RUSOHEXTBHRaZH'S SERIES. 
 
 1' iiOS'.S . NAT1 : . 
 
 OLOGY: 
 
 OF 
 
 SCHOOLS AND COLLEGES, 
 
 B V 
 
 W. S. W. RUSCHENBERGER, M.D. 
 
 in the U. S. ITavy ; i'ellow of the College of Physicians; Hon. 
 
 ^dical Society; Meml- 
 tural Sciences of Philadelphia, &c. &c. 
 
 FROM THE YtflvT.OF 
 
 MILNE EDWARDS, AND ACHILLE COMTE, 
 
 YKOFF.SSORS OF NATURAL HISTORY IN THE COLLEGES 
 0? HENRI IV, AND CHARLEMAGNE, 
 
 WITH PLATES. 
 
 PHILADELPHIA: 
 
 GRIGG & ELLIOT, 
 
 NO, 9 NORTH FOURTH STREET 
 
 .15. 
 
E. FOOTE, M. D., 
 
 adelphia, Pa. 
 
 
 BIOLOGY 
 
 LIBRARY 
 
 G 
 
 
RTJSCKENBERGER'S SEHIES, 
 
 FIRST BOOKS OF NATURAL HISTORY, 
 
 ELEMENTS OF CONCHOLOGY: 
 
 PREPARED FOR THE USE OF 
 
 SCHOOLS AND COLLEGES, 
 
 BY 
 
 W. S. W. RUSCHENBERGER, M.D. 
 
 Surgeon in the U. S. Navy ; Fellow of the College of Physicians ; Hon. 
 
 Member of the Philadelphia Medical Society ; Member of the 
 
 Academy of Natural Sciences of Philadelphia. Sec. &c. 
 
 FROM THE TEXT OF 
 
 MILNE EDWARDS, AND ACHILLE COMTE, 
 
 PROFESSORS OF NATURAL HISTORY IN THE COLLEGES 
 OF HENRI IV, AND CHARLEMAGNE. 
 
 WITH PLATES. 
 
 PHILADELPHIA: 
 GRIGG & ELLIOT, 
 
 NO. 9 NORTH FOURTH STREET, 
 
 1845. 
 
GY 
 
 M 
 
 , according to the Act of Congress, in the year 1843, by 
 W. S. W. RUSCHENBERGER, M.D., 
 
 in the clerk's office of the District Court of the United States in and for the 
 Eastern District of Pennsylvania. 
 
 ?. K. k P G. Collins, Printers. 
 
 (4) 
 
PREFACE. 
 
 The fifth of the Series of First Books of Natural History, em- 
 braces that branch of our subject which treats of the Mollusca, 
 or soft animals, and, consequently, includes the Elements of Con- 
 chology. 
 
 In the beauty and singularity of their forms, the variety and 
 brilliancy of their colours, shells only yield to flowers. The 
 admiration of these deserted habitations of a very numerous class 
 of animals is very general, if not universal ; scarcely a house, at 
 least in sea-port towns, is without a few shells, and in many there 
 are large collections of them. Comparatively, few persons, how- 
 ever, view them in connection with animal existence for the 
 mass, they are merely beautiful things from the seas and rivers, 
 far and near. We care little how they grow, how they live, how 
 they breathe, upon what they feed, or for what use they were 
 created. Who stops to think an oyster has a heart and blood- 
 vessels, a breathing apparatus, a nervous system, or digestive 
 organs ? How very few are aware that certain snails possess 
 eyes and lay eggs ; nor is it universally known that we are in- 
 debted to the organization of soft animals for mother-of-pearl and 
 pearls ! 
 
 Limited as this little volume is, it may prove a key to stores 
 of information, even more interesting to many than the numerous 
 fictions of the day. " Truth is stranger than fiction," has been 
 often said ; and the beautiful truths brought to us by a study of 
 animal life, in its various forms, are certainly more admirable and 
 wonderful than any fiction of man's creation. 
 
 Is there any thing produced by the Bulwers or the James' of 
 the day, more worthy of admiration than the habits of a snail, 
 or the movements of a cockle-shell? When at the Sandwich 
 Islands, in 1836, we heard an anecdote which has an application 
 here. The officers of a British ship of war manifested a strong 
 desire to obtain " curiosities :" a young Kanaka, with a view to 
 
6 PREFACE. 
 
 profit, brought to one of these officers a chicken's foot, and 
 offered it for sale ; and by way of insisting upon its value, said, 
 as he> pulled the tendon which was attached to its toes, " See how 
 nicely it works ;" and was it not more worthy of attention and 
 thought than all the idols of wood and stone that could be col- 
 lected? 
 
 Fictions are the works of man, but the wonderful truths of the 
 universe are the creations of Omnipotence ; yet we bestow more 
 time and more interest on the last novel, in many instances, than 
 would be sufficient to lead us to the contemplation of all the beau- 
 tiful and magnificent productions which it was Adam's duty to 
 name. Whoever reveres his God, should be able to contemplate 
 his works understandingly, and be able to perceive the beauty of 
 design, the adaptation of the organization, the various forms of 
 life, to the circumstances in which life is placed, and perceive the 
 same wise hand in the structure of the snail, as in the complete 
 and perfect animal, man ; and learn too, that even an oyster is 
 within the scheme and protection of Providence. 
 
 In forming this little volume, besides the works of MM. Ed- 
 wards and Comte, those of Cuvier, Lamarck, Blainville and Cap- 
 tain Thomas Brown have been consulted and freely used. 
 
 Many of the engravings are copied from the works of M. Blain- 
 ville ; and, it is believed, the engraving, which was done by Mr. 
 G. Thomas, (No. 37 South Third Street,) will compare favour- 
 ably with anything of the kind ever offered to the American 
 public. 
 
 The etymology and pronunciation of the technical words have 
 been placed at the foot of the page. 
 
 This little volume offers the means of becoming acquainted 
 with the history of soft animals and conchology, and opens the 
 way to an advantageous perusal of more complete and ample 
 treatises on the subject. 
 
 Philadelphia, June 1, 1844. 
 
CONCHOLOGY. 
 
 CONTENTS. 
 
 LESSON I. 
 
 General Considerations. Mollusca in general Organization Nervous 
 System General Form Skin Mantle Shell Formation of Shell 
 Digestive Apparatus Circulation of the Blood Respiration Senses 
 Eggs Classification. 
 
 LESSON II. 
 
 Class of Cephalopoda. General Form Respiration Circulation Organa 
 of Digestion Cephalic Cartilage Organs of Locomotion Organs of 
 the Senses Nervous System Habits Division into two Families. 
 
 Family of Cephalopoda Dibranchiata. Octopus Vulgaris, or Poulpe Argo- 
 naut Calmaries Cuttle-fishes. 
 
 Family of Cephalopoda Tetrabranchiata. Nautilus Ammonites Belem 
 nites Foraminifera. 
 
 LESSON III. 
 
 Class of Gasteropoda. General Conformation Classification. 
 
 Order of Gasteropoda Pulmonea. Organization Division into two Families. 
 
 Family of Terrestrial Pulmonea. Limax Vaginulus Helix Bulimus 
 
 Pupa Chondrus Clausilia Achatina. 
 Family of Aquatic Pulmonea. Onchidium Planorbis Limnaea Physa 
 
 Auricula. 
 
 Order of Gasteropoda Pectinibranchiata. Organization Classification. 
 Family of Trochoides. Trochus Turbo Delphmula Turritella Cyclo- 
 
 stoma Valvata Paludina Littorina Monodon Phasianella Am. 
 
 pullaria Janthina Nerita. 
 
 LESSON IV. 
 
 Family of Buccinoides. Buccinum Buccinum properly so called Harpa 
 Purpura Cassis Cerithium Murex Strombus Voluta Ovula 
 Cyprsea Conus. 
 
 Family of Pectinibranchiata Capuloida. Pileopsis Hipponyx Crepidula 
 Calyptraea Siphonaria Sigaretus. 
 
 Order of Gasteropoda Tubulibranchiata. 
 
 Order of Gasteropoda Scutibranchiata. Haliotis Fissurella Emarginula. 
 
8 CONTENTS. 
 
 Order of Gasteropoda Cyclobranchiata. Patella Chiton. 
 
 Order of Gasteropoda Inferobranchiata. 
 
 Order of Gasteropoda Tectibranchiata. Pleurobranclms Aplysia Dola- 
 
 bella Bullea Bulla. 
 
 Order of Gasteropoda Nudibranchiata. Eolidia Glaucus. 
 Order of Gasteropoda Heteropoda. Carinaria. 
 Class of Mollusca Pteropoda. Clio borealis. 
 
 LESSON V. 
 
 Class of Mollusca Acephala, or Lamellibranchiata. Organization Classi- 
 fication. 
 
 Family of Ostracea. Classification Oysters Gry phaea Pecten Lima- 
 Malleus Anomia Spondy lus Perna Etheria Avicula Pearls- 
 Pearl Fishery Pinna Area Pectunculus Trigonia. 
 
 Family of Mytilacea. Mussels, (Mytilus) Modiolus Anodonta Unio. 
 
 Family of Chamacea. Tridacna Chama Isocardia. 
 
 LESSON VI. 
 
 Family of Cardiacea. Cardium Donax Cyclas Corbis Tellina Ve 
 
 nus Petricola Venerupis Mactra. 
 Family of Inclusa. Lutraria Mya Byssomia Hiatelia Solen San- 
 
 guinolaria Pholas Teredo Fistulana Gastrochaena ClavigelJa 
 
 Aspergillurn. 
 Class of Mollusca Brachiopoda. General Characters Lingula Terebra- 
 
 tula Orbicula. 
 Class of Mollusca Tun icata, or Acephala Nuda. Biphora Ascidia Botryl- 
 
 lus Pyrosoma Parts of Shells. 
 
ELEMENTS OF CQyCHOLOGY. 
 
 SECOND BRANCH OF THE ANIMAL KINGDOM. 
 
 MOLLUSC A: 
 
 MOLLUSKS, OR SOFT ANIMALS. 
 
 LESSON I. 
 
 GENERAL CONSIDERATIONS. Mollusca in general Organiza- 
 tion Nervous System General Form Skin Mantle 
 Shell Formation of Shell Digestive Apparatus Circula- 
 tion of the Blood Respiration Senses Eggs Classifica- 
 tion. 
 
 The long series of vertebrate animals, the history of which we 
 have already concluded, forms only a small part of the animal 
 kingdom, and to make the beings we are now about to study as 
 interesting as the vertebrata, we should be obliged to very far 
 exceed the limits of these lessons : but these animals are less 
 useful to us ; they attract less attention, and most of them pass 
 unnoticed, except by those who are at the pains of becoming ac- 
 quainted with them ; their faculties are more limited and their 
 structure is less complicated and less perfect. 
 
 1. All these lower animals want a spinal marrow and a true 
 internal skeleton ; this last character has obtained for them the 
 collective name of invertebrate animals ; but in a natural classi- 
 fication, they could not all be placed in the same group, because 
 they are evidently formed after three different types, and there- 
 fore should be divided into three distinct branches, namely : the 
 mollusca, the articulata^ the radiata, or zoophytes. 
 
 2. The branch of zoophytes is composed essentially of the 
 most imperfect animals : according to the classification of Cuvier, 
 which we follow, this branch comprises a certain number of beings 
 which seem, in a manner, to present the first sketch of the mode 
 of organization proper to mollusks and articulate animals ; its 
 place is therefore among the lowest grades of the animal series, 
 and passes, by gradual shades, from the type of the radiate ani- 
 mal to that of the two great branches which spring from it. These 
 two latter branches, one equally with the other, present a con- 
 stantly increasing complication of organization, and form, as it 
 
 1. What are inver'tebrate animals ? What groups or divisions include 
 the inver'tebrate animals ? 
 
 2. What are zo'ophytes ? Why are the mollus'ca placed before the artlc- 
 ulata in the series of animals ? 
 
 9 
 
10 NERVES O'F MOLLUSKS. 
 
 were, two p^rallex series. The series of articulate animals seems 
 to be the highest in the scale; but the mollusca, though less per- 
 fect in structure, seem to be less remote in their mode of orga- 
 nization from the vertebrata, and for this reason we have deter- 
 mined to place them first. 
 
 3. We give the name of Mollusca (from the Latin, mollis, 
 soft) to animals which, in the general features of their orga- 
 nization, resemble snails, oysters, &c. They have no articu- 
 lated skeleton nor vertebral canal, like the vertebrate animals ; 
 their body is soft, and their skin, which is often covered by a 
 shell, is never hardened so as to form a kind of external skele- 
 ton composed of a series of rings, as is the case in insects and 
 the Crustacea. 
 
 4. The nervous system, an apparatus of so much importance, 
 the action of which regulates all the phenomena of animal life, 
 and the functions of which must necessarily be in harmony with 
 its mode of conformation, differs altogether in the mollusca in 
 its general disposition, from what we observe in the vertebrata. 
 There exists a nervous centre which to a certain extent may be 
 compared to the brain in superior animals ; but this ganglionic 
 mass is not continuous with an organ analogous to the spinal 
 marrow ; the other central parts of the nervous system are found 
 on the opposite side of the digestive tube, and hence this canal is 
 always embraced by a sort -of medullary collar, from which the 
 different nerves of the body arise. In other respects, this appa- 
 ratus varies more in its arrangement than in the number of parts 
 composing it. 
 
 Fig. 1. NERVOUS SYSTEM OF A SOLEN. 
 
 5. In a great many of the least perfect mollusks, such as the 
 Solen and many other acephala, which inhabit bivalve shells, 
 the nervous system is generally composed of but two pairs of 
 ganglia, united by two long inter-ganglionic cords, giving rise 
 to different branches (fig. 1); the ganglia of the anterior pair 
 
 Explanation of Fig. 1. Nervous system of an acephalous mollusk 
 (Solen) : a, the pair of ganglia which is situate in front of the oesophagus 
 representing that portion of the nervous system of these animals, which is 
 
 3. What are the general characters of the Mollus'ca ? 
 
 4. What are the peculiarities of arrangement of the nerves of the Mollus'ca? 
 
 5. What are the general characters of the nervous system in acephalous 
 mollusks ? What are tnc peculiarities of the nervous system of gasteropods? 
 
NERVES OF MOLLUSKS. 
 
 11 
 
 Fig. 2. 
 
 NERVES OF A 
 JANTHINA. 
 
 (a) are sometimes considerably separated from 
 each other, and only united by an intermediate 
 cord, and sometimes glued one to the other, or 
 even confounded in a single mass : they are 
 situate above the O3sophagus, and far from the 
 posterior ganglia (6), which are placed beneath 
 the intestine towards the posterior part of the 
 body. In some mollusks, the nervous system 
 is still more simple in its composition ; but, in 
 general, the ganglia tend to approximate the 
 oesophagus more and more (Jig- 2), and in 
 most of these animals we find a greater num- 
 ber of small medullary masses, some of which 
 form a sort of nervous centre, and the others 
 
 are distributed in different parts 
 
 of the body. Thus, in the snails 
 
 and most mollusks constructed on 
 
 the same plan, and named gastero- 
 
 pods (from the Greek, gaster, 
 
 belly, and pous, foot), on account 
 
 of their mode of crawling on the 
 
 ventral surface of the body, there g 
 
 exists, above and in front of the p "' 
 
 oesophagus, a medullary mass (Jig. 
 
 3, c.), which is the representative d 
 
 of the anterior pair of ganglia 
 
 above mentioned, and which is re- a"" 
 
 garded by most anatomists as the Fig. 3. NERVES OF A SNAIL. 
 
 generally called the brain ; here, these two ganglia are considerably sepa- 
 rated from each other, and are united by a transverse band ; c. nerves 
 which arise anteriorly to be distributed to the tentacula, to the mantle, &c. ; 
 6. ventral pair of ganglia, which are united in a single mass, placed be- 
 neath the intestine, and joined to the anterior ganglia by two very long 
 nervous cords ; d. nerves which arise from the posterior ganglia to t>e dis- 
 tributed to the mantle, &c. 
 
 Explanation of Fig. 2. Nervous system of a Janthina ; a gasteropod 
 mollusk, in which the posterior ganglia (&) as well as the anterior ganglia 
 (a) are separated from each other ; but they are more approximated to the 
 latter, so that the inter-ganglionic cords are very short, and form a sort of 
 closely fitting collar around the oesophagus. 
 
 Explanation of Fig. 3. Central portion of the nervous system of the 
 snail : c. ganglia situate in front of the oesophagus, and constituting, by 
 their union, the mass which is called the brain in mollusca ; o. nerves of 
 the anterior parts of the body, the eyes, &c. ; g. the nervous mass formed 
 by the union of the ganglia of the posterior pair ; the oesophagus passes 
 through the collar or ring which unites it to the brain ; p. the nerves of 
 the foot ; n. nerves which go to the pulmonary cavity, &c. ; a. the nerve 
 which accompanies the principal artery ; d. the nerve which goes to the 
 diaphragm, &c. 
 
12 
 
 NERVES OF THE APLYSIA. 
 
 brain of these animals : it furnishes nerves to the organs of 
 the senses as well as to the neighbouring parts (o), and is 
 continued posteriorly by two inter-ganglionic cords, which em- 
 brace the oesophagus, and which, at a short distance, unite 
 with a second nervous mass (g), situate beneath the digest- 
 ive tube, and comparable to the posterior pair of ganglia, 
 
 which we remarked when 
 speaking of the acephalous 
 mollusks ; and two small 
 nerves, which arise from the 
 brain, unite to form a third 
 ganglion (fig. 4, *), below 
 the origin of the O3sophagus. 
 c In other gasteropods, the 
 o aplysice or sea-hares, for ex- 
 ample, to these ganglia is 
 g joined another (fg. 4, v), si- 
 tuated among the viscera, 
 and united by two commu- 
 nicating threads to the med- 
 ullary collar which surrounds 
 the oesophagus, and giving 
 rise to the nerves of the in- 
 testines, liver, branchiae, ova- 
 ries, &c. We also find in 
 these mollusks a fifth gan- 
 glion, which is very small, 
 belonging to these tatter or- 
 gans. And, in the poulpes 
 and the cuttle-fish (fg. 5). 
 A / /^^^^\ " v in which this system acquires 
 
 / \f/f' V its hi s hest de g ree r de - 
 
 velopmerit, the ganglionic 
 parts grouped around the 
 oesophagus, are larger and 
 more complicated ; for the 
 I cephalic and post-oosopha- 
 
 geal ganglia, united in a 
 
 Fig. 4. NERVES OF THE ArLYsiA. large cEsophageal collar, 
 
 present laterally a third 
 
 Explanation of Fig. 4. Nervous system of the aplysia (or sea-hare, as 
 it was called by the ancients), another gasteropod mollusk ; c. the brain ; 
 o. the nervous collar which surrounds the oesophagus ; g. the thoracic of 
 post-cesophageal ganglia ; v. the visceral ganglion ; t. the buccal ganglion. 
 
NERVES OF MOLLUSKS. 
 
 13 
 
 pair of ganglionic 
 swellings, which 
 are lodged in a 
 cartilaginous, cra- 
 nial cravity , from 
 them arise the 
 nerves of the feet 
 (Fig. 5). 
 
 To recapitulate, 
 we see that, in this 
 class of animals, 
 the nervous sys- 
 tem is essentially 
 composed of a 
 medullary collar, 
 embracing the ali- 
 mentary tube, and 
 formed by the 
 communicating 
 cords of the two 
 pairs of ganglia, 
 which are widely 
 separated in the 
 acephalous mol- 
 lusks, but approx- 
 imate more and 
 more as we ascend 
 in the series, form- 
 ed by the gaster- 
 opods and cepha- 
 lopods ; and the 
 
 Fig. 5. NERVOUS SYSTEM OF THE CUTTLE-FISH. 
 
 Explanation of Fig. 5. Nervous system of the cuttle-fish ; a, the ner- 
 vous collar which embraces the oesophagus, the course of which is indi- 
 cated by a bristle (s): c, the nervous mass, situate .in front of the eesophagus, 
 and commonly called the brain : the upper surface is surmounted by a very 
 large cordiform tubercle, and from its anterior part arise two nerves that 
 soon terminate in a circular ganglion, which, in its turn, gives rise to 
 another pair of nerves, which descend beneath the mouth so as to embrace 
 the oesophagus again, and then form a small anterior ganglion from which 
 arise the labial nerves ; &. the tentacular ganglia, from which arise the 
 nerves of the arm ; o. the optic nerves which arise from the lateral parts 
 of the brain, and soon swell into a large ganglion ; t. small nervous tuber- 
 cles, situate on the origin of the optic nerves ; g. the sub-cesophageal or 
 ventral ganglion; c. the great nerve of the viscera, one branch of which 
 presents an elongated ganglion (r\ and penetrates into the branchiae ; fit 
 nerves which also arise from the post-oasophageal ganglia, and which, in 
 their course, present a large star-like ganglion (e), the branches of which 
 are distributed to the mantle. 
 2 
 
14 FORM. SKIN.SHELI . 
 
 nerves which arise from each of these ganglia, to be distributed 
 to the different organs*, are at first simple, but very soon pre- 
 sent in different parts of the body ganglionic swellings ; but 
 these ganglia, however numerous they may be, never form a reg- 
 ular longitudinal chain, extending along the middle line of the 
 abdominal face of the body, as is the case in the articulated ani- 
 mals. 
 
 6. As we have already said, in this great branch of the animal 
 kingdom, there is neither an internal skeleton, analogous to the 
 solid frame of vertebrate animals, nor an external skeleton, sim- 
 ilar to the tegumentary sheath, which envelopes the whole body 
 of articulate animals in a series of rings, and serves the same 
 purposes as the skeleton, properly so called, of the superior ani- 
 mals. The general form of mollusks is extremely variable. 
 Their body is always soft, and in a very small number of them 
 only, there exists internally some solid pieces which are unarticu- 
 lated, and serve rather to protect the viscera than to furnish 
 levers and points of support to the apparatus of locomotion. The 
 muscles are attached directly to the integuments and act but 
 very little beyond their point of insertion ; their motions are slow, 
 and in general ill directed. In a small number of these beings, 
 there are elongated and flexible appendages, designed for locomo- 
 tion (fg. 7, page 23) ; but in most instances the animal can 
 change its place, only by successively contracting different points 
 of the inferior surface of its body, and, even when it possesses 
 extremities, they are united in a group at one end of the body, 
 and never arranged in a symmetrical series, as they are inverte- 
 brate and in articulate animals. 
 
 7. The skin of mollusks, always soft and viscid, often forms 
 folds that more or less completely envelope the body, and this 
 disposition has caused the name of mantle to be given to that 
 portion of integument which ordinarily furnishes these expansions. 
 Frequently this mantle or pallium is almost entirely free, and 
 constitutes two large veils which conceal all the rest of the ani- 
 mal, or rather, these two laminae or membranes unite together so 
 as to form a kind of tube ; but at other times, it consists only of 
 a sort of dorsal disk, the edges of which alone are free, or sur- 
 round the body more exactly under the form of a sack. 
 
 8. In general this soft skin is protected by a sort of stony 
 cuirass named shell. It is a secretion having some analogy to 
 
 6. What kind of a skeleton have mollusks ? What are the g-eneral cha- 
 racters of their body ? How is locomotion effected in molliasks ? 
 
 7. What is the mantle or pallium? 
 
 8. What is meant by shell ? What is meant by naked mollusks ? What 
 are testacea ? 
 
GROWTH OF SHELLS. 15 
 
 that of the epidermis which produces this envelope. The follicles, 
 ordinarily lodged in the edges of the mantle, deposit upon its 
 surface a semi-corneous matter, mixed with a greater or less pro- 
 portion of carbonate of lime, which moulds itself upon the sub- 
 jacent parts and solidifies. The lamina or layer, thus formed, 
 thickens and grows by successive deposits of new matter. Its 
 superficies is not stony, but in form of a kind of epidermis. 
 Sometimes it preserves a horny consistence throughout its whole 
 thickness. In general, however, the proportion of carbonate of 
 lime that it, contains rapidly increases and imparts to it a stony 
 hardness. The internal surface is often harder than the rest, 
 and possesses a particular structure which renders it vitreous or 
 shining and nacreous. Sometimes the shell always remains en- 
 closed in the thickness of the skin ; but, in general, it is external, 
 and extends beyond the mantle, so as to aiford the animal perfect 
 protection. Those which are unprovided with shells, or only 
 have an internal shell, are called naked mollusks, and those in 
 which the shell is visible are included under the name of con- 
 chifera, or sometimes testa' cea. 
 
 9. The manner in which the shell grows is easy to under- 
 stand. If we examine the shell of an oyster, for example, we 
 observe that it consists of a multitude of superposed laminae, the 
 separation of which may be effected by the assistance of heat._ 
 These laminre are formed successively by the mantle of the ani- 
 mal which they cover, and, consequently, the most external one 
 must be the oldest ; and it is also the smallest, and each new 
 lamina that is added, exceeds the lamina situate above, so that 
 while the shell is augmenting in thickness, it is also increasing in. 
 size. In general, the distinctness of the lamina is less marked^* 
 and often the new matter is deposited in such a manner, that its 
 molecules exactly correspond to the molecules of the matter 
 already consolidated, and thus gives to the whole a fibrous 
 structure. 
 
 10. Shells are adorned with most diversified and most agree- 
 ably arranged colours, which often vary with their age. They 
 are almost always entirely superficial, and seem to depend on a 
 sort of a dyeing process performed by the skin of the animal, 
 which is coloured in a manner corresponding with that of its en- 
 velope. The colouring matter seems to be deposited upon the 
 shell at the time of its formation : and its brightness is in pro- 
 portion to the newness of the latter. It is produced by the edge 
 of the mantle. When a shell happens to be broken and the ani- 
 
 9. How does the shell grow ? 
 10. How are the colours of shells produced ? 
 
16 COLOURS. OF SHELLS. 
 
 mal succeeds in repairing the accident, the part newly formed ia 
 always white, if it has not been in contact with the edge of the 
 mantle ; but if it correspond to this edge, it then assumes the 
 colour that the latter presents at the point touched. For exam- 
 ple, when this edge is spotted, we find corresponding spots on 
 the margin of the shell, and, in proportion as the latter is elon- 
 gated, these spots become confounded with those previously 
 formed, and produce lines perpendicular to crossing strite, or 
 they do not join the latter, but remain isolated, according as the 
 mantle remains unmoved, and preserves the same relation to the 
 margins of the shell, or 'frequently changes its position according 
 to the movements of the animal. Sometimes the secretion of 
 the colouring matter varies with age; and accidental circum- 
 stances may also modify it. Light, for example, exerts a very 
 remarkable influence on this phenomenon, for not only are shells 
 that are most exposed to the action of this physical agent, ordi- 
 narily most brightly coloured, but, when a mollusk lives fixed to 
 a rock, or in some spot hidden beneath a sponge, or other opaque 
 body, the part of the shell thus placed in darkness is always 
 
 / dull, and paler than that which is exposed to the contact of th 
 solar rays. 
 
 The duration of shells, and the length of time the animals live 
 
 i which inhabit them, are circumstances not yet determined. When 
 exposed to the action of the air and the vicissitudes of tempera- 
 ture and moisture for some time, shells usually change their 
 colours and gradually become white. The animal matter which 
 enters into its composition is destroyed, and disappears little by 
 little ; the laminre separate from each other, particularly under 
 the alternate influence of heat and cold, and become finally re- 
 duced to a calcareous powder, which is washed away by currents 
 of water. 
 
 11. All mollusks are provided with an alimentary canal, which 
 is more or less folded on itself and open at its two ends, either at 
 the extreme points of the body, or at points more or less near to 
 each other. There is always a voluminous liver, and we often 
 find them furnished also with salivary glands and organs of mas- 
 tication ; but the intestines are never held in their place by the 
 assistance of a mesentery. 
 
 12. The blood of these animals is cold and colourless or slightly 
 bluish, and circulates in a very complicated vascular apparatus, 
 composed of arteries and veins. A heart, formed of a ventricle (v) 
 
 11. What are the general characters of the digestive apparatus of mol- 
 lusks .' 
 
 12. What is the nature of the blood of mollusks ? How is it circulated ? 
 
CIRCULATION SENSES. 
 
 17 
 
 and one or two auricles (o) 
 is found in the track of the 
 arterial blood, and sends 
 this liquid to all parts of 
 the body, from which it re- 
 turns to the organs of respi- 
 ration. Sometimes we also r 
 find, at the base of the ves- 
 sels which enter this latter 
 apparatus, venous reser- 
 voirs, erroneously called pul- 
 monary hearts ; for, having 
 nothing in their structure re- 
 sembling muscle, they can- 
 not set the blood in motion, 
 and consequently do not me- 
 rit this name. (See Jig. 9, 
 Page 21.) 
 
 13. The organs of respira- 
 tion vary so much that they 
 cannot be well described at 
 this place : we will merely 
 mention that they are some- 
 times in the form of lungs, 
 and at others, in that of 
 branchiae or gills. 
 
 14. Nor can we say any thing generally of the structure of 
 the organs of the senses, which are, however, always less com- 
 plete than in the vertebrate animals. Certain mollusks appear to 
 be endowed only with the sense of touch and with the sense of taste, 
 but in a great many we find eyes which vary in structure, and 
 in some of these animals there even exists an apparatus of hear- 
 ing : but none is known to possess a particular organ of smell. 
 
 15. Mollusks are re-produced from eggs; but are sometimes 
 hatched without, and sometimes within the body of the mother, 
 
 Fig. 6. HEART OF AN ACEPHALOUS 
 
 3IOLLUSK. 
 
 Explanation of Fig- 6. Heart of an acephalous mollusk : v. the ventri- 
 cle, which in these animals has the rectum (r) passing through it, and 
 gives rise to two arteries (a) ; c. one of the auriculo-ventricular openings ; 
 o. the two auricles receiving the blood from the branchial veins (&) 
 
 In the above diagram, the ventricle (?>) is open, and the rectum, (r, r) 
 has been divided, and the lower part turned downwards : a (at the lower 
 part of the figure) represents the origin of one artery, the other artery 
 having a similar origin above. 
 
 1 3. What is the character of the organs of respiration in mollusks ? 
 
 14. What senses are possessed by mollusks ? 
 
 15. How are mollusks re-produced ? 
 
 2* 
 
IB 
 
 CLASSIFICATION. 
 
 and then the young are born alive. In all cases they possess at 
 birth nearly the form they preserve through life, and do not un- 
 dergo metamorphosis. 
 
 We have already stated that mollusks differ very much in the 
 general form of their body, and as these external modifications 
 are accompanied by corresponding differences in the degree of 
 complication of their internal organization, they enable us to di- 
 vide these animals into six natural groups. The following table 
 will give an idea of this classification : 
 
 (CLASSES.) 
 
 in the form of an open sack in front, from ) 
 which the head appears, surrounded by > CEPHALOPODA. 
 tentacula (Fig. 7, Page 19). ^ 
 
 f having a 
 
 distinct 
 
 head, and 
 
 the body 
 
 not in the form of an f membranous fins in 
 open sack in front, I the form of wings 
 and the head is not | on the sides of the 
 surrounded with ten- I neck, 
 tacula. 
 
 a fleshy foot occu-' 
 
 T> 
 
 PTEROPOI)A ' 
 
 pying the ventral 
 
 having no 
 
 apparent > 
 
 head 
 
 the principal organs 
 .of motion being 
 
 disk, or sometimes 
 ^of fins. 
 
 having four branchiae distinct from the 
 mantle, and almost always a fleshy foot. 
 
 having no fleshy foot f" provided with two 
 and seldom branchiae 
 distinct from the 
 mantle. 
 
 A 
 
 of them. J ' 
 
 unprovided with ) 
 
 arms and special > TUNICATA. 
 
 organs of motion. } 
 
 Cuvier, and many other zoologists, arrange the cirrhopoda also 
 in the branch of mollusca ; but it is now ascertained that these 
 animals belong to the branch of articulata, the third great divi- 
 sion of the animal kingdom. 
 
 16 Into how many classes is the branch of mollus'ca divided? 
 
CLASS OF CEPHALOPODS. . 19 
 
 LESSON II. 
 
 CLASS OF CEPHALOPODA. General Form Respiration Cir- 
 culation Organs of Digestion Cephalic Cartilage 
 Organs of Locomotion Organs of the Senses Nervous 
 System Habits Division into two Families. 
 
 FAMILY OF CEPHALOPODA DIBRANCHIATA. Octopus vulgaris, 
 or Poulpe Argonaut Calmaries Cuttle-Jishes. 
 
 FAMILY OF CEPHALOPODA TETRABRANCHIATA. Nautilus 
 Ammonites Belemnites Foraminafera. 
 
 CLASS OF CEPHALOPODS, 
 
 1. This class is composed of mollusks which are of fantastical 
 shape, for their head is placed between the trunk and feet, or 
 tentacula, which serve them for locomotion, and when they walk, 
 the body is uppermost, and the head down, dragging on the 
 ground. Their feet are attached, around the mouth, to the head, 
 which circumstance has obtained for them the name of Cephalo- 
 poda (from the Greek, Tcephole, head, and pous> foot pro- 
 nounced Jcef-a-lo-pod). 
 
 Fig. 7. OCTOPUS* VULGARIS, OR COMMON POULPE. 
 
 2. The trunk of these animals is covered by the mantle, 
 which is in the form of a sack, sometimes almost spherical, 
 and sometimes more or less elongated ; it encloses all the 
 
 * From the Greek, okto, eight, and pous, foot, eight feet. 
 
 1. What kind of animals compose the class of Cephalopods ? Why are 
 sy called Cephalopods ? 
 
 2. What are the general form and characters of the Cephalopods ? 
 
20 
 
 STRUCTURE OF CEPHALOPODS. 
 
 * 
 
 viscera and is open only in front, (Jig. 8, o). The head issues 
 from this opening : it is round and generally provided with two 
 round eyes, very analogous in their structure to those of verte- 
 brate animals. The mouth occupies the centre : it is armed 
 with two jaws ; and around this opening is found a crown of 
 flexible and fleshy appendages, which are termed, indifferently, 
 legs or arms, because they seem to be entitled to either appella- 
 tion ; for they serve both as organs of prehension and locomo- 
 tion (fi.g. 7). 
 
 3. The cephalopods are essentially aquatic animals, and 
 consequently they breathe by means of branchiae. These 
 organs are always perfectly symmetrical, and are found con- 
 cealed beneath the 
 mantle, in a particu- 
 lar cavity (fig. 8), the. 
 parietes of which alter- 
 nately contract and di- 
 late, and the interior 
 communicates exter- 
 nally by two openings ; 
 one (o) in form of a 
 slit, serving for the 
 entrance of the water, 
 and the other pro- 
 longed in the shape of 
 a tube or funnel (/), 
 serving for the escape 
 of water and excre- 
 ment. Each branchia 
 (6), which is in form 
 of an elongated pyra- 
 mid, the summit of 
 which is directed forward, is composed of a great number of 
 membranous lamella or leaves, placed transversely and fixed 
 on each side of a middle stalk. Each one of these leaves is 
 divided into lamella?, which are in turn again subdivided, and 
 it is in their substance that we find the capillary vessels where 
 
 Fig. 8. BODY OF A POULPE. 
 
 Explanation of Fig. 8. The body of a poulpe seen from beneath (the 
 mantle is slit up on the middle line, and, on one side, raised up to show the 
 interior of the respiratory cavity) : a. the base of the head ; t. the tube 
 by which the water escapes from the respiratory cavity ; o. one of the two 
 lateral openings through which the water enters this cavity ; b. one of the 
 branchiae or gills. 
 
 3. How do cephalopods breathe ? How many branchise have cephalopods 1 
 
CIRCULATION IN CEPHALOPODS. 
 
 21 
 
 the venous is changed into arterial blood. The number of 
 branchiae varies, and this difference is characteristic of the two 
 great natural divisions, of which this class is composed. In 
 some there is but a single pair, while in others two pairs of 
 branchiae are found. For this reason the first have been called 
 cephalapoda dibranchiata (from the Greek dis, two, and 
 bragchos, branchia or gills, two-gilled), and the last, cephalo- 
 poda tetrabranchiata (from the Greek, tetras, four, and bragchos, 
 branchia, four-gilled). 
 
 4. The heart is situated between the branchise on the middle 
 line of the body, and consists only of a single ventricle 
 (fg. 9, c) : the blood reaches it from the branchiaB by the 
 
 br 
 
 vv av a cs vv 
 
 Fig. 9. ORGANS OF CIRCULATION AND RESPIRATION IN THE CUTTLE-FISH. 
 
 Explanation of Fig. 9. The organs of circulation and respiration of the 
 cuttle-fish ; c. the aortic heart, the upper extremity of which is continuous 
 with the superior aorta, which distributes the blood to the head, &c. ; 6. 
 branches of this vessel ; a. the inferior aorta, which has a bulb at its origin, 
 and soon divides into two branches (w, D) ; vc. the vena cava, the parietes 
 of which are covered by the spongy bodies (cs) ; av. veins of the viscera, 
 going to empty into the two branches of the vena cava ; cb, venous sinus 
 or branchial heart ; s. swelling at the base of the branchial arteries ; br. 
 branchia? ; ab. branchial artery ; vl. branchial vein ; bu. bulb of the 
 branchial veins, situate near the termination of these vessels in the heart, 
 
 4. What is the character of the heart in cephalopods 1 What are the 
 peculiarities of the circulation 1 
 
22 CIRCULATION IN CEPHALOPODS. 
 
 branchial veins (vb), the openings of which are furnished with 
 valves, and then penetrates the arteries which arise from this 
 organ. The latter vessels are two or three in number ; but one 
 of them is always much larger than the rest, and one of them 
 also has at its base a swelling or bulb, which is more or less 
 muscular, and analogous to that found at the origin of the aorta 
 in batrachians. The great artery to which we generally give the 
 name of aorta, is carried forward and distributes its branches to 
 a part of the viscera, the head and legs. The other arteries go 
 to the viscera ; and the blood, after having in this way passed 
 through all the organs, returns by the veins, and is emptied by 
 them into a great vena cava, situate near the heart. The bran- 
 chial arteries arise from the inferior extremity of this last vessel, 
 and, in the dibranchial cephalopods, present a very remarkable 
 arrangement ; for, before penetrating the branchia?, each one of 
 them dilates so as to form a great venous sinus (Jig* 9, c&), 
 which most authors regard as a branchial heart, but its parietes 
 do not appear to be really muscular. 
 
 5. We see, therefore, that the circulation is here carried on in 
 a manner opposite to that of fishes ; for the heart is found in the 
 track followed by the arterial blood, while in fishes the venous 
 blood passes through this organ ; but in other respects, there is 
 a great resemblance in the general disposition of the circulatory 
 apparatus of these two classes of animals ; for, in both, the 
 blood passes but once through the heart, and the whole of it 
 traverses the respiratory apparatus before returning to the differ- 
 ent organs. 
 
 6. On the vena cava and its principal branches, we remark a 
 multitude of very singular spongy bodies (fig- 9, <*s), which, 
 when squeezed, yield a mucosity, and which are attached to the 
 parietes of these vessels ; these appendages are enclosed in two 
 membranous pouches, which perform the functions of a pericar- 
 dium, and, at the same time, communicate by particular openings 
 with the branchial cavity. In this way the water from without 
 laves them, and their interior, which is hollow, communicates by 
 other holes with the interior of the veins, so that the blood must 
 enter them. We know nothing certain in regard to their uses; 
 but it is probable they are the seat of some secretion, and that 
 they serve as a reservoir to contain the superabundant blood of 
 the veins, when the circulation is interrupted in the vessels, much 
 in the same manner as the spleen seems to do in the superior 
 animals. 
 
 5. How does the circulation in cephalopods differ from that of fishes ? 
 
 6. What is remarkable about the vena cava ? 
 
DIGESTION IN CEPHALOPODS. 
 
 23 
 
 7. The apparatus of digestion is very complicated. The 
 mouth is surrounded by a circular lip, and armed with two ver- 
 tical mandibles, which closely resemble the beak of a parrot ; 
 they are set in motion by powerful muscles. A fleshy tongue, 
 furnished with papillae and many horny pieces, occupies the in- 
 terior of this cavity, and is attached to a particular cartilage. 
 Salivary glands, the number and arrangement of which vary a 
 little, surround the pharynx and oesophagus, and pour into the 
 alimentary canal the product of their secretion. The oesopha- 
 gus contracts in general, and before terminating in the stomach, 
 presents a large dilatation or crop (Jig. 10, j) ; but some- 
 times, this first 
 digestive pouch is 
 wanting. Com- 
 monly the stom- 
 ach is in the form 
 of an elongated 
 sack ; its parietes 
 are muscular, and 
 its structure re- 
 minds us of the 
 gizzard of birds. 
 A third cavity (s) ' 
 succeeds this or- as 
 gan, which, in di- 
 branchial cepha- 
 lopods, is in the 1 
 form of a coecum 
 spirally folded, 
 while in the tetra- 
 branchial, it as- 
 sumes that of a 
 spherical sack in- 
 ternally lamella- 
 
 br 
 
 a v 
 
 cb~ 
 
 Flg. 10. VISCERA OF A POULPE. 
 
 Explanation of Fig. 10. Viscera of a poulpe : j. the crop situated be- 
 neath the cephalic cartilage ; gs. inferior salivary glands ; /. mass formed 
 by the liver and ink-bag ; e. excretory duct of the ink-bag going to empty 
 in the funnel ; t. this funnel or tube ; m. the open mantle ; s. the ccecum 
 spirally folded ; i. a part of the intestine, the rest being removed to show 
 the organs situate beneath ; o. the oviducts ; c. the heart ; a. the inferior 
 aorta ; as. the superior aorta ; vb. the branchial veins ; br. the branchiae ; 
 cl. the partition by which these organs adhere to the parietes of the re- 
 spiratory cavity ; ab. the branchial arteries ; cb. venous sinus or branchial 
 hearts ; v. venae cavae ;fm. muscular fasciculi. 
 
 7. What organs constitute the apparatus of digestion in cephalopods ? 
 What is remarkable about the mouth ? What is the character of the 
 stomach ? What is the nature of the liver ? 
 
24 ORGANS OF LOCOMOTION. 
 
 ted : the bile is poured into this cavity by two canals. The 
 liver is very voluminous, sometimes simple, and sometimes di- 
 vided into two or more lobes : its colour is reddish yellow, and 
 its texture very soft. The intestine, which arises very near the 
 cardiac orifice, is simple, and communicates, at a short distance 
 from the pylorus, with a glandular pouch which seems to be ana- 
 logous to the pancreas ; and, after making several curves, this 
 tube empties into the branchial cavity, at the base of the funnel 
 through which the water escapes that has served the purposes of 
 respiration. 
 
 8. In dibranchial cephalopods, there exists in the neighbour- 
 hood of the liver another very remarkable secretory organ, which 
 produces in abundance a blackish liquid, called ink ; the excre- 
 tory duct of this gland (fig. 10, e) empties -into the intestine near 
 its extremity, and, when the animal is in danger, pours out, 
 through the funnel or tube, enough of this liquid to darken the 
 water around, and thus conceal itself from the sight of its ene- 
 mies. The ink of one of these cephalopods the cuttle-fish is 
 employed in painting, under the name of sepia ; and many au- 
 thors suppose that the Indian ink of the Chinese is an analogous 
 substance, though it appears the material commonly used in the 
 manufacture of Indian ink is nothing but very finely powdered 
 charcoal. The tetrabranchial cephalopods do not possess any- 
 thing similar. 
 
 9. It has been already stated that mollusks have no solid, ar- 
 ticulated frame within their body, similar to the skeleton of ver- 
 tebrate animals. In the cephalopods, however, we find traces of 
 something analogous; for there exists in the head a cartilage 
 which not only protects the brain, but enlarges the head in differ- 
 ent directions, to furnish points of insertion to the principal mus- 
 cles of the animal. 
 
 10. The disposition of the organs of locomotion and prehen- 
 sion, which are fixed around the mouth, varies in these animals. 
 In the dibranchial cephalopods, there is a crown of eight or ten 
 large fleshy tentacula, the inferior surface of which is furnished 
 with suckers, like cupping-glasses, by aid of which they fix them- 
 selves very strongly to bodies that they embrace (see fig. 7, page 
 19). In the tetrabranchial cephalopods, on the contrary, these 
 appendages, though very numerous, are slender and unprovided 
 with suckers. 
 
 11. The organs of the senses are most perfect in the dibran- 
 
 8. What is sepia ? How is it formed ? What is Indian ink ? 
 
 9. Have cephalopods anything resembling an internal skeleton ? 
 10. What is the disposition of the organs of locomotion? 
 
SENSES OF CEPHALOPODS. 25 
 
 chial cephalopods. In these mollusks there are two very large 
 eyes of spheroidal form, lodged in the lateral parts of the head. 
 These organs are composed of a transparent cornea, let into the 
 skin, and sometimes protected by a fold, like an eyelid, a crystal- 
 line lens, a vitreous body, a retina, a choroid coat, a sclerotica, 
 &c., nearly the same as in vertebrate animals. In the tetrabran- 
 chial cephalopods the eyes are borne on projecting peduncles, and 
 consist of a cavity only, the black interior of which contains a 
 retina, and receives the luminous rays through a circular open- 
 ing. No auditory apparatus has yet been discovered in the first 
 of these two families. We find in the cephalic cartilage of the 
 latter, two small cavities, closed on all sides, except at the point 
 through which the nerve penetrates ; they lodge a membranous 
 vesicle, and are filled with a peculiar fluid, containing a small 
 stone. This, as we see, is a still more simple arrangement than 
 that of fishes ; for the whole apparatus is reduced to a vestibule 
 and a nerve only. 
 
 12. The nervous system of the cephalopods is more compli- 
 cated than that of the other mollusks, and the different ganglia, 
 grouped around the oesophagus, have a greater tendency to be- 
 come confounded in a single mass. The medullary collar, thus 
 formed, is composed of three pairs of ganglia, namely : the 
 cephalic ganglia (fig. 11, c), the tentacular ganglia (), and the 
 thoracic ganglia (g) ; the two first pairs are placed above the 
 oesophagus, and, by joining the first, form a double collar around 
 this tube; sometimes they are very distinct, but at others, they 
 are almost entirely confounded. The cephalic ganglia give rise 
 laterally to two large nervous cords, which, from their origin, 
 enlarge into ganglia, and then furnish the optic nerves ; from 
 this species of brain, nerves also arise, which go to the mouth, 
 and sometimes form around this opening a new collar, fur- 
 nished with two pairs of small ganglia (fig- 5, page 13). The 
 tentacular ganglia afford origin to the nerves of the feet or ten- 
 tacula, which, before ramifying on these organs, also present 
 ganglionic swellings. Finally, the thoracic ganglia, sometimes 
 very distinct from the preceding, and at others confounded with 
 them (see fig. 6, page 17), furnish many nerves, the most import- 
 ant of which are, 1st, The two nerves of the viscera (fig. 11, fl), 
 which in their course present a pair of ganglia and distribute 
 their branches to the branchiae, the heart, stomach, &c. ; 2d, The 
 nerves of the mantle, which, in the dibranchial cephalopods, 
 
 11. Where are the eyes situated in cephalopods? Are cephalopods ca- 
 pable of hearing ? 
 
 12. What is the general character of the nervous system of cephalopoda ' 
 
 3 
 
26 
 
 NERVES OF CEPHALOPODS. 
 
 also terminate in ganglia, 
 from which arise a great 
 many filaments. In the tetra- 
 branchial cephalopods, the 
 cesophageal collar is simply 
 protected by the cephalic car- 
 tilage; but in the dibranchial 
 cephalopods, in which the 
 nervous system acquires its 
 highest degree of develop- 
 ment, this medullary mass 
 is lodged in a special cavity, 
 hollowed in the cartilage 
 through which the oesopha- 
 gus passes. 
 
 13. The cephalopods are 
 never hermaphrodite, as are 
 most others of the mollusca. 
 The ovary is always simple 
 and lodged at the bottom of 
 a sac formed by the body of 
 the animal ; sometimes there 
 is but a single oviduct ; at 
 others, we find two, which 
 open at the base of the fun- 
 nel ; finally, all these ani- 
 mals are oviparous. 
 
 14. All these mollusks 
 are marine : they are very 
 voracious, and feed chiefly 
 on crustacea and fishes, 
 
 which they seize by the aid of their supple and vigorous arms, 
 and easily devour by means of their sharp mandibles. Their 
 flesh is eaten. 
 
 15. This class is divided into two families. 
 
 Fig, 11. NERVOUS SYSTEM OF 
 
 THE NAUTILUS. 
 
 Explanation of Fig. 11. Nervous system of the Nautilus : c. the brain; 
 o. the optic nerves ; g. the sub-cesophageal or thoracic ganglia ; f. the 
 tentacular ganglia ; p. nerves of the tentacula ; e. the nerves of the funnel ; 
 a. a ganglion from which arise other tentacular nerves (ft) ; d. a second, 
 and similar ganglion, also giving rise to tentacular nerves (/) ; m. nerves 
 of the mantle, &c. v. the great visceral nerves, each of which gives rise to 
 a ganglion (gv~), from which the principal nerves of the viscera take their 
 origin. 
 
 13. Do cephalopods lay eggs? 
 
 14. Where are cephalopods found ? Upon what do they feed ? 
 
 15. How is the class of cephalopoda divided ? 
 
DIBRANCHIAL CEPHALOPODS. 27 
 
 16. The family of CEPHALOPODA, DIBRANCHIATA, or ACE- 
 TABULI'FERA, that is, cupping-glass bearers, is very numerous. 
 In it are placed the poulpes, cuttle-fishes, calmaries, argonauts, 
 &c. Most of these mollusks have no external shell, and their 
 naked skin includes a great number of contractile vesicles, filled 
 with differently coloured fluids, which, by alternately contracting 
 and expanding, produce and cause again to disappear, in turn, 
 often very brilliant spots; but we find in their interior a more or 
 less developed shell, situated on the back. This shell is largest 
 in the cuttle-fishes ; it is oval, and composed for the most part of 
 a great number of transverse calcareous laminaB ; it is very com- 
 mon on the sea-shore, and is generally known under the name 
 of cuttle-fish bone. In the calmaries it is of a horny consistence, 
 and in its form resembles a feather or lamella ; and in the poul- 
 pes it is merely represented by two horny stylets, lodged in the 
 thickness of the mantle. 
 
 17. The tentacula of these cephalopods form a simple crown 
 around the mouth, and bear on their internal face circular cups 
 or suckers, the number of which varies from eight to ten. In 
 the following family we shall find an entirely different arrange- 
 ment. 
 
 18. The POULPES Octopus (Fig. 7, Page 19) are easily 
 recognised by their naked body, which is in the form of an 
 oval sack, unprovided with fins, and their eight very large and 
 nearly equal feet. They make use of these last organs to 
 seize their prey as well as to swim and crawl upon- the ground, 
 and are even formidable to swimmers on account of the force 
 with which they press those bodies they embrace. These ani- 
 mals are essentially carnivorous. Their size is often very great : 
 there is one species in the Pacific Ocean which attains about 
 six feet in length. These mollusks are objects of terror to 
 the natives of the Polynesian Islands, who dive to the bottom 
 of the sea for shells; but their size and strength are wonder- 
 fully exaggerated. Pliny speaks of a poulpe that had arms 
 thirty feet long; and a modern author gravely relates the 
 history of one of these gigantic mollusks, which, attacking a 
 vessel, nearly upset it ! The Common Poulpe Sepia Octopo- 
 dia is about two feet long ; it inhabits the coasts of Europe, 
 and commonly keeps among rocks : it destroys a great many 
 fishes and Crustacea. 
 
 16. What are the general characters of the cephalopoda dibranchiata ? 
 What is cuttle-fish bone ? 
 
 17. How are the tentacula of cephalopods arranged? 
 
 18. What are the general characters of the poulpes ? What is the nature 
 of their food ? Where are they found ? 
 
28 
 
 ARGONAUTS. 
 
 Fig. 12. ARGONAUT. 
 
 19. The ARGONAUTS Argonauta (Fig. 12) are cephalopods 
 very closely allied to the poulpe, but the pair of feet which is 
 nearest the back is dilated at the extremity into a broad mem- 
 brane, and the body is always lodged in a very delicate and ex- 
 tremely beautiful shell, vulgarly called the paper nautilus. It is 
 not certainly known, however, whether this shell really belongs 
 to the animal that inhabits it, or whether it is derived from some 
 other rnollusk. Be this as it may, the cephalopod does not ad- 
 here to it, but uses it as a boat to float on the surface of the water 
 
 19 What are the general characters of the argonaut ? 
 
CALM ARIES CALM A RETS. 
 
 29 
 
 when the sea is calm. Six of its tentacula are then folded be- 
 neath and act as oars, and it is pretended that the two others, 
 the extremities of which are enlarged and raised up, are spread 
 for sails, as represented in the figure (12) ; but we should not 
 infer from their structure that these tentacula are adapted to such 
 a purpose. The common species is found in the Mediterranean, 
 the Indian Ocean, &c. ; it was known to the ancients under the 
 name of nautilus, and pompilius. 
 
 20. The CALMAKIES Loligo differ from the preceding in their 
 elongated sack, and being provided with two terminal fins, by the 
 horny lamina, lodged in 
 the back, which supplies 
 the place of shell, and by 
 their tentacula, which are 
 ten in number, and not 
 of the same configura- 
 tion throughout (fg. 13). * 13 THE COMMON 
 Eight of these feet are of moderate size, and are armed with little 
 cups in their whole length, while the two others are very much 
 elongated and have cups only near their extremities. 
 
 21. TheCALMAHETS Lo- 
 
 ligopsis are remarkable for 
 the great length of two of their 
 arms (fg. 14), which are fili- 
 form, and widened at the end 
 only ; in other respects they 
 differ but little from the Cal- 
 maries : they are found in the 
 Mediterranean. 
 
 22. Certain cephalopods, 
 which resemble the Calmaries 
 very much, but have their 
 long arms furnished with 
 hooks, form the genus of 
 Onychoteuthis (from the 
 Greek onux, in the genitive 
 onuchos, nail, and teuthis, a 
 calmary, that is, a calmary 
 with nails. 
 
 23. The CUTTLE-FISHES 
 Fig. 14. THE CALMARET. Sepia have the tentacular 
 
 20. How do the Calmaries differ from the Argonauts ? 
 
 21. What are Calmarets? 
 
 22. What is the ony'choteuthis ? (pronounced o-ni-ko-tu-this.) 
 
 23. What are the general characters of the cuttle-fish ? Of what use is 
 cuttle-fish bone ? 
 
30 CUTTLE-FISHES. NAUTILUS. 
 
 appendages arranged like the calmaries; but their body, which 
 is oval and depressed, is furnished with fleshy, lateral fins, occu- 
 pying the whole length of the sack, and the back is sustained by 
 a large internal shell, the structure of which has been already 
 mentioned. The species most commonly found in the seas of 
 Europe Sepia officinalis attains a foot in length or more. 
 The cuttle-fish bone or shell, in powder, is used as a dentifrice, 
 and is employed in the arts for several purposes, as for polishing, 
 for forming moulds for silver castings, and as a pounce. 
 
 24. The family of CEPHALOPODA TETRABRANCHIATA has for 
 its type the NAUTILUS, a very remarkable mollusk, the body of 
 which is enclosed in the last chamber (a) of a large shell, folded 
 
 spirally, and divided by transverse 
 partitions (b) into several cavities, 
 (Jig. 15). Each one of these par- 
 titions is pierced by a hole, and the 
 canal thus formed, which is called 
 the syphon (s), extends to the pos- 
 terior extremity of the shell; it is 
 traversed by a contractile mem- 
 branous tube, posterior to the body 
 of the animal. This structure 
 b c seems designed to facilitate the as- 
 Fig. 15. SECTION OF A cent or descent of the animal in the 
 NAUTILUS. water, by increasing or diminishing 
 
 the specific gravity of the shell ; for the syphon communicates 
 with an external reservoir, and can empty or distend itself with 
 the water found in it ; now, the chambers which it passes through 
 are filled with air, and when this tube becomes inflated, it must 
 compress this elastic fluid, and increase its density, which, at the 
 same time, augments the specific gravity of the whole shell, and 
 must give it a tendency to sink towards the bottom of the water 
 in which it floats. 
 
 25. The conformation of the animal differs very much from 
 that of the poulpes, calmaries, and other dibranchial cephalopods. 
 The head of the nautilus is surrounded by a large fleshy disk, 
 which bears some analogy to the foot of the gasteropods, and 
 
 Explanation of Fig. 15. Vertical section of the nautilus shell : a. the 
 last chamber, in which the animal is lodged ; 6. one of the partitions which 
 divides the chambers (c) from each other j s. the syphon. 
 
 24. What are the peculiarities of the nautilus shell ? What seems to be 
 the object of this peculiar structure ? 
 
 25. How is the animal of the nautilus characterized ? 
 
AMMONITES. 
 
 31 
 
 probably serves 
 the animal in 
 crawling. The 
 tentacula, \vhich 
 are inserted near 
 the mouth, are 
 not furnished 
 with cups as in 
 the preceding 
 family : they are 
 retractile and in 
 considerable 
 number. The 
 eyes are pedun- 
 culate, that is, 
 supported on a 
 sort of foot-stalk 
 or stem : there 
 is no organ of 
 hearing, nor 
 pouch, nor fins, 
 and the branchiae 
 are four in num- 
 
 m p 
 
 Fig. 16. NAUTILUS. 
 
 26. A great number of shells are found in the fossil state 
 which are very analogous in structure to the nautilus, and which 
 probably belonged to cephalopods of similar conformation ; they 
 are the AMMONITES (Jig. 17), vulgarly called Horns of Ammon, 
 in consequence of the resemblance of 
 their volutes or whorls to those of a 
 ram's horn. These animals were 
 among the most ancient inhabitants of 
 the earth and lived in every sea. Their 
 remains abound in the secondary for- 
 mations (See GEOLOGY), and are met 
 with in all parts of the world ; but they 
 have long since disappeared from the 
 surface of the earth, and in those lay- 
 ers which rest upon the chalk, not 
 Fig. 17. AMMONITE. 
 
 quently, their destruction must have occurred at a period long 
 
 Explanation of Fig. 1 6. The nautilus shell opened : t. the tentacula ; 
 e. the funnel or reservoir ; p. the foot ; m. part of the mantle ; o. the eye ; 
 s. the syphon. 
 
 26. What are ammonites ? Where are they found ? 
 
32 BELEMNITES. NUMMULITES, &c. 
 
 anterior to the creation of nearly all the mammals ; they vary 
 much in form, and still more in size ; some are not larger than a 
 bean, and others are more than four feet in diameter. More than 
 three hundred species of them are known, and they are divided 
 into several genera, according to the manner in which the shell is 
 rolled, the position of the syphon, the form of the partitions, &c. 
 
 27. We give the name of BELEMNITES (from the Greek belem- 
 non, a dart) to other fossils, which also seem to have belonged to 
 the cephalopods, but which, in place of being an external shell, 
 must have been lodged in the interior of the animal, like the bone 
 of the cuttle-fish. They are conical in form, and are chiefly 
 composed of a series of little horns, fitting one in the other like 
 boxes in a nest, traversed by a syphon and terminated anteriorly 
 by a horny plate that forms a sort of chamber, in the interior of 
 which we sometimes find the remains of an ink-bag, similar to 
 the sack which fulfils the same purposes in the naked cephalo- 
 pods. The belemnites are not met with in strata as old as the 
 ammonites ; but they abound in the middle and upper layers of 
 the secondary formation, and cease to exist in the upper layers 
 of the chalk. 
 
 Until lately, a host of microscopic shells of lenticular form and 
 without apparent opening, designated by authors under the names 
 of NUMMULITES (from the Latin numma, a piece of money), 
 CAMERINES (from the Latin camera, chamber), FORAMINIFERA 
 (from the Latin foramen, a hole, and fero, I bear), &c., were' 
 referred to the order of cephalopods ; these little bodies abound 
 to such an extent in certain soils, that they of themselves exclu- 
 sively constitute chains of hills and immense banks of building 
 stone ; but they are also found in European seas, and, on observ- 
 ing them when alive, we are convinced that the animals to which 
 they belong do not resemble either the cephalopods or even the 
 mollusks, in anything : they are beings of a very peculiar struc- 
 ture, and seem more to approximate the polypi. 
 
 27. What are belemnites ? What are their characters ? Where are they 
 found ? 
 
CLASS OF GASTEROPODA. 33 
 
 LESSON III. 
 
 CLASS OF GASTEROPODA. General Conformation Classifi- 
 cation. 
 
 ORDER OF GASTEROPODA PULMONEA. Organization Division 
 into two families. 
 
 FAMILY OF TERRESTRIAL PULMONEA. Limax Vaginulus 
 Helix Bulimus Pupa Chondrus Clausilia Achatina. 
 
 FAMILY OF AQUATIC PULMONEA. Oncliidium Planorbis 
 Limnceus Physa Auricula. 
 
 ORDER OF GASTEROPODA PECTINIBRANCHIATA. Organization 
 Cla ssification. 
 
 FAMILY OF TROCHOIDES. Trochus^- Turbo Delphinula 
 Turritella Cyclostoma Valvata Paludina Littorina 
 Monodon Phasianella Ampullaria Janthina Nerita. 
 
 CLASS OF GASTEROPODA. 
 
 1. Mollusks that are provided with a head, and crawl upon the 
 belly, or swim by means of a fin formed of this part of the body, 
 constitute a very numerous class, the type of which is the slug 
 and snail. The body is elongated, and terminated anteriorly by 
 a more or less developed head, which ordinarily has tentacula 
 inserted above the mouth ; the back is furnished with a mantle, 
 which extends more or less, and the belly is covered by a 
 fleshy mass, generally in form of a broad disk (fig. 18), and 
 serves the animal for crawling on the ground, but which is some- 
 times very much 
 compressed, and 
 then constitutes a 
 vertical fin (fig. 
 78). Many of these 
 animals are en- 
 tirely naked; 
 others have an in- 
 ternal shell con- 
 cealed in the thick- 
 ness of the mantle ; 
 but most of them 
 have an external Fig. 18. LIMN* FRESH-WATER SNAIL. 
 
 shell, and this 
 
 calcareous envelope is almost always sufficiently large to contain 
 them entirely, and afford them protection. 
 
 1. What is the general character of the class of ga'steropods ? Have they 
 any shell ? 
 
34 
 
 COLUMELLA. UMBILICUS. 
 
 2. The arrangement of these shells varies much ; sometimes 
 they are composed of many pieces, at others, of a single piece , 
 sometimes they are symmetrical, at others not symmetrical, and 
 in this last case, in proportion as they are elongated, they are 
 rolled or twisted upon themselves, and constitute a spirally 
 twisted cone. This last form, which is 
 seen in the shell of the snail, is the most 
 common in gasteropods, and presents 
 numerous varieties. Sometimes the part 
 which grows less rapidly and upon which 
 the cone rolls itself, is full (fig. 19), and 
 s sometimes empty ; it is called columella 
 or pillar (c), and, when empty, we give 
 
 d the mime of vmbilicus to this opening 
 
 (fig- 20 > M )- ^ the turns of the shell 
 ^ remain in the same plane, the spire is 
 
 p. lq flat or concave, and the general form of the 
 
 A '? URB E E C D rl S HELL F she11 is ^ SCQ ^ resembling a disk, as in the 
 
 A i U KlilJN A 1 tiU bHbJLL. . i' / /* rrk\ >. i L Lt 
 
 planorbis (jig- 29) ; sometimes the height 
 
 of each turn completely envelopes thepreceding involutions, so that 
 the spire is concealed ; but in most cases the turns are inclined 
 towards the edge of the columella, and there results an oblique 
 spire, which is more acute in proportion as 
 the cone is less rapidly widened (fig. 19). 
 Those shells are called turbinated, in 
 which the first turns are raised up above 
 the succeeding ones (fig. 19), forming a 
 projecting spire, and it is remarked that U ... 
 the turns or whorls are almost always di- 
 rected from the right side. Sometimes how- 
 ever the spire of these turbinated shells is 
 turned from the left side of the animal 
 (fig. 25), and in this case they are said to Fig, 20. NATICA. 
 be perverse. 
 
 Explanation of Fig. 19. Section of a turbinated shell to show how it is 
 spirally wound upon itself: 6. the mouth or aperture of the shell ; c. the 
 columella; d. the part of the columella included in the last turn of the spire ; 
 8. turn of the spire next to the last; p. the apex or summit of the shell ; 
 i. part of the columella. 
 
 2. Do the shells of ga'steropods consist of a single piece ? What is meant 
 by the colume'lla ? What is the umbili'cus ? What is meant by a turbinated 
 shell ? What is meant by a perverse shell ? 
 
STRUCTURE OF GASTREOPODS. 
 
 85 
 
 ap p 
 
 3. The mass of the viscera occupies the upper part of the 
 cone formed by these shells, and always remains enclosed in it ; 
 but the head and foot project externally when the animal extends 
 itself to walk, and return again into the last turn of the spire, 
 when it contracts : and the size of this latter part of the shell and 
 the form of its open- 
 
 ing are always in 
 
 relative proportion to f 
 
 the Toot. In most of *' 
 
 the aquatic gastero- 
 
 pod mollusks, with a . 
 
 spiral shell, there is l " 
 
 a horny or calcare- P"' 
 
 ous disk or door, o-r j 
 
 called operculum 
 
 (fg. 32, o), which 
 
 is fixed to the poste- 
 
 rior part of the foot, 
 
 and which closes the 
 
 entrance of the shell, 
 
 when the animal 
 
 retires into it.- 
 
 The operculum of certain small shells constitutes what is vulgar- 
 
 ly termed an eye-stone. 
 
 4. The organs of respiration are formed sometimes for breath- 
 ing the air, and sometimes for aquatic respiration ; but in mollusks 
 with a spiral shell, they are always lodged in the last turn of the 
 spire, and receive the ambient element beneath its edge, either by 
 a hole pierced through the mantle, or between the body and the 
 free edge of this cutaneous fold, which is also often prolonged 
 into a canal, by means of which the animal can obtain the fluid 
 (whether air or water) necessary for its respiration, without 
 
 ! 
 
 e d pi 
 
 21. -ANATOMY OF A SNA n.. 
 
 Explanation of Fig. 21. Anatomy of a snail ; pi. the foot; t. the tenta- 
 cles partly contracted ; d. a sort of diaphragm which separates the respira- 
 tory cavity from the other viscera ; e. a portion of the stomach ; /. the 
 liver ; o. the ovary ; i. the intestines ; r. the rectum ; a. the anus ; c. 
 the heart (the pericardium the sack containing 1 the heart being open ; 
 ap. the pulmonary artery ramifying- on the parietes of the pulmonary cavity 
 (p) ; v. the gland which secretes the viscosity ; cv. its excretory canal, 
 going to open near the anus. 
 
 3. In what part of spiral shells are the viscera of the animal contained ? 
 What part of the shell contains the head and foot ? What is the operculum ? 
 What are eye-stones ? 
 
 4. In what part of the spiral shells are the organs of respiration placed ? 
 By what means is the air or water admitted to these organs ? Where is the 
 respiratory tube situated ? 
 
36 STRUCTURE OF GASTEROPODS. 
 
 putting its head or foot out of its shell. In this latter case, the 
 shell has on its edge a notch or canal, destined to lodge the re- 
 spiratory tube ; this notch is near the termination of the columella, 
 and on the side opposite to that towards which the spire is di- 
 rected. Consequently this canal is to the left, in the common 
 species, and to the right, in perverse shells. 
 
 5. The heart {Jig. 21, c) is always aortic : it is generally com- 
 posed of an auricle and a ventricle, and its position, as is the 
 case with the respiratory tube, is in relation to the direction of 
 the spire of the shell. This organ is situate on the same side 
 with the tube, that is, on the side opposite to that towards which 
 the shell turns, and the procreative organs (the form of which 
 varies much) are always placed on this latter side, and conse- 
 quently on the side opposite to the heart. 
 
 6. The mouth is surrounded by contractile lips, and sometimes 
 armed with horny teeth which occupy the palate. In many other 
 animals of this class, the anterior part of the O3sophagus is very 
 fleshy, and possesses the faculty of projecting itself externally, in 
 such a manner as to constitute a trunk. Sometimes the stomach 
 is also furnished with cartilaginous or bony pieces, proper for 
 dividing food; the intestine is folded on itself and lodged between 
 the lobes of the liver arid ovary; and the anus (fig* 21, a) is 
 almost always situate on the right side of the body. 
 
 7. In this class, the organs of the senses are less developed 
 than in the cephalopods ; the tentacles, which most gasteropods 
 bear on their front, varying in number from two to six, serve 
 chiefly for tact and perhaps for smell. No organ of Hearing 
 has been found, and their eyes, which are sometimes wanting, 
 are very small, and of a very simple structure: they resemble 
 those of the nautilus, and are sometimes adherent to the head, 
 and sometimes borne at the base on the side, or at the end of the 
 tentacula. 
 
 8. The class of gasteropods is divided into eight orders, the 
 principal characteristics of which are derived from the disposition 
 of the branchial (brank-e-al] apparatus, as may be seen in the 
 following table : 
 
 5. What is the character of the heart in ga'steropods ? 
 
 6. What are the peculiarities of the digestive organs ? 
 
 7. Where are the tenta'cula placed ? What is the number of tentacles in 
 ga'steropods ? Where are their eyes situated ? 
 
 8. Into how many orders is the class of ga'steropods divided ? Upon what 
 are these divisions founded ? 
 
CLASSIFICATION OP GASTEROPODS. 
 
 87 
 
 O 
 
 having lungs 
 
 (ORDERS.) 
 { PULMONEA. 
 
 ... I 
 
 in a dorsal 
 cavity, open 
 above the 
 head. 
 Shell 
 
 Tubiform, J- TUBULIBRANCHIATA. 
 
 Very open ; "j 
 ordinarily in [ 
 form of a 
 shield. 
 
 8 
 
 beneath a fold of the mantle, 1 
 which almost always con- I TKCTIBRANCHIATA 
 tains a shell, or beneath a f A 
 . straight edge of the foot, j 
 
 {shell not turbi- f 
 nate; of one or > CYCLOBRANCHIATA. 
 more pieces, i 
 Without a shell } INFEROBRAJJCHIATA. 
 
 { upon the back. 
 
 } NUDIBRANCHIATA. 
 
 vertically compressed, and only fit for i HETEROPODA . 
 .swimming. ^ 
 
 ORDER OF GASTEROPODA PUUKONEA. 
 
 9. Gasteropods formed for aerial respiration have no branchiae, 
 but have a cavity on the back, upon the parietes of which the 
 pulmonary vessels form a complicated net-work (See fig. 21, 
 page 35), and the lung receives the external air through a hole 
 in the edge of the mantle above the right side of the nape, which 
 is susceptible of being opened or shut at the will of the animal. 
 All the pulmonic gasteropods are not however terrestrial mol- 
 lusks. Many of them live in the water; but then they are 
 obliged to come to the surface from time to time, to obtain air 
 necessary for their respiration. All these animals feed on vege- 
 table substances. 
 
 10. The order of pulmonic gasteropods is divided into two 
 families ; the terrestrial pulmonea^ and the aquatic pulmonea. 
 
 11. The FAMILY OF PULMONEA TERRESTRIA are general- 
 ly recognised with ease by their four tentacles. These append- 
 ages are retractile, and those forming the upper pair, which 
 
 9. What are the general characters of the breathing apparatus of the 
 order of Ga'steropoda Pulmonea ? Upon what do they feed ? 
 
 10. How is the order of pulmonic ga'steropods divided ? 
 
 11. What are the characters of the family of terrestrial pulmonea? 
 
SLUGS. 
 
 are longest, have the eyes at their extremities. The mouth is 
 armed with one palatine tooth, and a small tongue studded with 
 microscopic teeth ; and the body varies in form ; some are 
 naked or only provided with an internal shell, while others have 
 an external shell spirally twisted, with a blunt summit, and the 
 mouth without a notch. The small tribe formed by the first is 
 divided into Limax, Vaginula, &c. The tribe ofterrestrialpul- 
 monea with an external shell comprises the genera of helix, vitrina, 
 bulimus, pupa, chondrus, succinea, clausilia, and achatina. 
 
 12. The LIMACES (slugs) form the type of the terrestrial 
 pulmonea without apparent shell. The body, as every one 
 knows, is elongated, and their mantle is a fleshy disk, scarcely 
 separated from the rest of the skin (Jig. 22, m,) and which only 
 occupies the fore part of the back, where it covers the pulmo- 
 nary cavity ; it often encloses in its thickness a small, flat shell. 
 On the right side of this species of shield, there is a notch, at 
 the bottom of which we observe a contractile opening (fig. 22, 
 ro), that leads into the pulmonary cavity ; the anus is situate 
 upon the anterior border of this respiratory orifice, and a third 
 opening belonging to the procreative apparatus is situate on the 
 external side of the base of "the right superior tentacle. The 
 four tentacula are cylindrical, more or less swelled at the end, 
 and hollow ; they are drawn in and pushed out, on unrolling 
 themselves, like the inverted fingers of a glove, by the aid of 
 muscular fibres lodged in their interior ; the eyes, which are 
 borne on the ends of the superior tentacles (fig. 22, st), are 
 black ; the mouth is armed with a sort of palatine tooth in the 
 form of a crescent, and a smooth tongue. The heart is lodged 
 in a particular cavity beneath the mantle, and is composed of an 
 oval auricle, which receives a large pulmonary vein, and a pear- 
 shaped ventricle, from which the aorta arises. And there exists 
 near the heart a secretory apparatus which pours out a viscid 
 matter upon the external surface, through an excretory canal, 
 opening near the respiratory orifice. 
 
 13. These animals are herbivorous: they feed principally 
 upon young plants, fruits, mushrooms, and are most voracious 
 towards evening. During the heat of the day they remain con- 
 cealed in holes under stones, or some heap of half-decayed 
 leaves, or even in the earth, and they seldom go out except in 
 the morning and evening, when the air is humid ; they are 
 especially abundant after rain. During the cold season they 
 bury themselves in the ground and remain torpid. 
 
 12. What are the general characters of the Lima'ces ? 
 
 13. Upon what do the Lima'ces feed ? Where are they found ? What 
 becomes of them in the cold season ? 
 
SLUGS. SNAILS. 
 
 14. Some, called ARIONS, have the pulmonary orifice situate 
 near the anterior part of the dorsal shield, such as the Limax 
 rufus, which is everywhere met with in wet weather; [a de- 
 coction of this species is sometimes used in France for pulmo- 
 nary disorders :] the others, named Limax properly so called, or 
 
 m ro 
 
 4h 
 
 -. st 
 
 Fig. 22. LIMAX RUFUS. 
 
 Lima, have this orifice situate more posteriorly, and frequently 
 have a pretty well formed internal shell ; the Limax cinereus, 
 wm'ch inhabits caves and shady forests, belongs to this division, 
 as well as the Limax agrestis, which abounds in some countries, 
 and is very injurious to agriculture. 
 
 We give the names of VAGINULA, TESTACELLA, and PARMA- 
 CELLA to other naked gasteropods, nearly resembling the limaces, 
 but which differ from them in the position of the anus, the extent 
 of the mantle, &c. 
 
 15. The SNAILS Helix form the most important tribe of 
 terrestrial pulmonea with a complete and apparent shell. 
 Their organization differs very little from that of the limaces ; 
 the mantle, instead of being in the form of a convex shield, 
 constitutes a large cone twisted on itself, containing the viscera, 
 which is covered by the shell (fig- 21, p. 35). We distinguish 
 them by their shell, the opening of which is ordinarily raised 
 like a pad or collar, forming a thickened lip in the adult ; the shell 
 is a little twisted by the projection of the penultimate whorl of 
 the spire, and in this way takes somewhat of a crescent shape. 
 In snails properly so called, this opening is at least as broad 
 as high, and the shell is sometimes globular and sometimes 
 depressed. The habits of these mollusks are nearly the same 
 as those of the limaces. In summer they are very voracious, 
 but in the autumn they eat very little, and, on tbe approach of 
 
 Explanation of Fig. 22. Limax rufus : st. the eyes on the extremity 
 of the superior tentacles ; m. the mantle ; ro. the notch over the pulmona- 
 ry cavity. 
 
 14. What are Arions ? 
 
 15. What are the general characters of snails ? What are their habits ? 
 Do their wounds heal ? In what respect does the genus Heiu differ from 
 the genus Limax ? 
 
40 
 
 BTJLIME8, PUPA, 
 
 winter, they retire into some hole, draw themselves into their 
 shell, shutting up the mouth with a calcareous matter, secreted 
 by the edge of the mantle, and remain torpid until spring. 
 Very curious, and frequently repeated experiments, have proved 
 that not only do wounds inflicted 'on these animals readily heal, 
 but that considerable portions of the body, after being removed, 
 can be renewed. The eyes, the tentacles, and even the head of 
 snails have been known to be entirely renewed in this way. A 
 very great number of species of snails are known ; they are found 
 in all parts of the world. 
 
 16. We give the name of VITRINA to snails 
 the shell of which is very thin, flattened ami un- 
 provided with a thickened lip, and too small to 
 enclose the body entirely f some small species 
 are found in Europe. The BULIMES Bulimus 
 (Jig. 23) have an elongated shell, the open- 
 ing higher than wide, furnished with a thicken- 
 ed lip, and without notches. A small species 
 which is found in France, is" re- 
 markable for the singular habit of 
 successively breaking the whorls of 
 the apex of the shell. There is a 
 large species in Brazil which is 
 eaten as a delicacy. Other mollusks of the same 
 tribe, the genus Pupa, have an ellipsoid, or even 
 almost cylindrical shell, with the opening higher 
 than wide, furnished with a thickened, notched, and 
 generally dentate lip (Jtg. 24) : they are of small 
 size, and live in humid places, among moss, &c. 
 Shells of the genus Chondrus also 
 have a notched and dentate lip; but 
 their form is more ovoid. 
 
 17. The genus of CLAUSILIA is composed of small 
 mollusks which live in moss, at the roots of trees, and 
 have a shell similar to that of the Pupa, but much 
 more slender and pointed (Jig' 25). 
 
 18. The AMBRETTES Succinea differ from all 
 the preceding in the absence of a thickened lip around 
 the opening of the shell, which is oval, and too -small 
 
 Fig. 23. 
 
 BULIMUS. 
 
 Fig. 24. 
 
 PUPA. 
 
 16. What is the Vitrina? What are the characters of the genus Buli. 
 mus ? How is the gejius Pupa distinguished ? 
 
 17. Of what is the genus Clausi'lia composed ? 
 
 18. What are the distinguishing marks of the Ambrettes ? Where are 
 they found ? 
 
ACHATINA. ONCHIDIUM. 
 
 41 
 
 Fig. 26. 
 
 AMBRETTE. 
 
 to lodge the entire animal (jig. 26) : the shell 
 is thin and translucent, and obtains its name 
 from a supposed resemblance to amber: they 
 live upon plants that grow along the margins 
 of rivulets and brooks. 
 
 19. The genus of 
 ACHATINA (Jig. 
 27) is composed of 
 large snails, which, 
 in warm countries, 
 feed on shrubs ; they have an oblong 
 shell with the opening wider than it 
 is high, without a thickened lip, and 
 truncate at the extremity of the colu- 
 mella, a disposition somewhat analo- 
 gous to that of the shell of most ma- 
 rine gasteropods. 
 
 20. The family of PULMONEA 
 AQUATICA have but two tentacles 
 (fig. 18, page 33); their mode of 
 respiration obliges them to come fre- 
 quently to the surface of the water to 
 breathe : they cannot keep at great 
 depths, and they ordinarily live in 
 fresh waters, or near coasts. 
 
 21. As in the preceding family, we find here mollusks without 
 a shell, and others that are provided with one : the first form the 
 genus of Onchidivm (fig. 28), which have a very straight and 
 very extensible elongated body ; they inhabit the fresh waters of 
 
 Fig. 27. ACHATINA. 
 
 Fig. 28. oNCHiniuM 
 
 19. What shells form the genus of Achatina? (pronounced a-ka-te-ncT), 
 
 20. What are the characters of the family of Pulmonea Aquatica. 
 
 21. What are the characters of the genus Onchidium ? 
 
42 
 
 PLANORBIS. LIMN.EA PHYSA. AURICULA. 
 
 Fig. 29. PLANORBIS. 
 
 the warm parts of both continents : the second are subdivided into 
 the genera of PLANORBIS, LIMN.EA, AURICULA, &c. 
 
 22. The mollusks of the genus PLANORBIS have a thin shell 
 rolled upon the same plane, which is consequently discoid, and 
 the whorls very gradually increase in size (Jig. 29). Their 
 
 tentacles are long and 
 filiform, and the eyes 
 are placed at the internal 
 side of their base. These 
 gasteropods feed on vege- 
 table substances, and in- 
 habit stagnant waters ; in 
 winter they bury them- 
 selves in the mud, and 
 lie torpid. 
 
 23. The LIMN.EA (fig. 
 18, page 33) have the 
 same habits, and are almost always found in the same localities 
 as the planorbis, from which they are readily distinguished by 
 the form of their shell, the spire of which is oblong ; their tenta- 
 cles are thick and triangular. In the laying season, they are 
 often found in great numbers joined together, so as to form a sort 
 of chaplet. They swim on the back with the ventral disk extend- 
 ed on the surface of the water, and in winter they become torpid 
 like the planorbis. 
 
 24. We give the name of PHYSA 
 to small mollusks found in foun- 
 tains, the shell of which (fig. 30) is 
 similar to that of the limnsea, but 
 very thin, without a thick lip, and 
 without a fold on the columella. 
 The animal, when it crawls or 
 swims, covers its shell with the two lobes of 
 its mantle. In other respects it closely re- 
 sembles the limneea. 
 
 25. The AURICULAE differ from the pre- 
 ceding by having large oblique grooves upon 
 the columella of their shell, which is oval or Fig. 31. 
 
 oblong (fig. 31). The name is derived AURICULA. 
 
 22. What are the characters of the genus Planorbis ? Upon what do ani- 
 mals of this genus feed ? Where are they found ? 
 
 23. How is the genus Limnse'a distinguished from the genus Planorbis ? 
 What are the habits of this genus? 
 
 24. What are the characters of the genus Physa? 
 
 25. How is the genus Auri'cula characterized ? (Auri'oula ia formed 
 from the Latin, aunt, ear, and means a little ear.) 
 
 Fig. 30. 
 
 PHYSA. 
 
STRUCTURE OF THE TURBO PICA. 
 
 43 
 
 from the shape of the opening, resembling a human ear. Many 
 of these gasteropods are of considerable size. One species is 
 found on the shores of the Mediterranean. 
 
 ORDER OF PECTXNXBRANCHXATA.* 
 
 26. This division of the class of Gasteropods is the most 
 numerous in genera and species : it comprises nearly all the 
 mollusca, in which the shell is univalve and spirally twisted, 
 m vb b ab ov 
 
 Fig. 32. ANATOMY OF A PECTINIBRANCH GASTEROPOD. Turbo PlCd (See Jig. 44). 
 
 Explanation of Fig. 32. Anatomy of a pectinibranch gasteropod (the 
 Turbo pica}, to show the arrangement of the respiratory cavity : p. the foot 
 of the animal ; o. the operculum ; t. the trunk ; ta. the tentacles ; y. the 
 eyes ; m. the mantle, split open longitudinally so as to expose the respi- 
 ratory cavity : /. the anterior edge of the mantle, which in its natural po- 
 sition covers the back of the animal, and leaves there an opening or great 
 slit, through which the water reaches the branchiae ; b. the branchia? : vb. 
 the branchial vein which goes to the heart (c) ; ab. the branchial artery ; 
 a. the anus ; i. the intestine ; e. the stomach and liver ; ov. the oviduct. 
 Above the nucha or nape, we see the cephalic (nervous) ganglion, and the 
 salivary glands ; d. fringed membrane, which below borders the left side 
 of the opening of the respiratory cavity. 
 
 * Pec'tinibranchia'ta. From the Latin, pecten, a comb, and branchi<B t 
 gills ; because the branchiae or gills (Jig. 32, 6) resemble a comb in form. 
 
 26. What are the peculiarities of the pectinibranch ga'steropods ? 
 what parts of the shell do we find the respiratory cavity ? 
 
 In 
 
44 RESPIRATORY CAVITY OF PECTINIBRANCHIATA. 
 
 and many of those in which the shell is simply conical. The 
 most remarkable feature of almost all these animals is the ar- 
 rangement of the branchial apparatus; but this character is not 
 constant ; for in two genera (cyclostoma and helicina), which, in 
 other respects, are too nearly allied to the ordinary pectinibran- 
 chiata to be separated from them, there are no branchiee, and 
 their respiration, which is aerial as in pulmonea, is carried on 
 by means of a vascular net-work that lines the bottom of the 
 respiratory cavity. This cavity occupies the last whorl of the 
 shell and opens externally by a ejreat slit, situate betwixt the body 
 and the edge of the mantle; in most instances it lodges branchise 
 (j%"' *^ ^)' wmcn are composed of small leaves or fringes ar- 
 ranged parallel and attached to its superior parietes upon one, two, 
 or three lines, according to the genus. All these mollusks have two 
 tentacles (ta) and two eyes, sometimes borne on particular pedun- 
 cles ; the mouth is in the form of a tube or trunk (J), and encloses 
 a tongue armed with small hooks ; the males have, on the right 
 side of the neck, an appendage, sometimes very thick, which 
 cannot, in general, be drawn into the body of the animal, but is 
 folded into the branchial cavity ; the rectum and the oviduct (ov) 
 are also found on the right side of this cavity, and near them we 
 remark a particular organ, enclosing a very viscid humour, de- 
 signed to form a common envelope around the eggs. 
 
 27. This order is divided into three families. In the two 
 first (that of the Trochoides and of the Capuloides), there is no 
 syphon by the aid of which the animal can breathe without 
 leaving its shell (Jig. 33), while in the third family (that of the 
 Buccinoides) there is a respiratory tube, formed by a prolonga- 
 tion of the edge of the pulmonary cavity of the left side, which 
 
 ses through a corresponding canal or notch, in the shell 
 .34). 
 
 Fig. 33. TURRITELLA. Fig. 34. CASSIS. 
 
 27. How is the order of pectinibranch ga'steropods divided? How does 
 the family of Buccinoides differ from the other two families, the Trochoides 
 and Capuloides ? 
 
TROCHUS. 45 
 
 28. The family of TROCHOIDES are distinguished from other 
 pectinibranch gasteropods without a syphon, by the form of their 
 shell, which is spiral, with an entire aperture, and by the exist- 
 ence of an operculum, or some organ in the place of it. This 
 family is divided into three tribes, which are distinguished by 
 the form of the opening of the shell ; namely, Trochus, in which 
 this opening, angular at its external edge, is nearly quadrangular, 
 and, as regards the axis of the shell, lies in an oblique plane 
 (Figs. 35 and 36) ; the tribe Turbo, in which the mouth of the 
 shell is perfectly round (Figs. 43, 45 and 46), and the tribe of 
 Hemicyclostoma, in which this opening is more or less in the 
 form of a crescent, as in the Helices (Figs. 26 and 27). 
 
 29. The TROCHUS so called from the general form of the 
 shell, that of a top; its spire is more or less raised, and terminates 
 in a point, and the circumference is trenchant or carinate : ani- 
 mals of this tribe are mollusks with a short foot, the mantle or- 
 dinarily furnished on the edge with two or three pairs of filiform 
 appendages, the two eyes being placed on a swelling at the base 
 of the tentacles, the mouth armed with a sort of spirally rolled 
 tongue, and the anus opens on the right side of the respiratory 
 cavity, which encloses two unequal branchiffi. The operculum 
 is horny, and marked by numerous spiral turns. The tribe of 
 Trochus is divided into several little groups, according to the ab- 
 sence or presence of an umbilicus, and some other not very im- 
 portant characters. Figure 35 gives a view of the base of the 
 Trochvs niloticus, showing the umbilicus or hole in the base of 
 
 u mA 
 
 Fig. 35. TROCHUS NILOTICUS. Fig. 36. 
 
 the columella (w), while Figure 36 is another view of the same 
 shell. The Solarium is a trochus in which the shell is conical in 
 
 28. What are the peculiarities of the family of Trochoides ? (pronounced 
 tro-koi-des.) Into how many tribes is this family divided ? 
 
 29. What are the characters of the tribe of Trochus ? (pronounced 
 tro-kue.) 
 
46 
 
 TROCHUS. 
 
 form (fg. 37), with a quadrangular aperture, and an extremely 
 flaring umbilicus (Jig, 38, u) ; the anterior edges of all the invo- 
 
 Fig. 39. TROCHUS AGGLUTINANS. 
 
 Fig. 37. SOLARIUM PfiRSPECTIVUM. Fig. 38. 
 
 lutions or whorls of the spire are marked by a crenulated cord, 
 
 that is, notched on the edge (Jig. 38). 
 
 30. Among the TROCHI 
 properly so called, with an 
 umbilicated shell, we will men- 
 tion the Trochus agglutinans y 
 which is found in the West 
 Indies and Pacific. It has the 
 singular faculty of glueing to 
 itself movable bodies found on 
 the ground on which it rests ; 
 sometimes it glues stones and 
 sometimes shells or pieces of 
 shells, according to the place 
 where it is found. From this 
 habit of building out its habita- 
 tion from materials not its own, 
 it is sometimes called the Ma- 
 son (Fig. 39). 
 
 There are some without an 
 umbilicus, very conical, and 
 very tall, that are marked by 
 numerous whorls in the spire, 
 with crossing striae ; the ex- 
 tremity of the columella is 
 much twisted, and projects be- 
 yond the origin of the lip. A 
 specimen of this variety is seen 
 in the annexed figure of the 
 telescope trochus (Fig. 40). 
 
 Fig. 40. TROCHUS TELESCOPIUM. 
 
 30. What are the peculiarities of the Trochus Agglutinans ? 
 
TROCHUS TURBO. 
 
 47 
 
 Fig. 41. TRCCHUS CONCAVUS. 
 
 Fig. 42. 
 
 TROCHUS IRIS. 
 
 Another variety is remarka- 
 ble for a deep excavation at the 
 base of the columella, resem- 
 bling an umbilicus, and a pro- 
 jection of the circumference, as 
 is seen in the figure of the con- 
 cave trochus (fg. 41), which 
 inhabits the Indian Seas, and is 
 considered rare. 
 
 There are 
 other species, 
 without an umbi- 
 licus, conical with 
 a very oblique 
 
 base; the aperture large, slightly angular i the 
 columella twisted, and forming a kind of tooth at 
 its termination. Such is the rainbow trochus 
 (fg. 42), the nacre of which is a beautiful golden 
 green, with very brilliant reflections of red. 
 
 31. The tribe of TURBO comprises all the pecti- 
 nibranch gasteropods which have a completely and 
 regularly turbinated shell, terminated by an entirely round aper- 
 ture In it we range the turbo 
 properly so called, delphinula, turri- 
 tella, scalaria, cyclostoma, valvata, 
 &c. (fg. 43). 
 
 32. The TURBOS properly so 
 called are recognised by their round 
 or oval thick shell, in which the ap- 
 erture is completed within by the 
 whorl of the spire next to the last. 
 These mollusks have two long ten- 
 tacles, which, 
 at their base, 
 externally, 
 
 support the pedunculated eyes ; on the 
 sides of the foot we remark membranous 
 wings, sometimes simple, sometimes fringed 
 or furnished with one or two filaments ; 
 and their operculum is sometimes horny, at 
 others calcareous, or extremely thick. 
 Among the varieties of this genus is the 
 Tvrbo Pica (fg. 44), which inhabits the 
 
 31. What are the characters of the tribe of Turbo ? (Turbo is a Latin 
 word, meaning a whirling or twisting.) 
 
 32 What are the characters of the Turbo properly so called ? 
 
 Fig. 43. TURBO. 
 
 Fig. 44. TURBO PICA. 
 
48 
 
 SCALARIA. CYCLOSTOMA. VALVATA. 
 
 Fig. 45. DELPHINULA. 
 
 The Wentletrap or 
 
 equatorial regions of the Atlantic Ocean. It is a common, 
 heavy shell ; it has a horny operculum, and is remarkable for a 
 tooth situate at the orifice of the umbilicus. 
 
 33. The DELPHINULA has a thick shell like the last, but rolled 
 almost in the same plane, and the aperture is entirely formed 
 by the last whorl of the spire (fig. 45): 
 
 the most common species is remarkable 
 for its twisted and branching spines. 
 
 34. The TURRITELLA and Scalaria 
 have a very elongated spire : in the first 
 (fig. 33, page 44), the mouth or aper- 
 ture of the shell is formed as in the 
 Turbo, properly so called, and in the last, 
 
 it is similar to that 
 of the Delphinula. 
 
 Precious Scalaria (fig- 46) has the volu- 
 tions connected by longitudinal ribs. 
 
 35. The CYCLOSTOM^E, which are dis- 
 tinguished by the absence of branchiae, and 
 by their aerial respiration, also have a shell 
 with a round mouth, 
 closed by a thin circu- 
 lar operculum (fig- 47, 
 o) ; it is in form of an 
 oval spire, and finely 
 striated transversely. 
 These animals live in 
 woods, under moss and 
 Fig. 46. SCALARIA. stones. 
 
 36. Finally, the fresh-water mollusks, named VALVATA, in 
 which the shell somewhat resembles that of the Planorbis, but 
 has a circular aperture, furnished with an 
 operculum, also take their place here. One 
 species, which inhabits stagnant waters in 
 France, has been called the feather bearer, 
 from the manner in which the branchia, which 
 is in form of a feather, is protruded and floats 
 
 Fig. 48. on tne surface of the water when the animal 
 
 VALVATA. wishes to breathe. 
 
 o 
 
 Fig. 47. 
 
 CYCLOSTOMA. 
 
 33. What are the characters of the Delphirm'la? 
 
 34. What are the characters of the Turrite'lla and Scala'ria? 
 
 35. What are the characters of the Cyclo'stomae ? (Cyclostoma : from the 
 Greek, Tcuklos, round, and stoma, mouth, round-mouth.} 
 
 36. What animals belong to the genus Valva'ta ? (Valvata, Latin, formed 
 from valvce, folding doors). 
 
PALUDINA. LITTORINA. MONODON. 
 
 49 
 
 Fig. 49. PALUDINA. 
 
 37. The tribe of HEMI'CYCLO'STOMA is composed of pectini- 
 branch gasteropods, which resemble snails in the form of their 
 shell, of which the whorl next to the last presents a sunken arch, 
 which gives its aperture more or less resemblance to a crescent. 
 They form many genera, among which we will mention the 
 Paludina, Littorina, Monodonta, Janthina, and Nerita. 
 
 38. The PALUDINJS were, for a long time, confounded with 
 the cyclostomse, but the aperture of their shell is without the 
 rolled lip, and they are provided with branchiae for breathing in 
 
 water ; they show the first vestiges of the 
 syphon \v.hich always exists in the follow- 
 ing family ; we observe on each side of 
 the body a sort of membranous wing, and 
 on the right side this prolongation curves 
 into a small canal, through which water 
 is introduced into the branchial cavity. 
 Many species are found in fresh waters 
 in the United States. A common species, 
 the Palvdina vivi'para, so called because 
 its young are born alive, is marked by 
 
 purplish longitudinal bands, and the shell is greenish ; it abounds 
 
 in the standing waters of France. 
 
 39. The LITTORINA do not differ much from the Paludinse, 
 except that they have a thicker shell, 
 
 and inhabit the sea. The Vigneau, or 
 Turbo littoreusi the shell of which is 
 round, of a brown colour, streaked with 
 black, belongs to this genus ; it abounds 
 on the coast of France, where it is eaten 
 by the natives. 
 
 40. The MONODONS are distinguished 
 from the littorinse by the presence of a 
 blunt, slightly projecting tooth at the base 
 of the columella. The animal generally 
 bears on each side three or" four filaments, 
 as long as the tentacles, and has the eyes 
 
 supported on peculiar pedicles. A small species, the Trochus 
 tesselatvs, with a brown shell, spotted whitish, abounds on the 
 coasts of France. 
 
 Fig. 50. 
 
 LITTORINA VIGNEAU. 
 
 37. What is the characteristic of the Hemi'cyclo'stoma ? 
 
 38. What are the characters of the genus Paludi'na ? (Paludina, formed 
 from the Latin palus, a marsh.) 
 
 39. What are the characters of the genus Littorina ? 
 
 40. What are -the characters of the genus Monodon? 
 
 5 
 
50 
 
 PHASIANELLA. AMPULLARIA. MELANIA. 
 
 Fig. 51. 
 
 PHASIANELLA P1CTA. 
 
 41. The PHASIANELLA (jig. 51) have an 
 oblong or pointed shell ; the aperture is higher 
 than it is wide, and furnished with a strong 
 operculum ; the base of the columella is flatten- 
 ed, but there is no umbilicus. These animals 
 inhabit the Indian Ocean, and their shells are 
 much sought after by collectors, on account of 
 the beauty of 
 their colours. 
 
 42. The 
 shell of the 
 AMPULLARIA 
 (Jig. 52) is 
 round, ventri- 
 cose, with a 
 
 short spire, as in most of the 
 
 Helices ; the aperture is higher 
 
 than it is wide, and provided with 
 
 an operculum ; the columella is 
 
 umbilicated. The Ampullarise 
 
 inhabit the fresh or brackish 
 
 waters of hot countries. Many 
 
 species are found in the United 
 
 States. 
 
 43. The shell of the MELANIA (fig. 53) 
 has the aperture higher than wide, and it 
 enlarges opposite to the spire ; the colu- 
 mella has neither plicae (folds) nor umbili- 
 cus ; the length of the spire is very various. 
 The animal has long tentacles, the eyes be- 
 ing at about one-third of their length, on 
 the external side. The Melaniae inhabit 
 fresh-water rivers ; a number of species is 
 met with in the United States. 
 
 44. The JANTHiTfjE (fig* 54) resemble 
 snails in the general form of their shell, but 
 
 Fig. 52. AMPULLARIA. 
 
 Fig. 53. MELANIA. 
 
 differ considerably from the different mollusks we have described 
 
 41. How is the genus Phasiane'lla characterized ? (Phasianella, from 
 the Greek, Phasianos, a pheasant, because this shell bears some resem- 
 blance to the pheasant in its colours.) 
 
 42. How is the genus Ampulla'ria recognised ? 
 
 43. What are the characters of the genus Mela'nia ? (Melania, from the 
 Greek, melas, black.) 
 
 44. What are the characters of the genus Janthi'na ? (Janthina, from the 
 <5re<?k ianthon, violet colour.) 
 
JANTHlftA. NERITA. 51 
 
 in the form of the animal. It has no oper- 
 culum, but carries on its foot a substantial 
 vesicular organ, which resembles froth bub- 
 bles, which hinders it from crawling, but en- 
 ables it to float on the surface of the water. 
 Its head is in the form of a trunk, and has a 
 forked tentacle on each side. The common Fi Z' ^.-J 
 species Janthinafragilis with a very thin violet-coloured shell, 
 is very common in the Mediterranean, and the seas of all warm 
 regions. Great numbers of them are frequently met with in per- 
 fectly calm weather floating on the surface of the ocean. When 
 the animal is touched, it ejects a deep violet-coloured liquor, which 
 dyes the water all round it. The vesicular or froth-like buoy is 
 about three times the size of the animal ; it is in the form of a 
 cone, projecting from one side. 
 
 45. The NERIT^E are distinguished by 
 the columella being a straight line, which 
 makes the aperture of the shell either 
 semi-circular or semi-elliptical. They 
 are divided into Natica^ in which the shell 
 is umbilicate (fig. 20, page 34) and the 
 operculum horny ; into Nerita, properly 
 so called, in which the shell is not umbili- 
 cate, thick ( fig. 55), and the operculum Fi %' 55 ' 
 stony, and into Neritina, in which the N **' PELORONTA ' 
 shell is also without an umbilicus, very *'"* j 
 thin, and the operculum is horny. The last live in fresh waters. 
 
 45. How is the genus Neri'ta distinguished ? 
 
FAMILY OF BUCCINOIDES. 
 
 LESSON IV. 
 
 FAMILY OF BUCCINOIDES. Buccinum Buccinum properly so 
 
 called Harpa Purpvra Cassis Cerithium Murex 
 
 Strombus Voluta Ovula Cypr&a Convs. 
 FAMILY OF PECTINIBRANCHIATA CAPULOIDA. Pileopsis 
 
 Hypponyx Crepidula Calyptraa Siphonaria Siga- 
 
 retus. 
 
 ORDER OF GASTEROPODA TUBULIBRAWCHIATA. 
 ORDER OF GASTEROPODA SCUTIBRANGHIATA. Haliotis Fis- 
 
 surella Emarginula . 
 ORDER OF GASTEROPODA CYCLOBRANCHIATA. Patella ~ 
 
 Chiton. 
 
 ORDER OF GASTEROPODA INFEROBRANCHIATA. 
 ORDER OF GASTEROPODA TECTIBRANCHIATA. Pleurobran* 
 
 chus Aplysia Dolabella Bullea Bvlla. 
 ORDER OF GASTEROPODA NUDIBRANCHIATA. Eolidia 
 
 Glaucus. 
 
 ORDER OF GASTEROPODA HETEROPODA. Carinaria. 
 CLASS OF MOLLUSCA PTEROPODA. Clio borealis. 
 
 1. In the FAMILY OF BUCCINOIDES, the shell is spiral, and in 
 its aperture, near the extremity of the cohimella, there is a canai 
 or notch, serving for the passage of the syphon or respiratory 
 tube (fg. 56), which is formed by a fold of the mantle, ana 
 destined to afford the animal the power of breathing, without 
 going out of its shell. This family is divided into three tribes, 
 namely : Buccinum, Murex, and Angiostoma. 
 
 2. The TRIBE OF BUCCINUM comprises all the Buccinoides in 
 
 which the shell is with- 
 out a plica (fold) in its 
 columella, but is fur- 
 nished with a notch or 
 short canal inflected 
 towards the left, and its 
 aperture is very large. 
 The foot of these mol- 
 lusks is generally of 
 Fig. 56.-voLUTA. moderate length, and 
 
 rounded in front (jigs. 33 and 34.) The mantle is unprovided 
 with fringe, and is prolonged anteriorly into a long canal, which 
 
 1. What are the characters of the shell in the family of Buccinoides ? 
 Into how many tribes is this family divided ? 
 
 2. How is the tribe of Buc'cinura characterized ? (Buccinum, Latin a 
 trumpet) 
 
BUCCINUM. NASSA. HARPA. 
 
 53 
 
 is always uncovered. The mouth is armed with a trunk, and 
 there is generally a small horny operculum. 
 
 3. The BUCCINUM PROPERLY so CALLED 
 (jig. 57), has an oval, elongated shell, the 
 aperture of which is oval, notched, and with- 
 out a canal. The operculum is complete, and 
 these animals have no veil on the head like 
 the Cerita. A great many species are known. 
 Lamarck describes fifty-eight species. 
 
 4. We give the name of 
 
 NASSA to mollusks that differ 
 
 very little from the preceding, 
 
 but in which the columella of 
 
 the shell, in place of being 
 
 convex and naked, is covered by BUCCINUM UNDATUM. 
 
 a plate of greater or less thickness (Jig. 58). Dolium 
 
 also belongs to this tribe, arid is 
 
 remarkable for the length of its 
 
 trunk and the size of its foot. 
 
 It is without operculum, and 
 
 the shell is recognised by being 
 almost globose, very ventricose and fur- 
 nished with projecting ribs, which follow 
 the direction of the whorls of the spire, 
 and make the margin of the aperture un- 
 dulated (Jig- 59). A very large species is 
 found in the Mediterranean. Fig. 59. DOLIUM 
 
 Fig. 57. 
 
 Fig. 58. 
 
 NASSA. 
 
 b 
 
 Fig. 60. HARPA. 
 
 5. The HARPS Harpa 
 
 have a more oval shell, 
 furnished with projecting ribs 
 parallel with the margin of 
 the aperture, and differ from 
 the preceding in the form of 
 their foot (fig. 60). 
 
 6. The PURPURA is fur- 
 nished with an operculum, 
 like the Buccinum properly so 
 
 Explanation of Fig. 60. Harp : a. the shell ; 6. the foot of the animal ; 
 c. the tentacles ; d. the syphon. 
 
 3. What are the characters of the Buccinum properly so called ? 
 
 4. What are the characters of the genus Nassa? (Nassa, Latin, a net). 
 What are the characters of Do'lium ? (Dolium, Latin, tub, a tun). 
 
 5. How is the Harp characterized ? 
 
 6. What are the characters of the genus Pir'pura ? (Purpura, Latin, 
 purple.) 
 
 5* 
 
54 
 
 CASSIS. TEREBRA. CERITHIUM. 
 
 called, which it very much resembles. The shell is ovate, thick, 
 most frequently tuberculated, and characterized by its flattened 
 columella, which is trenchant towards the end opposite to the 
 spire, and forming, at that point with the external margin of the 
 aperture, an unprojectmg canal. 
 
 CASSIS. 
 
 Fig-. 62. 
 
 Fig. 61. 
 
 7. The HELMET CASSIS (figs. 34, 61, 62) also very 
 much resembles the ordinary Buccinum ; but their shell, which 
 is ovate, with a short, slightfy projecting spire, is furnished with 
 a transversely wrinkled plate, covering the 
 columella, like the Nassa. The aperture, 
 sometimes oblong, sometimes straight, is 
 also wrinkled externally, and its notch termi- 
 nates in a little short canal which is curved 
 backwards. 
 
 6. The TEREBRA differs still less from the 
 Buccinum properly so called : it is distin- 
 guished from it only by the elongation of its 
 spire. 
 
 9. The CERITHIUM (fig. 63), the shell of 
 which is turreted, like that of the Terebra, but 
 furnished with a short canal curved to the left 
 or backwards, also differs from other Buccina 
 by having a veil above the head : this animal 
 has but a single branchia. Some of the mol- 
 lusks of this genus inhabit the sea, and others 
 Fig. 63. f resn water - A g reat man Y living species are 
 
 CERITHIUM ALUCO. known ; but they were formerly more abun- 
 
 7. What are the characters of the genus Cassis? (Cassis, Latin, a 
 helmet.) 
 
 8. How is Terebra distinguished from Buc'cinura ? (Buccinum, Latin, 
 a trumpet, a shell- fish.) 
 
 9. What are the characters of Cerithium ? 
 
MUREX. FUSUS. STROMBUS. 
 
 55 
 
 dant than in our day ; for, in certain formations, such as the 
 calcareous tertiary of the environs of Paris, an immense number 
 is found in the fossil state. 
 
 10. In the TRIBE OF MUREX, the aperture of the shell is 
 always prolonged into a canal, either straight or inflected 
 (Jig. 64). The animals themselves very closely resemble 
 those of the tribe of Buccinum ; they have a trunk, no veU. 
 on the head, the right edge of 
 the mantle furnished with lobes or 
 filaments, and a horny operculum. 
 They are all carnivorous and inhabit 
 the sea. They are subdivided, ac- 
 cording to the form of the shell, 
 into Murex properly so called, 
 Fvsus, Strombus, &c. 
 
 11.. The Mu rices properly so 
 called are distinguished by their shell, 
 the canal of which is projecting and 
 straight, and the whorls are furnish- 
 ed with transverse elevations, in 
 form of varices or ridges, which 
 often present spines, or ramified and 
 slashed plates, or lamellae. 
 
 12. The Fusus has a canal 
 formed like the common Murex; 
 but the shell is without varices, that 
 is, longitudinal ribs. 
 
 Fig. 64. MUREX. 
 
 13, The STROMBUS has a shell in which the 
 canal is straight or curved to the right, and its 
 external edge expands with age, and this canal 
 presents a sinus (hollow) behind, in which 
 the head lodges, when the animal extends 
 itself. In the STROMBUS PROPERLY so 
 CALLED, the sort of wing formed by this prolon- 
 gation of the margin of the shell is entire (Jig. 
 65), while, in the PTEROCERA, it is divided, in 
 the adult, into long and slender digitations. 
 
 Fig. 65. 
 
 STROMBUS, 
 
 10. How is the tribe of Mu'rex characterised ? (Murex, Latin, a shellfish.) 
 
 11. How are Mu'rices properly so called distinguished ? 
 
 12. What are the characters of Fusus ? (Fusus, Latin, a spindle.) 
 
 13. What are the distinguishing characters of Strom/bus? (Strombus, 
 Latin, name of a shellfish.) 
 
56 
 
 VOLUTA. OLIVA. OVULA. 
 
 All have the aperture of the shell very narrow (Jig. 
 
 66), a disposition approaching to the characteristic of 
 
 the following tribe. 
 
 14. In the TRIBE OF ANGIOSTOMA, the aperture 
 
 is generally so narrow that, to enter it, the foot of the 
 
 animal is obliged to be doubled. 
 
 In some, designated under the com- 
 mon name of VOLUTES Valuta the 
 aperture, which is of various forms, is 
 terminated by a notch without a canal, 
 and thecolumella is marked by oblique, 
 projecting plicee (folds), (fg. 67) : they are sub- 
 divided into VOLUTES PROPER (fg> 56, page 52), 
 in which the aperture is wide, and the columella 
 is marked by some large plica?, and the last 
 whorl of the spire is sometimes ventricose, some- 
 times conical ; in the MITRA the spire is in 
 general pointed and elongated, and in OLIVA, so 
 called from the oblong or ellipsoid form of the 
 shell, the aperture is long, narrow, and notched 
 opposite to the spire, and the columeila is marked 
 by numerous plica? (fig- 67). 
 
 16. In others the shell is oval, the spire is 
 concealed, and the aperture, which is long and 
 narrow, has no plicce on the side of the columella, 
 
 but presents a notch or canal at its two extremities j these are 
 
 the OVUL^E (fg. 68). 
 
 Fig. 67. 
 
 OLIVA. 
 
 Fig. 68. OVULA VOLVA. 
 
 17. In others again, the CYPRJE.E (PORCELANA), the shell, 
 which is protuberant in the middle, and almost as much con- 
 
 14. What is the peculiarity of the tribe of Angio'stoma ? (Angiostoma, 
 Greek, apgeion, a vessel, and stoma, mouth.) 
 
 15. What are the characters of Volu'ta ? (Voluta, Latin, a wreath.) 
 What is the character of Oli'va ? (Oliva, Latin, an olive.) 
 
 16. What are the characters of the genus O'vula? (Ovula, from the 
 Latin, owwm, an egg.) 
 
 17. What are the characters of the genus Cyprae'a ? (Cypreea, Latin, 
 a cowry. 
 
CYPR^A. CONUS. 
 
 57 
 
 tracted at the two extremities, has a very narrow aperture, trans- 
 versely wrinkled on both sides ; when the animal expands it- 
 self, the mantle extends over the shell and envelopes it entirely 
 
 (fig. 69), which, in the 
 progress of time, pro- 
 duces considerable mo- 
 dification in the colours 
 of the latter ; for, at a 
 certain period, it depo- 
 sits new layers of calca- 
 reous matter, not only 
 
 F i g , GQ.-CYPR^A. around the aperture, but 
 
 also upon the whole external surface of this solid envelope. 
 
 18. Also to this tribe of mollusks belongs the 
 genus CONUS (fig. 70), which differs from all the 
 preceding in the conical form of the shell, which 
 gives the genus its name ; a slightly, or not at all 
 projecting spire, forms the base of this cone, and the 
 aperture, which is nearly straight, extends from one 
 end of the shell to the other. 
 
 19. A great number of the shells, the principal 
 characters of which we have briefly noted, are re- 
 markable for the elegance of their form and the 
 beauty of their colours; the Cones, the porcelain 
 shells (CypraBa), the Volutes, and the Olives especial- 
 ly, are much admired for the brilliance of their mark- 
 ings. Many other mollusks of the family of Buccinoides are also 
 worthy of attention on account of the viscid liquid, secreted by 
 the gland placed, as we have already seen in the snails, betwixt 
 the heart and rectum. And in a considerable number of these 
 animals, this humour has the property of changing colour when 
 exposed to the action of air and light, and thus passes from 
 greenish yellow to purple ; spread upon stuffs, it imparts to them 
 this rich shade, and appears to be the material employed by the 
 ancients for producing their beautiful purple dyes. Pliny relates 
 that on the shores of Tyre, and many other points along the 
 coasts of the Mediterranean, there are found two genera of shells, 
 called Buccinum and Purpura, both of which furnished dye for 
 the colours termed purple and conchilian. The first of these 
 mollusks appears to be the Buccinum lapillus, and the second 
 the Murex brandaris (fig. 64) ; but the quantity of colouring 
 
 Fig. 70. 
 
 1 8. What are the characters of the genus Co'nus ? (Conus, Latin, a 
 cone.) 
 
 19. What animals are supposed to yield the purple dye which was cele- 
 brated among the ancients ? . 
 
58 
 
 CAPULUS. HIPPONYX. CREPIDULA. 
 
 matter these animals yield is so small, it is difficult to explain 
 how they could furnish so active a trade ; and it must have been 
 that the ancients used for the same purposes the purple liquid 
 secreted by larger and more common mollusks, such as the 
 aplysi<E) which we have yet to mention. 
 
 20. The FAMILY OF PECTINIERANCH CAPULOIDES is recog- 
 nised by the shell being widely open, slightly turbinated, and 
 without either notch, syphon, or operculum. The conformation 
 of the animal differs but little from that of other mollusks of the 
 same order ; there is only a single branchia, often with very long 
 filaments, attached transversely -to the arch of the respiratory 
 cavity. 
 
 In this division are arranged the genera of Pileopsis, Hippo- 
 nyx , Crepidula, CalyptrcRd^ Sigaretus, <fyc. 
 
 21. Animals of the genus Pileopsis, or Capulus 
 (fig' ^1)5 have their branchise on the anterior edge 
 of the respiratory cavity ; the shell is conical, and 
 presents at its summit the commencement of a spire; 
 their neck is covered by a membranous plaited veil, 
 and they have two conical tentacles, and a tolerably 
 long trunk or proboscis. They inhabit the sea- 
 shores of warm countries. 
 
 22. The genus of 
 Hipponyx (fig> 72) con- 
 sists of fossil shells, 
 
 which closely resemble the preceding, 
 
 but are very remarkable for a support 
 
 formed by calcareous layers, upon 
 
 which they rest, and which seem to 
 
 have been secreted by the foot of the 
 
 animal. 
 
 23. The CrepididtJB have an oval 
 shell, the whole base of which is 
 half closed by a horizontal plate, 
 which supports the abdominal sac 
 above it, and is covered beneath by 
 the foot (fig. 73). 
 Fig. 73. CREPIDULA. 
 
 20. How is the family of Pectinibranch Capuloi'des distinguished ? 
 (Capuloides, from the Latin, capulus, a hilt or handle, and the Greek, eidos, 
 resemblance.) 
 
 21. What are the characters of the genus Ca'pulus? (Capulus, Latin, a 
 hilt.) 
 
 22. What are the characters of the genus Hippony'x ? (Hipponyx, from 
 the Greek, ippos, a horse, and onux, nail ; horse nail, or hoof.) 
 
 23. What are the characters of the genus Crepi'dula ? (Crepidula, Latin, 
 slipper.) 
 
 72 - HIPPONYX - 
 
CALYPTR^. SIPHONARIA. SIGARETUS. 
 
 59 
 
 Fig. 74. 
 
 CALYPTR^EA. 
 
 24. The Calyptrwce have in the interior of the 
 shell, in form of a hollow cone, a small plate pro- 
 jecting downwards, which seems to be the com- 
 mencement of a columella, and is embraced in a 
 fold of the abdominal sac ; their branchiae are 
 composed of long slender filaments like hairs. 
 In some of them the plate or lamina adheres to 
 the bottom of the cone, being itself bent into a 
 portion of a cone or of a tube, and descending 
 vertically. 
 
 25. The Siphonaria deserve notice, because 
 
 they show how much the organization of mollusks may vary with- 
 out any very striking difference in the form of their shell. Until 
 recently these animals have been ranged with the patella3, to be 
 described in the sequel, which they resemble in their shell, but 
 differ from them very much in the structure of their most im 
 portant organs ; their branchia is composed of a few leaflets 
 transversely attached to the bottom of a respiratory cavity, 
 which is on the back, and communicat- 
 ing externally by a lateral hole in the 
 mantle; they do not appear to possess 
 tentacles, but have a narrow veil on the 
 head. 
 
 26. The genus Sigaretus (fg. 75) 
 has a flattened shell, with a slight spire, 
 arid a very large aperture, which is 
 Fig. 75. SIGARETUS. concealed in the mantle. 
 
 ORDER OF GASTEROPODA TTJETJLIBRANCHIATA- 
 
 27. Tubulibranch gasteropods are very analogous to the 
 pectinibranch gasteropods, but are distinguished from them by 
 very important differences in the organization of some of their 
 organs, and in the structure of their shell, which is fixed to sub- 
 marine bodies, and is in the form of a more or less irregular tube, 
 the commencement of which only is spiral. It is divided into the 
 genera Vermetus, Magilus, and Siliquaria. 
 
 24. What are the characters of the genus Calyptrse'a? (Calyptrse'a, 
 from the Greek, kaluptra, a hood.) 
 
 25. What are the characters of the genus Siphona'ria ? 
 
 26. What are the characters of the genus Sigare'tus ? 
 
 27. How are the tubu'libranch distinguished from the pecti'nibranch 
 gasteropods^? (Tubu'libranch, from the Latin, tubulus, a little tube, and 
 branchiae, gills). 
 
60 
 
 HALIOTIS. FISSURELLA. 
 
 ORDER OF GASTEROPODA SCUTIBHANCHIATA. 
 
 28. In the general form of their body and the position of 
 their branchice, the scutibranch resemble the pectinibranch 
 gasteropods ; but they differ from the latter in their anatomical 
 and physiological characters. Their shell is very open, slightly 
 or not at all turbinated, and, like a shield, it covers the branchiae 
 or even the whole body. A peculiarity of their internal organi- 
 zation approximates them to the acephalous mollusks ; their heart 
 is traversed by the rectum and receives the blood by two auricles. 
 They aro not numerous, and are divided into Haliotis, Fis- 
 surella^ fyc. 
 
 29. The Haliotides (fig. 76) have a slightly turbinated shell, 
 with a spire so small that it is only seen from the inside : it is 
 flattened and the aperture is very large. In the Haliotides 
 properly so called, there is along the columella a series of holes, 
 
 through which the water reaches 
 a slit on the right side of the 
 mantle, and penetrates to the 
 branchial cavity ; the filiform ap- 
 pendages of the edge of the mantle 
 can be protruded through these 
 holes, and all around the foot there 
 
 Fig. 76. HALIOTIS. 
 
 is a double membrane cut in 
 
 fringes and furnished with long filaments. On the outside of the 
 tentacles we find two cylindrical pedicles, bearing the eyes ; and 
 the mouth is armed with a trunk or proboscis. The external 
 surface of the shells of these mollusks are not remarkable ; but 
 internally they are covered by a layer of nacre, of the richest and 
 most beautifully iridescent colours. They are found in great num- 
 bers on the rocky shores of California. o 
 30. The Fissurella, \. 
 
 (fig- 77 ) are rec .g- 
 nised by their conical 
 shell placed upon the m 
 middle of the back, and p 
 pierced at its summit 
 by a small opening 
 
 which serves to give 
 
 Fig. 77. FISSURELLA. 
 
 Explanation of Fig. 77. p. the foot of the animal ; m. the mantle ; 0. 
 the opening at the apex of the shell, and the anus. 
 
 28. What are the characters of the scuti'branch ga'steropods ? (Scuti- 
 branch, from the Latin, scutum, a shield, and branchiae, gills.) 
 
 29. What are the characters of the Halio'tides ? (Haliotides, from the 
 Greek, als, the sea, and ous, ear ; sea-ear, or haliotis, and eidos, resemblance.) 
 
 30. How is the genus Fissure'lla recognised ? XFissurella, Latin, Fis- 
 ura, a slit.) 
 
EMARGINULA. PATELLA. 
 
 61 
 
 passage to the air necessary for respiration, and also for the ex- 
 pulsion of the excrements. 
 
 31. We give the name of Emarginula to mollusks very much 
 like the Fissurellse, but their shell, m 1 place of being open at the 
 top, presents a slit or notch in front, communicating with the 
 branchial cavity. 
 
 ORDER OF GASTEROPODA CYCLOERAI'TCHIATA. 
 
 32. The cyclobranch gasteropods closely approximate the pre- 
 ceding, either in their general form, or in the disposition of their 
 internal organs ; but they are distinguished by their branchiae 
 being fixed around the edges of the mantle (Jig. 78). 
 
 38. Some, the Patella 
 (fg. 78), for example, are 
 provided with a broad-based, 
 conical shell, which covers 
 the whole body ; they very 
 much resemble the Fissurel- 
 lae and Emarginulse, but the 
 shell is not perforated at the 
 apex, nor is there a notch in j i 
 front as in the latter. The 
 head is furnished with two 
 pointed tentacles, having the 
 eyes at their base, and a 
 stout trunk ; the anus is 
 situate to the right, and a 
 little above the head, and the 
 branchiae are composed of 
 
 Fig. 78. PATELLA. 
 
 leaflets or fringes, arranged in a row around the body, under the 
 edges of the mantle. Patellse are found in almost all parts of the 
 world ; they are found on rocks to which they adhere, and lie 
 completely concealed beneath their shell, even after they are left 
 by the ebbing sea. 
 
 Explanation of Fiy. 78. The animal of the patella seen from below ;e. 
 the edge of the shell ; p. the foot ; m. the mantle ; b. the branchiee ; t. 
 the "head. 
 
 31. How does the genus Emargi'nula differ from Fissure'lla? (Emargi- 
 nula, from the Latin, e, from, and margo, marginis, the margin from 
 the margin notched.) 
 
 32. How are cy'clobranch ga'steropods distinguished ? (Cyclobranch, 
 from the Greek, kuklos, a wheel, and bragchia, gills.) 
 
 33. What are the characters of the genus Pate'lla? (Patella, Latin, 
 knee-pan. 
 
 6 
 
CHITON. 
 
 34. Other cyclobranch gastero- 
 pods, called Chiton (fig. 79), differ 
 from all mollusks, in the nature of 
 their shell, which, instead of a tur- 
 binated or shield-like piece, is com- 
 posed of a row of testaceous and 
 symmetrical scales, generally eight 
 in number, let into the mantle, and 
 occupying the middle line of the 
 back. The edges of this mantle, 
 thus protected, are also very 
 leathery, and often furnished with 
 little scales, spines, or hairs. A 
 membranous veil placed over the 
 mouth, takes the place of tentacles ; 
 the branchiae are composed of 
 Fig. 79. CHITON. lamellar pyramids, arranged on each 
 
 side, beneath the edge of the mantle ; the anus is at the posterior 
 extremity of the body. Chitons most abound on the shores of 
 tropical seas. 
 
 ORDER OF GASTEROPODA INFEROBRASSTCHIATA. 
 
 35. The order of Inferobranch gasteropods is composed of a 
 very small number of naked mollusks, characterized by their 
 branchia3, consisting of a long series of leaflets, placed on each 
 side of the body, between the foot, and the advanced edge of the 
 mantle. Like the preceding, they are marine, and differ from 
 them, not only in the absence of every vestige of shell, but also 
 in some points of their internal anatomy, which approximate 
 them to the gasteropods. They are divided into PHYLLIDIA 
 (from the Greek, phullon, a leaf), in which the anus is posterior 
 to the mantle, and the head is furnished with four tentacles ; 
 and into DIPHYLLIDIA (from the Greek, dis, two, and phullon^ 
 leaf), in which the anus is on the right side, and the head has a 
 pointed tentacle, and small tubercle on each side. In all of them, 
 the body is oval, or more or less tuberculous. 
 
 ORDER OF GASTEROPODA TECTXBHANCHIATA. 
 
 36. The Tectibranch gasteropods are, like the preceding, ma- 
 rine mollusks, but their branchiae are not symmetrical ; they 
 
 34. What are the characters of the genus Chi'ton ? (pronounced Icy-ton.) 
 (Chiton; Greek, a garment.) 
 
 35. How are the In'ferobranch ga'steropods characterized ? (Infero- 
 branch ; from the Latin, inferus, below, and branchiae, gills.) 
 
 36. What are the characters of the tecMlbranch gasteropods ? (Tecti- 
 branch ; from the Latin tego, I cover, and bronchia, gills.) 
 
PLEUROBRANCHUS. APLYSIA. 
 
 t 
 
 . SO.-PLEUROBRANCHUS. 
 
 are composed of leaflets, 
 more or less divided, at- 
 tached along the right side 
 (fig. 80, br), or on the 
 back (fig. 81), and more 
 or less covered by the 
 mantle, which almost al- 
 ways encloses a small 
 shell in its thickness. 
 Their form is very variable. They are divided into Pleurobran- 
 chus, Pleurobranchides, Aplysia, Dolabella, Akera, &c. 
 
 37. The PLEUROBRANCHI are mol- 
 lusks of an oval form ; in which the 
 
 t branchiae are fixed on the right side, 
 between the mantle and foot (Jig. 80). 
 y The mouth is in the form of a proboscis 
 t or trunk, and is surmounted by a small 
 triangular veil, and two tentacles; they 
 have four stomachs, the second one of 
 which is sometimes armed with bony 
 pieces, and the anus opens behind the 
 branchise. One species, of a lemon 
 yellow colour, is found on the coasts of 
 France. 
 
 38. The APLYSUE, which the ancients 
 called sea-hares, have a very singular 
 form ; the body resembles that of a 
 sort of Limax ; but the edges of the 
 foot, erected in flexible crests, surround 
 the back and may be even reflected over 
 it. Their head is supported by a neck 
 of greater or less length, and furnished 
 with four tentacles (fig. 81, f), the two 
 upper ones being hollowed like the ears 
 of a quadruped, and placed above the 
 
 eyes (y). The branchiae, in the form of very complicated 
 
 Fig. 81. APLYSIA. 
 
 Explanation of Fig. 80. m. the mantle, raised up to show the branchiae, 
 br ; a. the anus ; b. the mouth and trunk ; v. the veil ; t. the tentacles ; 
 p. the foot. 
 
 Explanation of Fig. 81. , t. the tentacles ; y. the eyes ; m. the mantle ; 
 b. the branchice. 
 
 37. What are the characters of the genus Pleu'robranchus ? (Pleuro- 
 branchus, from the Greek, pleura, side, and bragchia, gills.) 
 
 38. What are the characters of the genus Ap/y'sia? (Aplysia, from 
 the Greek, aplusia, uncleanness.) 
 
64 
 
 DOLABELLA. AKERA. 
 
 6. it~ 
 
 leaflets, are fixed upon the 
 back, by means of a broad 
 membranous pedicle, and 
 ^ covered by a small mantle 
 r (m), in the thickness of 
 which we find a small 
 horny shell. And the anus 
 is situate behind the bran- 
 d chia3. These mollusks live 
 on fucus, and are provided 
 f ]e with an enormous crop, 
 and three other stomachs 
 g (fig. 82, d), the second 
 and third of which are arm- 
 ^ ed internally with sharp 
 hooks, and cartilaginous 
 plates. A particular gland 
 secretes an acrid liquor, and 
 pours it out through an 
 opening situate on the right 
 side. A purple coloured 
 liquid exudes sweats 
 from the edge of the 
 mantle, when the animal 
 contracts, and is sufficient 
 in quantity to dye the 
 water to a considerable distance around it. Several species 
 of Aplysiee, which vary in colour, are found on the coasts 
 of France. 
 
 39. The DolabellcB do not differ much from the Aplysia?, 
 except in the position of their branchia3, and their mantle at the 
 posterior extremity of the body. They are found in the Medi- 
 terranean as well as in the Indian seas. 
 
 40. The Akera (fig. 83) also resemble the Aplysise in the 
 complication and armature of the stomach, as well as in the posi- 
 tion of their branchia3, and several other important points of their 
 organization ; but they are distinguished by their tentacles, which 
 are short, very thick, and so arranged as to form together a 
 
 Fig. 82. APLYSIA. 
 
 Explanation of Fig. 82. Anatomy of the Aplysia : a. the head ; b. the 
 pharynx ; e. oesophagus ; d. the three stomachs ; c. the intestines ; /. 
 the nervous collar surrounding the oesophagus ; g. the heart ; h. the 
 branchise ; i. the liver ; j. the anus ; k. the bladder : I. the ovary. 
 
 39. What is Dolabe'lla 1 (Dolahella, Latin, a little axe or hatchet.) 
 
 40. How are Ake'ras distinguished from the Aplysiae 1 (Akera, from the 
 Gjeek, a, without, and keras, horn.) 
 
NUDIBRANCH GASTEROPODS. 
 
 Fig. 83. BULLA HYDATIS. 
 
 large fleshy shield above the eyes 
 (fig. 83, v). Many of these ani- P 
 mals effuse a purple liquid. Some 
 are entirely unprovided with shell, v~ 
 or have only the vestige of a shell : 
 these are the Akera properly so 
 
 called i others have a shell some- f d 
 
 what rolled upon itself, and with- 
 out a projecting spire or notch, 
 which is concealed in the thick- 
 ness of the mantle ; these form the genus Bullcea ; and there 
 are still others in which the shell, onfy covered by a slight epi- 
 dermis, is more convoluted and sufficiently large to afford 
 a retreat for the animal : these constitute the division of 
 Bvlla. 
 
 ORDER OF GASTEROPODA NUDIBRANCHIATA. 
 
 41. The mollusks composing this group are without a shell 
 and carry their branchiae on some part of the back (fig* 84). 
 The structure of some of their internal organs approximates 
 them to the Pulmonea, the Inferobranchiata, and the Tectibran- 
 chiata ; they all inhabit the sea. 
 
 Fig. 84.7 EOLIDIA. 
 
 42. Among the genera possessing this kind of organization, 
 we will cite the Doris, the general form of which is nearly the 
 same as that of the Pleurobranchus (fig- 83), and in which the 
 branchise are inserted in a circle around the anus, at the pos- 
 terior part of the back ; the TRITONIA, in which the branchiaB, 
 in form of miniature trees, are attached along the two sides of 
 
 Explanation of Fig. 83. Animal of the Bulla liydatis :c. the shell ; 
 p, p. the two lobes of the foot ; d. posterior part of the foot : v. the sort of 
 veil formed by the union of the tentacles ; a. the anus. 
 
 41. What are the characters of the Nudi'branch gasteropods ? (Nudi- 
 branch ; from the Latin, nudus, naked, and bronchia, gills.) 
 
 42. What are the characters of the genus Glau'cus ? (Glaucus ; from the 
 Greek, glaukos, blue.) What are the characters of the Eolidia ? 
 
 6* 
 
66 
 
 GLAUCUS. C ARIN ARIA. 
 
 the back, and in which the mouth is 
 armed with lateral horny jaws, similar 
 to shears ; the GLATJCUS, remarkable 
 for its blue colour (Jig. 85), in which ;.'._ 
 the branchiae, three pairs in number, 
 are situated in the same manner, but 
 each one is composed of several long 
 fringes, spread like a fan ; and the 
 EOLIDI^E (fig. 84), which resemble 
 small Limaces in form, in which the 
 branchia? are composed of laminse, or 
 leaflets, arranged like scales, more or 
 less crowded together on each side 
 of the back. They are found in 
 every sea. 
 
 Fig. 85. GLAUCUS. 
 
 ORDER OF GASTEROPODA HETEROFODA. 
 
 43. These gasteropods are not organized, like all the pre- 
 ceding, for crawling on the belly, but for swimming only. In 
 fact, their foot, in place of forming a horizontal fleshy disk, is 
 compressed into a vertical membranous plate, which is used as a 
 fin. Their body is formed of a transparent, gelatinous sub- 
 stance, and their branchiae are placed on the posterior part of the 
 back. 
 
 The principal genera of this group are the CARINARIA and 
 
 FlOROLA. 
 
 ye br c 
 
 p v 
 
 Fig. 86. CARINARIA MEDITERRANEA. 
 
 Explanation of Fig. 86. 6. the mouth ; t. the tentacles ; y. the eyes ; 
 e. the stomach ; f. the liver ; c. the shell ; br. the branchiae ; p. the foot ; 
 v. a small sucker situate on the side of the foot. 
 
 43. What are the characters of the Heteropo'da ? (Heteropoda ; from the 
 Greek, eteros, various, and pous> foot.) 
 
PTEROPODA. 
 
 67 
 
 44. The CARINARI^E have the abdomen (that is to say, a 
 kind of sac enclosing the heart, the liver and some other organs) 
 covered by a symmetrical and conical shell, the apex of which 
 is curved backwards, and the anterior edge covers the base of the 
 branchiae (Jig. 86, br}. There is one species in the Mediterra- 
 nean, but three have been discovered. 
 
 The FIOROLJE have no shell, but, in other respects, very much 
 resemble the Carinarise. 
 
 CLASS OF MOLLTJSCA PTEROPODA. 
 
 45. The mollusks composing this group 
 are organized for swimming only: they 
 possess no organ by means of which they 
 can crawl, or even attach themselves to 
 submarine bodies, but continually float in 
 the sea, and move by the assistance of fins, 
 placed like wings on each side of the mouth 
 (fg. 87). They are all of small size, 
 and most of them inhabit the seas of warm 
 countries ; but they arc also found in the 
 neighbourhood of the poles. The Clio 
 borealis, for example, abounds so exten- 
 Fig. 87 HYALEA. sively in the arctic regions, that, in spite 
 of their very small size (scarcely an inch long), they become, 
 in certain seasons, the ordinary food of whales. Their form 
 varies much : some of them are naked ; others are provided with 
 a shell. They constitute several genera, the principal of which 
 are the Clio, Hyalea, Cleodora, Cymbulia, &c. 
 
 44. What are the characters of the genus Carina'ria ? (Carinaria ; from 
 the Latin, cari'na, a keel.) 
 
 45. How are the Pte'ropoda characterized ? (Pteropoda ; from the Greek, 
 pteron, wing, and pous, foot.) 
 
LAMELLIBRANCH MOLLUSKS. 
 
 LESSON V. 
 
 CLASS OF MOLLUSCA ACEPHALA, or, LAMELLIBRANCHIATA. 
 
 Organization Classification. 
 FAMILY OF OSTRACEA. Classification Oysters Gryphcea 
 
 Pecten Lima Malleus Anomia Spondylus Perna 
 
 Etheria A vicula Pearls Pearl fishery Pinna .Area 
 
 Pectunculus Trigonia. 
 FAMILY OF MYTILACEA. Mussels (Mytilus) ModioZws Ano- 
 
 donta Unio. 
 FAMILY OF CHAMACEA. Tridacna Chama Isocardia. 
 
 CLASS OF 1MOLLT7SCA LAMELLIBRANCHIATA. 
 
 1. All the mollusks we have heretofore considered have a dis- 
 tinct head ; those we have yet to mention are without this part, 
 and their whole organization is of the simplest kind. The 
 mouth is always concealed at the bottom of the mantle, or be- 
 tween its folds : they hfave neither teeth nor eyes. The nervous 
 system is very simple, and the organs of locomotion are very 
 incomplete or lamellibranch. 
 
 2. In animals which form the class of acephalous mollusks 
 (called by Lamarck Mollusca conchifera), the mantle is very 
 large and folded in two, so as to enclose the body, as the leaves 
 of a book are enclosed by its covers. Sometimes these two leaves 
 are free at their inferior edge, sometimes united so as to con- 
 stitute a tube (fig* 88, ts, ti). A shell, composed of two 
 pieces, called valves, covers this mantle entirely or in part, and 
 at its superior part there is a hinge furnished with an elastic 
 ligament, the play of which causes the valves to gape whenever 
 the muscles (ma, mp), which extend from one valve to the other, 
 do not contract so as to keep them shut. The branchiae (br) 
 are in form of great leaves, transversely and regularly striated ; 
 they are always four in number, and placed between the in- 
 ternal face of the mantle (or pallial membrane) and the body of 
 the animal. The mouth is at one. of the extremities of the body, 
 and has on each side of it two small triangular bodies (), 
 which are formed by the extremities of the lips and serve as 
 tentacula ; the stomach, liver, and other viscera, are lodged 
 between the mouth and anus, and beneath the heart (co), 
 which is situate on the back ; and the lower part of the body 
 
 1. What is the distinguishing feature of the lamellibra'nch mollusks? 
 (Lamellibranch ; from the Latin, lamella, a thin plate, and bronchia, gills.) 
 
 2. What are the general characters of acephalous mollusks ? (pronounced 
 a-Jcef-alus ; from the Greek, a, without, and kephalc, head. 
 
ANATOMY OF A MACTRA. 
 
 Fig. 88. ANATOMY OF A. MACTRA. 
 
 Explanation of Fig. 88. Anatomy of a rnactra ; one valve of the shell, 
 the corresponding half of the mantle and the branchiae have been removed 
 on the left side : c. the shell ; wi. the mantle ; ma. the anterior muscle ; 
 mp. the posterior muscle ; b. the mouth; t. the tentacle; e. the sto- 
 mach; as. appendix of the stomach ; i. the intestines ; /. the liver ; p. 
 the foot ; co. the heart traversed by the rectum (r) ; ts. the superior tube 
 into which the anus (a) opens ; ti. the inferior or respiratory tube ; br. the 
 branchiae of the right side ; ga. the anterior ganglia ; na. nerves arising 
 from them; ng. inter-ganglionic nerves; gp. posterior ganglia; np~ 
 nerves arising from them and distributed to the mantle. 
 
70 
 
 DIVISION OF TH, ACEPHALA. 
 
 is almost always prolonged into a fleshy mass (/?), called the 
 ) which serves for motion, and sometimes has at its base a 
 undle of horny threads, called byssus> by means of which the 
 animal fixes itself to submarine bodies. 
 
 3. This class is divided into five great families, which may be 
 recognised by the following characters : 
 
 (FAMILIES.) 
 
 f having the mantle open, and without tubes or particular \ ^ 
 apertures. \ 
 
 open in front, and having"} 
 
 but one separate aperture U YTILACEA< 
 
 for the escape of excre- I 
 
 fnent. J 
 
 
 r not prolonged 
 
 
 so as to form 
 
 
 tubes. The " 
 
 having the 
 
 mantle 
 
 mantle 
 
 
 closed be- 
 
 
 hind, so as 
 
 
 to form par- < 
 
 
 ticular 
 
 
 , openings. 
 
 
 
 prolonged so 
 
 
 as to form two 
 
 
 tubes. The " 
 
 
 mantle 
 
 closed and pierced by 
 three apertures, the first 
 of which serves for the 
 passage of the foot, the 
 second for respiration, and 
 the third for the exit of 
 excrement. 
 
 CHAMACEA. 
 
 open in front and present- J CARDIACEA> 
 ing two tubes behind. ^ 
 
 closed, and not having, in "j 
 front or below, but a single I 
 opening for the passage of > INCLUSA. 
 the foot, and behind, two j 
 tubes. 
 
 4. The FAMILY of OSTRACEA has the oyster for its type, 
 and is composed of a great number of mollusks, that are 
 entirely without a foot, or having a very small one only, and 
 which, for the most part, live attached to submarine bodies, 
 either by their shell or by their byssus. The mantle is open 
 behind as well as in front, and its two lobes are nowhere united 
 to form particular openings, as we have remarked in all other 
 acephala. 
 
 5. This group is divided into two tribes, according as there 
 is a single muscle, going from one valve to the other, or two 
 
 3. Into how many families is the class of lamellibranch mollusks divided ? 
 
 4. What are the characters of the family of Ostra'coa ? (From the Latin, 
 ostrea, an oyster.) 
 
 5. What is the distinguishing character of the tribe of Mono'mya'ria ? 
 (Mono'mya'ria. From the Greek, monos, single, and rawon, muscle.) How 
 is the tribe of Di'mya'ria distinguished ? (Di'mya'ria. From the Greek, 
 dis, two, and mudn, muscle.) 
 
OYSTERS. 
 
 71 
 
 of these organs, one placed near the anus and the other in front 
 of the mouthf, an arrangement which exists in nearly all other 
 acephala. The first tribe, in which there is but one muscle, is 
 called Monomyaria, and the second Dimyaria. 
 
 6. To the first of these divisions belong the OYSTERS,- 
 Ostrea. The shell of these mollusks is irregular, laminated, and 
 composed of two unequal valves, united by a short ligament 
 lodged at either extremity in a pit, and the hinge is without teeth 
 or projecting lamina. The structure of the animal itself is 
 
 
 c a 
 
 Fig. 89. ANATOMY OF AN OYSTER. 
 
 very simple. Its mantle, the lobes of which are united above 
 near the hinge (6), has a double fringed border : there is no 
 appearance of foot. The adductor muscle (e) of the valves (com- 
 monly called the heart), is situate near the centre of the body, 
 and the heart (Z), instead of being placed as usual on the back, 
 
 Explanation of Fig. 89. Anatomy of an oyster ; a. one of the valves of 
 the shell ; 6. the hinge ; c. mantle of the left side ; d. portion of tho 
 right lobe of the mantle ; e. the muscle ; f. the mouth ; g. the labial 
 tentacula ; h. the liver ; i. the intestine : j. the anus ; k. the branchiae ; 
 /. the heart. 
 
 6. What are the characters of the family of Ostracea? Where are oysters 
 found? 
 
72 OYSTERS. 
 
 is found between this muscle and the mass of the viscera, where 
 it is readily distinguished by the brown colour of its*auricle ; the 
 mouth is concealed under a sort of hood, formed by the union of 
 the upper portion of the two lobes of the mantle; the tentacles, 
 which surround this opening, closely resemble the branchiae, 
 which are large and cover the whole abdomen; and the anus is 
 seen above the muscle. All these mollusks have an ovary and 
 produce eggs, which, at the time of laying, are extremely small 
 and suspended in a whitish liquid, the appearance of which is 
 analogous to that of minute drops of tallow. This spawn 
 floats on the water and soon adheres to neighbouring shells or 
 some other submarine body : and the young oysters are always 
 adherent, either to each other or to an adult oyster or to the rocks 
 on which they live ; but, in the first case, they generally detach 
 themselves as they advance in age, and form extensive masses 
 which are called beds or banks. Their growth is very rapid. 
 We are assured that at the end of three months after being 
 spawned, they are of the size of a quarter of a dollar, and at 
 the end of the first year, they are about two inches in diame- 
 ter ; and in three years they attain to about three inches in 
 length. Nothing is precisely known of the duration of their 
 existence. 
 
 7. Many species of oysters are described : the most interest- 
 ing and most extensively diffused is the Ostrea edulis the 
 edible oyster ; it affords us a wholesome and agreeable article of 
 diet, and its consumption has been immense since the remotest 
 antiquity. These mollusks are ordinarily found in great 
 numbers together, forming beds of considerable extent, situate 
 near sea coasts, in bays or estuaries, or in localities where 
 the sea is not very deep. They are objects of active pursuit, 
 and are caught by means of a kind of rake with a net attach- 
 ed, called a drag, or dredge, which is drawn over the joyster- 
 bed ; or where the water is shallow, they are taklh up by long 
 tongs of a suitable formation : in France, after being caught they 
 are not immediately consumed, but are placed (planted out) 
 in particular basins, where they are kept for a time, and where they 
 fatten and acquire a more delicate flavour. The largest are 
 usually taken from the shell and pickled ; but the others are 
 eaten without preparation, and are esteemed by many only 
 while alive. In fact their preservation for any length of time 
 is prevented by the habit these animals have of closing the 
 shell as soon as they are taken out of the water. When dead 
 their shell remains open. 
 
 7. How are oysters caught 1 
 
GRYPH.EA. PECTEN. 73 
 
 8. European oysters possess a much more decided flavour, a 
 stronger taste, than those of the United States ; Americans, on first 
 eating oysters in London or Paris, commonly complain of their 
 strong coppery taste, and it is not until after several trials they 
 learn to prefer them to our own. The locality of oyster beds 
 exercises a great influence over the taste of the oyster ; within 
 the tropics they are rarely found good, and they are almost un- 
 known in the Pacific Ocean. Oysters taken near the entrance 
 of the Chesapeake and Delaware Bays have a high reputation, 
 and are consumed in great quantities. Norfolk oysters are pro- 
 verbially excellent. 
 
 The markets of Paris and the north of France are chiefly 
 supplied from the bay of Cancale; from which the boats of 
 Houlle, near Cancale, and Granville, carry away more than 
 eighty millions of these mollusks every year, the major part of 
 which are sent to Courseulles and other parts of Normandy, 
 where there are considerable establishments for the parkage 
 (planting out) of oysters, whence they are sent post to Paris. 
 About the beginning of summer these mollusks cast their spawn : 
 at this season it is customary not to eat them, and it is generally 
 believed they are then unwholesome, but this opinion does not 
 appear to be well founded. 
 
 9. We give the name of GRYPHUEA to shells, which for the 
 most part are fossil, and which are very analogous to oysters, 
 but the convex valve is more pro- 
 jecting at the apex or beak, and at 
 
 that point bends into a hook (fig. 90). 
 They are found in very ancient for- 
 mations. There is but one living 
 species known. 
 
 10. The SCALLOPS Pecten (also 
 called the pilgrim's shell, from being 
 
 worn as an ornament by pilgrims) Fl &' 9 ^* GRYP1LEA - 
 
 resemble the oysters in the disposition of the hinge, and may 
 be easily recognised by their inequivalve, semicircular shell, 
 almost always marked by ribs, radiating from the apex of each 
 valve towards their margin, and having on each side of the 
 hinge an angular enlargement called the ear (Jig. 91, e). In 
 some species of Pecten there is a byssus ; but most of these mol- 
 
 8. How do European oysters differ from those of the United States ? 
 
 9. What is the character of the Gryphae'a ? (Gryphsea ; from the Greek, 
 grvpos, incurved.) 
 
 10. What are the characters of the genus Pecten? (Pecten, Latin, a 
 comb.) What is meant by the ear of a shell ? 
 
74 
 
 MALLEUS. ANOMIA. SPONDYLUS. 
 
 Fig. 91. PECTEN JACOB^EUS. 
 
 and Pedum, the shells of 
 what resembling the shell 
 of the Scallop in their gene- 
 ral form : 
 
 1 1 . The Hammer Oys~ 
 ters Malleus (fig. 92) 
 which have a notch near 
 the hinge for the passage 
 of a byssus : the shell is 
 irregular and the ears are 
 prolonged, making its 
 shape slightly resemble a 
 hammer : the ANOMIJS, 
 in which the interior valve 
 is deeply notched (fig. 93) 
 
 lusks are not adherent, and can even 
 swim with considerable rapidity by 
 suddenly closing their valves. The 
 mouth is furnished with many 
 branched tentacula, which take the 
 place of labial lamelhe, and be- 
 tween the branchias there is a small 
 oval foot. St. James' Pecten is 
 found on the coast of France. The 
 species of this genus are very nu- 
 merous and are very generally dif- 
 fused. 
 
 The following genera are also 
 
 placed among the oysters ; Lima 
 
 which are oval or oblong and some* 
 
 93. ANOMIA. 
 
 Fig. 92. MALLEUS. 
 
 alongside of the ligament, permitting 
 the central part of the muscle to pass 
 through it to be inserted into a plate, 
 sometimes horny, sometimes stony, 
 by aid of which the animal attaches 
 itself: 
 
 12. SPONDYLUS, in which the 
 shell is foliated or even spiny, and 
 on each valve at the hinge there 
 are two teeth which are received 
 into pits in the opposite valve : 
 
 11. What are the characters of the genus Ma'lleus ? (Malleus, Latin, a 
 hammer.) What are the characters of the genus Ano'mia ? (Anomia ; 
 from the Greek, a, without, and nomos, law ; because not easly placed accor- 
 ding to the laws of classification.) 
 
 12. How is the genus Spo'ndylus known ? (Spondylus, Latin, a spindle, 
 or shellfish.) 
 
PERNA ETHERIA. AVICULA. 75 
 
 13. PERNA (fig. 94), in 
 which the hinge is composed 
 of several ligaments inserted 
 into particular pits; besides 
 a great many other shells, 
 either recent or fossil. 
 
 Among the Oslracea 
 provided with two distinct 
 muscles, and the shells con- 
 sequently marked, on the 
 internal surface of each 
 valve, by two irregular sur- 
 faces (muscular depressions) 
 
 corresponding with the in- & 94> PERNA - 
 
 sertion of these organs, we will mention Etheria, Avicula, 
 Pinna, Area, and Trigonia. 
 
 14. The EtherifB are very analogous to oysters : their shell is 
 large, inequivalve, very irregular, without teeth at the hinge and 
 provided with a ligament, which is partly internal and partly 
 external. They are very rare shells, and have been overlooked 
 by travellers from being attached to rocks at considerable depths. 
 They inhabit the East Indian seas. 
 
 15. The AVICUL^E are recognised by their inequivalve shell, 
 with a rectilinear hinge furnished with a narrow ligament, and 
 
 frequently elongated 
 into wings at its two 
 extremities (fig- 95). 
 The body of these 
 mollusks is very smal 1 
 and prolonged into a 
 vermiform and coni- 
 cal foot, and furnished 
 with a byssus, for 
 
 the passage of which 
 Fig. 95,-AvieuLA. there ig a notch in the 
 
 side of the shell. The anterior adductor muscle is extremely small 
 and the labial appendages very large. These mollusks have 
 
 13. What is the genus Per'na? (Perna, Latin, a gammon of bacon, a 
 shell-fish.) 
 
 14. What are the characters of the genus Ethe'ria ? (Etheria, from the 
 Greek, aithb, I shine.) 
 
 15. How is theAvi'cula recognised? (Avieula, from the Latin, avis, a 
 bird ; because, when the shell is widely open, it bears a remote resemblance 
 to a bird with spread wings.) How does the genus Meleagri'na differ 
 from Avieula ? (Meleagri'na ; from the Greek, meleag'ris, a guinea-hen.) 
 
76 
 
 MELEAGRINA. PEARLS. 
 
 Fig. 96. MELEAGRINA 
 
 MARGARITiFERA. 
 
 been divided, perhaps without sufficient reason, into two genera, 
 AVICULA and MELEAGRINA, according as the shell is with 
 
 or without the wing-like prolon- 
 gations, and the hinge is armed 
 with a tooth or unprovided with a 
 similar protuberance : the shell of 
 the latter is nearly equivalve, and 
 the passage of the byssus produces 
 in each valve a notch. The 
 Meleagrince are more scaly ex- 
 ternally than the Aviculse. Their 
 nacre is sometimes very thick and 
 very brilliant ; and the extravasa- 
 tion of the liquid destined for the 
 periodical augmentation of the in- 
 terior of the shell, frequently gives 
 rise to isolated deposits of this 
 beautiful nacre, forming pearls. 
 The shell of the Pearl Oyster is 
 nearly semicircular, scaly and greenish brown externally; it 
 grows to considerable size, and is to be found on the coast of 
 Ceylon, in the Persian Gulf, the Gulf of Mexico, and in many 
 other localities, where it occurs in extensive beds, attached by 
 its byssus to submarine rocks : it is the object of an active 
 fishery. 
 
 16. Pearls, as stated above, are bodies of the same nature 
 as the brilliant nacre lining the shell : they are composed of 
 concentric layers of nacre very closely applied one over the 
 other, like the coats of an onion, and are produced whenever 
 this matter, instead of being spread out in thin layers over those 
 already deposited, constitutes small isolated masses like little 
 drops, or adhering to the shell by a mere pedicle. Their for- 
 mation depends upon a kind of disease, or, at least, upon an 
 anomalous activity of the secretory process which gives rise to 
 nacre : hence every circumstance that stimulates this secretion, 
 such as the presence of a grain of sand or other foreign body 
 betwixt the shell and the mantle of the animal, tends to bring 
 about this formation. Pearl Oysters are not the only mollusks 
 that produce pearls. All shells that are internally nacreous 
 may contain them. Patella?, Haliotides, and our common mus- 
 sels sometimes contain them, and it is not uncommon to find 
 them in a sort of large mussel (Unio) which inhabits the great 
 rivers of northern Europe and the United States ; but the 
 
 16. What are pearls ? 
 
PEARL FISHING. 77 
 
 Meleagrinse furnish the greatest quantity and yield the most 
 beautiful pearls. 
 
 17. The chief pearl fisheries are in the Gulf of Manaar on the 
 coast of Ceylon, in the Persian Gulf, the Gulf of Panama, and 
 on the coast of California ; but there are banks of Meleagrinse 
 (pearl oysters) in many other localities, sucfy as the coasts of 
 Japan, Cumana, &c. To obtain these precious mollusks, men 
 accustomed to the exercise dive to the bottom of the sea and 
 collect them at depths of from twenty to fifty feet. To accel- 
 erate his descent the diver seizes a stone (weighing from 15 to 
 25 pounds) with his toes, and on reaching the bottom he aban- 
 dons the diving stone (which is drawn up by attendants in the 
 boat, to be prepared to take him down again), clings to the 
 ground, and begins to fill a net which he carries down with him 
 for the purpose. When, from the necessity of breathing or fear 
 of sharks, he wishes to ascend, he checks the cord of the net, 
 which is instantly felt by the attendants, who commence pulling 
 up as fast as they are able ; the diver remains with the net until 
 it is so far clear of the bottom as to be in no danger of upsetting, 
 and then commences hauling himself up by the cord (hand 
 over hand), which his attendants are likewise pulling ; when by 
 these measures his body has acquired an impetus upwards, he 
 forsakes the cord and rapidly ascends to the surface, swims to 
 his diving stone, aad by the time the contents of his net have 
 been emptied into the boat, he is ready to go down again. One 
 diver will take up in a day from one to four thousand oysters. 
 The diver seldom exceeds a minute under water; the more 
 common time is from 53 to 57 seconds. In order that the banks 
 may not be devastated, they are under regulation, and it is sup- 
 posed that seven years are required for the oyster to attain its 
 full size. At Ceylon the fishing season lasts from the middle of 
 February to the end of March. 
 
 " During this period, the shores of Arippo are enlivened by crowds of 
 people from all parts of the country ; divers, boat-owners, speculators, and 
 the curious, assemble to behold 
 
 4 Pale glistening pearls, and rainbow-colour'd shells,' 
 
 while the lapidary attends with his wooden stand and bow, to drill the 
 pearls and fit them to be strung 1 , so soon as they are got out of the 
 oyster, which, according- to all accounts, is a tedious and rather disgusting- 
 operation. The oysters are put into pens, and there left until the animal 
 matter becomes softened by putrefaction, when it is subjected to frequent 
 washing-s, and the pearls shine forth, emblems of purity in the loathsome 
 mass. Some are of a bluish, some of a yellowish, and some of a whitish 
 lustre ; each class finds a ready market among its admirers; in the East, 
 the bluish and yellowish varieties are most prized, but in the eyes of the 
 Christian fair the pure white shines brightest." Ruschenberger's Voyage 
 round the World. 
 
 17. How are pearls obtained ? 
 
 7* 
 
78 
 
 PINNA. ARCA. PECTUNCULUS. 
 
 The annual revenue from the pearl fishery of Ceylon is esti- 
 mated at about $80,000. 
 
 18. The PINNAE have two equal valves in form of a half-open 
 fan, gaping and united by a ligament along one of their sides. 
 A very large species is found in the Mediterranean, which lives 
 half-buried in the sand, and anchored by its byssus, the fila- 
 i ments of which, being very strong, fine, and brilliant as silk, are 
 employed by the inhabitants of some parts of Calabria and Sicily 
 in the manufacture of precious stuffs. 
 
 19. The ARC^E are dis- 
 tinguished from all the 
 preceding by their equi- 
 valve shell. The hinge 
 which extends along the 
 side of the valves is 
 studded with a great many 
 little teeth, which fit into 
 the intervals of those of 
 Fig. 97. ARCA. t h e pp OS ite side recipro- 
 
 cally ; in some, the ARCA PROPERLY so CALLED (fig. 97), the 
 hinge is rectilinear, and the shell is 
 longer in -a direction parallel to 
 this junction ; in others, named 
 PECTUNCULUS (fig. 98), the hinge 
 is curved, and the shell is lenticu- 
 lar in form. The first are met with 
 near the shore in rocky situations, 
 and are ordinarily covered by a 
 hairy epidermis ; the latter live in 
 the mud. 
 
 20. Finally, the TRIGONIJE, most 
 of the species of which are fossil, 
 are remarkable for their peculiar 
 hinge ; the right valvq is furnished 
 with two projecting plates, crenulate Fig. 98. PECTUNCULUS. 
 
 18. What are the characters of the genus Pi'nna? (Pinna, Latin, & 
 fin.) 
 
 19. What are the characters of the genus Area ? What are the charac- 
 ters of the genus Pectu'nculus ? (Pectunculus, Latin, the diminutive of 
 pecten, a comb.) 
 
 20. What is Trigo'nia ? (From the Greek, trigonos, having three cor- 
 ners.) 
 
TRIGONIA. MUSSELS. 79 
 
 on each face (jig. 99), 
 and entering between 
 four plates of the left 
 (opposite) valve, like- 
 wise crenulated upon 
 their internal face 
 only. There is but 
 one living species 
 known, Trigonia 
 pectinata, which in- 
 habits the seas of Figt 99._ TR1GON iA PECTINATA. 
 New Holland ; exter- 
 nally, it has the aspect of Pecten without ears. 
 
 21. In the Family of MYTILACEA, the mantle is widely open 
 in front, as in the Ostracea, but there is a particular opening for 
 the escape of excrement ; this orifice, however, is not prolonged 
 into a tube, as in the families that follow, and there is no special 
 aperture for the passage of water for the purpose of respiration. 
 There is always a distinct foot, and the valves are approxi- 
 mated by the action of two adductor muscles. 
 
 The Mytilacea? resemble each other sufficiently to be commonly 
 known under the single name of Mussels, but they require, never- 
 theless, to be separated into several genera, the most important 
 of which are, Mussels properly so called, Mytilus, Anodonta, 
 and Unio. 
 
 22. MUSSELS PROPERLY so CALLED Mytilus abound on the 
 rocks of the coast of France and of other countries, where they 
 live fixed by the byssus, and generally closely united to each 
 other. Their shell is shut, and its valves, triangular in form, 
 are equal, arched and united by a narrow ligament on the side of 
 their acute angle. The mouth of the animal is situate near 
 the summit of the shell, the opposite extremity of which gives 
 passage to the byssus ; the anus also is placed near the hinge ; 
 and opposite to this orifice there is a particular opening or small 
 tube formed by the mantle; towards the round angle of the shell, 
 where the water necessary for respiration passes, the edge of 
 the mantle is fringed ; and the foot is slender, cylindrical, and 
 furnished behind with a silky byssus. Mussels are generally 
 eaten as food, but they sometimes occasion a kind of poisoning, 
 accompanied by very violent symptoms, occasionally followed 
 by death. 
 
 21. What are the characters of the family of Mytila'cea ? 
 
 22. What are the characters of the genus My'tilus ? (From the Greek, 
 mutilos, a mussel.) 
 
80 
 
 ANODONTA. UNIO. 
 
 23. We distinguish those Mussels which have the hinge placed 
 lower, under the name of MODIOLUS, and another is called 
 LITHODOMUS, which has the shell almost equally rounded at both 
 ends, and excavates holes in stones, to which it was at first only 
 suspended. 
 
 Fig. 100. ANODONTA. 
 
 ft 
 
 24. The ANODONTA live in fresh waters, and are recog 
 nised by their thin shell, moderately inflated, oval, close, and 
 without teeth in the hinge (fig. 100); they want the byssus, and 
 ate provided with a very large foot, compressed and almost 
 quadrangular in form, by means of which they crawl on the 
 sand or mud. A great many species are found in the great rivers 
 of the United States. 
 
 25. The UNIONES closely resemble the Anodontce, but have a 
 more complicated hinge, the right valve having a pit (fossette) 
 into which a tooth of the left valve penetrates, presenting behind 
 a long lamina, which, in its turn, is received between two 
 laminae of the opposite side. These mollusks also inhabit fresh 
 waters, but prefer those which are running. A very great num- 
 ber of species are found in our Western waters, for the descrip- 
 tion of most of which we^are indebted to the labours of Mr. I. 
 Lea, of Philadelphia. 
 
 23. What is the genus Litho'domus ? (From the Greek, lithos, a stone, 
 and the Latin, domus, a house.) 
 
 24. How is the genus Anodo'nta recognised? (Anodonta, from the 
 Greek, a, without, and odous, in the genitive case, odontos, a tooth.) 
 
 25. What are the characters of the genus U'nio ? (Unio, Latin, a 
 pearl.) 
 
FAMILY OF CHAMACEA. 
 
 81 
 
 Fig. 101. UNIO. 
 
 We also place in this same group certain marine mollusks, 
 which resemble the Unios in their organization and the general 
 disposition of the hinge, but in which the beaks (summits) of 
 the shell are more arched, and from which projecting ribs 
 radiate towards the circumference ; such are the genus CAR- 
 DITA, the form of which is more or less oblong or cordiform 
 (heart-shape) ; the CYPRICARDIA, in which the tooth beneath the 
 summit of theshell is divided intotwoor three ; the CORALLIOPHAGA, 
 in which the shell is thin and the lateral plate much effaced, &c. 
 
 26. In the FAMILY OF CHAMACEA the mantle is closed 
 and perforated by three open- 
 ings only; through the anterior 
 one passes the foot (fig. 102, 
 p) ; the next (r) gives passage 
 to the water necessary for res- 
 piration, and the third (e) is 
 for the expulsion of effete 
 matters. As we have already 
 stated, the last two openings 
 are not prolonged into tubes, P ( 
 as in the next two families. 
 And the hinge is very analo- 
 gous to that of the Unios ; for 
 the left valve has a tooth near 
 the summit, and funher back, a projecting plate, which are re- 
 ceived into fossa? (pits) in the opposite valve. 
 
 Explanation of Fig. 102. A Chama divested of its shell to show the dis- 
 position of its mantle : p. the foot ; r. opening for respiration ; e. the 
 opening for the passage of excrement. 
 
 26. What are the characters of the family of Chama'cea ? 
 
 , WITHOUT ITS SHELL. 
 
TRIDACNA. CHAMA. ISOCARDIA. 
 
 This family is divided into Tridacna, Chama, Isocardia, &c. 
 27. The TEIDACN^E have an equivalve shell, which is elon- 
 gate and gaping in front, or its edges are dentate (fig. 103). 
 
 Their internal orga- 
 nization is remarka- 
 ble in several particu- 
 lars. The valves have 
 only a single adductor 
 muscle. The mantle 
 ~\. ; ; is widely open in front, 
 to give passage to 
 the byssus, and a 
 little beneath the an- 
 terior angle presents 
 Fig. 103. TRIDACNA. another opening, by 
 
 which water is conveyed to the branchiae; and the third open- 
 ing, which corresponds to the anus, is situate near the middle 
 of the inferior border. To this genus belongs an enormous 
 
 shell of the Indian Ocean, known 
 under the vulgar name of the 
 Holy-water Pot ; it adheres to 
 the rocks by its byssus, which is 
 so large sometimes that an axe is 
 required to cut it, and the shell 
 itself occasionally weighs over 
 three hundred pouuds. 
 
 28. The CHAMA have an ir- 
 regular, equivalve shell, which is 
 usually lamellar and rough; they 
 live attached to rocks, coral, &c., 
 like oysters, and they have a 
 small foot bent like that of man 
 (fig. 102). 
 
 29. The JSOCARDIJE (#-.104), 
 on the contrary, have a free, 
 regular, convex shell with spirally 
 curved summits, divided anterior, 
 ly. A large, smooth, red species, 
 the Chama cor, inhabits the 
 
 Fig. 104-isocARDiA. Mediterranean. 
 
 27. What are the characters of the genus Trida'cna ? 
 
 28. How is the genus Chama distinguished ? (Chama, pronounced 
 fca'wjcr, from the Greek, chad, I gape.) 
 
 29. What are the characters of the genus Isoca'rdia ? (Isocardia, from 
 the Greek, isus, like, and kardia, a heart, heart-shape.) 
 
FAMILY OF CARDIACEA. 
 
 83 
 
 LESSON VI. 
 
 FAMILY or CARDIACEA. Cardium Donax Cyclas Corbis 
 
 Tellina Venus Petricola Venerupis Mactra. 
 FAMILY OF INCLUSA. Lutraria My a Byssomia Hiatella 
 
 Solen Sanguinolaria Pholas Teredo Fistulana 
 Gastrochcp.na Clamigella Aspergillum. 
 
 CLASS OF MOLLUSCA BRACHIOPODA. General Characters 
 
 Lingulo Terebratula Orbicula. 
 
 CLASS OF MOLLUSCA TUNICATA, or ACEPHALA NUDA. Biphora 
 Ascidia Botryllus Pyrosoma. 
 
 CLASS OF ACEPHALA, CONTINUED. 
 
 1. The FAMILY OF CARDIACEA is characterized by having 
 the mantle open in front, and prolonged posteriorly into twp 
 tubes, which are sometimes ^ 
 
 distinct, and at others united 
 in a single mass ; one of them a 
 (fiS" 105, r) serves for respi- 
 ration, and the other (e) for 
 the passage of excrement. 
 This mode of conformation is p 
 recognised in the shell by the 
 impression made by the at- 
 tachment of the edge of the 
 mantle, called the pallia! line (jig. 106, Z), which before 
 
 joining the posterior muscular 
 impression or cicatrix (mi), 
 curves more or less deeply in- 
 I wards. In all these mollusks, 
 there is a transverse muscle 
 and a foot (fig. 105, p), which 
 generally enables the animal to 
 crawl. The species of Cardia- 
 cese that have long tubes, ordi- 
 narily live buried in the sand or 
 Fig. 106. VENERUPIS. mud. 
 
 Fig. 105. TELLINA. 
 
 ai 
 
 Explanation of Fig. 105. Tellina : a. the shell ; fc, the hinge ; r. tube 
 for respiration ; e. tube for excrement ; p. the foot. 
 
 Explanation of Fig. 106. Veneru'pis : 1. pallial line ; ai. anterior 
 muscular impression ; mi. posterior muscular impression or cicatrix. 
 
 1. How is the family of Cardia'cea characterized ? (Cardiacea, from the 
 Latin, cardium, heart.) 
 
84 CARDIUM. DONAX. CYCLAS. CORBIS. TELLINA. 
 
 2. In this family we place Cardium, Donax, Cyclas, Corbis, 
 Tellina, Lucina, Venus, Petricola, Mactra, &c., genera which, 
 for the most part, are very numerous in species. 
 
 3. The CARDIA Cardium are chiefly characterized by 
 the hinge, which consists of two small teeth in each valve, situate 
 in the centre, and a projecting plate or tooth placed at some 
 distance in front and behind. The shell is equivalve, convex, 
 and furnished with ribs radiating from the summit towards 
 the circumference. And when looked at from one side, its 
 general form reminds us of that of a heart, from the manner in 
 which the summits (beaks) of the valves rise up, and curve in- 
 wards towards each other. 
 
 4. The DONACES Donax have a hinge formed nearly like 
 that of the Cardia; but their shell is flattened, nearly triangular, 
 inequilateral, and the summits are nearly vertical. Several small 
 species are found on the coasts of France, the shells of which are 
 very pretty. 
 
 5. The CYCLADES Cyclas have the same hinge and are 
 distinguished from the preceding by the rounded form of the 
 shell, which is equilateral (that is, the two halves of the valve, 
 situate on each side of a vertical line drawn through its summit, 
 are alike), and striated transversely. One species, Tellina 
 cornea, is common on the coast of France. The genera Cyrena 
 and Cyprina belong to this group. 
 
 6. The Corbis are transversely oblong marine shells, which 
 resemble the preceding in the hinge; their external surface is 
 very regularly marked by transverse ribs, crossed by diverging 
 rays. 
 
 7. The TELLING (fig. 105) Tellina closely resemble the 
 Donaces; but they have the middle of the hinge armed with one 
 tooth to the left, and two to the right. The shell is slightly 
 gaping. Like the Donaces, they have two long tubes (fig. 105), 
 which can be entirely concealed within the shell when the animal 
 contracts. Both live buried in the sand and are found on the 
 coast of France. 
 
 2. What are the principal genera belonging to the family of Cardiacea ? 
 
 3. What are the characters of the genus Cardium ? 
 
 4. What are the characters of the genus Donax ? 
 
 5. How is the genus Cy'clas characterized ? (Cyclas, from the GreeK, 
 luMos, a circle.) 
 
 6. What are the characters of the genus Corbis ? 
 
 7. How is the genus Telli'na characterized ? 
 
VENUS. MACTRA. 
 
 85 
 
 EXCAVATION 
 
 OFTHEPALLIAL 
 
 IMPRESSION 
 
 Fig. 107. VENUS. 
 
 8. The VENUS 
 (fig. 107) is re- 
 cognised by the 
 
 hinge, the ante- /."I"." 
 rior and* poste- 
 rior plates of * 
 which, instead 
 of being sepa- 
 rated from the 
 middle tooth, as ^ 
 in the Cardia, 
 &c., are approxi- 
 mated in a sin- 
 gle group be- 
 neath the sum- 
 mit. The shell 
 is generally thick, moderately convex, and a little elongated 
 The species of this genus are very numerous. 
 
 9. The genera Petricola and Venerupis (fig- 106) resemble 
 the Venus very much, and have obtained their names from living 
 in the interior of stones which they perforate. 
 
 10. The MACTR^E differ from other cardiacese in having an 
 internal ligament, lodged in two pits in the hinge, corresponding 
 
 with each other (fig. 108). There 
 are some large species on our 
 own coast. 
 
 11. The fifth and last family of 
 testaceous acephalse or INCLUSA, 
 is composed of mollusks in which 
 the mantle is only open at its an- 
 terior extremity, or near the mid- 
 dle, for the passage of the foot, 
 and is prolonged posteriorly in a 
 double tube ; in other parts it is 
 completely closed (fig. 109). 
 The shell is always gaping at the 
 
 Fig. 108. MACTRA. 
 
 Explanation of Fig. 107. Cytherea, or Venus ; s. the summit or beak ; 
 I. the lunule ; p. pit ; A. anterior, and P. posterior extremity of the shell. 
 
 8. What are the characters of the genus Venus ? 
 
 9. From what circumstance do the genera Petrico'la and Venerupis ob- 
 tain their names ? (Petricola, from the Latin, petra, a stone, and coZo, I 
 inhabit. Venerupis, Latin, Venus', and rupes, a rock.) 
 
 10. How is the genus Mac'tra characterized ? (Mactra, Latin, a 
 trough.) 
 
 11. What are the general characters of the family of Inclusa ? (Inclusa, 
 Latin, enclosed.) 
 
86 LUTRARIA. MYA. BYSSOMIA. HYATELLA. SOLEN. 
 
 extremities, and most of these animals live buried in the 
 sand or mud .; sometimes they excavate holes in stones or wood. 
 They are divide^into Mya, Lutraria, Anatina, Glycymera, 
 Solemya, Byssomia, Hyatella, Solen, Psammobia, Pholas, Tere- 
 do, Fistulana, &c. 
 
 12. The LUTRARI^E closely resemble the Mactrse ; but their 
 hinge is unprovided with lateral lamina?, and their valves are very 
 gaping, particularly behind, through which passes the thick fleshy 
 cylinder formed by their double tube. A large species is found 
 in the sand, at the mouths of several rivers in France. 
 
 13. In the Myse there is a projecting plate in one of the valves 
 and a pit in the other, joined by a ligament ; the ANATIN^E have 
 a small plate in each valve, giving attachment to a ligament ; 
 and the SOLEMYA and GLYCYMER^E differ from the MYJE in their 
 external ligament. 
 
 14. The BYSSOMIJE, in place of living in the sand like the 
 preceding, penetrate stones and corals, .and attach themselves to 
 them by the aid of a byssus. Their shell is oblong, without a 
 distinct tooth, and gaping about the middle of the inferior edge, 
 for the passage of the foot. 
 
 15. The HYATELL.E have nearly the same general form; but 
 the tooth of the hinge is more marked. 
 
 Fig. 109. SOLEN. 
 
 16. The SOLENS, commonly called razor shells, knife handles 
 (fig. 109), from the cylindrical and elongated form of their 
 
 Explanation of Fig. 109. c. the shell ; a. the anterior extremity of the 
 mantle ; p. the foot ; t. the tentacles. 
 
 12. How is the genus Lutra'ria characterized ? 
 
 13. What are the characters of the genus Mya ? 
 
 14. What are the characters of the genus Bysso'mia ? 
 
 15. How is the genus Hyate'lla characterized ? 
 
 16. What are the characters of the genus Solen ? 
 
PHOLAS. TEREDO. 87 
 
 shell, have the hinge furnished with an external ligament, and 
 armed on each side with two or three projecting and very de- 
 cided teeth. Their foot is conical and is pushed out at the anterior 
 extremity of the sheJL They live in the sand, and bury them- 
 selves with great rapidity by the motions of their foot. 
 
 17. The PHOLADES are distinguishable from all the preceding 
 by one or more calcareous pieces, situate between the two valves 
 of the shell, near the hinge. The valves, which are broad and 
 convex anteriorly, are elongated on the opposite side, and leave 
 betwixt them a great oblique opening at each end ; their hinge 
 resembles that of the Myse ; their double tube is not retractile 
 and may be very much elongated. - These animals inhabit tubes 
 or long cells, which they excavate, either in the mud, or stones 
 or wood. There are large species on the coast of France, in the 
 West Indies, and on the coast of Peru. 
 
 18. The TEREDINES, or ship worms, are celebrated for the 
 ravages they commit by boring into ships' bottoms, piles of 
 dikes, bridges, &c. These are mollusks with a 
 
 very elongated and almost vermiform body, which 
 is enveloped in a tubular mantle, open at the 
 anterior and inferior part for the passage of the 
 foot ; it is provided posteriorly with two very short, 
 distinct tubes, and its base is furnished on each side 
 with a movable stony plate ; the shell is composed 
 of two rhomboidal valves, but is very small, and 
 covers only a very small portion of the mantle. It 
 seems that the animal, by moving the extremity 
 of its shell like an auger, excavates, in submerged 
 wood, the hole which serves as its abode, and, as it 
 advances or buries itself deeper, it lines the exca- 
 vation with a calcareous matter, so that in a short 
 time it finds itself lodged in a stony tube, which at 
 first might be mistaken for a second shell. It 
 begins its attack upon wood when very young ; 
 hence the external opening of its gallery is very 
 small, but it digs on until the termination of its 
 growth, and progressively augments the size of its 
 dwelling ; the two tubes which occupy the posterior 
 extremity of the mantle always remain near the 
 opening of the gallery, and through one of them it causes the 
 water necessary for respiration and nutrition to enter, for it 
 
 1 7 How is the genus Pholas characterized ? (Pholas, from the Greek, 
 pholeos, a lurking-place.) 
 
 18. What are the characters of the genus Teredo ? (Teredo, Latin, a 
 chip-worm.) 
 
88 FISTULANA. GASTROCH^ENA. ASPERGILLUM. 
 
 always remains in its hole, with the mouth down and the anus 
 above. The common Teredo, which is about six inches long, it 
 is said was brought from the torrid zone, but it is widely 
 spread in the seas of France, and infests the dikes of Holland 
 to such an extent that its unperceived ravages have, more than 
 once, been near producing terrible inundations. Vessels have 
 been sunk by the holes bored through their bottoms by these 
 animals. To guard against such accidents, is one among the 
 reasons why ships' bottoms are covered under water by thin 
 sheets of copper. 
 
 19. The FISTTJLAN.E also live buried in submerged wood or 
 other analogous substances, and also line the interior of their 
 hole with a calcareous mortar which constitutes a tube, com- 
 pletely closed at the large end, having more or less resemblance 
 to a bottle. Like the Teredines, they have externally a small 
 bivalve shell and two plates, which may be regarded as analo- 
 gous to the operculum pieces of the gasteropods. They inhabit 
 the Indian Seas. 
 
 20. The GASTROCH^EN^E differ very little from the preceding; 
 their shell, which is unprovided with teeth, is very gaping in 
 front, and their double tube, which can be retracted entirely with- 
 in the shell, is susceptible of great elongation ; they excavate 
 holes in stones or masses of madrepore, and often line these holes 
 with calcareous matter which, on becoming hard, constitutes a 
 tube similar to that formed by the Teredo and Fistulana. 
 
 21. We also place in this division the CLAVIGELLA and 
 ASPERGILLUM, which also construct a calcareous tube; in the 
 first, one of the valves is clasped by the tube, while the other 
 remains free in its 'interior ; and in the last, the tube has, at its 
 closed extremity, a disk perforated by a great many little tube- 
 like holes, an arrangement which has obtained for it the name of 
 " watering-pot shell." 
 
 CLASS OF BHACHIOPOD MOLLUSKS. 
 
 22. These mollusks are very analogous to the common 
 acephalse ; they are also provided with a two-lobed mantle, 
 
 19. What are the characters of the genus Fistulana? (Fistulana, from 
 the Latin, fistula, a pipe.) 
 
 20. What are the characters of the genus Gastrochana ? (Gastrochsena, 
 from the Greek, gaster, helly, and chaino, I gape.) 
 
 21. What are the characters of Clavigella ? (Clavigella, from the Latin, 
 clavis, a nail or spike.) How is the genus Aspergillurn distinguished ? 
 (Aspergillum, Latin, a watering-pot.) 
 
 22. What are the characters of Brachiopod mollusks ? (Brachiopod, 
 pronounced brak-e-opod, from the Greek, brachion, an arm, and jpows, foot.) 
 
LINGULA TEREBRATULA. 
 
 Fig. Ul. 
 
 TEREBRATULA. 
 
 and a bivalve shell ; they have no foot, but 
 in place of it, two fleshy arms furnished 
 with filaments, and susceptible of being un- 
 folded externally, or drawn within the shell 
 by folding spirally (Jig. Ill, a); their 
 branchia? are not distinct from the mantle, 
 and the mass formed by their viscera is very 
 small. They are unprovided with organs of 
 locomotion, and live attached to submarine 
 bodies. 
 
 The principal genera composing this 
 group, are the Lingula, Terebratula, and 
 Orbicula. 
 
 23. The LHNGUL.E are provided with a long fleshy peduncle, 
 one extremity of which is generally attached to the rocks these 
 animals ordinarily inhabit, and the other is furnished with two 
 oblong, flattened valves. Their arms, which are inserted in the 
 sides of the mouth, are very long ; and the branchial vessels 
 are distributed on the internal face of the mantle, and there form 
 on each side a series of small parallel folds. They are found in 
 the Asiatic Seas. 
 
 24. The TEREBRATULJE have two 
 unequal valves joined by a hinge, 
 and one of them (fig. 112) has a 
 hole through its summit for the pas- 
 sage of a fleshy peduncle, by means 
 of which the animal attaches itself. 
 Their branchiae are less distinct than 
 in the Lingula?, and consist simply of 
 a vascular net-work spread over the 
 internal face of the mantle ; but 
 their muscular system is more de- 
 veloped, and there is found in the 
 interior of the shell a small solid 
 frame (fig. 113), the structure of 
 which is sometimes very compli- 
 cated ; its chief uses are to afford 
 attachment to muscles, and to as- 
 sist in separating the valves. Some 
 living Terebratulse are found in 
 the South Seas ; but they abound 
 most in the fossil state; and are Fig. 113. TEREBRATULA. 
 
 23. What arc the characters of the genus Lin'gula ? (Lingula, Latin, a 
 latchet, or tongue of a shoe.) 
 
 24. What are the characters of the Terebra'tulu ? (Terebratula. from the 
 Latin terebro, I bore.) 
 
 8* 
 
 Fig. 112. TEREBRATULA. 
 
90 
 
 BIPHORA. 
 
 found in the most ancient fossiliferous strata or layers of the 
 earth's crust. 
 
 25. The ORBICULJE have one round, conical valve, like the 
 shell of the Patellae (fig. 78, p), while the other is flat and 
 perforated for the passage of a very small peduncle ; the confor- 
 mation of their arms, and the arrangement of their branchial 
 vessels, very closely resemble those of the Terebratulse. 
 
 CZiASS OF 3XZOLLTJSC A TUNICATA, OR ACEPHALA 
 WITHOUT SHELLS. 
 
 26. The acephalous mollusks without shells, which have also 
 been called Tunicata, differ much from all the preceding in their 
 general form, as well as in many important particulars of their 
 organization. Their mantle consists sometimes of a simple 
 tube open at both ends, and sometimes of a sack ; their branchiae 
 present different forms, but always very little developed, and arc 
 never divided into four leaflets or laminae, as in the ordinary 
 acephalse, or lamellibranch testacea, among which they are 
 placed by many authors ; they have neither foot nor arm ; and 
 they evidently form the connecting link between the mollusks 
 we have just described and inferior animals which are ranged 
 among the Polypi in the branch of Zoophytes. 
 
 27. The BIPHORJE of all the Tunicata possess the most com- 
 plicated organization. Their mantle is tubular, furnished with 
 transverse muscular bands, and enclosed in a transparent, car- 
 
 / on 
 
 p 
 
 a--- 
 
 br 
 
 Fig. 114. BIPHORA. 
 
 tilaginous envelope ; both extremities are open, and the posterior 
 orifice (p) is supplied with a little valve, so arranged as to 
 admit the water, but not to allow its escape ; the mouth 
 
 Explanation of Fig. 114. a. the anterior opening of the mantle; b. the 
 mouth ; /. the liver, &c. ; an. the anus ; br. the branchiae ; p. posterior 
 opening of the mantle. 
 
 25. What are the characters of the genus Orbicula ? 
 
 26. What are the general characters of the class of Tunicata ? 
 
 27. What are the characters of the genus Biphora? 
 
ASCIDIA AGGREGATA. 91 
 
 is placed in the tube formed by the mantle towards its anterior 
 extremity ; and the heart, liver, and other viscera, are united 
 into a small mass near this opening ; the anus is situate far be- 
 hind, and the only branchia, which is formed of a membrane 
 transversely plaited, extends obliquely from the superior to the 
 inferior parietes of the pallial cavity ; the water which traverses 
 this tube, consequently laves the respiratory apparatus, and the 
 animal moves by forcibly expelling it from the side of the mouth : 
 hence, we see it must necessarily swim backwards. When 
 full grown, these mollusks are free ; but at birth they are fre- 
 quently united to each other, forming a long chain, and swim 
 in this manner for a long time; it seems that the individuals 
 thus united, after becoming free or separated, produce young, 
 which are not joined together in a chain as just described, and 
 differ from tfrem in form, and that the young arising from the 
 last are united and similar to the first ; so that in these singu- 
 lar animals there is the most remarkable alternation, the same 
 form and the same mode of existence not being transmitted from 
 one generation to the other, but constantly returning to the 
 second generation. 
 
 The Biphorse ' are found in the Mediterranean, and in the 
 warmer regions of the ocean ; they frequently emit a phosphoric 
 light. 
 
 28. The simple ASCIDIA cannot move like the Biphorse, but 
 live attached to rocks ; their mantle is in the form of a sack, 
 with two orifices, and the interior of this cavity is lined with a 
 net-work composed of the branchial vessels ; the mouth and the 
 little bag or sack containing the viscera, are attached to the bot- 
 tom of the great branchial cavity, and the anus is found near one 
 of its openings. 
 
 29. Other Tunicata, closely resembling the preceding in their 
 organization, live united in a common mass, and for this reason 
 they are designated under the name of ASCIDIA COMPOSITA or 
 AGGREGATA. A gelatinous or cartilaginous tissue encloses a 
 great number of these little beings, the surface of which presents 
 a multitude of six-pointed stars formed by their openings ; their 
 propagation seems to be effected in two ways ; sometimes the 
 mass grows by the development of reproductive buds in this 
 common tissue, sometimes the young formed in an ovary are 
 expelled externally, and swim about free or separately for some 
 time, until they become attached to some submarine body, where 
 they establish a new colony. 
 
 28. What are the characters of the genus Ascidia? (Ascidia, from the 
 Greek, askos, a bottle or pouch.) 
 
 29. What is meant by the Aggregata? (Aggregata; Latin, gathered 
 together.) 
 
92 BOTRYLLUS PYROSOMA. 
 
 30. We give the name of BOTRYLLUS to small aggregated 
 Tunicata of an oval form, which differ little from the preceding, 
 except their branchial sack is open at both extremities, and the 
 anal orifice terminates in a central cavity, around which ten or 
 twelve of these mollusks are grouped like the rays of a star. 
 
 Fig. 115. PYROSOMA. 
 
 31. The PYROSOMA unite in great numbers, forming a large 
 hollow cylinder, open at one end and closed at the other, which 
 swims in the ocean by the alternate contraction and dilatation of 
 the animals that compose it. In their individual organization they 
 are similar to the preceding. 
 
 OF THE PARTS OF SHELLS. 
 
 We have now brought our history of the Mollusca to a close ; 
 but with the view of imparting clearer notions on the subject of 
 Conchology, or History of Shells, we shall add here a few 
 words in relation to the parts of shells. It is absolutely neces- 
 sary to understand these parts, before we can comprehend the 
 descriptions given by conchologists, or be able to describe shells 
 in such a way as conchologists can recognise them. 
 
 The most simple farm of a shell is the cone (fg- 70, page 
 57). The apex of the cone is oblique and excentric. In the 
 Limpets (Patella), Argonaut, and Nautilus, the apex is directed 
 towards the head, but in most other mollusks, towards the oppo- 
 site extremity of the body. 
 
 A shell may consist of one piece, as in the inopercular 
 univalves that is, univalves without an operculum or door. 
 
 A shell may consist of two pieces, as in the opercular 
 univalves (univalves with an operculum), and in most bivalves. 
 
 A shell may consist of three pieces, as in the Terebratula 
 (Jigs. 112 and 113, page 89). 
 
 A shell may consist of four or more pieces, as in some of the 
 Pholades. 
 
 A shell may consist of many pieces, in which case it consti- 
 tutes a multivalve, as the Chiton (fg. 79). 
 
 30. What are the characters of the Botryllus. (Botryllus, from the 
 Greek, botrus, a bunch of grapes.) 
 
 31. What are the characters of the genus Pyrosoma ? (Pyrosoma, from 
 the Greek, pur, fire, and sower, body fire-bodies ; so called from possessing 
 the faculty of emitting light.) 
 
PARTS OF UNIVALVE SHELLS. 93 
 
 The univalve shells are much more numerous than any others, 
 both in genera and species ; and it requires a considerable de- 
 gree of attention to discriminate many of the species, as they 
 run into each other so much. 
 
 In the examination of univalve shells, the general outline or 
 contour of the whole shell is the first particular to be attended 
 to, as this leads to those distinctions necessary in the definition 
 of simple, spiral, or turbinated shells, or more strictly, accord- 
 ing to the Linnean method of discrimination, univalves with a 
 regular spire, and those without a regular spire. Univalve 
 shells are classified principally from the shape of the aperture, 
 taken in conjunction with the general shape of the shell ; from 
 the spire being lengthened or depressed, being with or without a 
 canal, the length of the beak and its direction, together with 
 the particular form of the outer or external lip : the colour of 
 shells only serves as a specific distinction, and, even in this 
 respect, cannot in all cases be depended upon, although, in 
 others, it is an unvarying test. The particular manner in which 
 the spots are disposed, frequently characterizes species. 
 
 Apex, is the summit, tip, or highest part of a shell (fig* 116). 
 
 Base, is the opposite extremity from the apex (Jig. 116). In 
 shells with a beak or rostrum (as the Murex,^-. 64), it implies 
 the tip of such beak ; in shells without a beak it is understood 
 to be the lower part, as before mentioned, opposite the apex. In 
 the Patella, and some others, the base of the shell is that part on 
 which it rests when it is laid on its mouth ; in the Teredo, and 
 similar shells, it is the wider end. 
 
 Body of the shell, is the first or lower whorl of the spire, in 
 which the aperture is situated ; this whorl is generally longer 
 than the others (Jig. 18). 
 
 Front of the shell, is that side where the aperture is situated. 
 
 Back of the shell, is the opposite side to that in which the aper 
 ture is placed. 
 
 The venter or belly, is the most prominent part of the lower 
 whorl or body, generally situated in the vicinity of the lip over 
 the aperture, and formed by the convexity of the aperture. In 
 general this term is only made use of in describing shells 
 whose body is large in proportion to the size of the spire ( fas. 
 52 and 59). 
 
 Sides of a shell, are the extreme edges of the shell, when 
 viewed either in front or from the back. The right side is the 
 one next the observer's left hand, when the shell is viewed in 
 front ; arid the side with the aperture in it, is the left side. 
 
 The conical univalve shell is generally spirally convoluted ; 
 sometimes, as in the nautilus (Jigs. 15 and 16), in the same 
 
04 
 
 PARTS OF UNIVALVE SHELLS. 
 
 plane, but more usually in an oblique direction. As a general 
 rule, the spiral univalve, if viewed in 
 Base. the position in which its inhabitant 
 
 would carry it, if moving forwards 
 from the observer, is twisted, from the 
 apex downwards, from left to right, 
 the spire being directed obliquely to- 
 wards the right. The annexed figure 
 (Jig. 116) shows the involutions or 
 whorls of the spire of the Pleurotoma. 
 In some genera, for example, Clausilia 
 (from the Latin, clausus, shut, jig. 25, 
 page 40) and Physa (from the Greek, 
 phusa, a bubble, fig, 30, page 42), the 
 shell is twisted in an opposite direc- 
 tion : such shells are called " per- 
 verse," or " sinistral." 
 
 The aperture or mouth, is that part 
 of the lower whorl or body through 
 which the animal protrudes itself. 
 This is one of the principal means of 
 distinguishing the genera of univalve 
 shells, and it varies much in its form; 
 some apertures are rounded (figs. 43 
 and 46); others semilunar (fig. 55); 
 others angular (fig. 37), &c. Some 
 apertures have a canal at their base 
 (figs. 63 and 11 6), and others are with- 
 out it (fig. 51). In various genera, 
 the aperture extends the whole length 
 of the shell, as in Ovula (fig. 68), 
 Cyprsea, and some of the Cones with 
 depressed spires (fig. 70). In several individuals, the aperture 
 is either entirely open, or closed by an operculum or door, which 
 is usually affixed to the foot of the animal. 
 
 When without a notch or canal, the aperture is said to be 
 entire (fig. 51). The aperture has two lips or borders; the 
 internal lip, or border, is on the side of the aperture, formed by 
 the columella, and the external, or outer lip, or border, is oppo- 
 site, as in the Pleurotoma (fig. 116) ; the letter b. indicates the 
 pallial notch ; n. notch of the syphon. 
 
 Canal, or gutter (fig. 116), is the space or hollow, formed by 
 the prolongation of the two lips of the aperture. Some shells 
 have two canals, one situated at the point where the outer lip and 
 body join. 
 
 Apex. 
 Fig. 116. PLEUROTOMA. 
 
PARTS OF UNIVALVE SHELLS. 95 
 
 Beak or rostrum, is that lengthened process in which the 
 canal is situate. This process is not so conspicuous in some of 
 the species of Voluta, but is more marked in the genera Murex, 
 Fusus, &c. 
 
 The columella or pillar, is that process which runs through 
 the centre of the shell in the inside, from the base to the apex, 
 and around which the whorls or wreaths of the spire are wound 
 (fig. 19, page 34). When the columella is marked by ridges 
 or folds, as in Auricula (Jig. 31) and Oliva (Jig. 67), it is said 
 to be plicated or plaited, but when it is smooth, as in Jig. 116, 
 it is simple. 
 
 Pillar lip, is a continuation of the glassy process with which 
 the aperture is lined, and expanded on the columella (figs. 58 
 and 66). It is also called the inner or internal lip (fig. 116). 
 
 The outer lip, or external border, is the expansion or con- 
 tinuation of the body of the shell, on the left margin of the 
 aperture, and is also lined with the glossy process of the aperture 
 
 (fig- H6). 
 
 Spire consists of all the whorls of the shell except the lower 
 one, which, as before observed, is termed the body of the shell. 
 This spire is a prominent feature of the univalve ; and upon its 
 being elevated, depressed, &c., depends much of the generic and 
 specific definition of these shells. 
 
 It is a remarkable circumstance, that many of the young 
 shells have not the same number of wreaths as the adults ; 
 from which it would appear, that the part of the animal nearest 
 the apex never increases in size. The number of wreaths 
 cannot, at all times, be depended upon. A full-grown shell 
 may, however, be known from the outer lip, whicl^has generally 
 an unfinished appearance in young shells. Indeed, in all the 
 land and fresh-water shells, it is a distinct criterion, as they are 
 never complete in the form of the outer lip, till full-grown. 
 
 Whorl is one of the wreaths or volutions of the shell (fig. 
 116). 
 
 Depressed spire is when the spire is very flat, as in the shells 
 of the genus Planorbis (fig. 29, page 42). 
 
 Involuted spire, is where the spire is concealed in the inside 
 of the first whorl or body, as in some of the Nautili, Cvprsese, 
 Ovulie, &c. (fig. 68). 
 
 Suture of the spire, or whorls, is a fine spiral line or seam, 
 formed by the joining together of the whorls ; it is sometimes 
 crenulated, undulated (waved), or sulcated (grooved), and not 
 unfrequently elevated or projecting (fig. 116). 
 
 Reversed, or heterostrophe spire, is when the volutions of the 
 spire revolve in the same manner as the common corkscrew, or 
 
96 PARTS OF BIVALVE SHELLS. 
 
 when the aperture is placed downwards, the nature of the spire 
 runs upwards from the right hand to the left (Jig- 25). 
 
 Chambers are the cavities, divided by partitions at regular or 
 irregular intervals, as in the Nautilus (Jig. 15, page 30). 
 
 Umbilicus is a circular perforation in the base of the lower 
 whorl or body. (See page 38). 
 
 Sub-nmbilicated shells, are those which have the umbilicus 
 covered, in a greater or less degree, by a thin process ; which, 
 in some, almost entirely closes the aperture or mouth. This 
 character is most commonly to be met with among species of 
 Buccinum and Murex. 
 
 Umbilical fissure, is a groove extending from the umbilicus 
 (fig. US). 
 
 Shells which have no umbilicus are termed imperforate. 
 
 Siphunculus (little syphon) is that small round perforation 
 which forms a communication between the chambers in the 
 Nautilus, and penetrates through the whole spire of the shell 
 (Jigs. 15 and 16). 
 
 Varices are transverse ribs which cross the whorls of shells 
 in some species of Buccinum, Murex, &c. Varices are formed 
 by the periodical growth of the shells, these being the margin of 
 the outer lip, to which the animal has attached its periodical 
 enlargements (Jig- 46). In some species they have more the 
 form of sutures than ribs ; this is owing to the margin of the 
 outer lip being but slightly developed. 
 
 Ribs are those longitudinal and transverse protuberances 
 which are in many of the univalve shells (fig. 46). 
 
 Teeth of univalves, according to Colonel Montagu, are not 
 properly tootrnshaped protuberances, but are fine white Iamina3 
 or ridges, running spirally backwards, in a direction parallel to 
 each other ; those on the exterior lip may, in most instances, be 
 traced through the outside of the shell, and are nearly alike in 
 length (figs. 24, 25 and 42). 
 
 Epidermis is a skin, or cuticle, covering the exterior surface 
 of many shells, destined by nature to protect their surface from 
 being injured. 
 
 True bivalve shells are peculiar to the acephalous mollusca; 
 and their presence is constant, although they are in a few 
 instances too small to cover the whole body, and in the ship- 
 borers (Teredo) exist only as small instruments, limited to the 
 function of excavating the burrows inhabited by these mollusks. 
 But all the species, in which the bivalve shell is inadequate to 
 the protection of the whole body, derive extrinsic defence by 
 burrowing in sand, or stone, or wood ; and they also commonly 
 line their burrows with a layer of smooth and compact cal- 
 
PARTS OF BIVALVE SHELLS. 97 
 
 careous matter, forming a tube. This calcareous tube, in some 
 cases, is of considerable size and thickness. In the Clavigella 
 one valve, and in the Aspergillum both valves, are soldered to 
 this tube, which, in the latter, presents a peculiar modification 
 of its exposed extremity, which resembles the end of the spout 
 of a watering-pot. No two shells can present a greater con- 
 trast than do those of the Placuna and Aspergillvm ; yet the 
 organization of their respective constructors is essentially the 
 same. In a classification of shells, the calcareous tubes of the 
 Dentalium, Serpula, Aspergillum, Vermetus, &c., would be 
 associated in the same general group : but it needs only to 
 observe how these products of animals, belonging not only to 
 different classes, but to distinct primary divisions of the animal 
 kingdom, are arranged in the cabinets of collectors, to be con- 
 vinced that Conchology as a classificatory science, apart from 
 Malacology (the science of mollusks), no longer exists. 
 
 With regard to the structure and physiological relations of 
 bivalve shells, it may be observed, first, that in all acephalous 
 mollusks which breathe by distinct iamellaled gills (branchiae), 
 Lamellibranckiata, one valve corresponds to the left, the 
 other to the right side of the animal ; but in the brachiopodous 
 bivalves, one valve is applied to the ventral, and the other to the 
 dorsal aspect of the animal. 
 
 In all the lamellibranch bivalves which are free, the two 
 valves are symmetrical, and the shell is termed equivalve ; in 
 all those which adhere by one of their valves to foreign bodies, 
 this valve is deeper and larger than the unattached valve ; such 
 shells are termed inequivalve. Of those acephalans which are 
 attached to foreign bodies by means of a byssus, some, as the 
 Tridacna (fig. 103), are equivalve, and both valves are 
 notched, to form the hole for the passage of the byssus ; while 
 others, as the Pecten (fig. 91), and Avicula (fig. 95), are 
 inequivalve, the byssus passing through a groove in the right 
 valve. 
 
 If the shell of the common cockle be examined, each valve 
 will be seen to be produced into a conical prominence bent 
 towards, and nearly meeting at, that part by which the valves 
 are joined together. These prominences are termed the umbones> 
 or sometimes beaks. The apex of the umbo corresponds to 
 the apex of the univalve shell, and is the point at which the 
 development of the bivalve commences. When the apex is 
 directed in the transverse plane of the shell, and so placed, 
 that a division of the shell in that plane through the apices 
 shall divide the valve into two equal parts* the shell is termed 
 equilateral; of this form the Pecten (fig. 91) is au example, 
 9 
 
98 PARTS OF BIVALVE SHELLS. 
 
 When upon a similar division, a slight difference is observed 
 in the two valves, the shell is termed subequilateral ; but 
 where the difference is well marked, it is an inequilateral bivalve 
 (Jig. 117). When the apex is bent, as is commonly the 
 case, out of the transverse plane, it is always directed more or 
 less towards the anterior part of the shell ; if such a bivalve 
 shell as the Cytherea, or Isocardia, be held before the observer, 
 with the umbones directed forward, and the hinge above, in the 
 position, in fact, in which the living animal would place itself 
 if it were creeping forwards from the observer, the right valve 
 will of course correspond with the right hand of the observer, and 
 the left with the left. 
 
 Superior or dorsal border. 
 
 * 
 
 Fig. 117. LEFT VALVE OF A CYTHEREA. 
 
 The annexed figure (117) represents the left valve of a. 
 Cytherea, the common clam belongs to this group, and would 
 answer our purpose as well. You see that the superior or 
 dorsal margin is on the side where the hinge is placed, and the 
 ventral or inferior border opposite to it; A, is the anterior 
 margin or slope ; P, the posterior margin or slope ; the umbo 
 is marked " BEAK," and s, points to the summit or apex of the 
 beak ; /, shows the situation of the Ivnule. Now, if a bivalve 
 in which the apices have a spiral twist, as in the Isocardia 
 (fig. 104), be placed in the above position, and compared with 
 the univalve shell of the Purpvra, it will be seen that the left 
 valve corresponds with the ordinary or dextral spiral univalve, 
 and the right valve to the perverse or sinistral univalve. 
 
 When the circumference or margin of one valve fits exactly, 
 at every part, that of its fellow, it is said to be " regular" or 
 ".entire ;" but if it be notched at any part, so as not to come 
 
PARTS OF BIVALVE SHELLS. 
 
 in contact with the corresponding part of the opposite valve, it is 
 " irregular," or emarginate. 
 
 Besides the parts mentioned, A 
 
 we shall find in most cases, an- 
 terior to the apices of the beaks, 
 a depression of variable extent 
 and depth. This is the lunule 
 (fig. 118, 1) : it may be cordi- 
 form, or crescentic, lanceolate 
 (oblong, and gradually tapering 
 towards each extremity), oval, 
 deep, superficial, &c. Behind 
 the beaks is another depression, 
 longer and narrower than the 
 lunule, and which is called the 
 fissure (f), and its margins 
 are named lips of the fissure 
 ( I/). Behind the fissure there is 
 sometimes a small depression 
 called the suture (s). The 
 general more or less convex 
 surface of each valve is called 
 the "venter," or belly, which 
 terminates in the limb, circum- 
 ference or margin. In the figure (118), the letters designate 
 parts, as follows : A, anterior slope ; P, posterior slope ; L, left 
 valve ; JR, right valve ; Z, lunule ; /. fissure ; //*, lips of the fis- 
 sure ,* s, suture ; lig, ligament ; ny, the nymphse. 
 
 ny 
 
 Fig. 118. CYTHEREA. 
 
 /LIGAMENT-. \ 
 ' .MWHAEv \ \ 
 
 gCARUTV .'OF THE PALLIAL 
 IMPRESSION 
 
 Fig. 119. RIGHT VALVE OF A CYTHEREA. 
 
 The most important part of the margin is that which is 
 
100 PARTS OF BIVALVE SHELLS. 
 
 modified to form the joint or hinge upon which the two valves 
 open and shut. This part is called the " cardinal edge" (jig. 
 119), and generally presents certain prominences and depressions ; 
 the projections of one valve interlocking with the depressions of 
 the other. The projections, or " teeth," together with the cavi- 
 ties, or " cardinal pits" (p), are very regular in their formation 
 in each genus and species of bivalve, but what is of more impor- 
 tance is, that every modification in the structure of the hinge is 
 generally found to coincide with some recognisable and more or 
 less important difference in the organization of the soft parts ; so 
 that conchologists have justly attached great value to the charac- 
 ters derivable from the hinge, especially for the purpose of gene- 
 ric distinctions. When the teeth are situate beneath the apex (s) 
 or centre of the hinge, they are called cardinal, or primary / 
 when they are removed from the centre of the hinge, they are 
 named lateral teeth ; when two only are present, one is called 
 anterior, the other posterior ; when there are three, they are dis- 
 tinguished respectively as anterior, median or middle, and pos- 
 terior teeth ; but when the hinge is composed of a great number 
 of teeth, it is said to be " serial," as in Area (Jig. 97) ; some 
 hinges have no visible teeth, and are termed inarticulate. 
 
 The direct medium of union of the two valves is a dense fasci- 
 culus (bundle) of elastic fibres, generally of a brown colour, called 
 ligament, or elastic ligament. The fibres of this part are at- 
 tached by their extremities to the two valves, which, in most cases, 
 present a particular depression for their reception. The ligament 
 is always so long as to prevent the actual closing of the valves, 
 except when its elasticity is overcome by a certain force, as by 
 that of the contraction of the adductor muscle or muscles : thus, 
 the inorganic power of elasticity is made the direct antagonist of 
 a vital and muscular contraction ; and as the open or expanded 
 condition of the bivalve shell is that which the exigences of the 
 animal most constantly require, it is assigned to a force which 
 can act without ever causing fatigue, while the occasional or 
 protective action of forcibly closing the valves, is due to an ac- 
 tion under the immediate control of the will or instinctive sensa- 
 tion. The modifications of the internal surface of a bivalve 
 shell are caused by the structure of the animal inhabiting it : 
 hence, they afford the characters by which the habits of. an ex- 
 tinct genus may be to a great extent determined. 
 
 These modifications are marked on the last figure. 
 
 The pallial impression shows the development of the muscu- 
 lar margin of the mantle. 
 
GLOSSAKY. 
 
 CONCHOLOGY. 
 
 ABDO'MEN. The belly; the cavity 
 which contains the stomach, liver, 
 &c. 
 
 ABDO'MINAL. Belonging or relating 
 to the belly. 
 
 ACE'PHALA (a-ke'f-ala.) From the 
 Greek, a, without, and kephale, 
 head, without a head. The Latin 
 word animalia, animals, is under- 
 stood ; therefore, acephala means 
 animals without a head. 
 
 ACE'PHALA (a-ke'f-alay'). Latin. Flu- 
 ral of acephala. 
 
 ACE'PHALOUS (a-ke'f-alous). Head- 
 less ; belonging or relating to ace- 
 phalae. 
 
 ACETA'BULIFE'RA. From the Latin, 
 aceta'bulum, a little cup, and fero, 
 I carry. Applied to those cephalo- 
 pods that have cups or suckers on 
 their arms or tentacles. 
 
 ACHATI'NA (akate'na). From the 
 Greek, achates, agate. Name of a 
 genus of terrestrial gasteropods, 
 sometimes known as the agate 
 snails. All the species of this 
 genus are ovi'parous, and one, the 
 Achatina zebra, figured on page 
 41, lays eggs with a hard, white 
 shell and as large as those of a 
 sparrow. 
 
 ADDU'CTOR (muscle) From the Latin, 
 addu'co, I draw towards. The 
 muscle which draws the valves 
 of a bivalve shell towards each 
 other, is so called. 
 
 AD'NATE. Adhering or growing to- 
 gether. 
 
 AGGLU'TINANS. Latin. Glueing; a 
 
 gasteropod which has the faculty 
 
 of causing other species, or parts 
 
 of shells, to adhere to it, is so 
 
 named. 
 
 AGGREGA'TA. Latin. Gathered to- 
 gether. 
 
 AGGRE'STIS. Latin. Rural, wild. 
 
 AKE'RA. From the Greek, a, with- 
 9* 
 
 out, and keras, horn, hornless. 
 Name of certain mollusks that 
 have very short tentacles, or none 
 at all (page 64). 
 
 AKE'RA. Plural of Akera. 
 
 ALA'TED. Winged. 
 
 ALIMEN'TARY (canal). The intestinal 
 tube is so called because it is the 
 medium through which food is 
 conveyed into the body. 
 
 ALU'CO. Specific name of a shell 
 (page 54). 
 
 AM'BIENT. 'Surrounding, investing. 
 
 AMBRE'TTE. From the French, 
 ambre, amber ; name of a shell 
 supposed to resemble amber (page 
 41). 
 
 AM'MON. From the Greek, ammos, 
 sand. Name of a heathen divinity 
 whose temple was in the sands of 
 the desert. 
 
 AM'MONITES. Ammonites, -vulgarly 
 called Snake Stones, are fossil 
 shells found in the strata of the 
 secondary formation, varying from 
 the size of a bean to the dimen- 
 sions of a coach-wheel. Their 
 name is derived from their resem- 
 blance to the horns on the statue 
 of Jupiter Amtnon (page 31). 
 
 AMPULLA'RIA. From the Latin, am- 
 pulla, a bottle or jug ; any thing 
 puffed or swelled out. 
 
 AMPULLA'RIA. Plural of ampullaria. 
 
 ANA'TIFA. From the Latin, anas, 
 in the genitive case, anaiis, a duck, 
 and fero, I bear ; a genus of bra- 
 chiopod mollusks. It was for a 
 long time believed that certain 
 ducks were derived from the 
 metamorphosis of these animals ; 
 and for this reason they were 
 called anatifa. 
 
 ANATI'NA. Name of bivalves which 
 resemble the Solens (page 86). 
 
 ANGIO'STOMA. From the Greek, ag 
 
102 
 
 CONCI1GLOGY. GLOSSARY. 
 
 g.?ion, i vejjsely an.d stowa, mouth 
 (page 56). 
 
 ANODO'NTA. From the Greek, a, 
 without, odos, in the genitive, odon- 
 tos, tooth without teeth. Sys- 
 tematic name of a kind of mus- 
 sel, the shell of which is without 
 teeth. 
 
 ANODO'NTVE. Plural of Anodonta. 
 
 ANO'MIA. Greek, a, without, and 
 nomos, law. Systematic name of 
 certain mollusks (page 74). 
 
 ANOMI^E. Plural of Anomia. 
 
 A'NUS. Latin. The inferior opening 
 of the rectum for the passage of 
 excrement. 
 
 AOR'TA. The principal artery of the 
 body is so called. 
 
 AOR'TIC. Belonging or relating to 
 the aorta. 
 
 APERTURE. The mouth or opening 
 of the shell. 
 
 APEX. The tip or point of the spire 
 of a shell. 
 
 ArLY'siA.^-From the Greek, aplusia, 
 uncleannese; that which cannot 
 clean itself. Systematic name of 
 Sea-hares, to which the ancients 
 attributed many fabulous proper- 
 ties. 
 
 APLY'SI^E. Plural of Aplysia. 
 
 APPARATUS, Latin ; formed from dd, 
 for, and parare, to prepare. A col- 
 lection of organs or instruments 
 for any operation whatever. 
 
 AQUA'TICA. Latin. Aquatic ; be- 
 longing or relating to the water. 
 
 AR'CA. Latin. A chest, an ark or 
 coffer. Systematic name of cer- 
 tain mollusks. 
 
 AR'C.E (ar-kay). Plural of Area. 
 
 ARE'OLA. A small area or circle. 
 
 AR'GONAUT. From the Greek, Argo, 
 name of a vessel, and Nantes, a 
 navigator. The Grecian princes 
 who attempted the conquest of the 
 Golden Fleece, in the ship Argo, 
 under the command of Jason, were 
 called Argonauts. Systematic 
 name of a cephalopod (page 28). 
 
 ARGONAU'TA. Latin. Argonaut. 
 
 ARTERY. A blood-vessel that con- 
 veys blood from the heart to the 
 various organs of the body. 
 
 ABTICULA'TA. Latin. Having joints. 
 The word animalia, animals, being 
 
 understood, articulata means ani- 
 mals with joints, and is applied to 
 insects, &c. 
 
 ARTI'CULATE (animals). Having 
 joints. 
 
 ARTI'CULATED. Having joints. 
 
 ASCI'DIA. From the Greek, askos, a 
 bottle or pouch. Systematic name 
 of certain mollusks. 
 
 ASCI'DIA. Plural of Ascidia. 
 
 ASPE'RGILLUM. Latin. A watering, 
 pot. 
 
 AU'DITORY. Belonging or relating 
 to the sense of hearing. 
 
 AU'RICLE. Name of one of the cavi- 
 ties of the heart. 
 
 AURI'CULA. From the Latin, auris, 
 an ear. Name of a shell, from its 
 resemblance to the human ear. 
 
 AURI'CULO-VENTRI'CULAR (opening). 
 The aperture betwixt the auricle 
 and ventricle of the heart is so 
 called. 
 
 AVI'CULA. From the Latin, avis, a 
 bird. Name of a shell (Jig. 95). 
 
 BATRA'CHIAN (Ba-tra'-ke-an). From 
 the Greek, batrachos, a frog. Be- 
 longing to that order of reptiles 
 which includes frogs and toads. 
 
 BEAK. The continuation of the. 
 body of univalves in which the 
 canal is situate. 
 
 BELEM'NITES. From the Greek be- 
 lemnon, a dart. A genus of fbsi. 
 sil dibranchiate cephalopods, the 
 shells of which are chambered and 
 perforated by a syphon, but in- 
 ternal. They are long, straight, 
 and conical, and commonly called 
 " thunder-stones." They are often* 
 found in chalk. 
 
 BIPHO'RA. From the Greek bis, 
 double, and phored, I bear. (See 
 page 90, Jig. 114.) 
 
 BIPHO'R^E. Plural of Biphora. 
 
 BI'VALVE. From the Latin bis, two, 
 and valva, doors. Shells composed 
 of two pieces united by a hinge 
 are termed bivalves, as, for exam- 
 pie, clams, oysters, mussels, &c. 
 
 BOREA'LIS. Latin. Northern; be- 
 longing or relating to the north. 
 
 BOTRY'LLUS. From the Greek, bo- 
 trus, a bunch of grapes. (Seepage 
 88.) 
 
 BRA'CHIOPOD (Bra'.ke-o-pod). From 
 
CONCHOLOGY. GLOSSARY. 
 
 103 
 
 the Greek, brachion, an arm, and 
 pous, foot (page 92). 
 
 BRA'CHIOPO'DA. See Brachiopod. 
 
 BRA'NCHIA (Brarik-ea). Latin. A 
 gill. 
 
 BRA'NCHIA (bran'k-eay). Plural of 
 branchia. 
 
 BRANCHIAL, (brarik-eal), Belonging 
 or relating to the branchise, or gills. 
 
 BUC'CAL. From the Latin bucca, the 
 cheeks. Belonging to the cheeks. 
 
 BUC'CINUM. Latin. A trumpet or 
 horn ; a shell. 
 
 BUC'CINA. Latin. Plural of Buc- 
 cinum. 
 
 BUCCINOI'DES. From buccinum, and 
 the Greek, eidos, resemblance. 
 Systematic name of a family of 
 shells, the characters of which re- 
 semble those of the Buccinum. 
 
 BY'SSUS. From the Greek, bussos, 
 fine flax. A bundle of silky fila- 
 ments, secreted by a gland at the 
 foot of certain bivalves, and serv- 
 ing as an organ of adhesion to 
 submarine rocks and other foreign 
 bodies. 
 
 CALCA'REOUS. From the Latin, calx, 
 lime. Partaking of the nature of 
 lime. 
 
 CALMA'RIES. From an old French 
 word, calmar, an inkstand, or a pen- 
 case ; this word is from the Latin, 
 calamus, a pen. Name of a family 
 of cephalopods (pages 23 and 29). 
 
 CALYPTR^E'A. From the Greek, ka- 
 luptra, a covering. Name of a 
 genus of gasteropods (page 59). 
 
 CALYPTR^;'^;. Plural of Calyptrte'a. 
 
 CAM'ERINES. From the Latin, ca- 
 mera, chamber. Name of certain 
 microscopic shells (page 32). 
 
 CAPI'LLARY. From the Latin, capil- 
 lus, a hair. Hair-like. 
 
 CA'PULUS. Latin. A hilt or handle 
 (page 58). 
 
 CA PULOI DBS. From the Latin, capu- 
 lus, and the Greek, eidos, resem- 
 blance (page 58). 
 
 CA'PULOI'DA. Same as Capuloides. 
 
 CAR'DIA. Latin. Plural of cardium, 
 a cockle. A genus of the family 
 
 * of Cardiacea (page 84). 
 
 CAR'DIAC. From the Greek, kardia, 
 the heart. Belonging or relating 
 to the heart. 
 
 CARDIA'CEA. From the Latin, car- 
 dium, a cockle. Systematic name 
 of a family of acephalous mollusks 
 (page 83). 
 
 CARDIA'CEA. Plural of Cardiacea. 
 
 CAR'DITA. Genus of the family of 
 Cardiacea. 
 
 CARDINAL (tooth). From the Latin 
 cardo, a hinge. Belonging or re- 
 lating to the hinge (pages 99, 
 100). 
 
 CARDI'UM. Latin, a cockle. 
 
 CAR'TILAGE. Gristle. 
 
 CARTILA'GJNOUS. Belonging or re- 
 lating to cartilage. 
 
 CARINA'RTA. From the Latin, can'wor, 
 a keel. A genus of heteropodous 
 gasteropods (page 66). 
 
 CA'RINATE. From the Latin, carina, 
 a keel. When a surface has a 
 longitudinal elevated line like the 
 keel of a boat. 
 
 CARNI'VOROUS. From the Latin, caro, 
 in the genitive case, carnis, flesh, 
 and voro, I eat. Flesh eating. 
 
 CAS'SIS. Latin. A helmet (page 54). 
 
 CA'VA (Vena). A name given to the 
 two great veins of the body, which 
 meet at the right auricle of the 
 heart. 
 
 CEPHA'LIC. From the Greek, kephale, 
 the head. Belonging or relating 
 to the head. 
 
 CE'PHA LOPODS (ke'f-a-lo-pods). From 
 the Greek, kephale, head, and pous, 
 in the genitive case, podos, foot. A 
 class of mollusks which have the 
 head situated between the body and 
 feet (page 19). 
 
 CE'PHALOPO'DA. Latin. Cephalopods. 
 
 CE'RITA. ) /0 
 
 CERI'THIUM. f (See page 5^ 
 
 CHAMA (kama). From the Greek, 
 chad, I gape. A cockle. 
 
 CHAMA'CEA (ka-ma'-cea). From ch.a- 
 ma, a cockle. Systematic name 
 of a family of acephalous mollusks 
 (page 81). 
 
 CHI'TON (ky'-tori). From the Greek, 
 chiton, a garment. Name of a cy- 
 clobranch gasteropod (page 62). 
 
 CHON'DRUS (kon'drus). From the 
 Greek, chondros, cartilage. Name 
 of a genus of gasteropods (page 
 
 CHO'ROID (fro-royed). From the Greek, 
 
104 
 
 CONCHOLOGY. GLOSSARY. 
 
 chorivn, chorion, and eidos, re- 
 semblance. Name of the mem- 
 brane of the eye which lines the 
 sclerotica. 
 
 CICA'TRIX. From the Latin, coscare, 
 to conceal. The scar which re- 
 mains after the healing of a wound. 
 
 . The "muscular impressions" or 
 points where the adductor muscles 
 are attached in bivalve shells are 
 called cicatrices. 
 
 CICA'TRICES. Plural of cicatrix. 
 
 CI'LIATED. From the Latin, cilium, 
 eyelash. Fringed, like the eye- 
 lashes. 
 
 CINE'REUS. Latin. Like ashes ; ash- 
 colored. 
 
 CIRR'HOPODA, or CIRRIPEDIA. From 
 the Latin, cirrus, a tendril, a curl, 
 and the Greek, pous (podos\ foot. 
 Systematic name of a class of mol- 
 lusks. They are characterized by 
 having a number of long, curled, 
 articulated processes, analogous 
 to the feet of the Crustaceans, 
 which project from the central 
 aperture of the multivalve shell 
 protecting them. They are com- 
 monly called barnacles. This class 
 includes the genus Anatifa and 
 Balanus. 
 
 CLAUSI'LIA. From the Latin, clau- 
 sus, closed. A genus of land 
 shells, so named because the aper- 
 ture of the shell is closed inter- 
 nally by a spiral lid (page 40). 
 
 CLAVIGE'LLA. From the Latin, clavis, 
 a nail (page 88). 
 
 CLEODO'RA. Name of a genus of 
 pteropod mollusks (page 67). 
 
 CLIO. From the Greek, kleos, glory 
 (page 67). 
 
 CfficuM, or CAECUM. From the Latin, 
 coecus, blind. The Uind-gut, so 
 called from its being perforated at 
 one end only. 
 
 COLUME'LLA. Latin, a little column, 
 or pillar. The axis of a shell from 
 top to bottom (page 95). 
 
 COMPO'SITA. Latin. Compounded. 
 
 CON'CHIFE'RA. From the Greek, 
 conche, shell, and the Latin, fero, I 
 bear. Shell bearing. Applied to 
 mollusks with bivalve shells. 
 
 CONCHI'LJAN (kon-kii'-ean). Belong- 
 
 ing or relating to shells. The 
 name of a dye (page 57). 
 
 CONCHO'LOGY. From the Greek, 
 conche, a shell, and logos, a dis. 
 course. The science of shells. 
 
 CO'NUS. Latin. A cone. 
 
 COR. Latin. The heart. 
 
 CORALLI'OPHAGA. Latin. Formed 
 from the Greek, korallion, coral, 
 and phagein, to eat. Coral-eating. 
 
 COR'BIS. Latin. A twig basket, 
 or pannier. Name of a genus of 
 acephalous mollusks which have 
 the external surface of the shell 
 marked by ribs and transverse 
 lines, resembling basket-work 
 (page 84). 
 
 COR'DIFORM. From the Latin cor, m 
 the genitive case, cordis, heart, and 
 forma, shape. Heart-shaped. 
 
 COR'NEA. From the Latin, cornu, 
 horn. One of the coats of the eye, 
 so called because it has some re- 
 semblance to horn. It is the ante- 
 rior, transparent part, through 
 which light passes. 
 
 CRA'NIAL. From the Latin, cranium, 
 the skull. Belonging or relating 
 to the skull. 
 
 From the Latin, crena, 
 a notch. Having 
 rounded teeth. 
 
 CRE^ULA'TION. A rounded tooth, or 
 notch. 
 
 CREPJ'DULA. Latin. A slipper 
 (page 58). 
 
 CREPI'DUL^E. Plural of crepidula. 
 
 CRUSTA'CEA. From the Latin, crus- 
 ta, a hard covering. A class of 
 free articulate animals, with arti- 
 culated limbs, a branchial respi- 
 ration and a dorsal or ventrical 
 heart. 
 
 CRUSTA'CEA. Plural of Crustacea. 
 Crusta'ceans. 
 
 CRY'STALLINE LENS. The lens of the 
 eye. 
 
 CY'CLAS. From the Greek, kuklos, a 
 circle. A genus of fresh water 
 gasteropods, so named from the 
 circular form of the shell. 
 
 CY'CLADES. Plural of cyclas. 
 
 CY'CLOBRANCHI'ATA. From the Greek> 
 kuklos, a wheel, and bragcnia, gills. 
 Name of an order of mollusks 
 (page 61), 
 
 CRE'NULATE. 
 CRE'NULATED. 
 
CONCHOLOGY GLOSSARY. 
 
 105 
 
 CYCLO'STOMA. From the Greek, ku- 
 klos, a circle, and stoma, mouth. A 
 genus of gasteropods (page 48). 
 
 CYCLO'STOMA:. Plural of cy clostoma. 
 
 CYMBU'UA. From the Greek, kum- 
 balon, hollow. A genus of ptero- 
 poda, commonly called the gondola. 
 
 CYPR^'A. From the Greek, kupris, 
 Venus. Name of a genus of gas- 
 teropods. A cowry. 
 
 CYPIUE'^E. Plural of Cyproea. 
 
 CYPRICAR'DIA. From the Greek, ku- 
 pris, Venus, and cardium, a 
 cockle. A genus of the family of 
 Chama'cca. 
 
 CYPRI'NA. A genus belonging to 
 a group of Cy'clades. 
 
 CYRE'NA. A genus of the family of 
 Chama'cea. 
 
 DELPHI'NULA. Latin. A little dol- 
 phin. Name of a genus of the 
 family of Trochoides. 
 
 DEN'TATE. From the Latin, dens, 
 tooth. Marked with tooth-like 
 projections. 
 
 DEPRESSED SHELL. When the spire 
 is very flat. 
 
 DI'APHRAGM. Midriff. 
 
 DI'BRANCHIA'TA. From the Greek, 
 dis, two, and bragchos, gills two- 
 gilled. Name of a division of ce- 
 phalopods. 
 
 DIBRA'NCHIAL (di-bra'nk-eal). Hav- 
 ing double gills or branchiae. 
 
 DIGITA'TION. From the Latin, digi- 
 tus, ringer. A process resembling 
 a finger. 
 
 DIMYA'RIA. From the Greek, dis, 
 two, and mudn, muscle. All those 
 bivalves are so called which have 
 two distinct and separate adductor 
 muscles, and consequently two cor- 
 responding muscular impressions 
 on each valve. 
 
 DIMYA'RIA. Plural of dimyaria. 
 
 DIPHYLLI'DIA. From the Greek, dis, 
 two, and phullon, leaf. Name of a 
 division of gasteropods (page 62). 
 
 DI'SCOID. From the Greek, diskos, a 
 quoit, and eidos, resemblance. 
 This term is applied to those uni- 
 valve shells of which the whorls 
 are disposed vertically on the same 
 plane so as to form a disc ; as in 
 the Planorbis (page 44). 
 
 DOLA'BELLA. Latin. A little axe. 
 
 Name of a genus of gasteropods 
 (page 64). 
 
 DO'LIUM. Latin. A tun or tub. 
 Name of a genus of gasteropoda 
 (page 53). 
 
 DO'NAX. Latin and Greek. A reed ; 
 an arrow. Name of a genus of 
 mollusks of the family of Chama'- 
 cea (page 84). 
 
 DO'NACES. Plural of Donax. 
 
 DO'RIS. A sea goddess, the daughter 
 of Ocean and Thetys. Name of a 
 genus of nudibranch gasteropods 
 (page 65). 
 
 DO'RSAL. From the Latin, dorsum, 
 the back. Belonging or relating 
 to the back. 
 
 E'DULIS. Latin. Edible ; that which 
 may be safely eaten. 
 
 EMARGI'NULA. From the Latin, e, 
 from, and mar go, in the genitive, 
 marginis, border or margin. A 
 genus of gasteropods, character- 
 ized by a shell of simple conical 
 form, but having a narrow fissure, 
 extending from the margin to near 
 the summit (page 61). 
 
 ENTIRE OPENING. When the opening 
 of a shell has neither a notch or 
 canal on its margin, it is said to 
 be entire (page 94, and page 50, 
 Jig. 51). 
 
 E'OLIDIA. Name of a genus of gaste- 
 ropods (page 65). 
 . Pl 
 
 lural of Eolidia. 
 
 EPIDE'RMIS. From the Greek, epi, 
 upon, and derma, skin. The cu- 
 ticle or scarf-skin. 
 
 E'QUIVALVE. When the two valves 
 of a bivalve shell are symmetrical 
 they are said to be equivalve (page 
 97). 
 
 ETHE'RIA. From the Greek, aithd, I 
 shine. Name of a genus of the 
 family of Ostracea (page 75). 
 
 ETHE'RIA. Plural of Etheria. 
 
 EXCRE'TORY. Applied to any vessel 
 or duct which transmits the fluid 
 secreted by a gland, either exter- 
 nally or into the reservoir designed 
 to receive it. 
 
 EXTRAVASA'TION. From the Latin, 
 extra, out of, .and vasa, vessels. 
 Escape of fluids from vessels con 
 taining them and the effusion of 
 
106 
 
 OONCHOLOGY. GLOSSARY. 
 
 those fluids into the surrounding 
 textures. 
 
 FASCI'CULUS. Latin. A bundle. 
 
 FASCI'CULI. Plural of fasciculus. 
 
 FI'BROUS. Composed of fibres. 
 
 FILI'FORM. From the Latin, filum, 
 a thread. Thread-like. 
 
 FIRO'LA. Name of a genus of gaste- 
 ropods (page 67). 
 
 FIRO'LJE. Plural of Firola. 
 
 FISSURE' LLA. From the Latin, findo, 
 I split. A genus of gasteropods 
 having a split or opening in the 
 top of the shell. 
 
 FISSURE' LL;E. Plural of Fissurella. 
 
 FISTULA'NA. From the Latin, fistula, 
 a pipe. Name of a tribe of mol- 
 lusks (page 88). 
 
 FISTULA'NA. Plural of Fistulana. 
 
 FO'LLICLE. From the Latin, follis, a 
 bag. A little bag or sack. 
 
 FORAMI'NIFE'RA. From the Latin, 
 foramen, a hole, and fero, I bear. 
 Name of a tribe of very minute 
 shells. 
 
 FORMA'TION. A geological term ap- 
 plied to a group of deposits or strata 
 apparently referable to a common 
 origin or period. 
 
 FO'SSA. Latin. A pit, a hollow. 
 
 FOS'S.E. Plural of fossa. 
 
 FRA'GILIS. Latin. Fragile ; easily 
 broken. 
 
 Fu'cus. Latin. Sea-weed. 
 
 Fu'sus. Latin. A spindle. 
 
 GALE' A. Latin. A helmet. 
 
 GAN'GLIA. Plural of ganglion. 
 
 GA'NGLION. From the Greek, gag- 
 glion, a knot. An enlargement or 
 knot in the course of a nerve is 
 termed a ganglion. 
 
 GA'NGLIONIC. Consisting of, or re- 
 lating to ganglia. 
 
 GA'STEROPODS. From the Greek, 
 gaster, belly, and pous, foot. Sys- 
 tematic name of a class of mol- 
 lusks, comprehending those which 
 have a ventral muscular disc, 
 adapted for creeping. 
 
 GA'STEROPO'DA. Latin. Gasteropods. 
 
 GA'STEROPO'DOUS. Belonging or re- 
 lating to gasteropods. 
 
 GAS'TROCILE'NA. From the Greek, 
 gaster, belly, and chain o, I gape. 
 A genus of bivalve mollusks, in 
 
 which a large hiatus or gape inter- 
 venes between the closed valves, on 
 the ventral aspect of the animal 
 (page 88). 
 
 GAS' TROCHEE' N^E. Plural of gastro- 
 chaena. 
 
 GE'NUS. Latin. A kindred, breed, 
 race, stock, lineage or family. 
 
 GE'NKRA. Latin. Plural of genus. 
 
 GLAND. An organ for the purpose 
 of secreting a peculiar fluid, &c. 
 
 GLA'NDULAR. Relating to glands. 
 
 GLAU'CUS. From the Greek, glaukos, 
 blue. Name of a genus of mollusks 
 (page 66). 
 
 GLO'BOSE. Globe-like ; globular. 
 
 GLYCY'MERA, or GLYCI'MERIS. Name 
 of a genus of bivalve mollusks 
 (page 86). 
 
 GRYPH^E'A. From the Greek, gru- 
 pos, incurved. A genus of mol- 
 lusks of the family of Ostracea 
 (page 73). 
 
 HA'LIOTIS. From the Greek, als, the 
 sea, and ous, the ear. Name of a 
 genus of gasteropods (page 60). 
 
 HALIO'TIDES. Plural of Haliotis. 
 
 HAR'PA. Latin. A harp. 
 
 HELICI'NA. Name of a genus of gas. 
 teropods. 
 
 HE'LIX. From the Greek, elix, a 
 spiral, a whorl. Name of a genus 
 of gasteropods (page 39). 
 
 HELI'CES. Plural of Helix. 
 
 HEMI'CYCLO'STOMA. From the Greek, 
 emisus, half, kuklos, round, and 
 stoma, mouth. Name of a tribe of 
 gasteropods (page 49). 
 
 HERBI'VOR,OUS. From the Latin, 
 herba, plants, and voro, I eat. 
 Plant-eating ; applied to animals 
 that feed on vegetables. 
 
 HERMA'PHRODITE. From the Greek, 
 ermes, Mercury, and aphrodite, 
 Venus. An organized body, com- 
 bining in reality or appearance the 
 characteristics of both sexes. 
 
 HE'TEROPODS. From the Greek etc- 
 ros, various, and pous, foot. The 
 name of an order of gasteropods. 
 
 HE'TEROPO'DA. Latin. Heteropods 
 (page 66). 
 
 HE'TEROPO'DOUS. Belonging or relat- 
 ing to heteropods. 
 
 HIA'TUS. Latin. A yawning, a 
 gape. 
 
CONCHOLOGY. GLOSSARY. 
 
 107 
 
 HIPPO'NYX. From the Greek, ippos, 
 
 a horse, and onux, nail. Name of 
 
 a genus of gasteropods (page 58). 
 HYAL^E'A. From the Greek, ualos, 
 
 glass. A genus of beautiful ptero- 
 
 pods, remarkable for the trans- 
 
 parency and delicacy of the shell 
 
 (page 67). 
 HYDA'TIS. Latin. Formed from the 
 
 Greek, udor, water. Specific name 
 
 of a mollusk. 
 IM'BRICATE. Placed like the tiles of a 
 
 house. 
 INCLU'SA. From the Latin, includo, 
 
 I enclose. Name of a tribe of 
 
 acephalous mollusks. 
 INCURV'ED. When a part is turned 
 
 inwards. 
 INE'QUILATERAL. When the anterior 
 
 and posterior sides make different 
 
 angles with the hinge. 
 INE'QUIVALVE. Where one valve is 
 
 more convex than the other, or dis- 
 
 similar in other respects, as in the 
 
 common oyster. 
 IN'FEROBRANCHIA'TA. From the Lat- 
 
 in, infer us, below, and bronchia, 
 
 gills. Name of an order of gas- 
 
 teropods which have the branchiae 
 
 below the mantle (page 62). 
 INTE'GUMENT. F-rom the Latin, te- 
 
 gere, to cover, the covering, the 
 
 skin. 
 IN'TERGANGLIO'NIC. Applied to 
 
 nerves which are between ganglia. 
 IN'TERNODE. The space between one 
 
 knot or joint and another. 
 INTERRU'PTED. Divided, separated. 
 
 or joint of the spine or back-bone. 
 A division of the animal kingdom, 
 embracing mollusks, insects, and 
 other animals which have no ver- 
 tebrae, or internal bony skeleton. 
 
 INVE'RTEBRATE. Without vertebrae. 
 
 IN'VOUJTE. Having the exterior lip 
 turned inwards at the margin, as 
 in the CyprsBte. 
 
 INVOLUTION. That part which in- 
 volves or inwraps another. 
 
 ISO'CARDIA. From the Greek, isos, 
 like, and kardia, heart. Name of 
 a genus of Chama'cea (page 82). 
 ' of Isocardia. 
 
 JANTHI'NA. From the Greek, ianthon, 
 violet colour. A genus of the 
 family of Trochoides. 
 
 LA'BIAL. From the Latin, labium, 
 lip. Belonging or relating to the 
 lips. 
 
 LACI'NIATE. Jagged, or cut into ir- 
 regular segments. 
 
 LA'CUNOSE. Having the surface 
 covered with pits. 
 
 LAME'LLA. Latin. A little thin plate 
 or piece. 
 
 LAME'LL^E. Plural of lamella. 
 
 LAME'LLIBRA'NCHIATA- From the 
 Latin, lamella, a thin plate, and 
 bronchia, gills. An order of aceph- 
 alous mollusks. 
 
 LAME'LLIBRANCH. Belonging to the 
 lame 'llibra'nchiata. 
 
 LA'MINA. Latin. A plate, or thin 
 piece of metal or bone. 
 
 LA'MINME. Plural of lamina. 
 
 LA'MINATED. Divided into distinct 
 laminae. 
 
 LAPI'LLUS. Latin. A little stone. 
 
 LENTI'CULAR. From the Latin, len- 
 ticula, a little lens, a lentil. 
 Shaped like a lens. 
 
 LI'MA. Latin. A file. Name of a 
 genus of the family of Ostracea. 
 
 LI'MAX. Latin. A slug, a snail. 
 
 LIMA'CES. Plural of Umax. 
 
 LIMB. The margin of bivalve shells. 
 
 LIMN^E'A. From the Greek, limne, a 
 pool. Name of a genus of fresh- 
 water snails. 
 
 LI'NEAR. Composed of lines. 
 
 LI'NEATE. Marked with lines. 
 
 LI'NGULA. Latin. A little tongue. 
 Name of a genus of bivalves (page 
 89). 
 
 LI'NGULA. Plural of Lingula. 
 
 LITHO'DOMUS. From the Greek, 
 lithos, stone, and demo, I build. 
 Name of a genus of bivalves found 
 in rocks and stones, inhabiting 
 cavities which they form for that 
 purpose. 
 
 LITHO'DOMI. Plural of Lithodomus. 
 
 LJ'TTORAL. Belonging to the shore. 
 
 LITTORI'NA. From the Latin, litus, 
 the sea-shore. A genus of the 
 family of Trochoides (page 49). 
 
 LITTO'REUS. Latin. Belonging ox 
 relating to the sea-shore. 
 
108 
 
 CONCHOLOGY. GLOSSARY. 
 
 LO'BATED. Rounded at the edges. 
 
 LOBE. A round projecting part. 
 
 LO'LIGO. Latin. A calmary. 
 
 LOLIGO'PSIS. A calmaret; a little 
 calmary. 
 
 LONGITU'DINAL. The length of the 
 shell from the apex to the base. 
 
 LUBRI'CITY. Smoothness of surface, 
 slipperiness. 
 
 LU'NATED. Formed like a half-moon. 
 
 LUNU'LATED. Crescent-shaped. 
 
 LU'NULE. A crescent-like spot or 
 mark situated near the anterior 
 and posterior slopes in bivalve 
 shells. 
 
 LU'NIFORM. In the shape of a cres- 
 cent or half-moon. 
 
 LUTRA'RIA. Genus of the family of 
 Inclusa. 
 
 MACTRA. Latin. A kneading- 
 trough. Name of a genus of bi- 
 valves. 
 
 MA'DREPORE. A hybrid compound 
 of the French madre, spotted, and 
 Latin, porus, a pore. Name of a 
 genus of zoophytes. 
 
 MA'GILUS. Name of a genus of gas- 
 teropods. 
 
 MA'GUS. Latin. Magical. 
 
 MA'LLEUS. Latin. A hammer. A 
 genus of Ostracea. 
 
 MA'NDIBLE. From the Latin, man- 
 dibula, a jaw. The jaw of a bird. 
 
 MAN'TLE. The external fold of the 
 skin of mollusks. 
 
 MA'RGARITI'FERA. Latin. From mar- 
 garitum, a pearl, and fero, I bear. 
 Pearl-bearing. 
 
 MA'RGIN. The whole circumference 
 or outline of the shell in bivalves. 
 
 MA'RGINATED. Having a prominent 
 margin or border. 
 
 MEDITERRA'NEA. Latin. Belonging 
 or relating to the Mediterranean. 
 
 MEDU'LLARY. From the Latin, me- 
 dulla, the marrow. Belonging or 
 relating to nervous matter. 
 
 MELA'NIA. From the Greek, melas, 
 black. Genus of fresh- water gas- 
 teropods. 
 
 MELEAGRI'NA. From the Greek, me- 
 leagris, a guinea-hen. A genus 
 of the family of Ostracea. 
 
 MEM'BRANOUS. Belonging or relat- 
 ing to membrane. 
 
 ME'SENTERY. From the Greek, me- 
 
 sos, in the middle, and enleron, in- 
 testine. A membrane which 
 serves to retain the intestines in 
 their proper situation. 
 
 METAMO'RPHOSIS. From the Greek, 
 meta, indicating change, and mor- 
 phe, form. Transformation. 
 
 MICROSCO'PIC. From the Greek, mi- 
 kros, little, and skoped, I view. Di- 
 minutive. Not easily seen with- 
 out the aid of a magnifying-glass. 
 
 MI'TRA. Greek. A head-band, or 
 diadem. A genus of gasteropods. 
 
 MODIO'LUS. Latin. A bucket. A 
 genus of mussels. 
 
 MO'LECULE. An atom. 
 
 MOLLU'SCA. From the Latin, mollis, 
 soft. Name of the second branch 
 of the animal kingdom. 
 
 MO'LLUSK. A soft animal. 
 
 MO'NODON. From the Greek, monos, 
 single, and odous, tooth. A genus 
 of the family of Trochoides. 
 
 MONODON'TA. Latin. Monodons. 
 
 MONO'MYA'RJA. From the Greek, 
 monos, single, and muon, muscle. 
 Bivalves which have only one ad- 
 ductor muscle. 
 
 MU'CRONATE. Ending in a sharp, 
 rigid point. 
 
 MU'LTIVALVE. From the Latin, 
 multus, many, and valvtB, valves. 
 Composed of several, or more than 
 two calcareous pieces or valves. 
 
 MULTILO'CULAR. From the Latin, 
 multus, many, and loculus, a lodge. 
 Many-chambered ; consisting of 
 several divisions. 
 
 MU'REX. ^.Latin. A shell-fish. A 
 genus" o^fcasteropods. 
 
 MU'RICES. Plural of Murex. 
 
 MU'RICATED. Clothed with sharp 
 spines. 
 
 MU'SCLE. Fleshy fibres capable of 
 contraction and relaxation. 
 
 MU'SCUI.AR. Belonging or relating 
 to muscle. 
 
 MU'SSEL. An acephalous mollusk. 
 
 MY'A. From the Greek, muon, a 
 muscle. An acephalous mollusk. 
 
 MYTILA'CEA. From the Greek, mu- 
 tilos, a mussel. Name of a family 
 of mollusks. 
 
 MY'TILUS. Latin. A mussel. 
 
 NA'CRE. From the Spanish, nacar, 
 mother-of-pearl. 
 
CONCHOLOGY. GLOSSARY. 
 
 109 
 
 NA'CREOUS. Of the nature of mother- 
 of-pearl. 
 
 NA'SSA. Latin. A net, a snare. A 
 genus of gasteropods. 
 
 NA'TICA. Latin. Name of a genus 
 of gasteropods (pages 34 and 51). 
 
 NAU'TILUS. From the Greek, Nau- 
 tilos, name of the Argonaut. A 
 genus of cephalopods. 
 
 NE'MORAL. From the Latin, nemus, 
 a wood. Belonging or relating to 
 a wood or grove. 
 
 NERI'TA. Latin. A shell-fish. A 
 genus of gasteropods (page 51). 
 
 NERITI'NA. Latin. Diminutive of 
 Nerita. A genus of gasteropods 
 (page 51). 
 
 NERV'OUS. Belonging or relating to 
 the nerves. 
 
 NILO'TICUS. Latin. Belonging to 
 the Nile. 
 
 NI'TED. From the Latin, niteo, I 
 shine. Glossy. 
 
 NODO'SE. Knotty. 
 
 NU'CHA (nu-ka). The nape of the 
 neck. 
 
 NU'CLEUS. A kernel. A centre 
 around which matter has accumu- 
 lated. 
 
 NU'DA. Latin. Naked. 
 
 NU'DIBRANCH. Relating to the Nu- 
 dibranchiata. 
 
 NU'DIBRANCHIA'TA. From the Latin, 
 nudus, naked, and branchia, gills. 
 Name of an order of gasteropods. 
 
 NUMMULI'TES. From the Latin num- 
 mus, money, and the Greek, lithos, 
 stone. An extinct genus of cepha- 
 lopods, of a thin lenticujar shape, 
 divided internally into small cham- 
 bers. These occur so abundantly 
 in some parts of the chalk forma- 
 tion, that the name of nummulite 
 limestone is given to the strata so 
 characterized. 
 
 OB'LONG-O'VATE. Egg shaped, or oval. 
 
 OB'SOLETE. Indistinct, not well de- 
 nned. 
 
 O'CELLATED. From the Latin, ocu- 
 lus, an eye. Marked with eye- 
 like spots. 
 
 O'CHRKOUS (ok 1 -re-us}. Of the colour 
 of yellow ochre. 
 
 O'cTOPus. From the Greek, oJtto, 
 eight, and pous, foot. Name of a 
 genus of cephalopods. 
 
 10 
 
 OCTOPO'DIA. A tribe of cephalopods. 
 
 OZso'pHAGEAL. Belonging to the 
 oesophagus. 
 
 CEso'pHAGus. Latin. The gullet. 
 
 OF'FUSCATED. Darkened, clouded, 
 dimmed. 
 
 OFFICINA'LIS. Latin. Officinal. 
 From officina, a shop. Applied to 
 what is ready prepared. 
 
 OLI'VA. Latin. An olive. A genus 
 of gasteropods. 
 
 OLIVA'CEOUS. Being of a greenish 
 olive colour. 
 
 ONCHI'DIUM. A genus of gasteropods 
 (page 41). 
 
 OPA'QUE. From the Latin, opacus, 
 dark. Incapable of transmitting 
 light. 
 
 OPE'RCULUM. From the Latin, 
 operio, I cover. The lid or door 
 which covers anything. 
 
 O'PTIC. From the Greek, optomai, I 
 see. The principal nerve of vision, 
 is so called. 
 
 ORBI'CULA. From the Latin orbis, a 
 circle. A genus of brachiopod 
 mollusks (page 90). 
 
 ORBI'CULAR. Spherical, circular, 
 round. 
 
 O'RGAN. From the Greek, organon, 
 an instrument. Part of an organ- 
 ized being, destined to exercise 
 some particular function. 
 
 ORGANIZA'TION. A mode of structure. 
 
 OSTRA'CEA. Name of a family of 
 bivalves. 
 
 OS'TREA. Latin. An oyster. Name 
 of a genus of the family of Os- 
 tracea. 
 
 O'VARIES. Female organs which 
 contain the ova or eggs. 
 
 O'VATE. Shaped like the longitudi- 
 nal section of an egg. 
 
 O'VIDUCT. From the Latin ovum, an 
 egg, and duco, I conduct. The 
 tube which conveys the ovum from 
 the ovary. 
 
 OVI'PAROUS. From the Latin, ovum, 
 an egg, and pario, I produce. Ap- 
 plied to animals whose young are 
 produced by means of eggs. 
 
 O'vom. Oval. 
 
 O'VULA. From the Latin, ovum, an 
 egg. A genus of gasteropods. 
 
 O'VULJE. Plural of ovula. 
 
 PA'LATINE. Relating to the palate. 
 
110 
 
 CONCHOLOGY. GLOSSARY. 
 
 PA'LLIAL. Belonging or relating to 
 
 the pallium. 
 PA'LLIUM. Latin. A cloak. The 
 
 mantle of mollusks is so called. 
 PALUDI'NA. In the plural Paludinee. 
 
 From the Latin, palus, a marsh. 
 
 Name of a genus of fresh-water 
 
 gasteropods. 
 PAN'CREAS. A gland situated in the 
 
 abdomen. 
 PAPI'LLA. Plural, papilla. Latin. 
 
 A nipple. A nipple-like eminence. 
 ) Having the surface 
 . coverfdwithp im p,e S 
 
 } or dots. 
 PA'PILLOSE. Pimpled, dotted. 
 PAPYRA'CEOUS. From the Latin, pa- 
 pyrus, a sort of paper. Thin as 
 
 paper. 
 PARI'ETES. From the Latin, paries, 
 
 a wall. A name given to parts 
 
 that form the enclosures the 
 
 limits of different cavities of the 
 
 body. 
 PARMACE'LLA. From the Latin, 
 
 parma, a round buckler. A genus 
 
 of naked gasteropods. 
 PATE'LLA. In the plural patella. 
 
 Latin. The knee-pan. A genus 
 
 of gasteropods (page 61). 
 PA'TULOUS. With a gap or opening. 
 PE'CTEN. In the plural pectenes. 
 
 Latin. A comb. A genus of the 
 
 family of Ostracea (page 73). 
 PEC'TINA'TA. Latin. Pectinated. 
 PECTINATED. Resembling the teeth 
 
 of a comb. 
 PECTI'NIBRANCH. From the Latin, 
 
 pecten, comb, and bronchia, gills. 
 
 Relating to the Pectinibranchiata. 
 PECTINIBRANCHIA'TA. Name of an 
 
 order of gasteropods. 
 PECTU'NCUI-US. Latin. Name of a 
 
 genus of the family of Ostracea 
 
 (page 78). 
 
 PE'DICLE. A support. A little foot. 
 PE'DIFORM. Foot-shaped. 
 PEDU'NCLE. A foot- stalk or tube on 
 
 which anything is seated. 
 PEDU'NCULATE. Having a peduncle. 
 PELA'GIC. Belonging to the deep sea. 
 PE'LLICLE. A thin skin or film. 
 PENU'LTIMATE. Next to the last. 
 PE'RNA. In the plural pernce. Latin. 
 
 A gammon. A genus of the 
 
 family of Ostracea (page 75). 
 
 PERTCA'RDIUM. The sack which con. 
 
 tains the heart. 
 PETRACO'LA. From the Latin, pelra, 
 
 a stone, and colo, I inhabit. Name 
 
 of a family of Ostracea (page 85). 
 PHASIANE'LLA. From the Greek, pha. 
 
 sianos, a pheasant. A genus of 
 
 gasteropods (page 50). 
 PHARY'NX. The swallow. The su- 
 perior opening of the gullet. 
 PHO'LAS. In the plural pholades. 
 
 From the Greek, pholtos, a lurking. 
 
 place. A genus of the family of 
 
 Iriclusa (page 87). 
 
 PHOSPHO'RIC. ) Emitting light 
 
 PHOSPHORE' SCENT. ( in the dark. 
 PHYLLI'DIA. From the Greek, 
 
 phullon, a leaf. Name of a tribe 
 
 of mollusks (page 62). 
 PHY'SA. From the Greek, phusa, 
 
 a bubble. A genus of fresh-water 
 
 snails (page 42). 
 PI'CA. Latin. Black as pitch. 
 PILEO'PSIS. From the Greek, pilos, 
 
 a hat. A - genus of gasteropods 
 
 (page 58). 
 PI'LLAR. The internal continuation 
 
 of the columella, and extends from 
 
 the base to the apex. 
 PI'NNA. Latin. In the plural pinna. 
 
 A fin, a wing. A genus of the 
 
 family of Ostracea. 
 PI'NNATED. Winged. 
 PLANO'RBIS. From the Latin, planis t 
 
 flat, and orbis, an orb, a circle. A 
 
 genus of marsh-snails (page 42). 
 PLI'CA. Latin. A fold. 
 PLI'CATE. Folded or plaited, as in the 
 
 pillar of the Volute tribe. 
 PLEUROBR^'NCHUS (plu-ro-brari-kus). 
 
 From the Greek, pleura, side, 
 
 and bragchia, gills. A genus of 
 
 gasteropods (page 63). 
 PLEUROBRA'NCHI (plu-ro-bran'-ki). 
 
 Plural of Pleurobranchus. 
 PLUMO'SE. Having a feathery ap- 
 pearance. 
 
 PO'LYPI. Plural of Polypus. 
 PO'LYPUS. From the Greek, polus, 
 
 many, and pous, foot. A genus of 
 
 radiate animals. 
 POLYTHA'LAMOUS. From the Greek, 
 
 polus, many, and thalamos, cham- 
 ber. Having many chambers. 
 POR'CATE. Marked with raised 
 
 longitudinal lines. 
 
CONCHOLOGY GLOSSARY. 
 
 Ill 
 
 PORCELLA'NA. Latin. Porcelain. 
 PORRE'CTED. Projecting-. 
 POST-CESOPHA'GEAL.. Situate behind 
 
 the oesophagus. 
 POUNCE. A powder to prevent ink 
 
 from spreading- after erasures. 
 PREHE'NSION. The act of laying hold 
 
 of and conveying the food to the 
 
 mouth. 
 PROBO'SCIS. A trunk, a prolongation 
 
 of the nose. 
 
 PRODUCED. Lengthened out. 
 PSAMMO'BIA. From the Greek, psam- 
 
 mos, sand. A genus of bivalves. 
 PTERO'CERA. From the Greek, 
 
 pteron, wing, and keras, a horn. A 
 
 genus of gasteropods (page 55). 
 PTERO'PODA. From the Greek, 
 
 pteron, a wing, and pous, foot. 
 
 Name of a class of mollusks (page 
 
 67). 
 PUNC'TUATED. From the Latin, punc- 
 
 tum, a point. Having small hol- 
 lows like the punctures of a 
 
 thimble. 
 PU'LMONARY. Belonging or relating 
 
 to the lungs. 
 
 PULMONE'A. Latin. Pulmonary. 
 PU'PA. Latin. A puppet. A genus 
 
 of snails. 
 PUR'PURA. Latin. Purple. A genus 
 
 of the family of Buccinoides (page 
 
 53). 
 PYLO'RUS. The right orifice of the 
 
 stomach. 
 
 PY'RIFORM. Pear-shaped. 
 PYROSO'MA. In the plural pyrosomtB. 
 
 From the Greek, pur, fire, and 
 
 soma, body A genus of mollusks 
 
 (page 92). 
 QUADRA'NG ULAR. Having four 
 
 angles. 
 QUA'DRIPLICATED. Having four 
 
 plaits. 
 RADIA'TA. Latin. Name of a class 
 
 of Zoophytes. 
 RA'DIATE. From the Latin, radius, a 
 
 ray. Furnished with rays. 
 RE'CTUM. The terminating portion 
 
 of the intestine. 
 RECCJ'RVED. Bowed back. 
 REFLE'CTED. Bent backwards. 
 REFKA'CTED. Abruptly bent, as if 
 
 broken. 
 
 RE'NIFORM. Kidney -shaped. 
 REPA'ND. With a serpentine margin. 
 
 RE'PLICATED. Folded so as to form a 
 
 groove or channel. 
 RESPIRA'TION. The act or function of 
 
 breathing. 
 RESPI'RATORY. Relating to respira- 
 
 tion. 
 RETI'CULATED. Formed like a piece 
 
 of net- work. 
 RETRA'CTILE. Susceptible of being 
 
 drawn back. 
 
 RETROFLE'CTED. Bent backwards.. 
 RETROU'SSE. Backed up, turned up. 
 RETROVE'RTED. Turned back. 
 RETU'SE. Ending in an obtuse sinus. 
 RETUN'DATED. Blunted or turned at 
 
 the edge. 
 
 RE'VOLUTE. Rolled backwards. 
 RI'MA. The interstice between the 
 
 valves when the hymen is re- 
 
 moved. 
 ROS'TRUM. The beak. The exten- 
 
 sion of that part of the shell in 
 
 which the canal is situated. 
 ' ROTO'ND. Round, circular, spheri- 
 
 cal. 
 
 RU'FOUS. Of a reddish colour. 
 RU'FUS. Latin. Reddish. 
 RU'GOSE. Rugged, full of wrinkles. 
 SALI'VA. The fluid secreted in the 
 
 mouth by the salivary glands. 
 SA'LIVARY. Relating to saliva. 
 SANGUI'NOLA'RIA. From the Latin, 
 
 sanguis, blood. Name of a genus 
 
 of acephalous mollusks. 
 SANGUINA'CEOUS. Of a blood colour, 
 
 or resembling blood. 
 SCA'BROUS. From the Latin, scaber, 
 
 rough. Rough, harsh, rugged, or 
 
 like a file. 
 SCALA'RIA. From the Italian, scala, 
 
 a ladder, or series of stairs. Name 
 
 of a genus of gasteropods. 
 SCA'LLOPED. Indented at the edges. 
 SCLERO'TICA. From the Greek, skle- 
 
 ros, hard. One of the external 
 
 membranes of the eye-ball. 
 SCORBI'CULATE. Pitted, having the 
 
 surface covered with hollows. 
 
 SCUTIBRANCHIA'TA. From the Latin, 
 scutum, a shield, and branchia, gills. 
 An order of gasteropods. 
 
 SEAM. The line formed by the union 
 of the valves. 
 
 SE/CONDARY FORMA'TION. A series of 
 
112 
 
 CONCHOLOGY. GLOSSARY". 
 
 stratified rocks with certain cha- 
 racters by which they are distin- 
 guished from the primary rocks. 
 By the term formation geologists 
 understand a series of rocks of the 
 same age. Those rocks which 
 were first formed are called pri- 
 , mary ; those formed next in suc- 
 cession are secondary ; and so on. 
 
 SECRE'TION. From the Latin, secer- 
 nere, to separate. The process by 
 which organic structure is enabled 
 to separate from the fluids circu- 
 lating in it, other different fluids. 
 These separated fluids are also 
 called secretions. 
 
 SECRE'TORY. Belonging or relating 
 to secretion. 
 
 SEMICOR'NEOUS. From the Latin, 
 semi, half, and cornu, horn. Half 
 or partly horny in its nature. 
 
 SE'PIA. Latin. A cuttle-fish. A 
 kind of paint made from this ani- 
 mal. A genus of cephalopods. 
 
 SE'PTIFORW. From the Latin, sep- 
 tum, a partition. In the shape of a 
 partition. 
 
 SE'RRATED. From the Latin, sera, a 
 saw. Like the teeth of a saw. 
 
 SE'RRULATED. Very minutely ser- 
 rated. 
 
 SE'TA. Latin. A bristle. 
 
 SETA'CEOUS. ) Bristly ; covered with 
 
 SE'TOSE. bristles. 
 
 SIGARE'TUS. A genus of gasteropods. 
 
 SILIQUA'RIA. From the Latin, si'li- 
 qua, a pod. A genus of gastero- 
 poda tubulibranchiata. 
 
 SI'NISTER. The left. 
 
 SI'NUS. A groove or cavity. 
 
 SIPHONA'RIA. From the Greek, si- 
 phon, a tube. An order of cepha- 
 lopods. 
 
 SJPHU'NCULUS. A cylindrical canal 
 perforating the partitions in poly- 
 thalamous shells. 
 
 SO'LAR. From the Latin, sol, the sun. 
 Belonging or relating to the sun. 
 
 SOLA'RIUM. Latin. A sun-dial. A 
 genus of the family of Trochoides. 
 (page 46). 
 
 SOLEMY'A. A genus of the family of 
 Inclusa. 
 
 SO'LEN. From the Greek, solen, a 
 tube. A genus of acephalous mol- 
 lusks (page 86), 
 
 SPA'TULATE. Rounded and broad at 
 one end, and becoming narrow like 
 a battledore or spatula. 
 
 SPHEROI'DAL. Resembling a sphere 
 or globe. 
 
 SPI'NAL. Belonging or relating to 
 the spine. 
 
 SPI'NOUS. ) Covered with thorn -like 
 
 SPI'NY. processes or spines. 
 
 SPIRE. All the whorls of univalve 
 shells, except the one in which the 
 aperture is situated, which is term, 
 ed the body. 
 
 SPI'RAL. Twisted like a corkscrew. 
 
 SPLEEN. An organ of the body, the 
 use of which is not known : it is 
 vulgarly called the melt. 
 
 SPON'DYLUS. In Greek, spondulos, a 
 vertebra. A genus of bivalves, in 
 which the teeth of the hinge lock 
 into each other, like the vertebrae 
 of the spine. 
 
 SQUA'MOSE. From the Latin, squama, 
 a scale. Scaly. 
 
 STE'LLATED. Consisting of star-like 
 figures. 
 
 STRA'TA. Latin. Plural of stratum. 
 
 STRA'TUM. Latin. A bed, a layer. 
 
 STRI'A. Latin. In the plural stria. 
 A diminutive channel or crease. 
 
 STRI'ATED. Scored, or covered with 
 fine thread-like lines. 
 
 STRO'MBUS. Latin. In Greek strotn- 
 bos, a shell-fish. A genus of gas- 
 teropods. 
 
 STY'LET. A small style or slender 
 process. 
 
 SUBAR'CUATED. Somewhat arched. 
 
 SUBCO'NIC. Somewhat conical. 
 
 SuBtESOPHA'cEAL. Placed beneath the 
 oesophagus. 
 
 SUB'ROTUND. Nearly globular. 
 
 SUB'ULATE. Awl-shaped. 
 
 SUCCI'NEA. From the Latin, sue. 
 cinum, amber. A genus of gaste- 
 ropods, so called from the trans- 
 parent texture and amber colour 
 of the shell. 
 
 SU'LCATED. Furrowed. 
 
 SU'LCI. Plural of sulcus. 
 
 SU'LCUS. Latin. A furrow. 
 
 SU'MMIT. The tip or apex. 
 
 SU'PERFICIES. From the Latin, super, 
 above, and fades, face. The sur- 
 face. 
 
 SUPERPO'SED. From the Latin, super t 
 
CONCHOLOG7. GLOSS AK Y. 
 
 113 
 
 above, and pono, I place. Laid 
 one upon another ; lying above. 
 
 SU'TURE. The seam, or fine spiral 
 line which separates the whorls or 
 wreaths. 
 
 SY'PHON From the Greek, siphon, 
 a tube. 
 
 TACT. The sense which gives the 
 perception of touching. Touch is 
 active ; tact passive. 
 
 TECTIBRANCHIA'TA. From tego, I 
 cover, and branchia, gills. Name 
 of an order of gasteropods. 
 
 TEGUME'NTARY. Relating to the tegu- 
 ment or covering. . . 
 
 TELLI'XA. In the plural tellince. 
 From the Greek, telline, a species 
 of mussel. A genus of acephalous 
 mollusks. 
 
 TEN'TACLE. A feeler. 
 
 TENTA'CULA. The feelers of snails. 
 
 TENTA'CULAR. Belonging or relating 
 to tentacles. 
 
 TENTA'CULUM. Latin. A feeler. 
 
 TERE'BRA. Latin. From terebro, I 
 bore. A genus of gasteropods. 
 
 TEREBRA'TULA. Plural, terebratula. 
 A genus of acephalous mollusks 
 (page 89). 
 
 TERE'DO. Latin. A ship-worm. 
 
 TERE'DINES. Plural of teredo. 
 
 TERRE'STRIA. Latin. Terrestrial. 
 
 TER'TIARY FORMA'TION, or strata. A 
 series of sedimentary rocks which 
 lie above the primary and second- 
 ary strata, and distinguished from 
 them by their organic remains. 
 
 TE'SSELATED. Chequered like a 
 chess-board. 
 
 TESSELA'TUS. Latin. Tesselated. 
 
 TESTA'CEA. From the Latin, testa, a 
 shell. An order of acephala cover- 
 ed with a testaceous shell. 
 
 TESTA'CEOUS. Consisting of carbo- 
 nate of lime and animal matter. 
 
 TESTACE'LLA. A genus of snails 
 (page 39). 
 
 TE'TRABRANCH. Having four bran- 
 chiae. 
 
 TETRABRANCHIA'TA. From the Greek, 
 tetteres, four, and bragchia, gills, 
 Name of an order of gasteropods. 
 
 TE'TRAGONAL. Four cornered. 
 
 THORA'CIC. Belonging to the thorax. 
 
 THO'RAX. Latin. The chest. 
 
 TRANSVE'RSE. Placed crosswise. 
 10* 
 
 When the breadth of a shell is 
 greater than its length, it is termed 
 transverse. 
 
 TRAPE'ZIFORM. Shaped like a trape- 
 zium. 
 
 TRIDA'CXA. A genus of the family 
 of Chama'cea. 
 
 TRICO'RNIS." From the Latin, tres, 
 three, and cornw, horn. Three 
 horned. 
 
 TRIGO'NIA. From the Greek, trigo- 
 nos, three-cornered. A genus of 
 the family of Ostracea. 
 
 TRIGO'NAL. Three-cornered. 
 
 TRITO'NIA. A genus of gasteropods. 
 
 TROCHO'IDES. From the Greek, tro~ 
 chos, a wheel, and eidos, resem- 
 blance. Name of a family of gas- 
 teropods. 
 
 TRO'CHI. Plural of trochus. 
 
 TRO'CHUS (tro-kus}. A genus of gas- 
 teropods. 
 
 TRUNK. The body. 
 
 TRUN'CATE. Stunted, cut short or 
 abruptly off at the end. 
 
 TU'BERCLE. A little knot or pimple. 
 
 TUBE'RCULATED. Knotted or pirn- 
 pled. 
 
 TUBERO'SITIES. Prominent knobs or 
 excrescences. 
 
 TU'BULAR. In shape of a hollow tube 
 
 TU'BULATE. Hollow. 
 
 TUBULIBRANCHIA'TA. From the Latin 
 tubus, tube, and bronchia, gills. An 
 order of gasteropods which have 
 the branchias lodged in a tube 
 (page 59). 
 
 TUNICA'TA. Name of an order of 
 acephalous mollusks. 
 
 TU'NICATE. From the Latin, tunica, 
 a tunic. Coated. 
 
 TUR'BINATED. Shaped like a top of 
 pear. 
 
 TU'RGID. Swollen. 
 
 TU'RRETED. Resembling a tower 
 with turrets. 
 
 TU'RBO. Latin. A whirling or twist- 
 ing. A tribe of gasteropods (page 
 47). 
 
 TURRITE'LLA. Latin. A turret. A 
 genus of gasteropods. 
 
 UMBILI'CUS. The aperture or depres- 
 sion in the centre, round which the 
 shell is convoluted. 
 
 UMBILI'CATED. Having a depression 
 in the centre like an umbili'cus. 
 
114 
 
 CONCHOLOGY. GLOSSARY. 
 
 U'MBO. Latin. A protuberance or 
 boss. The round part of a bivalve 
 shell which turns over the hinge. 
 
 UM' BONES. Plural of umbo. 
 
 UM'BONATE. Bossed ; having a raised 
 knob in the centre. 
 
 UNARTI'CULATED. Not jointed. 
 
 UNDA'TUM. Latin. Waved. 
 
 UN'DULATED. Waved, 'having a 
 waved surface. 
 
 UNILO'CULAR. From the Latin, 
 unus, one, and loculus, partition. 
 Having a single chamber or com- 
 partment. 
 
 UNI'O. Latin. A pearl. A genus 
 of mussels (page 81). 
 
 UNIO'NES. Plural of Unio. 
 
 U'NIVALVE. Consisting of one piece 
 or valve. 
 
 UR'CEOLATE. Swelling in the middle 
 like a pitcher. 
 
 VAGI'NULA. Latin. A little sheath or 
 scabbard. A genus of naked gas- 
 teropods (page 39). It is the same 
 as vaginu'lus. 
 
 VALVA'TA. A genus of fresh-water 
 snails (page 48). 
 
 VA'RICES. Longitudinal ribs in uni- 
 valve shells. 
 
 VA'SCULAR. Composed of numerous 
 vessels. 
 
 VAU'LTED. Arched like the roof of 
 the mouth. 
 
 VE'NA. Latin. A vein. 
 
 VE'NOUS. Relating to veins. 
 
 VE'NTER. Latin. Belly. The most 
 prominent part of the shell when 
 the aperture is turned towards the 
 observer. 
 
 VE'NTRAL. Relating to the belly. 
 
 VEN'TRICOSE. Inflated ; swelled in 
 the middle. 
 
 VEN'TRICLE. A little belly. A part 
 of the heart. 
 
 VENERU'PIS. A genus of Cardiacea 
 (page 85). 
 
 VE'NUS. A genus of the family of 
 Cardiacea. 
 
 VERME'TUS. A genus of gasteropoda 
 (page 59). 
 
 VE'RMIFORM. Worm-shaped. 
 
 VE'RRUCOSE. From the Latin, verru- 
 ca, a wart. Warted. 
 
 VER'TEBRA. From the Latin, verier e, 
 to turn. A joint or bone of the 
 back-bone or spine. 
 
 VER'TEBRAL. Relating to the verte- 
 brae. 
 
 VERTEBRA'TA. Name of the first 
 branch of the animal kingdom. 
 
 VER'TEBRATE. Having vertebrae. 
 
 VERTI'CULATED. Whorled. 
 
 VE'SICLE. A diminutive bladder. 
 
 VESI'CULAR. Relating to vesicles. 
 
 Vi'scus. Any internal part, as the 
 heart, intestine, &c. 
 
 VI'SCERA. Plural of viscus. 
 
 VI'SCERAL. Relating to viscera. 
 
 VI'SCID. Glutinous, sticky. 
 
 VI'TREOUS. Resembling glass. A 
 humour of the eye is so termed. 
 
 VITRI'NA. From the Latin, vitrea, 
 glass. A genus of fresh-water 
 gasteropods. 
 
 VOLU'TA. Latin. A whorl. A genus 
 of gasteropods. 
 
 VULGA'RIS. Latin. Common. ' 
 
 WHORL. A wreath, or turning of the 
 spire of univalve shells. 
 
 ZONED. Surrounded with one or 
 more girdles. 
 
 ZOO'LOGY. From the Greek, zdon, 
 animal, and logos, discourse. The 
 science of animals. 
 
 ZOO'PHYTE. From the Greek, zdon, 
 animal, and phuton, plant. An 
 animal belonging to the fourth di- 
 vision of the animal kingdom. 
 
NEW AND IMPORTANT SCHOOL BOOKS. 
 
 TO TEACHERS, PRINCIPALS AND CONTROLLERS 
 
 OF SCHOOLS, ACADEMIES AND COLLEGES 
 
 We take the liberty of calling your attention to a Series 
 of Books on the subject of Natural History, which, in the 
 opinion of many of the most eminent men in our country, 
 is second to no branch of knowledge now taught in schools. 
 We ask your attention to these books, because we believe 
 them to be superior to any works of the kind ever offered 
 to the American public. They are small in size, extremely 
 cheap, as accurate in scientific arrangement as the most 
 voluminous works on similar subjects, and in every respect, 
 such as parents and teachers would wish to place in the 
 hands of their children. In confirmation of this opinion of 
 the worth of these works, we respectfully invite your 
 attention to the following testimonials. 
 
 . Very respectfully, your obedient servants, 
 
 GRIGG & ELLIOT, 
 JVb. 9 North Fourth Street, Philad'a. 
 
 These books have been introduced into the Public Schools of Pennsylvania 
 and Ohio, and no doubt will, ere long, be introduced into all the public schools 
 of our other States. 
 
 "We regard the introduction of these works into our public schools, among the 
 highest compliments they have received ; for we feel sure that the gentlemen 
 who constitute the committee for selecting books, possess too much discernment 
 and general knowledge, to pass favourably upon works of inferior pretensions. 
 The following gentlemen composed the Committee for selecting books for the 
 use of Public Schools." GEORGE M. WHARTON, Esq. 
 
 THOMAS H. FORSYTE, Esq. 
 GEORGE EMLEN, Jr., Esq. 
 FRANCIS LYONS, Esq. 
 JOHN C. SMITH, Esq. 
 Philadelphia. 
 
 In addition to the following flattering notices of the American Press, the pub- 
 iishers have received upwards of one hundred recommendations from the most 
 prominent professors and distinguished teachers of our country, to the superior 
 claims of these works, and urging their introduction as Class Beoks into all the 
 Schools, Academies, &c., throughout the United States. 
 
FcTJSCHENBEHGER'S SEZIIHS. 
 
 FIRST BOOKS 
 
 OF 
 
 NATURAL HISTORY, 
 
 IJR SCHOOLS, COLLEGES, AND FAMILIES. 
 
 1. ELEMENTS OF 
 
 ANATOMY AND PHYSIOLOGY. 
 
 2. ELEMENTS OF 
 
 MAMMALOGY, 
 
 The Natural History of Quadrupeds. 
 
 3. ELEMENTS OF 
 
 ORNITHOLOGY, 
 
 The Natural History of Birds. 
 
 4. ELEMENTS OF 
 
 HERPETOLOGY AND ICHTHYOLOGY, 
 
 The Natural History of Reptiles and Fishes. 
 
 5. ELEMENTS OF 
 
 CONCHOLOGY, 
 
 The Natural History of Shells and Mollusca. 
 
 6. ELEMENTS OF 
 
 ENTOMOLOGY, 
 
 The Natural History of Insects. 
 
 7. ELEMENTS OF 
 
 BOTANY, 
 
 The Natural History of Plants. 
 
 8. ELEMENTS OF 
 
 GEOLOGY, 
 
 The Natural History of the Earth's Structure. 
 
 This interesting series of books has already met with the most 
 flattering reception ever extended to any work issued from the Amer- 
 ican press. Introduced into the Public Schools of Pennsylvania, and 
 in nearly all the first class seminaries of learning in the United State*. 
 
RECOMMENDATORY NOTICES. 
 
 " Ruschenberger's Series of Books on Natural History, are among the 
 most valuable and useful wo.ks, for the use of Schools that have ever been 
 published. A knowledge of Natural History, is not only valmb'e, but 
 deeply interesting; and no one's education cm, with such facili ies us these 
 works afford, be considered complete without it." National Intelligencer. 
 
 " These are the most valuable additions of the day to our stock of School 
 Books. The avidity with which they have been seized upon is unprece- 
 dented. Though the first vol. was published for the first time only a few 
 months ngo, it hs already gone through its fifth edition; the second is fol. 
 lowing c!ose upon its heels; and the third promises even to be more popular 
 than either of the other two. These books have been adopted by the * Uoyal 
 Council of Public Instruction,' for the use of Schoo's throughout France. 
 They are recommended and have been adopted by some of the most emi 
 nent teachers in the United States." Southern Literary Messenger. 
 
 From ' The Ladies' Companion, a Monthly Magazine." June, 1842, New York. 
 W. Snowden, 109, Fulton Street. 
 
 "RuscHENBKRGEn's ORNITHOLOGY: Grigg & Elliot. This is an excel- 
 lent book, by one who shows himself perfectly qualified for the task he has 
 undertaken, which is the publishing of a series of works on the different 
 branches of education, for .the use of schools and colleges. The present 
 Ifesue is a general and synoptical view of Ornithology, one of the most 
 interesting subjects in Natural History, and will be found of great service, 
 both to teacher and student." 
 
 " This is a compendious, and, as it seems to us. a judiciously compiled 
 treatise on Ornithology, and one well calculated for the use of Schools ; for 
 which object it is intended." N. Y. Courier and Enquirer. 
 
 " In the work before us, the plan is happily carried out. In its small 
 compass it embraces an immense amount of useful and interesting infor- 
 mation." Buffalo Adv. and Journal. 
 
 " Ornithology. This is evidently, like its predecessors, an excellent work 
 of instruction; and hai been, in all respects well got up by the publishers.* 
 Pennsylvanian, 
 
 " A valuable little work, and is divided up and classified admirably. The 
 glossary, giving the derivation of the names of birds, is of itself worth the 
 price of the volume." New York Aurora. 
 
 "An exceedingly interesting, and very instructive book, and one which 
 possesses special attraction for young ladies." Baltimore Sun. 
 
 "RUSCHKNBERGER'S SERIES : Second Book. A highly useful and instructive 
 school book. Third Book> This we consider as decidedly an acquisition 
 to our list of school books, the subject is treated of in such a plain style as 
 to be adapted to the simplest capacity. Altogether we think the above 
 series as worthy to take a high and permanent place among our school 
 books." Buffalo Democrat. 
 
 " We wish we could induce our teachers generally to examine this, as 
 well as the earlier works of Dr. Ruschenberger ; they are admirably 
 arranged, and just the very books needed for schools. The work before 
 us on the Natural History of Birds is an admirable one, and no teacher 
 should neglect to introduce the series. * Cincinnati Gazette. 
 
 ' It is an excellent text book of an interesting science, comprising much 
 knowledge in a brief space, presented in a clear style and with lucid 
 nrrangement. Dr. Ruschenberger, who has already achieved a high charac- 
 ter in the literary world, is acquiring additionnl claims by his exertions i* 
 Ihe field of Natural Science. Spectator, Washington City. 
 
RECOMMENDATORY NOTICES. 
 
 " Ruschenberger's Series. These volumes are constructed upon a new 
 and admirable plan, combining great simplicity of arrangement, with a 
 perspicuity and sententiousness of style seldom found in works of this 
 class; and which has elicited the highest encomiums of upwards of thirty 
 of the leading professors of the country, whose opinions have again been 
 endorsed by most of the public prints." V. States Adv. 
 
 "The developement of the principles of classification, is among the very 
 best we have ever seen. Science is here dressed in her own native sim- 
 plicity and beauty, so that the philosopher may admire, while the child may 
 acquire it. Medical Reporter, 
 
 44 Jt is a choice, and well digested work." Atlas. 
 
 " An excellent publication adapted to the youthful mind, and a great help 
 to the more matured." Mercury. 
 
 "The study of Natural History though generally neglected in schools, 
 is of undoubted use : the present work contains a great amount of infor. 
 mation within a small compass, and properly condenses it for the young 
 mind." N. Y. Journal of Commerce. 
 
 "Ruschenberger's Series. The subjects are tfrell treated, and from the 
 exceeding cheapness, and admirable arrangfineiii'of these elementary works, 
 they are well fitted for general use in public schools and academies."* 
 New York American. 
 
 "We do not hesitate to say, that this is the best work of the kind and 
 dimensions, that has even fallen under our notice. We hope all will embrace 
 the first opportunity of procuring a copy, as we are sure they will prize 
 it highly." Botanic Recorder. 
 
 " A well digested and carefully arranged abstract of the most interesting 
 parts of Natural Science." Philadelphia Gazette 
 
 "Admirably adapted to convey an elementary knowledge on the subject 
 of which it treats ; and will be found an excellent book for the student." 
 Public Ledger. 
 
 " Valuable in every respect, it contains a vast amount of information, 
 condensed into an available form, for the use of schools." Spirit of the Times. 
 
 "Just such a work as is wanted for elementary instruction, in this pleas- 
 ing branch of science." New York Evening Post. 
 
 " We regard this series as eminently useful, supplying adequately the 
 instruction in natural history necessary to a proper school education." 
 North American. 
 
 " It is an excellent little work for the purpose designed, written in a cl* ar 
 and familiar ^tyle, and will not fail to facilitate the studies of those who 
 wish to make themselve- acquainted with the subject." Saturday Courier. 
 
 "Admirably adapted for elementary instruction." Saturday Chronicle. 
 
 " We have great pleasure in recommending it as an excellent elementary 
 manual on the subject " Medical Examiner. 
 
 " Ornithology This book is equal in merit to the first and second, and 
 is a most valuable work. It is intended for the use of schools and acade- 
 mies, and we would call the attention of parents and others to the series of 
 books to which this belongs, assuring them at the same time, that it will 
 answer the purpose for which it is intended, better than any other work of 
 the kind that we ever saw, or, in our opinion, that was ever published in 
 this country. It is divided into questions and answers, contains an exten- 
 sive and valuable Glossary, and is illustrated by eight Plates ; and what is 
 more the price is so very low that every person can aftord to purchase it. 
 o)k New Era, 
 
 4 
 
RECOMMENDATORY NOTICES. 
 
 It has been justly observed, that " the double effect of the study of Natural Hiptoiy 
 is to impart certainty to the mind, and religion to the heart," and the Christian no less 
 than the man of science, must rejoice in every effort to throw more widely open the 
 sublime and boundless field which it presents. This is the design of Dr. Ruschenberger, 
 in a scries of First Books of Natural History, which he is preparing foi the use ol 
 schools and colleges. Banner of the Cross. 
 
 The series have met a demand and sale in France almost unparalleled, and the words 
 are well adapted, not only lor schools, but for popular reading and instruction. This 
 work is from the French of Edwards and Comte, and has received the warm commen- 
 dation of many of the best physicians and scholars in this country JV. Y. Eve. Tattltr. 
 
 It is highly commended by the very best authorities. JV*. Y. Tribune. 
 
 This book is highly commended by competent judges, and we therefore give our so- 
 lemn opinion that it is an excellent work. Boston Daily Times. 
 
 A small, but very valuable work. Boston Evening Transcript. 
 
 We have examined this new book for schools and colleges, with peculiar gratificatioB. 
 The style is succinct and clear, and the subject illustrated by appropriate drawings. We 
 should be glad to see this work introduced into all the schools. It teaches knowledge 
 the most important, which has been, however, strangely overlooked in our school and 
 college system. It is a book which should not be confined to seminaries alone. It may 
 be used with advantage by all individuals in society. We repeat, it is in all respects a 
 most excellent work, and we hope will receive the attention and patronage it meriu. 
 Brooklyn Evening vtar. 
 
 A. valuable work; we have read it with profit. JV*. Y. Mercury. 
 
 We are highly pleased with this work. For elementary instruction in families, 
 schools, and colleges, it is decidedly superior to any thing of the kind we have seen. It 
 gives much valuable information in a very small space, and in style it is generally free 
 from obstruse technicalities It has already received the highest recommendations from 
 a large number of professional men in different parts of the country ; and it must have, 
 we think, a general circulation. It gives that kind of knowledge which should be dif- 
 fused among the mass of the people, and it must and will be patronised as far as it* 
 merits are known. Ziun's Watchman. 
 
 This is a fine little book, containing the elements of much useful learning, illustra- 
 ted by anatomical plates of the human figure, its organs and their functions. It is a 
 highly use-fill work to the student indeed to every citizen it shows how fearfully and 
 wonderfully we are made, and what slight causes may derange and utterly destroy the 
 complicated machine. The Olive Branch 
 
 A very useful little work. JV. Y. Atlas. 
 
 As far as we are competent to determine, it may safely he welcomed as an important 
 addition to the means of elementary instruction in natural science, The Friend. 
 
 We recommend it as a highly instructive publication. JV*. Y. Times and Eve. Star. 
 
 This is a most valuable work, by Dr. Ruschenberger, and most admirably are the 
 plates, representing a!l the different parts of the body, done. It is cheap, and every pa 
 rent .should place one in the hands of their children. JV. Y. Herald. 
 
 We have examined this little volume with much pleasure, and think it admirably 
 adapted to the purpose for which it is intended. Animal Mechanism, as a study, hag 
 generally been neglected, except by the few, whose profession requires a knowledge of 
 it, anil who have time to spare in acquiring that knowledge. A prominent cause of 
 the neglect of this useful and interesting science by the general student, is, the want 
 of a suitable treatise upon the subject, those extant being too voluminous, technical, 
 and expensive for general use. The little work before us is happily calculated to sup- 
 ply this want. It will, we think, be introduced into our schools and colleges as a text- 
 book, but its circulation ought not to be confined there. Every private library should 
 be considered incomplete without it. JV. Y. Mechanic. 
 
 It seems to us to be well suited for the object for which it is designed, and it wiU 
 ibtless be introduced into many of our elementary schools. The .American Journal 
 the Medical Sciences. 
 
OPINION OF THE PUBLIC PRESS. 
 
 " Sach a little treatise is just the thing for our schools and academies and 
 no tune should be lost in introducing it." New 'York Mirror. 
 
 " This is a most excellent work, and we would most respectfully recom- 
 mend it to our common school tru tees, as worthy of introduction into tha 
 temples of learning under their supervision." New York New Era. 
 
 " The plan and arrangement of the work are admirable, and eminently 
 calculated to facilitate the progress of the pupil. We recommend it to 
 teachers and heads of families." Philadelphia Sat. Chronicle. 
 
 " We know of no books better calculated to convey elementary instruction 
 than these, and heartily recommend those which have appeared." Brothet 
 Jonathan. 
 
 "We cannot too earnestly recommend it to public attention." Cincinnati 
 Enquirer. 
 
 " Decidedly one of the best elementary works on the subject with which 
 we have ever met." New York Lancet. 
 
 "The information it contains is at once lucid, intelligible, and satisfactory; 
 it forms an ex?cllent text-book for classes in schools, and cannot fail to 
 infuse into the young mind a knowledge and love of Natural History. It 
 is concise and comprehensive, and must if adopted in seminaries of learning, 
 be exceedingly useful in inculcating a correct knowledge of the elements of 
 Zoology. The plan is excellent, and must be found eminently useful." 
 Alexandria Gazette. 
 
 " It is one of the most valuable works of the kind we have erer read. 
 Such are the books we like to see disseminated among the people." New 
 Orleans American. 
 
 "The reputation of the author is a guarantee that the work is a good one. 
 On examination we find it to be so. It is an admirable compend of the 
 subjects of which it treats: we should think, indeed, that it would attract 
 the attention of teachers, both from its cheapness, and the admirable manner 
 in which it is armnged." Cincinnati Gazette. 
 
 " The Second Book: this number treats of all animals that in infancy 
 feed on the rnilk of their mothers; from the human being down to the mus- 
 quito-catching bat. Like the " First Book," it is divided into questions and 
 answers, and a glossary ; and is illustrated by six plates. It is as cheap as 
 dirt ; and contains an abundance of useful information. There are thousands 
 of persons in this country, and millions in Europe, who do not know that 
 whales give milk." New York Era. 
 
 "We do not know a more useful set than this promises to be : and IS."- 
 New York Aurora. 
 
 " We hesitate not to say that it is a valuable work, and fully entitled to 
 the high encomiums bestowed upon it ; taken as a whole the work may be 
 justly regarded as invaluable to schools." New York Standard. 
 
 " It is a most valuable work, and one which we believe has no superior in 
 our seminaries, we know of nothing equal to it. It is very flatteringly 
 recommended by the most distinguished men in France and in the United 
 States, and deserves it." New York Courier and Enquirer. 
 
 Ruschenberger's Second-Book of Natural History. " This is another 01 
 those useful volumes, which Dr. Ruschenberger is so beneficially in editing. 
 His former volume has already been received into some of our public schools, 
 and we hope both it and the present may find their way into all." American 
 Medical Intelligencer. 
 
 The present work, is in our opinion quite a desideratum, and abounds 
 with information of the most useful and, at the same time, most necessary 
 character, every parent should place it in the hands of his children, and no 
 public instructor should neglect to give it a place in his academy. Philn 
 Spirit of the Times. 6 
 
**^^WP^ 
 
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 WILL BE ASSESSED FOR FAILURE TO RETURN 
 THIS BOOK ON THE DATE DUE. THE PENALTY 
 WILL INCREASE TO 5O CENTS ON THE FOURTH 
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 OVERDUE. 
 
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 1956 
 
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 ^H- 
 
 JUH 1 7 1970 16 
 
 General Library 
 

 . 
 
 C 
 
 
 
SERIES, 
 
 FIRST BOOKS 
 
 OP 
 
 NATURAL HISTORY, 
 
 FOR SCHOOLS, COLLEGES, AND FAMILIES. 
 
 1. ELEMENTS OF 
 
 ANATOMY AND PHYSIOLOGY. 
 
 2. ELEMENTS OF 
 
 MAMMALOGY, 
 
 The Natural History of Quadrupeds. 
 
 3. ELEMENTS OF 
 
 OB NIT H L G Y, 
 
 The Natural History of Birds. 
 
 4. ELEMENTS OF 
 
 } T EBPETOLOGY AND ICHTHYOLOGY, 
 
 The Natural I f Reptiles and Fishes* 
 
 VTS OF 
 
 CONG II L G T , 
 
 The Natural History of Slit; Us a id ~;fc Ju<ea. 
 
 6. ELEMENTS OF 
 
 ENTOMOLOGY, 
 
 The Natural History of Insects. 
 
 7. ELEMENTS OF 
 
 BOTANY, 
 
 The Natural History of Plants, 
 
 ELEMENTS OF 
 
 G E LO GY, 
 
 The Natursal Fiistory of the Earth's Structure. 
 
 : .- dread] ith 'he most fianer- 
 
 . issued I m she American press. 
 
 >;. a, and in nearl'/ all tho