narrow but deep. Young
Land-snails 357
examples have the epidermis covered with short hairs
which soon fall or get rubbed off.
The Carthusian Snail (H. carthusiana) claims close
kinship with the Kentish Snail, but it is smaller, more
depressed above, more convex beneath, more solid in
structure, less transparent. The colour is
yellowish white, tinged with fawn colour,
usually with a white spiral band on the
body-whorl as in the Kentish Snail. The
mouth is strengthened by a white rib, but
it is placed nearer the opening than in the las.
species. Umbilicus narrow, and partly concealed by
the growth of the lip. It occurs only in hollows of
the South Downs in Kent and Sussex.
The Copse Snail (H. arbustorum) has a solid and
very globular shell three-quarters of an inch across.
Its colour is a pinkish brown splashed and spotted with
yellow, and with a darker brown spiral line running
just above the middle of the whorls. In many
specimens the thin epidermis has largely perished.
The mouth is strengthened by a broad white rib at
the lip. The small umbilicus is almost hidden by
the outer lip. Although its range extends through-
out Great Britain, it is distinctly local in its occur-
rence, and does not appear to inhabit Ireland. Moist
and shady woods, especially of alder and willow, and
the neighbourhood of streams, are its favourite resorts.
It is possible that this species finds abundant moisture
a necessity, for Mr. T. Scott has recorded that a
specimen kept in a kitchen knew the way to the
cold-water tap which it was in the habit of visiting,
and apparently enjoyed the water which fell upon it.
The Sandhill Snail (H.pisana) whose specific name
358 Shell Life
indicates that the original description of it by Petiver
was founded on specimens obtained at Pisa, in Italy
measures three-quarters of an inch across its five and
a half whorls. The ground colour of the globular shell
is yellowish white, over which runs a varying number
of spiral brown lines and short oblique streaks. The
mouth of the shell describes two-thirds of a circle,
and is strengthened by a slight rib. The small
umbilicus is partially closed by the expansion of the
lip. The animal feeds in this country on Sea Holly
(Eryngium maritimum) and thistles, to which it may
be found clinging in the daytime in the few places it
inhabits. These are in the neighbour-
hood of Tenby and Manorbeer, in Pem-
broke ; Swansea, where planted by Mr.
Jeffreys ; St. Ives and Whitsand Bay, in
sandhill snail Cornwall ; Meath and Dublin Counties
in Ireland, and at Jersey and Guernse}^
It is only found on sandhills close to the sea, and
this fact implies that it may owe its presence in these
islands to accidental importation with ballast from
the Continent, where it is found far inland, as for
example in central France and Spain. In the hot
dry weather of summer it buries itself in the sand
at the roots of plants. Not only does it skeletonise
the plants mentioned it also has a taste for animal
food ; the Rev. A. H. Cooke relates how he placed
living specimens of this species and the Heath Snail
(H. ericetorum) in a box together, but when they
were inspected twenty-four hours later, pisana had
cleaned out all the shells of ericetorum.
The Banded Snail (H. virgata) is an exceedingly
variable species, a dozen forms being sufficiently
Land-s nails 359
distinct to have received varietal names. It is very
probable that H. pisana, ericetorum, and caperata
have been evolved from this species. In the typical
form the shell is conical, somewhat globose, and .fairly
solid, though not quite opaque. The ground colour
is white or of a creamy tint. A brown band of vary-
ing breadth and tint runs spirally just above the
periphery, and below this there may be five or more
thinner and less distinct bands which are more or less
broken and blurred. The tip of the raised spire is
usually brown and shiny. The very regular curves
of the mouth describe three-quarters of a circle, and
a little way within a rib is formed in adult shells.
In many cases the rib is coloured brown, but often
it is white. The umbilicus is of moderate width, and
deep. Among the varieties is one totally devoid of
colour in which the spiral lines are still very evident
owing to their being less opaque than the rest of the
shell. The Banded Snail is widely distributed in
England, Ireland, and Wales, but in Scotland appears
to be found only in Ayrshire. It is most abundant
along the south coast, especially in Cornwall, on
Dartmoor, and along the South Downs. To get an
accurate idea of its profusion in these parts it is
advisable to walk out on the pastures after heavy
summer rain ; then one can excuse the local idea that
these snails come not from among the herbage but
from the heavens, as though they were hailstones.
Fences, gates, stones, thistles, and grass stems are so
thickly coated with them that one marvels how it is
possible for them to find cover or food at other times.
These mollusks have long been regarded as the source
of the flavour peculiar to Down mutton, but I think
360 Shell Life
it is usually considered that they are eaten in-
advertently by the sheep in cropping the short
grass. I am assured by intelligent Cornish farmers,
however, that this is not so : when sheep are turned
out to feed on the cliff-pastures they make by prefer-
ence for those parts near the edge where the " sheep-
snails " (H. virgata and H. acuta) are most plentiful,
and they thrive exceedingly upon them. They do not
appear to hibernate. Full-grown specimens measure
a little more than half an inch across.
The Heath Snail (H. ericetorum) is like a large
Banded Snail that has been depressed until the spire
is very little higher than the large body - whorl.
White predominates as the ground colour in small
specimens, but in large individuals it is chiefly cream
or pale buff, only the top of the inner whorls being
white ; the bands are less numerous and not as deeply
coloured. The mouth is more nearly round, and equal
to four-fifths of a circle. The internal rib is only
developed occasionally ; and the umbilicus is very
wide. Large specimens measure three-quarters of an
inch across. It frequents dry pastures and downs,
both inland and maritime, where it may be found
about thistles and furze - bushes. It is very shy.
Jeffreys describes it as going into hibernation in
November, yet I have on several occasions found it
in Surrey during mid-winter hanging to dead thistle-
stems and grasses on the borders of fields whose
newly ploughed ridges were frozen hard. It is said
to suffer from the attacks of the Devil's Coach-horse
Beetle (Ocypus olens), which attacks it with its strong
mandibles and eats it. It is widely distributed through
the United Kingdom.
Land-snails 3 6 1
The Wrinkled Snail (H. caperata) may be regarded
as a smaller edition of the Banded Snail in which the
spiral lines have got broken up ; though in typical
specimens the principal band, just above the periphery,
is well defined. Its ground tint is not white, but a
pale fawn colour, and it is without the gloss of the
three previous species. This last character is due to
the growth lines across the whorls being here very
prominent, as indicated in its names. It is also much
depressed, and its umbilicus is relatively larger than
that of H. virgata. The mouth is the same shape as
in that species, and the animal has much the same
trick of showing its abundance after rain. It
inhabits the same situations as virgata, but is also
frequently found in woods, on the trunks of beech-
trees. Some forms are as conical as virgata, whilst
others are as depressed as ericetorwm.
Some of the varieties closely resemble varieties of
virgata, but those of caperata can al ways be
distinguished by the wrinkles. The var. ornata is
smaller, with broader and darker bands, and the
Rev. S. S. Pearce some years since, in the Journal of
Conchology, explained why this variety is found
almost exclusively on downs where sheep are
pastured. Occurring with the ordinary mottled form,
he argued, ornata was far more conspicuous, and
therefore the sheep could avoid them, whereas the
less conspicuous mottled forms were eaten, leaving
more of the dark form to live and propagate their
beneficent variation. Now this reasoning would be
satisfactory, but for one thing : it proceeds on the
assumption that sheep object to snails and wish to
avoid them ; whereas, as we have shown in the case
362 Shell Life
of virgata, they esteem them as food. It is more
likely that the dark colour of the shell may be
accompanied by a difference in the flavour of the
mollusk which renders them less palatable to the
sheep, which have learned to avoid them by means
of the colour.
The Pointed Snail (H. acuta), owing to the great
height of the spire, resembles a Bulimus. Jeffreys,
following Forbes and Hanley, actually included it in
that genus ; but by general agreement it has since
been restored to the position originally assigned to
it by Muller. As will be seen from the figure, its
shell is a cylindrical cone a little more than half an
inch high, of an impure white colour, streaked
across the whorls with brown, and one or two
spiral bands of dark brown or black fre-
quently reduced to one, which is restricted to
the body-whorl, and sometimes entirely want-
ing. The spire tapers regularly, but ends in
a blunt tip. The oval mouth has a thin lip,
and the narrow umbilicus is almost covered. It
inhabits sandhills and grassy downs close to the sea,
chiefly in the south and west of England ; Wales ;
islands off the west coast of Scotland, and along the
Irish coast. It is exceedingly abundant, and shares
the double distinction with virgata of being a " sheep
snail " and being reputed to fall in showers from the
clouds. Sheep are exceedingly fond of it, and I have
often seen them feeding on dangerous loose edges of
cliffs though precisely the same grasses grew on firm
ground above, but in the former position this sheep-
snail was abundant, and therefore the feed was more
desirable. When the air is dry the snail glues the
i TO 15 BROWN-LIPPED SNAIL (Helix nemot a/is).
SHOWING SOME OF THE VARIATIONS IN COLOUR AND BANDING.
Land-snails 363
lip of its shell to a grass stem and retires well
inside.
The Brown-lipped Snail (H. nemoralis) is globular,
or what would be regarded as the typical form of a
snail's shell. Commonly the ground colour is a
clear yellow, but it varies from white to pink and
sometimes brown. Upon this are laid five cleanly
marked brown spiral lines, of which the two broadest
are below the periphery, and three narrower ones
above. The epidermis is thin and glossy, but in
many mature individuals it is more or less dull and
perished. There are about five and a half whorls, and
full-grown shells measure little short of 1 inch across.
The mouth is an irregular crescent in
shape, with the brown lip turned
slightly outward and strengthened by
a dark bar within. There is a narrow
umbilicus, which is open until the
shell is full-sized, when it is covered Brown-ii PP ed
over entirely. There is considerable
variation, as we have indicated, in the colouring of
this shell, but a much greater amount is seen in the
presence, absence, or amalgamation of some or all of
the five spiral bands. In some, apart from the dark
lip, the shell is quite unicolorous ; in others only the
central band is present. The three upper and the
two lower bands may be united into two broad areas
separated by a thin line of yellow and flanked above
and below by the lighter tint ; in fact nearly every
possible permutation may be found in a large number
of specimens. This snail is exceedingly abundant in
hedgerows throughout the country. It appears to be
specially partial to the Stinging Nettle as food and
364 Shell Life
shelter, but on dewy evenings and after rain it roams
freely over the adjacent hedges. It is the snail
whose shelly fragments chiefly surround the thrush's
sacrificial stone. It has long been a serious question
among conchologists whether this and the form
known as H. hortensis are distinct or one, and there
are earnest and convinced advocates of each view.
We agree with the " lumpers " that the possession of
a pale lip and column can scarcely be held a
sufficient reason for the separation of two forms that
agree so closely in almost every point especially
when they are admittedly the most variable among
our land shells in respect of colour and banding.
However, for convenience we here treat them
separately.
The White-lipped Snail (H. hortensis) agrees with
the foregoing, except that it is usually somewhat
smaller, with the mouth, rib, and central column pale
coloured. It is found in similar situations to the
dark-lipped form, but not often with it ; and it is
less widely distributed, though equally plentiful
where it occurs.
The Common Garden Snail (H. aspersa} is far too
common to please any gardener. Full-grown indi-
viduals measure nearly 1^ inches across the five-
whorled shell. The epidermis has a little gloss, but
this soon passes, and as a rule its appearance is dull
and shabby. The ground colour is normally a
brownish yellow, over which run five very dark
brown bands, but these are always much broken and
the yellow appears across them in zigzag streaks.
The spire is not much raised, and the tip of it is
broad. The lip is white, thickened, and reflected.
WHITE-LIPPED SNAIL (flelix hortensis)
SHOWING SOME OF THE VARIATIONS IN COLOUR AND BAND]
Land-snails 365
Umbilicus perceptible only in young specimens.
The Garden Snail is widely distributed throughout
these islands, and in some places is remarkably
abundant. Each individual deposits about a hundred
eggs, so that, unless the thrushes, blackbirds, and
glow-wormfl come to his aid, the prospects of the
cultivator are very bad. They go into hiberna-
tion rather early, many clustering together, and
attaching the mouth to the shells of their fellows in
some snug corner. They have their regular roosting
place, from which marked individuals have been
noted to emerge on their food-finding expeditions at
evening, and returning to the identical spot next
morning, much as the limpet does to his pit on the
rocks. A few years since I noticed that a Richardia,
that stood in a large pot in front of the house, had
been much eaten, and a large thick-shelled aspersa
was found clinging to the shady side of the pot.
Pencilling my initals on his shell I hurled the snail as
far as I could. Next morning he was again attached
to the pot, though to regain it he had to cross a very
broad road and climb a low wall. A second and a
third time the same thing happened ; but the third
time his shell was a good deal damaged ; and when,
after again hurling him away, he did not return I
concluded that the coastguard's foot had come upon
him in the dark. Mr. C. Ashford, experimenting in
the same way, marked seven aspersa with white
paint as they lay under a broken flagstone. At ten
p.m. three of them had disappeared, but they were
back next morning. That night at ten o'clock it was
found that five had gone off', but the following
morning six out of seven were at home again. The
366 Shell Life
eggs are laid in cup-shaped hollows at the roots of
grass, etc., and covered with a little earth. The snail
becomes full-grown in about twelve months from the
time of hatching, and lives about five years. This
species appears still to be eaten in the north of England.
The Apple Snail or Roman Snail (H. pomatia) is
the largest of our native species. The Garden Snail
has usually an untidy vagabondish appearance, but
the Apple Snail as constantly looks neat and clean.
The ground colour of his shell is a creamy tint,
and upon it are from three to five spiral bands
usually of pale brown. The surface is not so smooth
as in aspersa, the lines of growth being more dis-
tinctly raised. There are five whorls, and the mouth
is nearly round. The umbilicus is very small. The
fact that this species is restricted in range to a few
southern English counties, and its local occurrence
even there, has caused a wide belief in the legend
that it is not indigenous, but is one of those
creature-comforts introduced by our Roman con-
querors, and left behind as a contribution to the
future civilisation of the British barbarians. Others
have placed the date of its supposed introduction in
the sixteenth century, and more than one individual
has been indicated as the philanthropist to whom we
are indebted for so fine an item in our molluscan fauna.
The Pro-Romanists, however, point to a number of
acknowledged sites of Roman camps and villas in
whose neighbourhood this snail is found : here, say
they, is evidence that the Romans and the snail were
fellow colonists. On the other hand, those who put
forward the autochthonic claim, point to the fact
that there are many important Roman stations such
-
2 COMMON GARDEN SNAIL; 3, 4 APPLE SNAIL (3 WITH EI-IPHRAGM);
5 EGG OF Ai'Pi.rc SNAIL; 6 HELIX TERRESTRIS.
Land-snails 367
as York where there is no vestige of the snail, whilst
on the chalk ranges of the south it is abundant with-
out the slightest regard to sites of Roman habitations.
There is a general impression that the name Apple-
snail is reflected in the specific name pomatia, but
this is a mistake, the word being taken not from the
Latin p&mum, an apple, but from the Greek poma, a
pot-lid. The reference here is to the solid chalky
epiphragm with which it closes the mouth of its
shell before hibernation. When the time comes for
its winter rest it seeks the shelter of stubs in the
copse, and there burrows down through the dead
leaves, sometimes a little into the earth beneath them.
With its slime it unites some of the leaves to form a
roof, and then getting its shell in such a position
that the mouth is upward, it constructs the thick
epiphragm, and within that again an ordinary filmy
epiphragm such as other species make. It is usual
with snails to leave a minute aperture in the
epiphragm to admit air, but this thick " pot-lid " of
pomatia is not perforated; rather is it that the
whole structure is porous, as though made of plaster
of Paris, which it resembles. About April the
mollusk wakes up and pushes aside its doors, coming
out with a good appetite to feed on the tender young
leaves. In May these snails pair, and in the first half
of June they deposit their eggs.
In the year 1854 Mr. E. J. Lowe, F.R.S., communi-
cated to the Royal Society some observations on the
growth of land-snails, in which he stated that " most
species bury themselves in the ground to increase the
dimensions of their shells. H. pomatia and other shells
(sic) retreat for that purpose in summer, having their
24
368 Shell Life
heads and the mouths of their shells downwards."
Although this statement was quoted by Jeffreys and
most subsequent writers, it did not appear to be sub-
stantiated by further independent observation, and it
always appeared to me to be founded on an error,
because the beginning of shell enlargement is a
delicate film which has to be hardened by exposure to
dry air before the more mineral portions are spread
upon it. Such a process seems impossible in the
earth. On 9th June 1894, when in company with a
party of fellow naturalists on the chalk - hills at
Reigate, I felt sure at last that Mr. Lowe's theory
was the right one, for I found dozens of H. pomatia
with their shells partially buried in the chalky soil !
Closer investigation, however, revealed the fact that
instead of burying themselves for shell enlargement,
the snails were excavating holes in which to deposit
eggs. A number of snails were actually removed
from above holes which they had roofed in, all but a
small central aperture. Several of these chambers
were opened, the eggs counted and removed. The
internal space was equal to the size of the shell, and
the contained eggs varied from seventeen to thirty-
one * in number. Probably it was the excavation of
these pits effected with the foot I imagine that Mr.
Lowe mistook for the beginning of aestivation.
The eggs of pomatia have a rough-surfaced, dead-
white, chalky shell, which may be blown like the egg
of a bird, and will permanently retain its irregular
roundish form. They hatch in from twenty to forty
days, and the snail-chicks on emergence are as large
1 Miss F. M. Hele tells me that her captive pomatia have laid as
many as seventy eggs.
La nd-sna Us 369
as the egg-shell, which they use for their first meal
after the manner of caterpillars.
In the Descent of Man, Darwin relates a circum-
stance that happened to Mr. Lonsdale, in which H.
pomatia appears in a new light. A couple of these
snails were turned into a small garden but ill-provided
for their comfort, and one of them was in a sickly
condition. Next door was a garden of a better sort,
so when the robust snail climbed over the wall into
this better land it looked as though friendship was
hot so strong as self-interest ; and yet he had gone
but as a pioneer to spy out the land and save his
friend needless exertion should it prove to be less
suitable than it appeared. About twenty-four hours
later the absentee returned, and evidently gave the
other a glowing account of the world beyond the wall,
for they both started off on the same track and turned
their backs on the unsatisfactory enclosure.
A very pretty snail of pyramidal form, with flat
base and keeled whorls (H. terrestris), was found in
the year 1890 by Mrs. M'Dakin, a few miles out of
Dover. There was a colony extending for half a mile
along a chalky bank by the roadside, far from houses
and gardens. The snails climb tall grasses, like H.
acuta ; and they pass the winter among lumps of
chalk, their shells closed by an epiphragm. It is
almost certainly not a native, but was probably intro-
duced from the shores of the Mediterranean some few
years prior to Mrs. M'Dakin's discovery.
And now we have done not only with the great
genus Helix, but with the family Helicidce ; the family
Pupidce claims attention. In this family we shall find
the shell of an elongated, more or less cylindrical
370 Shell Life
form, the mouth narrowed, and often further reduced
by tooth-like growths. The genus Buliminus, which
has but two British representatives, agrees generally
with Helix, but the tentacles of the animals are shorter,
and the character of the lingual teeth is different, the
rows being curved towards the margins. The Moun-
tain Bulin (B. montanus) has a semi-transparent shell
about two-thirds of an inch long, slightly
glossy, and of a pale brown tint. The surface
is crossed by delicate spiral and transverse
lines, the crossing of which gives the shell the
appearance of being minutely shagreened.
There are seven and a half whorls, the body-
whorl accounting for one-half the shell. The
oval mouth, which has a white lip, is reddish within.
It is found on the trunks of ash, beech, and hornbeam,
in Somerset, Oxfordshire, Gloucestershire, and Suffolk
only. The Lesser Bulin {B. obscurus) is very like it, but
smaller a little more than one-third of an inch long.
It is further distinguished from the very similar
montanus by being more glossy, the absence of spiral
lines preventing the shagreened appearance of its con-
gener; there are only six and a half whorls,
the lip is not so thick, the inside of the mouth effl
is white, and the body-whorl is only equal to S|Jg)
two-fifths of the whole. It is an inactive Lesser
creature, sticking on the bark of trees (beech
chiefly), apparently feeding upon the immature mosses
and lichens that grow thereon, and disguising itself
so that snail-hunting birds may pass it as a bit of
dirt or one of the small knots that are so common
on beech bark. It does this by covering its shell
with slime and dragging it across dirt of various
Land-snails 371
kinds, which gets picked up by the slime. The
process several times repeated, the shell soon bears no
resemblance to itself. The young of B. montanus
sometimes covers itself in the same way, as does the
young of the next species.
The snails of the genus Pupa are elongated like
those of Buliminus, but the spire ends in a short
point. The mouth, which is usually horse-shoe shaped,
or half-oval, is guarded by teeth or spiral plaits or
folds. Some of the animals have the lower pair of
tentacles in a rudimentary condition, or they are
altogether wanting; these are sometimes separated
to form another genus, Vertigo. There are fourteen
native species, and most of these are so minute that
we shall not attempt to give distinguishing descrip-
tions of each, but a list of them will be found in the
Appendix. They are social in their habits, and where
one or two specimens are found a slight search will
soon be rewarded by the discovery of others. Old
mossy walls with crevices, stone dikes, the loose bark
of trees, and among moss, are the favourite resorts of
these Chrysalis-snails.
The Large Chrysalis-snail (P. secede) is only largo
by comparison with the others ; it is about one-third
of an inch in length. There are eight or nine
yellow-brown whorls, of which the last four
are of pretty equal width. The mouth is
largely occupied by eight or nine tooth-like
extensions of the thickened lip. It is a local
form, found on rocks and in woods in England
only, and chiefly in the south. P. cylindracea
is the most widely distributed of the genus. It is about
one-seventh of an inch long, almost oval in form ; the
372 Shell Life
almost triangular mouth with a tooth on the pillar
and one on the pillar-lip. P. anglica, found no farther
south than Herefordshire, measures only one-twelfth
of an inch, and has a semicircular mouth protected
by seven or eight teeth. P. muscorum is one-seventh
of an inch, has a white rib outside the lip, and a small
tooth on the pillar. Widely distributed south of
Scotland. P. edentula, of similar proportions to the
last, has a semi-oval mouth without teeth. Generally
distributed. P. minutissima is similar to the last,
but smaller (one-twelfth of an inch), without teeth.
Recorded only from the Isle of Wight, south-west
Yorkshire, Durham ; Edinburghshire ; and Kerry. P.
alpestris, one-twelfth of an inch, has a semi-oval
mouth with four or five teeth. It occurs only in south-
west Yorks, south Northumberland, Westmoreland, and
County Londonderry. P. lilljeboryi, one-tenth of an
inch, globose, mouth semi-oval, with four equidistant
teeth, strengthened by a slight rib outside. Found only
in County Gal way. P. moulinsiana, similar to the last,
but more barrel-shaped, and with a stronger rib out-
side lip. Found only at Otterbourne, Hants ; Hitchin
and Rye House, Herts. P. pygniax.1, oval, one-tenth
of an inch, mouth strengthened by an outer rib which
protrudes slightly inside and from which spring two or
three of the four or five teeth. Common, and widely
distributed. P. substriata, one-twelfth of an inch,
mouth somewhat pear-shaped, with from four to six
teeth, two or three of which spring from a white rib
inside the outer lip. Occurs in Anglesey, Derbyshire,
south-west Yorks, Durham ; and County Londonderry.
P. antivertigo, one-twelfth of an inch, mouth half-oval
with from six to ten red-brown teeth, and strengthened
Land-snails 373
by an external rib. Moderately common. P. pusilla
and P. angustior differ from all the rest in having
sinistral shells, i.e. the mouth opening faces our
left side as we look at it. P. pusilla is one-
fourteenth of an inch, the mouth triangular-
oval, with six or seven teeth, and a strong an ^
yellowish-white rib both inside and outside. It
is very local, but has been reported from north Devon,
Oxfordshire, Notts, Derbyshire, west Yorks, Durham,
Northumberland; Ayrshire; and County Londonderry.
P. angustior is only one-sixteenth of an inch, and pro-
portionately narrower than pusilla ; the mouth more
triangular and narrow, with four or five teeth, and a
rib as in the previous species. It occurs at the roots
of grass in wet places, but is very local. Its recorded
stations are in Derbyshire, Yorks ; Sutherland ; County
Londonderry, Sligo, Galway west, Cork south.
It is to be presumed that the teeth, which are so
important a character of these shells, serve a practical
purpose in keeping out minute insect enemies which
frequent the same situations.
The Tree Snail (Balea perversa) is the sole British
representative of its genus. It is not greatly unlike
a Buliminus. The animal is much the same,
though its teeth and their arrangement on the
radula are different. There is a central tooth
with 20 laterals on either side in each row, and
the number of rows is 130 a total of 5330.
The shell is club-shaped, thin and glossy, coiled
to the left as in P. pusilla ; yellowish brown
in colour. The mouth is somewhat pear - shaped,
without teeth, except that occasionally full-grown
specimens are found with a small one near the
374 Shell Life
centre of the base of the last whorl but one. The
length of the shell is about one-third of an inch. It
affects old mossy trees and lichened rocks, hiding
under the loose bark of the one, and in crevices of the
other so long as the air is dry ; but after rain the
whole colony walks out upon the surface. It is
widely distributed, but local.
The Door-shells (Clausilici) belong to a very exten-
sive genus, nearly a thousand species being known,
but in this country repre. ited by four species only.
These are spindle - shaped, twisted to the left like
Balea, contracted into a throat behind the pear-shaped
mouth. Within the mouth are seen two spiral
plates, and on turning the shell over these may
be traced through the shell some distance into
the body-whorl. In some species there are
intermediate ridges on the pillar and the outer
lip. Within the throat there is a narrow
twisted plate of shelly matter, attached to the
pillar by an elastic foot. This plate is the
dausiliwm,, which automatically closes the
throat when the mollusk withdraws inside, and which
is pushed aside when the animal emerges, and so acts
as an operculum. The clausilium is obviously a
protection from the inroads of beetles of .the family
Staphylinidcv and other small insects, but it is strange
that such defence should not be provided until the
mollusk has reached maturity. Until the shell is
nearly full-grown there is no sign of this device.
There is a slight slit-like umbilicus almost hidden
by the thickened and expanded lip. They are all
herbivorous, and probably at times retain their eggs
until hatched.
M 4
4 5
I
11
9 10
4
i LESSER BULIN ; 2 MOUNTAIN BULIN ; 3 LARGE CHRYSAI.IS-SNAII. ; 4 PUPA ANGI.ICA ;
5 PUPA MUSCOKUM ; 6 TREE SNAIL; 7 SLIPPERY MOSS-SNAIL; 8 THKKK-TOOTHEIJ
MOSS-SNAIL; 9 PLAITED DOOR-SHELL AND WHITE VARIETY (10) ; n TWO-TOOTHED
DOOR-SNAIL; 12 ROI.PH'S DOOR-SNAIL; 13 TWO-LIPPED DOOR-SNAIL; 14 LARGE
Land-snails 375
The Plaited Door -shell (C. laminata} is smooth
and glossy, semi - transparent, yellow - brown in the
upper half deepening to ruddy - brown below. The
whorls are more rounded than in the other species,
and the teeth in the pillar are stronger. There are
three or four plaits or folds within the outer lip,
which are visible through the shell. The oblong
clausilium has a deep marginal notch near the base.
The length of the shell is two-thirds of an inch.
Although we must call it a local species it is widely
distributed over England and Wales from Northum-
berland to North Devon and the Channel Islands ; it
also occurs in Perthshire. It feeds upon mosses and
the germinating spores of lichens, etc., which abound
on tree-trunks. Ash 'and beech are its favourite trees,
especially beech, whose trunks it ascends at evening,
spending the day except in wet weather in the
angles between the roots. There appears to be a pro-
tective value in the shape, size, and tint of their shells,
in spring-time, at least, when in their first journeys up
the trunk they are more exposed to the scrutiny of
birds. At this time the brown envelopes of the beech
buds are falling in millions and stick on bark and
moss, and as these exactly resemble the laminata,
shells birds in searching for the latter must have a
trying time. In the angles between the roots numbers
of these envelopes gather and persist for months ;
there also under these G. laminata will be found
gregarious. The eggs are described by Bouchard-
Chantereaux as of enormous size when compared with
the animal, to be even larger than the mouth of the
shell, and to number about a dozen. Deposited in
August or September, they hatch in three weeks, and
376 Shell Life
the young arrive at full size in two years. I have
found the white variety in plenty living in caverns
wrought by other creatures in the rotten stump of
a felled beech, and fancy the deficiency of colour may
be due to the darkness of their habitat. The greenish-
white shell is certainly more protective amid such
surroundings than the ordinary colour would be ; and
it is not difficult to realise how natural selection would
bring about a distinct race of white Clausilias under
such conditions.
The Two-lipped Door-shell (0. biplicata) is slightly
less in size than (7. laminata, and instead of being
rounded and glossy the whorls are com-
pressed and closely covered by fine but
distinct ridges, some of which are half
white. It is a duller, more grey-looking
shell than that of the glossy laminata,
but a further distinction is found in
the mouth. In laminata this is con-
tracted above into a narrow channel
like the lip of a jug; in biplicata there is such a
lip below as well as above. It is a very rare species,
and has only been recorded from the counties of
Wilts, London, and Herts. The London localities
lie along the Thames between Putney and Hammer-
smith, but recent municipal "improvements" have at
least restricted these. Fifteen or sixteen years ago
at Putney I could always put my hand on a few
specimens for a conchological friend, but I under-
stand that an embankment of the most solid type has
improved away my particular hunting ground and
buried the Clausilias. Biplicata spends its days at the
roots of willow-trees, and at night ascends the trunks.
Land-snails 377
The Two - toothed Door - shell (C. bidentata) is
generally similar to the last named, but much
smaller (half an inch long) and more slender in pro-
portion. The whorls are covered with ridges in like
manner, but these are not so high as in biplicatd.
The mouth, too, is similar, though smaller, but the
base is rounder, less channelled than in the last.
The clausilia of the last species, this, arid the next,
differ from that of laminata in not being notched.
This is a very variable as well as abundant shell.
On mossy walls, stone dikes, and the trunks of
trees throughout these islands, it may be found in
great numbers. Jeffreys expresses a form of astonish-
ment produced by specimens that were partially
smooth, and which Dr. Turton and himself once
considered to be the Continental C. parvula. Such
examples are common, and if Jeffreys had examined
them with a lens he would have discovered that the
ridges are almost entirely a matter of epidermis, and
that where this has been removed by abrasion in
dragging the shell into narrow chinks, or by the
radula of a brother, the shell is left nearly smooth
agreeing well with his own description of C. parvula,
" quite smooth with the exception of some very faint
transverse lines, which are only observable with a
lens."
Rolph's Door-shell (C. rolplii) is about the same
length as C. bidentata, but of greater breadth and of
thinner material, and covered with a slightly glossy
red-brown epidermis which is wrinkled into ridges as
in the last species. In many specimens the ridges
have almost entirely disappeared, leaving a dull dirty
grey surface. There are fewer whorls nine or ten
378 Shell Life
as compared with twelve or thirteen in the other
species. The mouth is much the same as in bidentata.
One mark of distinction given by authors is the
presence in rolphi of several minute teeth between
the folds on the pillar ; but this is not reliable, for I
have specimens of bidentata with these teeth. The
chief differences between the two consist in the more
slender proportions of bidentata, the coarser ridges of
rolphi, the larger and broader mouth of the latter,
and its lighter colour. It occurs among dead leaves
and under the bark of trees. It is distinctly local,
its distribution in these islands being restricted to
the following English counties : Hants north, Sussex,
Kent, Surrey, Berks, Gloster east, and Notts.
The family Stenogyridcv is represented in this
country by two genera and three species of small
snails. The animals have the radula teeth arranged
as follows: central tooth small and narrow, the
lateral teeth much larger, with their ends divided
into three points, of which the central is the largest,
and the marginal teeth are similar to the laterals,
but swollen. The shell is a long dextral spiral
with a blunt apex, more or less translucent and
shining.
The Slippery Moss-snail (Ferussacia lubrica} well
deserves its name, for it is so excessively
glossy that it readily slips through the fingers
and vanishes among the moss. There are
only five whorls of a pale yellow-brown tint,
transparent, the last whorl being equal to
half the shell. Mouth nearly oval, the lip
thickened within and rounded. It is found among
moss and at the roots of grass ; also under stones,
Land-snails 379
dead leaves, and decaying wood, in damp and shady
situations. So habituated is it to damp that it can
endure immersion for several hours, a degree of
endurance fostered probably by the occasional
flooding of its haunts, drowning off those less
hardy in this respect. It is generally distributed.
Length, a quarter of an inch.
The Three - toothed Moss-snail (F. tridens) is of
much the same dimensions as the last, but owing to
the seven whorls being individually less
rounded its outline is not broken by the
sutures. The colour, too, has a suggestion of
red in it, which is more evident about the
lip. The mouth would be pear-shaped but
for three strong teeth arising from the very
thick lip. It lives gregariously among moss
and dead leaves in woods, but it is local, one might
almost say rare. Its range extends from Cornwall
and Sussex to Northumberland.
The Agate Snail (Ccecilianella acicula), though only
about one-fifth of an inch in length, is interesting on
several grounds. It is entirely subter-
fi ranean in its habits, it is blind, and it is
f,4 carnivorous, or at least supposed to exist
upon animal matter. The animal is white
and almost transparent; its shell also is
of ivory-whiteness, thin and transparent,
with an iridescent gloss. It lives at a
depth of from 1 to 3 feet below the surface, and
to show preference for the neighbourhood of bury-
ing grounds. It never comes to the surface unless
turned up by the spade, or thrown out of their
burrows by rabbits. As a consequence the search for
380
Shell 'Life
it is attended with some difficulty. It is very local,
and does not appear to have been recorded for Wales,
Scotland, or Ireland.
The Amber Snails represent the family Saccineidce,
and comprise four native species. The animals are of
a gelatinous consistency,
and are usually a little
too big for their shells.-
There are four tentacles,
but the lower pair are
very short (in some
species wanting). The
foot is large and oblong.
The characters of the
radula are shown in the figure below of the median
and lateral teeth. A complete row consists of 65
teeth, and there are 50 rows, or 3250 in all. The shell
is very thin, containing little mineral matter, amber
coloured, with a short dextral spire, a large body-whorl
and mouth. They frequent the margins of lakes,
ponds, and ditches, feeding upon the vegetation, and
capable of enduring temporary submersion, which is
th of radula of Succinea putris
probably often of a voluntary character. They may
sometimes be seen floating on the surface, shell down-
wards after the manner of Limncea and Physa.
The Large Amber Snail (Succinea putris) has a
semi-transparent oval shell of three or four whorls,
the last being equal to four-fifths of the whole shell,
Land-snails
is
very common on the
growing in the water.
tentacles
Large Am be
with an oval mouth. It
aerial portions of plants
Specimens are sometimes found with
abnormally distended, a feature
that would be sufficient to cause
some enthusiastic " splitter " to
make a new species of it, dubbing
it crassicornis ! But this is really
a similar case to that mentioned in connection with
LimncBO, truncatula and the Liver Fluke in an earlier
chapter. In the present instance it is a fluke that is
destructive to birds Distoma macrostomum. Birds
like the blackbird, thrush, and wagtail are very partial
to Amber Snails, and the parasite having hereditary
knowledge of the fact, gets its young into S. putris,
where they push their way into the tentacles and
thrive at the snail's expense. But the completion of
their life cycle must take place in the body of a verte-
brate ; so when the Amber Snail is eaten by the bird,
the Distoma is in a position to fulfil its destiny. The
Graceful Amber Snail (S. elegans) has a darker and
more slender shell, with a longer and sharper spire,
but it is open to doubt if it is anything more than a
variety of 8. putris, with which it is found,
and, according to Rimmer, with which it
couples. The Small Amber Snail (8. oblonga)
has certainly more claim to be considered dis-
tinct, for its form is nearer to that of Limncea
and its habitat is different. The shell is
oblong-oval, rather solid, brownish, and with
a proportionately large spire, the body-whorl being
equal to only two-thirds of the whole. The mouth
is rounder than in the other species. Its length is
382 Shell Life
about a quarter of an inch. Instead of frequenting
watersides it prefers ditches that are dry, and to
retire beneath stones, but it is very restricted in its
stations so far as they have been discovered in this
country. It has been found in north-east Yorks,
in Glamorganshire, in Edinburghshire, and in County
Cork.
The last of these land Mollusca that we have to
notice is a very remarkable creature, the solitary
British representative of the family Onchidiidce. It
is a little-known slug, Onchidiella celtica, which is
found only on the Cornish and south Devon coasts,
where little colonies live so near the sea that, follow-
ing the ebb and retiring before the flowing tide, the
waves break over them without permanently sub-
merging them. The young are provided with a
shell, but this is afterwards cast off, and the adult is
only covered by a thick warty mantle. In some
species some of these warts bear sense - organs or
" eye-spots." There is only one pair of tentacles,
supporting the eyes. The sexual orifices are widely
separate, that of the male under the right tentacle,
that of the female at the end of the body. There is
no pulmonary chamber as in all the snails and slugs
we have been describing, and breathing has to be
performed through the skin and the warts on the
back. Their food consists of sand or rather they
eat sand in order to digest out the particles of
organic matter that have become mixed with it.
They are regarded as air-breathing land-mollusks
that are reverting to a marine or semi-marine mode
of life.
COMMON OCTOPUS ; 2 CURLED OCTOPUS.
UTTLE-FISHES is the ortho-
dox popular name, but as
the compound word implies
a creature very different
from any mollusk, the less it is used the better. At
first sight it is difficult to imagine that the re-
markable creatures included in the class Cephalopoda
have anything but the most remote relationship to
the slugs, snails, and bivalves treated in the fore-
going chapters. It is by far the most highly
organised class of Mollusca, and there does not
appear to be any existing forms helping to bridge
over the gulf between it and the other classes.
As all the British species belong to the order
Dibranchia, our remarks will apply only to them
as types of the class. Unlike most mollusks they
are symmetrical animals, the right and left sides
being equally developed. The shell, variously
25
384 Shell Life
modified, is internal, though the Nautilus of the
order Tetrabranchiata possesses an external shell.
They have powerful jaws developed into some
semblance to a parrot's mandibles, and acting like
these. Within these jaws there is a comparatively
small radula, the jaws preforming much of the
work falling upon this organ among the Gasteropoda.
The teeth are not numerous, and they do not exhibit
that great diversity of form and size seen in other
groups. This is largely due to the fact that the
Cephalopods are all carnivorous ; and the uniformity
of food produces similarity of teeth.
Their bodies are divided not always distinctly
into two regions, the head and the trunk. The
head is encircled by eight so-called " arms," con-
nected at their bases by a skin. Attention to the
embryonic development of Cuttles shows that these
arms are analogous to the "foot" in the Gasteropods.
At first the mouth is in advance of them, but
ultimately they come to encircle it. Beneath the
arms are two large eyes, much more highly
specialised than in other mollusks but differing in
structure from the eyes of vertebrates. There is
a transparent cornea, an anterior optic chamber
between it and the lens, an iris, a posterior optic
chamber, and a retina. These eyes are serviceable
not merely for transmitting light sensations to the
nervous system as in the snails, but for actual
observation, as may be proved by experiment.
Owing to the concentration of the chief nerve
ganglia into one unbroken mass, we have in the
Cuttles the nearest approach to a brain afforded
by the Mollusca. The inner face of the arms is
Cuttles
385
covered by rows of stalked or sessile suckers of
such great clinging power that the arm itself may
be torn to pieces before the suckers will leave the
surface to which they have been attached. In the
sub - order Octopoda these
suckers are entirely fleshy,
but in the Decapoda they
have a horny rim some-
times toothed. The suckers
are disks depressed in the
middle, which can be worked
piston-fashion. When the
margins have been applied
to any surface the centre is
withdrawn, and a vacuum
created which ensures a
powerful attachment. One
of the arms in the male
the sexes being separate in
the Cuttles undergoes a
change, and is charged with
spermatozoa, but it is never detached as in some
exotic species.
The heart consists of two auricles connecting with
the two branchiee which give the name to this order.
After the oxygenated blood has been received from
these organs into the single ventricle it is distributed
fore and aft to the creature's body by the two aortse
and the connected arteries, returning to the branchise
later by veins. The so-called " funnel " comes out
on the lower surface forward. It is the general
excretory organ, and connected with it is the ink-
sac. This is divided into two portions, the ink-gland
Suckers of Cuttle
386 Shell Life
in which the ink is produced, and a larger cavity
call the ink-reservoir in which a store of diluted ink
is kept always ready for use. A long tube connects
this with the neck of the funnel, its opening being
guarded by a double set of sphincter muscles. When
danger threatens a quantity of ink is discharged
into the funnel, and the rectum being forcibly
emptied the stream carries the ink into the sea
and surrounds the mollusk with an aqueous cloud,
under cover of which it makes off. The stream of
water from the funnel also has the effect of sending
the Cuttle quickly backwards through the water.
Another important feature of these mollusks is
found in the spots of colouring matter with which
the skin is dotted. These pigment-spots are so
much under the control of the nervous system that
they can be instantly dilated or contracted at the
will of the animal. It is by this means that the
chameleon-like changes of colour are so rapidly
effected, and the creature so harmonised with the
hue .of its immediate surroundings as to become
practically invisible.
The sub-order Octopoda presents us with the species
most familiar to "the man in the street" by reason
of its frequent representation pictorially, and by
the presence of living examples in our large public
aquaria. In the quiescent condition they are very
unsightly creatures, the body consisting of a rounded
bag, above which stare the great eyes, whilst the
long arms coil about it in all directions. We have
two species.
The Common Octopus (Octopus vulgaris) is chiefly
found along the south coast and in the Channel
Cuttles 387
Islands, but it is also recorded from Liverpool,
Lamlash Bay, the Firth of Forth, and the Irish
coasts. The young are gregarious, but the adult
lives a solitary life in some rock cavity of the
laminarian zone, the door of which is strewn with
the broken shells of the bivalves upon which he
chiefly subsists. The arms are connected at their
base by a thick web, and the suckers are arranged
on them in two rows. There is no shell, though it
is indicated by the presence of two small stylets
embedded in the mantle. The colour is normally
dusky, varying to purplish, yellowish, or grey, and
spotted with orange, brown, and purple. The length
of the body without the arms is only about 6
inches, but the eight arms measure a couple of feet
each. In the male there is a peculiar modification
{hectocotylus} of the third arm on the right side.
It is much shorter than the others, has very few
suckers, and ends in a flat plate which connects
with the basal web by a groove in the skin. The
spermatozoa are produced in little cylindrical
packets (spermatophores), which are probably passed
along this groove to the terminal plate. The male
of Sepia has been seen to attach similar sperma-
tophores to the female, and it may be presumed that
a similar transference takes place in Octopus. In
certain genera (Argonauta, Ocythoe, and Tremoctopus)
of this sub-order, the specialised arm itself, charged
with spermatophores, is detached by the male and left
with the female. When the ova are discharged these
packets open and their contents fertilise the eggs.
These, to the number of several thousands, are attached
to a central cord in long cylindrical masses.
388 Shell Life
A second species, 0. arcticus, was captured by
trawling in deep water off the south of Ireland in
1889 by Mr. G. C. Bourne.
The genus Eledone, which differs from Octopus in
having only one row of suckers, is represented by
a single species.
The Curled Octopus (E. cirrosa) is not so
repulsive as the common species in appearance,
the eyes not being so large and staring, and the
arms being more proportioned to the size of the
body. The body measures about 6 inches, and the
arms are only twice that length. The upper surface
is dotted with reddish brown, the under-side is bluish
white with larger and more regularly disposed spots.
The eyes are orange coloured, with silvery white
lids. It is as distinctly a northern species as 0.
vulgaris is a southern form ; but as well as being
fairly plentiful in deep water off the Scottish coasts,
Tenby, North Wales, south-west Ireland, and the
Butt of Lewis, it occasionally turns up at Plymouth
Sound, Falmouth, and Mount's Bay in the far south.
These are our only eight-armed species. In all the
rest the eight arms are supplemented by two others
of a different shape, having a different origin, and
called tentacles. Cuttles of this character form the
sub-order Decapoda. Their sides are developed into
fins, the margin of the mantle "buttons" to the base
of the funnel, and there is an internal shell. The
tentacular arms are three or four times the length
of the ordinary arms, their ends with flat expan-
sions which alone bear the suckers. One member
of this sub-order, Spirula peronii, abounds on the
Atlantic coast, and its delicate shell, which is
Cuttles 389
chambered like that of the nautilus, is brought
across the ocean by the Gulf Stream and afterwards
drifted by currents to our southern
and western shores ; but the living
animal has not been so transported,
and in its native waters the animal is
scarcely ever seen. Our knowledge
. . , v ri -i Splrula peronii
or it is by no means reliable, because
only damaged specimens of the mollusk have been
found. We give a figure
of the shell for the pur-
pose of identification.
The family Sepiidcv
possess an internal shell
which is well known as
" Cuttle - bone," being
largely used by bird
fanciers for their pets
to peck at, and formerly
much in request for
making "pounce," now
superseded by blotting-
paper.
The Common Cuttle
(Sepia, officinalis), whose
shell is a common object
on many shores all round
these islands, has been
well-known from anti-
quity. The ancients used
Common Cuttle . .
its ink for writing and
painting, and its shell in medicine as an antacid. The
animal is not by any means a familiar sight, and
390
Shell Life
there is little doubt that we owe the abundance of
well-cleaned shells cast up on our rocks and beaches
to the steady efforts of the conger and other large
fishes to keep down the numbers of Cuttles. Its
form is well represented in the preceding figure. Its
broad brown back is striped with white, zebra fashion,
and dotted with purple and white. The
margins form thin narrow fins. The
arms are short, but the tentacles are
very long, the expansions at the tip
covered with unequal suckers. When
not in use the two tentacles are entirely
withdrawn into pockets in the head.
The suckers, as in all the Decapods, are
stalked, and have horny rings. Those
on the arms are in four rows, and are
pretty regular in size. The head is
much narrower than the body, and the
prominent eyes are black. Its length
is about a foot, without the tentacles.
The shell or "bone" is about three-
quarters of the animal's length, of a
broad lance-shape, with a border of
cartilage, and almost filled with thin
overlapping plates of a soft porous shell-
matter, which is exceedingly buoyant,
and which may be powdered by the
finger-nail. Among the maritime population in
Cornwall the name is Cuddle, and this no doubt is
the correct form of a word having a common origin
with our modern verb cuddle, and referring to the
embracing action of the arms.
S. rupellaria is a much smaller species (3 inches
,f
Shell of Sepia
Cuttles 3 9 1
long), of a greyish-pink colour spotted with purple-
brown. The suckers are in two rows on some arms
and in three rows on others. The shell is more lance-
shaped and slender, 2i inches long ; its convex side
of a rosy flesh tint. The complete mollusk was taken
by Laughrin at Polperro in Cornwall, and the shells
have been cast up in Oxwich Bay near Swansea, on
the coast of Northumberland, at Mawgan Forth,
Cornwall, in Guernsey, and at Magilligan, County
Derry. 8. elegans has a shell about 4 inches long, some-
what similar in colour, etc., to the last mentioned.
The eggs of the Sepias are large and black, with
beaked ends, attached by flexible stalks until they
resemble bunches of grapes. These are attached to
large weeds in the larninarian zone, where the parent
lives upon fishes and crabs. These eggs, thrown
up on the beach after a storm, may be hatched
in a vessel of sea-water.
The remaining families have the shell reduced
to a gladius of thin horn, commonly called the
pen. In the family Sepiolidcs the fins are en-
larged and spring from the back, the tentacles Pen of
are retractile into pockets as in Sepia, and C uttie
the two central upper arms in the male are
hectocotylised. The pen is half the length of the
body.
The Little Cuttle (Sepiola atlantica) is common in
shallow water on all our coasts, and is frequently
taken when shrimping. It is a smooth flesh-coloured
creature, less than 2 inches in length. In the male
the tentacles are twice the length of the animal, less
the arms ; but in the female they are little longer
than the arms. The late P. H. Gosse recorded its
392
Shell Life
curious habit of burying itself in the sand, pouring
out a stream of water from its funnel and directing
it upon one spot so that the light grains would be
blown out until a hole was formed sufficiently large
to accommodate it. Where small stones mingle with
the sand, however, the creature knows that its current
has not sufficient power to lift these, so it proceeds
Cuttles 393
to move them by means of its suckers. A second
species, S. scandica, has been taken in the dredge off
Little Cumbrae, Firth of Clyde, in 50 fathoms ; at the
mouth of Loch Fyne in 48 fathoms.
Ross' Cuttle (Rossia macrosoma) differs but little
from Sepiola, except that the mantle above instead of
being connected to the neck by a broad band, as in
Sepiola, has a free margin all round. The fins are
relatively smaller. The entire length exclusive of
the tentacles is from 2^ to 3 inches, and the " pen "
about 1^ inches. Jeffreys described it as " rare or not
often met with," but since his day the trawl has been
more largely used in the deep waters off our shores ;
so that Canon Norman, who has done much exploring
work of this sort, can now say, " the use of the trawl
has shown it to be far from uncommon in 40 to 90
fathoms in the Clyde District, and off the west of
Scotland." It is also recorded from the Minch ; off
the coast of Wexford ; off the Butt of Lewis (40
fathoms), Dublin Bay, Plymouth Sound, and the Isle
of Wight. R. glaucopis, a smaller species, has been
taken in from 60 to 100 fathoms, off the north of
Shetland, and the Outer Haaf, Shetland. A third
species, R. sublevis, was obtained in one of the
trawling expeditions of the Flying Fox, off the
south of Ireland in 250 fathoms of water.
In the family Loliginidce, the body is longer, the
tentacles only partially retractile, the pen as long
as the animal's back, pointed like a quill-pen in
front, and strengthened by a keel along the lower
side.
The Common Squid (Loligo forbesii) is the largest
of our common Cuttles. Exclusive of the tentacles,
394
Shell Life
adult examples measure about 2 feet in length.
The body is cylindrical, tapering to a blunt point
behind, and furnished with two large triangular fins
which are united behind. The arms bear two
irregular rows of suckers ; the expanded tips of the
tentacles have four rows. The fourth left arm of
the male has the tip hectocotylised. When freshly
extracted from the mantle where it lies without
muscular attachment the long pen (15 to 1.8 inches)
Cuttles 395
is quite transparent, but as it dries it becomes less so,
and shrinks. Squids appear in shoals, swimming on
the surface of the sea, whether smooth or rough, and
in the brightest sunshine. They feed upon fishes, and
the fishes are only too eager to reciprocate. The
somewhat gelatinous flesh makes a splendid bait
for sea-fishing. The professional fishermen fish
for Squid to use for baiting their boulters. The
Squid is a wary and an active quarry, and some skill
and adroitness is required to capture him, for he does
not make the mistake of taking a baited hook as a
fish does. The modus operandi for catching a Squid
is quite different from that where a little bit of the
captured Squid is used to entrap a fish. The fisher-
man securely fastens a pilchard to a strong line, and
throws this out from his boat. Near at hand he has
a light gaff, made by splicing a number of mackerel
hooks to the end of a bamboo rod in such manner
that the barbed tips are all turned outward, but
pointing towards his hand. The Squid's sense of
smell soon attracts him to the pilchard, which he
clings to with his suckers and tears with his beak.
Now the fisher hauls in his line very gently so as not
to alarm the Squid, until at length he is within
striking distance. Then when the Cuttle is in the
right position he is firmly gaffed in the hinder part
of his body and held with his head away. There is
a tremendous spouting of water and ink from the
funnel, the Squid making effort by this means to
escape. When he is for a time exhausted he is taken
on board. An inexperienced assistant essaying to
catch his first Squid will almost certainly gaff it and
haul in head first, with the result that his face and
396 Shell Life
clothes are well covered with the jet-black ink, which
has a painful burning effect on the skin, as well as
being difficult to wash off. On a coast where this
species is very plentiful, and where the " bones " of
Sepia are abundant along the beaches, I have never
seen a pen of the Squid so cast up. The explanation
appears to be that when conger and other fishes bolt
the Sepia they are unable to digest its shell, which is
afterwards vomited in a clean condition. The " pen" of
Loligo under similar conditions appears to be digested
and so is got rid of altogether. The eggs of this
species are deposited in long gelatinous sheaths, each
containing many ova. These egg-cases are united to
form large masses known as " sea-mops," which float
loosely in the sea. Bohadsch estimated one of these
mops to contain 40,000 eggs. The Common Squid
occurs on all our coasts.
Two other species are included in the British
fauna : L. marmorce with much broader fins
situated farther back taken off Youghal, Ireland;
and L. media, found at Jersey, Plymouth, Tenby,
and Lamlash Bay. These are both small species,
measuring only 4 or 5 inches, excluding the tentacles.
All the Loligos can swim forwards by using their
fins, as well as dart backwards by expelling water
from the funnel.
In the family Ommastrephidce the animal is of
similar shape to Loligo, but the fins are only half
the length and placed right at the end of the body.
The rows of suckers on the arms vary in number,
and the arms have a more voluminous web for
swimming. The attachment of the mantle-margin
to the neck is more elaborate than in preceding
Cuttles 397
species. The pen is very narrow and bears a hollow
cone at its hinder end.
The Flying Squid (Ommastrephes sagittatus), or
Sea Arrow of sailors, gets its name from the shape
and position of the fins. If the animal be viewed
with the arms towards us and the fins away, its
form is seen to be that of a thick arrow with barbed
point ; and as the seamen see these hurl themselves
from mid-ocean to the vessel's deck they come like
flying arrows, point first. This species is about 15
inches long, and has been taken at Shetland, St.
Andrews, the Firth of Forth, and Durham. 0.
eblance has been taken at Plymouth, Belfast, and in
Dublin Bay ; and a third species, 0. coindeti, is re-
corded from the Firth of Forth and Eastbourne.
The Flying Squids occur in schools, and are of
great importance in connection with the New-
foundland cod fishery, forming as they do the
principal bait used in that industry. They also
form important items in the bills of fare of whales,
dolphins, and some of the larger oceanic birds.
To the same family belongs the genus Architeuthis,
containing the largest species of Cuttles known to us
the creatures that have often been still further
enlarged by the. sensational writer, acting on the
principle of " to him that hath shall be given."
More than once some giants of this tribe have shown
themselves in the vicinity of these islands, so that
we are able to claim A. monachus as sometimes
British. More than two hundred years ago a gigantic
Cephalopod was cast ashore at Dingle, County Kerry,
whose length was 19 feet. Its tentacles were 11
feet, but they had been mutilated, so that their
398 Shell Life
original length must have been greater. The arms
were of 'the thickness of a man's leg, and varied from
6 to 8 feet long, bearing two rows of toothed suckers.
The entire animal is said to have been as large as a
big horse, and its beak like an eagle's but broader.
Mr. Verrill, who has an intimate acquaintance with
the large American species of this genus thinks there
is no reason to suppose it was other than A.
monachus.
This was not the only visit paid to our islands
by this species, for Jeffreys has told us how "the
mutilated carcase of a huge Cephalopod, perhaps
belonging to Steenstrup's species [A. monachus], was
stranded in 1860 or 1861 between Hillswick and
Scalloway, on the west of Shetland. From a com-
munication received by Professor Allman it appears
that the tentacles were 16 feet long, the pedal arms
about half that length, and the mantle-sac 7 feet;
the mantle was terminated by fins ; one of the
suckers examined by Professor Allman was three-
quarters of an inch in diameter."
A more recent example was met with on the north-
west of Boffin Island, Connemara, on the 26th of
April 1875, when a floating mass surrounded by
gulls was observed to seaward and thought to be a
wreck. A canvas boat (curragh) was put off to it,
but to the astonishment of the crew it was found to
be an enormous cuttle-fish, lying still as if basking
in the sun. They paddled up cautiously, and suc-
ceeded in lopping off an arm before the creature
became alarmed. It then rushed out to sea at a
tremendous pace, but the canvas boat followed, and
by hard pulling for five miles the crew came up to
3 A
L) ; 3 FLYING SQUI
Cuttles 399
the cuttle, and severed its head and another arm.
The body sank, and the head and eyes were un-
fortunately lost. From a detailed description given
by Mr. A. G. More in the Annals and Magazine of
Natural History we glean these particulars: The
arms were 8 feet in length with a circumference of
15 inches round the base ; the tentacles 30 feet long,
of which the club was probably over three feet when
fresh, for its present preserved and shrunken length
is 2 feet 9 inches. The centre of this club had two
rows of 14 large stalked suckers nearly 1 inch across,
and outside these on either side was a row of alter-
nating suckers to the same number, but only half
the dimensions. There was also a cluster of still
smaller suckers in transverse rows at the base of the
club. The half-inch suckers were furnished with bony
rings having their edge cut into about 28 teeth all
pointing inwards; and it is believed that the 1-inch
suckers had been of similar character, but their rings
had been removed or had fallen out before they were
examined. The long slender stalk of the tentacle
also bore a few suckers at intervals along the inner
surface, as customary in this genus. The beak had
a strong broad tooth above the middle of the edge of
the inner mandible, and a much narrower notch on
the outer mandible.
In addition to the foregoing species, two oceanic
Cuttles have been taken in British waters, but of
course have little claim to be considered anything
but chance visitors. Onychoteutkis banks ii, which is
very general in the Atlantic, Indian, and Pacific
Oceans, was captured at Banff in 1853, and two dead
specimens of Taonius hyperb&reus were found in
26
400 Shell Life
1869 by the Porcupine Expedition, floating at the
surface, 140 miles to the north-west of Ireland.
From the brief descriptions we have given of the
Cephalopods that occur on our coasts, it will be seen
that there is considerable difference in the characters
of the shell. Lankester considers that these differ-
ences may indicate successive stages in the develop-
ment of the shell. The probable course of such
development can only be appreciated by a comparative
study of the shells of all the genera, exotic as well
as native, fossil as well as recent ; but taking the
Chambered Nautilus (Nautilus pompilius) as one
end of the series, we can see in the shell of Spirilla
its degradation. No longer able to contain the
animal, it has become almost entirely enveloped in
folds of the mantle. " These folds gradually concresce
to form a definite shell-sac, by the walls of which
are secreted additional laminae of calcareous shell-
substance. These laminae invest the original shell,
which gradually (Spirulirostra, Belosepia) loses the
spiral form and becomes straight, eventually dis-
appearing, while the calcareous laminae alone remain
(Sepia). These in their turn disappear, leaving only
the plate or 'pen' upon which they were deposited
(Loligo), which itself also, with the shell-sac, finally
disappears, surviving only in the early stages of
Octopus."
APPENDIX
A CLASSIFIED LIST OF BRITISH MOLLUSKS
MOLLUSCA
CLASS I. CEPHALOPODA.
ORDER DIBRAXCHIATA ;
SUB-ORDER OCTOPODA.
FAM. OCTOPIDJE.
OCTOPUS VULGARIS, LAMK.
0. ARCTICUS, PEOSCII.
FAM. ELEDONID-ffi.
ELEDONE CIRROSA (LAMK.).
SUB-ORDER DECAPODA.
FAM. SPIRDLIDJE.
SPIRTJLA PERONII, LAMK.
FAM. SEPnDJE.
SEPIA OFFICINALIS, L.
S. RUPELLARIA, D'ORB.
S. ELEGANS, D'OKB.
S. BISERIALIS, DE MONT.
FAM. SEPIOLIDJE.
SEPIOLA SCANDICA, STEENST.
S. ATLANTICA, D*ORB.
ROSSIAMACROSOMA(CHIAJE).
R. GLAUCOPIS, LOVEN.
R. SUBLEVIS, VERR.
FAM. LOLIGINID^.
LOLIGO FORBESII, STEENST.
L. MARMOR.E, VERANY.
L. MEDIA (L.).
FAM. OMMASTREPHTD^.
OMMASTREPHES EBLAN^E,
(I:ALL).
o. COINDETI (VERANY).
0. SAGITTATUS (LAMK.).
ARCHITEUTHIS MONACHUS,
STEENST.
FAM. ONYCHOTEUTHnXE.
ONYCHOTEUTH1S BANKSII,
(LEACH).
FAM. CRANCHIIDJE.
TAONIUS HYPERIORETIS,
STEENST.
CLASS H. GASTEROPODA.
ORDER AMPHINEURA;
SUB-ORDER POLYPLACO-
PHORA.
FAM. MOPALOnXffi.
CHITON FASCICTLARIS, L.
C. DISCREPANS, BROWN.
c. HANLEYI, BEAN=DH:BILIS,
GRAY.
C. CANCELLATUS, SOW.
C. CINEREUS, L.
C. ALBUS, L.
C. MARGINATUS, PENN.
C. RUBER, LOWE.
C. LJEVIS, MTROS.
C. MARMORETJS, FAFR.
C. SCABRIDTTS, JEFF.
SUB-ORDER APLACOPHORA.
FAM. NEOMENIIDJE.
NEOMENIA CARINATA, TULL-
BERG.
402
FAM. NEOMENIIDJE-coHfinwwZ.
RHOPALOMENIA AGLAOPHE-
NLE, KOW. & MAR.
MYZOMEXIA BANYULENSIS,
PRUVOT.
FAM. CHJETODERMATID^l.
CH^TODERMA NITIDULUM,
LOVEN.
ORDER PROSOBRANCHIATA ;
SUB-ORDER DIOTOCARDIA.
FAM. ACM^IDJE.
ACM.EA TESTUDINALIS,
MULL.
A. VIRGINEA, MTJLL.
FAM. LEPETIDJE.
LEPETA FULVA, MULL.
L. C^BCA, MULL.
PROPILIDIUM AXCYLOIDES,
FORBES.
FAM. PATELLUXS.
PATELLA VULGATA, L.
HELCIOX PELLUCIDUM (L.).
FAM. FISSURELLnXE.
FISSURELLA GR^ECA(L.).
PUNCTURELLA NOACHIXA, L.
EMARGINULA FISSURA, L.
E. ROSEA, BELL.
E. CRASSA, SOW.
FAM. HALIOTIDJE.
HALIOTIS TUBERCULATUS, L.
FAM. PLEUROTOMARIIDJE.
SCISSURELLA CRISPATA,
FLEM.
FAM. CYCLOSTREMATID.S:.
CYCLOSTREMA MILLEPUNC-
TATUM, FRIELE.
C. NITENS, PHIL.
C. SERPULOIDES, MONT.
MOLLERIA L^EVIGATA, JEFF.
M. COSTULATA, MOLL.
FAM. TROCHID.ffi.
CIRCULUS STRIATCS, PHIL. =
TROCHTJS DUMIXYI.
TROCHUS HELICINUS, FABR.
T. OLIVACEU8, BROWN.
T. GRfENLANDICUS, CHEM.
T. CIXCTUS, PHIL.
T. MAGUS, L.
T. TUMIDUS, MONT.
T. CINERARIUS, L.
T. UMBILICATUS, MONT.
T. LINEATUS (D. C.).
T. MONTACUTI, WOOD.
T. STRIATTJS, L.
T. EXASPERATUS, PEXN.
T. MILIARIS, BROC.
T. GRANULATUS, BORN.
T. ZIZYPHINUS, L.
T. OCCIDENTALIS, MIGH.
FAM. TURBINID^!.
PHASIAXELLA PULLUS (L.).
FAM. NERITIDJE.
NERITINA FLUVIATILIS (L.).
SUB-ORDER MONOTOCARDIA.
FAM. IANTHINIDJE.
IANTHINA ROTUNDATA,
LEACH.
I. COMMUXIS, LAMK.
FAM.
SCALARIA TUPvTON.E (TURT.).
S. COMMUNIS, LAMK.
S. CLATHRATULA (ADAMS).
S. TREVELYANA, LEACH.
S. PSEUDOSCALAKIS, BROC.
ACLIS SUPRANITIDA, S.
WOOD.
A. ASCARIS, TURTOX.
A. WALLERI, JEFF.
PHERUSA GULSON^E, CLK.
CIONISCUS UNICUS, MONT.
FAM. NATICnXffi.
NATICA ISLANDICA, BEAN.
N. GRCENLANDICA, BECK.
N. SORDIDA, PHIL.
N. CATENA (D. C.).
N. GLAtlCINA, L.
N. MONTACUTI, FORBES.
N. AFFINIS, GMEL.
FAM. LAMELLARIIDJE.
MARSEXIA PERSPICUA, L.
VELUTINA L^IVIGATA
(PEN x. ).
Classified List of British Mollusks 403
FAM. TRICHOTROPID^E.
TRICHOTROPIS BOREALIS.
FAM. CAPULID.S.
CAPUI.US HUNGARICUS (L.).
CKEPIDULA FORNICATUS.
C. UNGUIFORMIS, LAMK.
CALYPTRJEA CHINENSIS, L.
FAM. HOMALOGYRIDJE.
HOMALOGYRA ATOMUS
(PHIL.).
H. ROTA (FOR. & HAN.).
FAM. LITTORINIDJE.
LITTORINA OBTUSATA (L.).
L. NER1TOIDES, I,.
L. RUDIS, MATOX.
L. LITTOREA (L.).
LACUNA CRASSIOR. MONT.
L. DIVARICATA (FAI!.).
L. PUTEOLUS (TURT.).
L. PALL1DULA (D. C.)
FAM. CYCLOSTOMATirxffi.
CYCLOSTOMA ELEGANS
(MULL.).
FAM. TRUNCATELLID^E.
TRUNCATELLA SUP.CYLIN-
DRICA, L.
FAM. ACICULID2E.
ACICULA LINEATA (DRAP.).
FAM. RISSOID^E.
RISSOA STRIATULA, MONT.
R. LACTEA, MICH.
R. CANCELLATA, DA C.
R. CALATHUS, F. & H.
R. RETICULATA, MONT.
R. CIMU'OIDES, FORBES.
R. JEFFREYS!, WALL.
R. PUNCTURA, MONT.
R. AI5YSSICOLA, FORIS.
R. COSTULATA, ALD.
R. ZETLANDICA, MONT.
P>. COSTATA, AD.
P.. PARVA, DA C.
R. INCONSPICUA, ALI).
R. ALBELLA, LOV.
R. MEMBRANACEA, AD.
R. VIOLACEA, DESM.
R. GUERINI, RECL.
R. STRIATA, AD.
R. PROXIMA, ALD.
R. VITREA, MOXT.
R. PULCHEKRIMA, JEFF.
R. FULGIDA, AD.
R. OBTUSA, CANT.
R. SEMISTRIATA, MONT.
R. TltlFASCIATA, AD.
BARLEEIA RUBRA, MONT.
FAM. HYDROBHD.S:.
HVDROBIA ULVjE, PENN.
H. VENTROSA, MONT.
H. SIMILIS.
H. JENKINS1I, SMITH.
BITHYNIA TENTACULATA, L.
B. LEACHII, SHEP.
FAM. ASSIMINEID^E.
ASSIMINEA GRAYANA,
LEACH.
FAM. SKENEID^l.
SKENEA PLANORBIS (FABR.).
FAM. JEFFREYSIID^:.
JEFFREYSIA DIAPHANA
(ALD.).
J. OPALINA, JEFF.
J. GLOBULARIS, JEFF.
FAM. ADEORBID5!.
ADEORBIS SUBCARINATUS
(MONT.).
A. UNISULCATTJS, CHASTER.
FAM. VIVIPARIDJE.
A'lVIPARA VIVIPAHA, L.
V. CONTECTA, MILL.
FAM. VALVATIDJE.
VALVATA PISCINALIS
(MULL.).
\. CRISTATA, MULL.
FAM CERITHIID-ffi.
TRIFORIS PERVERSA (L.).
CERITHIUM PKOCERUM,
JEFF.
BITTIUM RETICULATUM
(DA C.).
LOVENELLA METULA
(LOVEN).
CERITHIOPSLS TUBERCU-
LARIS (MONT.).
404
Appendix
FAM. CERITHIID.S! continued.
C. UARLEEI, JEFF.
C. CONCATENATA, COXTI.
C. PULCHELLA, JEFF.
c. METAXJE (CHIAJE).
C. COSTULATA (MOLLER).
FAM. TURRITELLID.E.
TURRITELLA COMMUNIS,
RISSO.
FAM. CCECID.S:.
COECUM TRACHEA, L.
C. GLABRUM (MONT.).
FAM. CHENOPODIDJE.
CHENOPUS PES-PELECANI, L.
. SERRESIAXUS, MICH.
FAM. CYPRJEID^E.
OVULA PATULA (PEXX.).
CYPR.EA EUKOP^A, MONT.
ERATO LJEVIS (DON.).
FAM. CASSIDIDJE.
CASSIDARIA RVGUSA (L.).
C. ECHINOPHORA, L.
FAM. TRITONIDJE.
TRITON NODIFER, LAMK.
T. CUTACEUS (L.).
FAM. ATLANTIDJE.
ATLANTA SP.
FAM. EULIMIDA
EULIMA POLITA, L.
E. INTERMEDIA, CANT.
E. PHILIPPII, WEINK.
E. EPHAMILLA, WATS.
K. SUBULATA, DON.
E. BILIXEATA, ALD.
E. CURVA, MO NTS.
E. PETITIANA, BRUS.
E. PERMINIMA, JEFF.
E. MONTEROSATI, DE BOriWi.
STILIFER TURTONI, BROD.
FAM. PYR AMIDE LLIDJE.
ODOSTOMIA MINIMA, JEFF.
0. NIVOSA, MONT.
0. TRUXOATULA, JEFF.
O. CLAVULA, LOVEN.
0. LUKISI, JEFF.
O. DELICATA, MONTE.
0. PALLIDA, MOXT.
0. CONOIDEA, BROCCHI.
0. UMBILICARIS, MALM.
O. ACUTA, JEFF.
0. CONSPICUA, ALD.
O. UNIDENTATA, MOXT.
0. TURRITA, H AX LEY.
' O. PLICATA, MONT.
O. INSCULPTA, MONT.
O. OBLOXGULA, MARSH.
O. DIAPHAXA, JEFF.
O. WAPvREXI, THOMl'S.
O. OBLIQUA, ALDER.
0. DOLIOLIFORMIS, JEFF.
O. DECUSSATA, MONT.
TURBOXILLA CLATHKATA,
JEFF.
T. IXDISTIXCTA, MOXT.
T. INTERSTINCTA, MONT.
T. SPIRALIS, MONT.
T. EXIMIA, JEFF.
T. FENESTRATA, FORTIES.
T. EXCAVATA, PHILIPPI.
T. SCALARIS, PHILIPIT.
T. RUFA, PHILIPPI.
T. MULTILIRATA, MONT-
EROS.
T. VERTICALIS, MARSH.
T. LACTEA, L.
T. PUSILLA, PHILIPPI.
T. IXNOVATA, MOXTEROS.
T. DELICATA, MONTEROS.
EULIMELLA SCILL^,
SCACCHI.
E. COMPACTILIS, JEFF.
E. ACICULA, PHILIPIT.
E. VEXTRICOSA, FORBES.
E. XITIDISSIMA, MOXT.
E. FALLAX, MONTEROS.
FAM. MURICID^!.
TROPHON Mt'RICATUS
(MOXT.).
T. BARVICENSIS, JOHNST.
T. TRUXCATUS (STROM.).
T. CARINATUS, JEFF.
OCINEBRA ERINACEA (LINN. ).
O. ACICULATA (LAMK.).
PURPURA LAPILLUS (L.).
Classified List of British Mollusks 405
FAM. COLUMBELLnXE.
COLUMBELLA HALIvETI,
JEFF.
FAM.
NASSA R.ETICULATA (L.).
N. INCRASSATA (STROM.).
N. PYGMjEA, LAMK.
FAM. BUCCINID.E.
CHRYSODOMUS ANTIQUA (L. ).
C. DESPECTA (L.).
c. TURTONI (BEAN)
C. NORVEGICA (CHEMN.).
C. ISLANDICUS (CHEMN.).
C. GRACILIS (DA C.).
C. TURGIDULUS (FRIELtf).
c. PROPINQUUS (ALDER).
C. JEFFREYSIANUS (FIS-
CHER).
C. ATTEXUATUS (JEFF.).
c. EBUR (MOHCH.).
c. FUSIFORMIS (BRODEKIP).
LIOMESUS DALEI (j. SOW.).
L. STRIATUS (JEFF.).
BUCCINUM UNDATUM, L.
B. HUMPHREYSIANUM,
BENNETT.
DONOVANIA MINIMA(MONT. ).
FAM. FASCIOLABIID.aE.
TROSCHELIA EERNICIENSIS
(KING).
FAM. CONIDJE.
D1ULMA SEMICOLON (S.
WOOD).
Sl'IROTROPIS CARINATA
(PHILIPPl).
TYPHLOMANGILIA NIVALIS
(LOVEN).
H.EDROPLEURA SEPTAyGU-
LARIS (MONT.).
BELA PYRAMIDALIS
(STROM.).
B. CANCELLATA (HIGH. ), VAR.
DECLIVIS (LOVEN).
B. CINEREA (MOLL.).
B. TREVELYANA (TURTON).
B. TENUICOSTATA (M. SARS.).
B. OVALIS, FRIELE.
B. BICARINATA (COUTHOUY).
B. EXARATA (MOLL).
B. TURRICULA (MONT.).
B. RUFA (MONT.).
MANGILIA STRIOLATA
(SCACCHl).
M. ATTENUATA (MONT.).
M. COST ATA (DON.).
M. RUGULOSA (PHILIPPl).
M. BRACHYSTOMA (PHILIPPl).
M. NEBULA (MONT.).
M. PACKARDI, VERRILL.
M. NANA (LOVEN).
M. ANCEPS (EICHW.).
M. GRACILIS (MONT.).
CLATHURELLA LINEARIS
(MONT.).
C. RETICULATA (liENIER).
c. PURPUREA (MONT.).
C. LEUFROYI (MICH.).
FAM. CANCELLARnXSi.
ADMETE VIRIDULA (FABR. ).
ORDER OPISTHOBRANCHI-
ATA;
SUB-ORDER TECTIBRANCHI-
ATA.
FAM. ACT^ONID^l.
ACTION TORNATILIS, L.
A. EXILIS, JEFF.
FAM. TOENATINID^!.
TORNATINA OBTUSA (MONT.).
T. MAMMILATA (PHILIPPl).
T. TRUNCATULA (BKTJG.).
T. UMBILICATA (MONT.).
T. NITIDULA, LOVEN.
T. OVATA (JEFF.).
VOLVULA ACUMINATA
(BURG.).
FAM. SCAPHANDRID.5!.
SCAPHANDER LIGNARIUS(L. ).
S. PUNCTOSTRIATUS (MIGH.).
CYLICHNA CYLINDRACEA
(PENN.).
C. NITIDULA (LOV.).
c. ALBA (BROWN).
AMPHTSPHYRA HYALINA
(TURTON).
406
Appendix
FAM. SCAPHANDRIDJE continued.
AGT.EONIA CORRUGATA,
A. EXPANSA (JEFF.).
A. & H.
A. VENTROSA(JEFF.).
CENIA COCKSI, A. & H.
A. GLOBOSA (LOVEN).
BERGHIA C.ERULESCENS,
CRYPTAXIS CREBRIPUNCTA-
LAURILL.
TU.S, JEFF.
FAM. BULLIDJE.
SUB-ORDER NUDIBRANCHI-
I5ULLA TJTRICULTIS, BROCCHI.
ATA.
B. SEMILEVIS, SEGUENZA.
HAMINEA HYDATIS (L.).
FAM. .ffiOLIDinxs:.
ACERA BULLATA, MULL.
^OLIS PAPILLOSA (L.).
FAM. PHILINID^!.
JE. GLAUCA, A. & H.
PHILINE APERTA (L.).
JE. ALDERI, COCKS.
P. NITIDA, JEFF.
JE. SANGUINEA, NORM.
P. SCABRA (MULL.).
p. CATENA (MONT.).
P. ANGULATA, JEFF.
CUTHONA NANA, A. & H.
C. AURANTIACA (A. & H.).
CRATENA VIRIDIS (FORBES).
P. QUADRATA (S. WOOJ>).
C. AM(ENA (A. & H. ).
p. PUNCTATA (CLARK).
p. PRUINOSA (CLARK).
C'OLPODASPIS PUSILLA, M.
C. OLIVACEA, A. & H.
C'. PUSTULATA (A. & H. ).
C. GLOTTENSIS (A. & H.).
SARS.
C. ARENICOLA (FORBES).
C. CONCINNA (A. & H.).
FAM. APLYSmXS.
C. PEACHII (A. & H.).
APLYSIA DEPILANS, L.
C. STIPATA (A. & H.).
A. PUNCTATA, CUV.
f. ANGULATA (A. & H.).
FAM. PLEUROBRANCHID.S.
C. INORNATA (A. & H.).
c. COUCHII (COCKS).
PLEUROBRANCHUS MEM-
BRANACEUS (MONT.).
C. NORTHUMBRICA (A. & II.).
TERGIPES DESPECTUS
p. PLUMULA (MONT. ).
(JOHNST.).
FAM. RUNCINID^B.
EMBLETONIA PULCHRA,
RUNCINA CORONATA
(QVATRE.).
A. & H.
E. MINUTA (FOR. & GOOD.).
E. PALLIDA, A. & H.
SUB-ORDER ASCOGLOSSA.
AMPHORINA OERTILEA
(MONT.).
FAM. HERMJEID.&:.
A. PCRPURASCENS (FLEM.).
HERM.EA BIFIDA (MONT.).
A. MOLIOS (HERDM.).
H. DENDRITICA, A. & H.
GALVINA EXIGUA, A. & H.
ALGERIA MODESTA (LOVEN).
G. TRICOLOR, FOR.
G. PICTA, A. & H.
FAM ELYSHDJE.
G. FARRAM, A. & H.
ELYSIA VIRIDIS (.MONT.).
G. ADELAIDE (w. THOMPS.)
G. VITTATA, A. & H.
FAM. LIMAPONTHDJE.
G. CINGULATA, A. & H.
LIMAPOXTIA CAPITATA
CORYPHELLA RUFIBRANCHI-
(MULL.).
ALTS (JOHNST.).
L. DEPRESSA, A. & H.
C. GRACILIS, A. & H.
Classified List of British Mollusks 407
FAM. JEOLIDIIDJE co;i inveil.
C. SMARAGDINA, A. & H.
C. LANDSBUKOII, A. & H.
C. PELLUCIDA, A. & H.
C. LINEATA (LOVEN).
FAVORINUS ALBUS, A. & II.
F. CARNEUS, A. & H.
FACELINA DRUMMONDII (\V.
THOMl'S. ).
F. COHONATA (FORBES).
F. PUN CT AT A, A. & H.
F. ELEGANS, A. & H.
CALMA GLAUCOIDES, A. & H.
FIONA MARINA (FORSK.).
ANTIOI'A CRISTATA (t'HIAJE).
A. HYALINA, A. & H.
PROCTONOTUS MUCRONIFER,
A. & H.
HEKO FORMOSA, LOVEN.
FAM. LOMANOTID-ffi.
LOMANOTUS MARMORATUS,
A. & H.
L. FLAVIDUS, A. & H.
L. PORTLANDICUS, W.
THOMl'S.
L. HANCOCKI, NORM.
FAM. DOTONIDJE.
DOTO FRAGILIS (FORBES).
]). PENNATIFIDA (MONT.).
D. COROSATA (GMELIN).
1). CUSl'IDATA, A. & H.
FAM. DENDRONOTID.S:.
DENDKONOTUS FRONDOSUS
(ASCAN.).
FAM. SCYLLJEIDJE.
SCYLL^A PELACJICA, 1..
FAM. PLEUROPHYLLIDIID^E.
I'LEUKOl'HVLI.IDIA LOVEXI,
BERGH.
FAM. TEITONIIDJE.
TRITONIA HOMBERGI, CUV.
T. ALBA, A. & H.
T. PLEBEIA, JOHNS'!'.
T. LINEATA, A. & H.
FAM. DORIDIDJE.
DORIS TUBERCULATA, CUV.
I). FLAMMEA, A. & H.
D. MACULATA, GARS.
D. JOHSSTONI, A. & H.
]). TESTUDINARIA, RISSO.
D. ZETLAND I (.'A, A. & H.
]). MILLEGRANA, A. & H.
D. REPANDA, A. & H.
D. COCCINEA, A. & II.
FAM. POLYCERIDJE.
.&GIRUS PUNCTILUCENS
(D'ORB.).
TRIOPA CLAVIGERA (MULL.).
CRIMORA PAPILLATA, A. & H.
THECACERA PENNIGERA
(MONT.).
T. VIRESCENS, A. & II.
T. CAPITATA, A. & H.
POLYCERA QUADRILINEATA
(MULL.).
p. LESSON ir, D'ORB.
FAM. GONIODORIDJE.
ACANTHODORIS PILOSA
(MULL.).
A. SUBQUADRATA, A. & H.
LAMKLLIDORIS ASPERA,
A. &H.
L. MURICATA (MULL.).
L. ULIDIANA (THOMP.S.).
L. DIAPHANA, A. & H.
L. BILAMELLATA (L.).
L. DEPRESSA, A. & II.
L. INCONSPICUA, A. & H.
L. PUSILLA, A. <fe II.
L. SPARSA, A. & H.
L. OBLONG A, A. & II.
L. PROXIMA, A. & II.
L. LOVENI, A. & H.
GONIODORIS NODOSA(MONT.).
G. CASTANEA, A. & H.
IDALINA ELEGANS (LAMK.).
I. LEAOHII, A. & H.
i. INEQUALIS (FORBES).
I. ASPERSA, A. & H.
I. QUADRICORNIS (MONT.).
I. PULCHELLA (A. & II.).
ANUULA CRISTATA (ALDER.).
408
SUB-ORDER PTEROPODA.
FAM. LIMACINID.S:.
LIMACIXA RETROVERSA
(FLKM.).
FAM. CAVOLINIDJE.
CLIO PYRAMIDATA, L.
FAM. CLIONIDJE.
CLIOXA LIMACIXA, PHIPPS.
ORDER PULMONATA ;
SUB-ORDER BASOMMATO-
PHORA.
FAM. AURICTJLTDJE.
CARYCHIUM MIXIMUM,
MULL.
ALEXIA MYOSOTIS (DRAP.).
A. DENTICULATA (MOXT.).
LEUCOXIA I1IDENTATA
(MOXT.).
FAM. OTINIDJE.
OTIXA OTIS (TUKTOX).
FAM. LIMNJEIDJE.
ANCYLUS FLUVIATILIS,
MULL.
A. LACUSTRIS (L.).
LIMX^A STAGXALIS (L.).
L. PALUSTRIS (MULL.).
L. TRUXCATULA (MULL.).
L. GLABRA (MULL.).
L. AURICULARIA (L.).
L. PEREGRA (MULL.).
AMPHIPEPLEA GLUTIXOSA
(MULL.).
A. INVOLUTA, THOMPS.
PLANORBIS CORXEUS (L.).
P. COXTORTUS (L.).
P. CARINATUS, MULL.
P. UMBILICATUS, MULL. =
COMPLAXATUS, JEFF.
P. VORTEX (L.).
P. SPIRORBIS (L.).
[P. DILATATUS, GOULD.]
P. GLABER, JEFF.
P. ALUUS, MULL.
P. XAUTILEUS (L.).
P. COMPLAXATUS (L.) =
xmnrs, GRAY.
SEGMEXTIXA XITIDA(MULL.)
= PL. LIXEATUS, WALK.
FAM. PHYSIDJE.
PHYSA FOXTIXALIS (L.).
P. HYPXORUM, L.
SUB-ORDER STYLOMMATO-
PHORA.
FAM. TESTACELLIDJE.
TESTACELLA HALIOTIDEA,
DRAP.
T. SCUTULUM, SOW.
T. MAUGEI, FERUSS.
FAM. LIMACIDJE.
LIMAX MAXIMUS, L.
L. C1NEREO-XIGKR, WOLF.
[L. TEXELLUS, NILSS.]
L. MARGINATUS, MULL. =
ARBORUM, B. C'H.
L. FLAVUS, L.
L. AGRESTIS, L.
L. L^VIS, MULL.
L. CARIXATUS, RISSO. =
MARGIXATUS, DRAP.
L. GAGATES, DRAP.
VITRINA PELLUCIDA(MULL. )
COXULUS FULA'A (MULL.).
HYALIXIA CRYSTALLIXA
(MULL.).
H. NITIDA (MULL.).
H. EXCAVATA (BEAN.).
H. PURA (ALDER).
[H. PETROXELLA (CHARI 1 .).]
H. RADIATULA (ALDEP.).
H. GLABRA (STUDER).
H. ALLIARIA (MULL.).
H. CELLARIA (MULL.).
H. DFAPARNAUDI (BECK).
H. XITIDULA (DRAP.).
FAM. HELICIDJE.
RION ATER (L.).
. SUBFUSCUS, DRAP.
. IXTERMEDIUS, NORM.
. HORTEXSIS (KERUSS.).
. CIRCUMSCRIPTUS,
JOHXST.
GF.OMALACUS MACULOSUS,
ALLM.
HELIX PYGMjEA, DRAP.
H. ROTUXDATA, MULL.
H. RUPESTRIS, STUDER.
A Classified List of British Mollusks
409
FAM. HELICIDJE continued.
II. PULCHELLA, MULL.
H. ACULEATA, MULL.
H. LAMELLATA, JEFF.
H. OBVOLUTA, MULL.
H. LAPICIDA, L.
H. HISPIDA, L.
II. KUFESCENS, PEXN.
H. GRANULATA, ALDER =
SERICEA, MULL.
H. REVELATA, FERTJSS.
H. FUSCA, MONT.
H. CAXTIAXA, MONT.
H. CAUTHUSIANA, MULL.
H. ARBUSTOKUM, L.
H. PISAXA, MULL.
H. VI KG ATA, DA 0.
H. ERICETORUM, MULL.
H. CAPERATA, MONT.
[H. TERRESTRIS, PEXN.]
H. ACUTA, MULL.
H. NEMORALIS, MULL.
H. HORTENSIS, MULL.
H. ASPERSA, MULL.
H. POMATIA, L.
FAM. POTION.
BULIMINUS MONTANUS,
DRAP.
B. OBSCURUS (MULL.).
PUPA CYLINDRACEA, DA C.
= UMBILICATA, DRAP.
p. ANGLICA (FERUSS.) =
RINGENS, JEFF.
P. SF.CALE, DRAP.
P. MUSCORUM, MULL. = MAR-
GINATA, DRAP.
P. EDENTULA, DRAP.
P. MINUTISSIMA, HARTM.
P. ALPESTRIS, ALDER.
P. LILLJEBORGI, WEST. =
VERTIGO MOULIXSIANA,
JEFF.
P. MOULINSIANA, DTJPTJY.
P. PYGMjEA, DRAP.
P. SUBSTRIATA, JEFF.
P. ANTIVERTIGO, DRAP.
P. PUSILLA, MULL.
P. ANGUSTIOR, JEFF.
BALEA PERVEKSA (L.).
CLAUSILIA LAMINATA
(MONT.).
c. I;IPLICATA (MONT. ).
C. BIDENTATA, STROM. =
RUGOSA (DRAP.).
c. ROLPHI (GRAY).
FAM. STENOGYRID^E.
FERUSSACIA LUBRICA
(MULL.).
F. TRIDENS (PULT.).
C^CILIANELLA ACICULA
(MULL.).
[sTEXOGYRA GOODALLI
(MULL.).]
FAM. SUCCINEIDJE.
SUCCINEA PUTRIS (L.).
S. ELEGANS, RISSO.
S. STAGNALIS, GASSIES.
S. OBLONGA, DRAP.
FAM. ONCHIDHDJE.
ONCHIDIELLA OELTICA
(CUV.).
CLASS III.-SCAPHOPODA.
DENTALIUM ENTALIS, L.
D. TARENTINUM, L.
SIPHODEXTALIUM LOFO-
TEXSE, G. 0. SARS.
. AFFINA, SARS.
CLASS IV.-PELECYPODA.
ORDER PROTOBRANCHIATA.
FAM. NUCDLLDJE.
NUCULA NUCLEUS, L.
N. SULCATA, BROWN.
N. TENUIS, JEFF.
N. N1TIDA, SOW.
LEDA PYGM^A, MUNST.
L. MINUTA, MULL.
L. PERNULA, MULL.
L. TENUIS, PHIL.
ORDER FILOBRANCHIATA ;
SUB-ORDER ANOMIACEA.
FAM. ANOMIIDJE.
ANOMIA EPHIPPIUM, L.
A. PATELLIFORMIS, L.
4io
Appendix
SUB-ORDER ARCACEA.
FAM. ARCADJE.
ARCA TETRAGONA, POLL
A. PECTUNCULOIDES, SCAC.
A. LACTEA, L.
A. OBLIQUA, PHIL.
A. NODULOSA, HULL.
PECTUNCULUS GLYCIMERIS,
L.
LIMOPSIS AURITA, BROC.
SUB-ORDER MYTILACEA.
FAM. MYTILID-ffi.
MYTILUS EDULIS, L.
MODIOLA MODIOLUS, L.
M. BARBATtJS, L.
M. ADRIATICA, LAMK.
M. PHASEOLINUS, PHIL.
CIIENELLA RHOMBEA, BERK.
C. DECUSSATA, MONT.
MODIOLAHIA MARMORATA
(FORBES).
M. COSTULATA (llISSO).
M. DISCORS, L.
II. NIGRA, GRAY
ORDER PSEUDOLAMELLI-
BRANCHIATA.
FAM. AVICDLIDJE.
AVICULA HIRUNDO. L
PINNA RITDIS, I,.
FAM. OSTREIDJE.
OSTREA EDULIS, L.
FAM. PECTINID.S.
PECTEN PUSIO, L.
P. VARIUS, L.
P. ARATUS, GMEL.
P. OPERCULARIS, L.
P. PES-LUTPwE, L.
P. TIGRINUS, MULL.
P. INCOMPARABILIS, RISSO.
P. STRIATUS, MULL.
P. SIMILIS, LASK.
P. MAXIMUS, L.
P. VITRErS, CH.
FAM. LIMIDJE.
LIMA ELLIPTICA, JEFF.
L. SrBATJRICULATA(MONT.).
L. LOSCOMBII, SOW.
L. HIANS, GMEL.
ORDER EULAMELLIBRAN-
CHIATA ;
SUB-ORDER SUBMYTILACEA.
FAM. ASTARTIDJE.
' ASTARTE SULCATA, D. C.
A. COMPRESSA, L.
A. TRIANGULARIS (MONT.).
A. CRENATA, GRAY.
FAM. CYPRINID^B.
CYPRINA ISLANDICA, L.
ISOCARDIA COR, L.
FAM. UNIONIDJE.
UNIO MARGARITIFER (L.).
r. PicTORX'M (L.).
V. TUMIDUS, PHIL.
ANODOXTA AXATINA (L.).
A. CYGNEA (L.).
FAM. DRIESSENSHD^E.
DRIESSENSIA POLYMORPHA,
PALL.
FAM. LUCINIDJS.
LUCINA BOREALIS (L. ).
L. SPINIFERA, MOXT.
LORIPES LACTEUS, L.
L. COMMUTATUS, PHIL.
L. DIVARICATUS, L.
AXINUS FERRUGINOSUS,
FORBES.
A. FLEXI'OSUS, MONT.
A. CROULINENSIS, JEFF.
A. CYCLADIUS, WOOD.
A. CUMYARIUS, M. SARS.
BIPLODONTA ROTUNDATA,
MONT.
MONTACUTA SUBSTKIATA
(MONT.).
M. BIDEXTATA (MONT.).
M. FERRUGINOSA (MONT.).
M. DAWSONI, JEFF.
M. TUMIDULA, JEFF.
M. DONACINA, WOOD.
SCINTILLA EDDYSTONIA,
MARSH.
FAM. ERYCINIDJE.
KELLIA SUBORBICULAIUS
(MONT.).
K. MINUTA (FABR.).
LAS.EA RUBRA (MONT.).
Classified List of British Moll us ks 411
FAM.
LKI'TON SQUAMOSUM, MONT.
L. NITIDUM, CLARK.
L. SULCATULUM, JEFF.
L. CLARKI^E, CLARK.
L. SYKESII, CHASTER.
FAM. GALEOMMID-ff!.
RALEOMMA TURTONI, EDS.
ZOOL. JOURX.
FAM. CYRENIDJE.
SPHJERIUM CORNEL T M (L.).
s. RIVICOLA (LEACH).
8. PALLIDUM, GRAY.
S. LACUSTRE (MULL.).
PISIDIUM AMNICUM (MULL.).
P. FONTINALE (DRAP.).
p. PUSILLUM (GMELIN).
P. NITIDUM, .TEN.
P. MILIUM, HELD.
SUB-ORDER TELLINACEA.
FAM. TELLINID-ffl.
TELLINA BALAUSTINA, L.
T. CRASSA (PENN.).
T. BALTHICA, L.
T. TEN U IS, D. C.
T. FABULA, GRON.
T. SERRATA, BROC.
T. SQUALIDA, PULT.
T. DONACINA, L.
T. PUSILLA, PH.
GASTRANA FRAGILIS (L.).
FAM. SCROBICULARinxaE.
SCROBICULARIA PRISMATICA
(MONT.).
S. NITIDA, MULL.
S. LONGICALLTJS, SC'AC.
SYNDOSMYA ALBA, S. WOOD.
s. PIPERATA (GMEL.).
S. TENUIS, MONT.
FAM. DONACiaS.
DONAX VITTATUS (D. C.).
D. POLITUS, POLL
D. TRUNCUL1 T S, L.
ERVILEA CASTANEA, MONT.
FAM. MACTRIDJE.
MACTRA SOLIDA, L.
M. ELLIPTICA, BRO.
M. SUBTRUNCATA, D. C.
M. STULTORUM, L.
M. GLAUCA, BORN.
SUB-ORDER VENERACEA.
FAM. VENERID^E.
CIRCE MINIMA (MONT.).
DOSINIA EXOLETA, L.
D. LUPIN A, L.
VENUS CHIONE, L.
V. FASCIATA (D. C. ).
V. CASINA, L.
V. VERRITCOSA, L.
V. OVATA, PENN.
V. GALLINA, L.
[V. MERCENARIA, L.]
LUCINOPSIS UNDATA (PENN. ).
TAPES AUREUS, GMEL.
T. VIRGINEUS, L.
T. PULLASTRA, L.
T. DECUSSATA, L.
VENERUPIS IRUS (L.).
FAM. PETRICOL.ID.ff:.
[PETRICOLA LITHOPHAGA,
RETZ.
P. PHOLADIFORMIS, LAMK.].
SUB-ORDER CARDIACEA.
FAM. CARDIIDJE.
CARD1UM ACULEATUM, L.
C. ECHINATUM, L.
C. TUBERCULATUM, L.
C. PAPILLOSUM, POLL
C. EXIGUUM, GMEL.
C. FASCIATUM, MONT.
C. NODOSUM, TURTON.
C. EDULE, L.
C. MINIMUM, PHIL.
C. NORVEGICUM, SPENG.
S LIB-ORDER MYACEA.
FAM. PSAMMOBIIDJE.
PSAMMOBIA TELLINELLA,
LMK.
P. COSTULATA, TURT.
P. FERROENSIS, CH.
P. VESPERTINA, CH.
FAM. MYID-ff!.
MYA ARENARIA, L.
M. TRUNCATA, L.
M. BINGHAMI (TURT.).
412
t/fppendix
FAM. VTiDS-contlnued.
OORBULA GIBBA, OLIVI.
NE^RA ABBREVIATA, FORB.
N. COSTELLATA, DESH.
N. CUSPIDATA, OLIVI.
PANOP^A PLICATA, MONT.
LUTRARIA ELLIPTICA,
1AMK.
L. OBLONGA, CH.
FAM. SOLENID.E.
SOLECURTUS SCOPULA, TURT.
S. ANTIQUATUS, PULT.
CERATISOLEN LEGUMEN (L.)
SOLEN PELLUCIDUS, PENN.
S. ENSIS, L.
S. SILIQUA, L.
S. VAGI X A, L.
FAM. GLYCIMERID^:.
SAXICAVA RUGOSA, L.
S. ARCTICA, L.
S. NORVEGICA, SPENG.
FAM. GASTROCHffiNID.ffi.
GASTROCH.ENA DTJBIA, PENN.
SUB-ORDER PHOLADACEA.
FAM. PHOLADID^E.
PHOLAS DACTYLUS, L.
P. CANDIDA, L.
P. PARVA, PENN.
P. CRISPATA, L.
PHOLADIDEA PAPYRACEA
TURT.
XYLOPHAGA DORSALIS,
TURT.
FAM. TEREDINIDJE.
TEREDO NORVEGICA, SPEXO.
T. NAVALIS L.
T. PEDICELLATA.
T. MEGOTARA, HAN.
SUB-ORDER ANATINACEA.
FAM. PANDORIDJE.
PANDORA IN^EQUIVALVIS, L.
FAM. LYONSIID^!.
LYONSIA NORVEGICA, CHEM.
FAM. ANATINIDJE.
THRACIA PR.ETENUIS
(PULT.).
T. PAPYRACEA (POLI.).
T. PUBESCENS, PULT.
T. CONVEXA, WOOD.
T. DISTOKTA (.MONT.).
ORDER SEPTIBRANCHIATA.
FAM. POROMYID^E.
POROMYA GRANULATA,
NYST.
** A List of the Classes, Orders, Families, and Species of the British
Mollusca in conformity with this Appendix, but specially printed on
one side of the paper only, for use as Labels for the Cabinet, is issued
by the Publishers. Price One Shilling net.
INDEX
TO POPULAR NAMES
ACTION-SHELLS, 270.
Agate Snail, 379.
Alder's Slug, 300.
Alexia-shells, 308.
Amber Snails, 380.
Ark-shells, 64.
Artemis- shells, 129.
Astarte- shells, 93.
Auger-shell, 240.
BASKET-SHELLS, 150.
Belted-shell, 234.
Bladder-snails, 325.
Blind-shell, 240.
Breathing, 44.
Bubble-shells, 271.
Bulin Snails, 370.
Bushy-backed Slug, 288.
" Butterflies of the Sea," 303.
Bithynia Snails, 233.
CANOE-SHELL, 272.
Carnivorous Slugs, 329.
Carpet-shells, 135.
Chink-shells, 225.
Chrysalis Snails, 371.
Circe-shell, 129.
Cockles, 139 ; Fresh-water, 107.
Coin-shells, 103.
Conelets, 265.
Cowry, 245.
Crenella-shells, 73.
Cuttles, 29, 389.
Cyprina-shell, 95.
DOG -COCKLE, 65.
Dog-whelks, 257.
Door-shells, 374.
Double-tooth, 99.
EAR-SHELLS, 196, 309.
Elephant's-tusk, 180.
Eyes, 51.
FALMOUTH SLUG, 302.
Fan Mussel, 77.
Feeding, 40.
File-shells, 87.
Flask- shells, 162.
Flat-coils, 319.
Fresh-water Cockles, 107.
Fresh-water Limpets, 309.
Fresh- water Mussels, 26, 114.
Furro\v-shells, 122.
GAPERS, 148.
Garden Snail, 22, 364.
Glass Snails, 338.
Glutinous Snail, 318.
Gulfweed Slug, 287.
HATCHET-SHELLS, 98.
Hearing, 53.
Heart-Cockle, 96.
Herald-shells, 306.
Horn-shells, 238.
Horse Mussel, 70.
Hungarian Cap, 220.
KELLY-SHELLS, 101.
LAND-SLUGS, 328.
Land-snails, 347.
Lantern-shells, 175.
Leda-shells, 59.
Limpets, 186, 220.
414
Index to Popular Names
Lobe-shell, 27.-).
Lucina-shells, 97.
MAIL-SHELLS, 180.
Marbled Slug, 290.
Margin-shell, 243.
Montagu-shells, 99.
Moss Snails, 378.
Mussels, 27, 67.
NECKLACE-SHELLS, 215.
Nut-shells, 56.
OCTOPUS, 386.
Orb-shells, 108.
Ormer, 196.
Otter-shells, 152.
Oyster, 78.
PANDORA-SHELLS, 173.
Pearl Mussels, 111.
Pea-shells, 109.
Pelican's-foot, 241.
Periwinkle, 222.
Pheasant-shell, 207.
Picklocks, 163.
Poached Egg, 244.
Point-shell, 230.
Pond-snails, 311.
Purple, 254.
Pyramid-shells, 250.
RAZOR-SHELLS, 155.
River Snails, 235.
Rock-borers, 138, 160.
Rock Venus, 137.
Round-mouth, 228.
SADDLE OYSTER, 61.
Scallops, 81.
Sea Hare, 276.
Sea Lemons, 281.
Sea-nymphs, 289.
Sea-slugs, 276.
Sentinel-shells, 233.
Shell-bearing Slugs, 329.
Shell-forms, 32.
" Shillifillies," 238.
Ship- worms, 170.
Skye Gaper, 177.
Slit-shell, 197.
Slugs, 328, 344.
Smell, Sense of, 54.
Spindle-shells, 252, 259.
Spire-shells, 231.
Squids, 393.
Sting-winkles, 253.
Sunset-shells, 145.
Swan Mussel., 26, 114.
TELLINS, 119.
Tooth-ribbon, 42.
Top-shells, 200.
Touch, Sense of, 55.
Tree Snail, 373.
Triton-slugs, 286.
Trough-shells, 125.
Trumpet-snails, 319.
URCHIN SNAIL, 250.
VALVE-SHELLS, 236.
Velvet-shell, 219.
Venus-shell, 128, 130.
Violet-snail, 210.
WEASEL-EYE, 106.
Wedge-shells, 124.
Wentletraps, 212.
Whelks, 259, 261.
Wing-shell, 91.
Winkles, 222.
ZEBRA MUSSEL, 116.
PRINTED BY MORRISON' AND Ollil) LIMITED, EDlXBfROII
Date Due
AUb' 6
1968
~ *.
d
PRINTED
IN U. S. A.
The RALPH B. REED LIBRARY
DEPARTMENT OF G^"* 3 *
UNIVERSITY of CALIFORNIA
LOS ANGELES, CALIF .
UCLA-Geology/Geophysics Library
QL425G7S8
UC SOUTHERN REGIONAL LIBRAR