THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA PRESENTED BY PROF. CHARLES A. KOFOID AND MRS. PRUDENCE W. KOFOID EARTH SCIENCES LIBRARY THE FOSSILS YORKSHIRE LIAS DESCRIBED FROM NATURE, WITH A CAEEFULLY MEASUEED SECTION OF THE STEATA, AND THE FOSSILS PECULIAE TO EACH. MARTIN ^IMPSON, LECTURER ON NATURAL SCIENCE, AND CURATOR OF THE WHITBY MUSEUM ; AUTHOR OF A GUIDE TO THE GEOLOGY OF YORKSHIRE. SECOND EDITION. WHITBY : PRINTED BY FOETH & SON, FLOWEEGATE. SOLD AT .THE MUSEUM. LONDON : JOHN WHELDON, NATURAL HISTOEY BOOKSELLEE, 58, GEEAT QUEEN STEEET-* LINCOLN'S INN FIELDS. 1881. QE733 PREFACE. EARTH SCIENCES LIBRARY THE Fossils of the Yorkshire Lias, and especially the Ammonites, had been objects of superstition, and poetick fiction, from mediaeval times, but re- specting their true nature, no one ventured to express an opinion. Whilst it was generally believed that the hills and valleys, and the whole face of nature, were the same as they had ever been, from the creation of the world, except some modification which it had suffered by a transient deluge, the forms of orga- nized beings found deeply buried in the earth remained inexplicable. It was only about the middle of last century that correct views respecting the changes which had taken place on the earth's surface were promulgated, and the origin of the noble, sublime, and popular science of Geology, now established upon indubitable evidence, can scarcely be placed earlier than the beginning of the present; whilst the systematick study of Fossil Remains, or Palaeontology, as it has been named, is still more recent. The honour of first introducing the study of the rocks and organick remains of eastern Yorkshire into Whitby and the region round about, is due to the Rev. George Young, M.A., of Edinburgh. In IV. 1818, he published his History of Whitby, a work of high literary character and antiquarian research, in which he gave a very luminous and correct ex- position of the rocks and organick remains of the district. The publication of this work immediately produced a general revolution in publick opinion respecting the fossil remains of the district, and excited great zeal for further discovery. There was, indeed, at this time, in Whitby, a strong desire after intellec- tual pursuits, not only amongst the learned, but amongst many whose circumstances in life were unfavourable to such pursuits. The cessation of a long and exhausting war, the energies aroused by that war, and the want of employment before the return of commercial prosperity, all had a tendency to intellectual pursuits, and, no doubt, contributed greatly to the establishment of Philosophical Insti- tutions and Museums, which the great wealth and the national prosperity of the present era scarcely sustain. Immediately after the publication of the History of Whitby, Young, with his companion, Mr. John Bird, an artist, and a man of a philosophical turn of mind, undertook a thorough investigation of all the strata of the Yorkshire coast, from the Hurnber to the Tees, and of their western outcrop towards the Vale of York and the Cleveland hills. This survey, in every way worthy of a pupil of the celebrated V. Playfair, was performed with great accuracy, minute investigation, and care, during four years of assidu- ous labour, and the result was published in 1822, under the title of a Geological Survey of the York- shire Coast. In this work a fair and accurate description of the series of strata along the coast was given, which formed an important guide in further researches. The publication of this work, and the visits of the authors to various localities, and their intercourse with men of scientifick tastes, gave a great impulse to geological pursuits through- out the district. At Scarborough, Mr. Bean and Mr. Williamson, by their enthusiastick and inde- pendent labours, rendered a great and lasting benefit to Palaeontology. In January of 1823, the Whitby Museum was established, and became the receptacle of the fine fossil, Teleosaurus Chapmanni, and other remains, which have rendered Whitby famous amongst all men of science. The Scarborough Museum was formed in 1831, where was soon displayed a fine and instructive collection of fossils from all the coast strata, arranged in systematick order. Thus, by the enthusiastick and perseveriug labours of not a few persons, such collections were made as enabled Mr. John Phillips, when, in 1829, he pub- lished his Illustrations of the Geology of Yorkshire, to give an extensive systematick catalogue of the fossils from all the strata, especially those of the VI. Oolite, which has proved of great utility in the promotion of the science. In 1837, I was appointed Lecturer on Natural Science to the Whitby Literary and Philosophical Society, and Curator of their Museum. Here I found a large accumulation of fossils from the Yorkshire strata, chiefly from the Lias, which, through want of means for displaying them, had remained un- touched for many years. As many of them had not been named, and others, though named, had been only imperfectly described, or described in books inaccessible, I resolved to make my own book, and wrote descriptions of every fossil which came under my notice. In the beginning of 1843, I published descriptions of more than one hundred Ammonites of the Yorkshire Lias, in a short Mono- graph. These being favourably received, in 1855, I published descriptions of all the then known fossils of the Yorkshire Lias, together with an outline of the Geology of the Yorkshire Coast, intended as a guide to strangers. In this I followed the divisions of the strata laid down by my predecessors ; and considered the Lias under three main divisions, the Upper, Middle, and Lower Lias. But being con- vinced by observation that few species of the Lias fossils had existed during the deposition of any great thickness of strata, but, on the contrary, were often confined to thin seams, I measured carefully, with a two feet rule, all the beds and seams of Lias, Vll. both to the south and north of Whitby, and at the same time collected the fossils from each stratum. This section I published in 1868, in the fourth edition of my Guide to the Geology of the York- shire Coast. This section I now reprint, with slight alterations, and to which the fossils in the catalogue are referred. Notwithstanding all this labour and research into the Lias formation in Yorkshire during more than half-a-century, two gentlemen of high scientifick attainments, and of indefatigable labour and zeal, Mr. Ralph Tate, now Professor of Natural Science in the University of Adelaide; and the Rev. J. F. Blake, M.A., now Professor of Natural Science in Nottingham College, had the courage to enter upon a thorough and exhaustive survey of the Yorkshire Lias, both as regards its Stratigraphical Phenomena, and its Palaeontology. As they expressed their intention to recognize and do justice to my previous researches and publications, I willingly laid open to them what I had been accumulating towards the further illustration of our Lias. Their work was published in 1876, and is the most exhaustive of any work which has appeared on that subject ; and the scrupulous fidelity and honour with which they have treated my labours gives me the highest grati- fication. After the publication of a work on our Lias so exhaustive, anything further from me on the subject might appear uncalled for ; but their work Vlll. is written for the learned, and, for the descriptions of many of the fossils, works by foreign authors in foreign languages are necessary. On the other hand, on whatever subject I write, I have constantly before me persons of ordinary education, and for their benefit I sink, as much as possible, anything which might appear technical or learned ; and on the issue of the former edition of this work, it gave me the greatest pleasure and satisfaction to find that illiterate persons could distinguish species by my descriptions. The publication of my catalogue of our Lias Fossils having been long delayed from causes over which I had little control, some foreign naturalists published descriptions of our fossils in their own language. The consequence is, that I have had to alter many of my names, as their names have the priority of publication. The names I gave to the ammonites, having priority, remain nearly the same as in the Monograph. To all friends who have assisted me, in any way, in my scientifick pursuits, I tender my grateful acknowledgments ; and for the honour done me by the Council of the London Geological Society in awarding to me a portion of the Murchison Donation Fund, u in recognition of my life-long researches into the Palaeontology of the Jurassic rocks of Yorkshire," I entertain sentiments of the deepest obligation and thankfulness. Whitby, June 3, 1884. A SECTION OF THE YORKSHIRE LIAS. As each bed of the Yorkshire Lias is strongly charac- terized by its peculiar fossils, some years ago I measured with much care all the accessible beds of Lias between Whitby and Peak, and also those to the north of Whitby, and, as far as I was able, assigned to each bed its peculiar fossils. In order to promote greater exactness in collecting specimens, I distinguished each bed by a numeral, or a letter of the alphabet, which, in collecting, might be applied to each example. After a lapse of ten years, with the hope of engaging other collectors in this sort of labour, and to give a more definite idea of our Lias than was then generally entertained, in 1868, I pub- lished this Section in the fourth edition of my Guide to the Geology of the Yorkshire Coast. Since that time, I have carefully collected the fossils of each bed, and paid particular attention to the Belemnites, which I found to be as strictly confined to certain strata as the Ammonites, or any other fossils. In these labours I have been greatly assisted by Professor Ealph Tate, F.G.S., who made important discoveries in our Lias fossils, and who very generously sent me examples of many new species ; and I have also availed myself of the permission to describe those he deposited in the Museum of Economick Geology in London ; so that I am now better able to assign each species to its particular bed. In the main divisions of our Lias I adopted those of previous British geologists, and considered it as divided into Upper, Middle, and Lower Lias. I subdivided the Middle into the Ironstone and Arenaceous beds ; and the Lower into the Ironstone series and the Indurated bands. The Yorkshire Lias is in general overlaid by strata of ferruginous sandstone, containing marine remains, and often by a band of ironstone nodules, the whole called by miners the top bed of ironstone; but these have X. been identified with the Inferior Oolite of the southern counties. Above these are often displayed in the cliffs, above thick beds of shale, clay and sandstone, sometimes mistaken for Lias ; but which are generally of a lighter colour. These are chiefly of fresh water origin, and contain numerous remains of plants, but in some localities they are entirely marine . The whole have been denominated E stua- rine or Deltick, from a supposition that they have formed the Delta of some large river, and are a local deposit, little of it reaching further southward than the Humber. UPPER LIAS. Alum. The Upper Lias in Yorkshire is very homogeneous in its lithological character, being a dark smooth slaty shale; but as different beds are strongly distinguished by different species of fossils, I find it advantageous to consider it under eight subdivisions. Div. Ft. In. 1. From the ferruginous sandstone bed of Inferior Oolilte, which caps the Lias, down to a nodular bed of Lias limestone, there is, near Whitby, 34 feet of blue shale, increasing gradually to 40 feet at Normanby Stye Batts, on the Hawsker shore. The top of this division in some localities is rather sandy, as at Peak. The upper half contains an abundance of nodules of Lias lime- stone, which is manufactured into a valuable hydraulick cement - - - - - -340 The fossils most characteristick of this division are Belemnites vulgaris, Ammonites communis and bifrons, Leda ovum, and Myacites donacif ormia ; all which are abundant. Here also have been found many remains of Saurians; Belemnites limatulus, glaber, inclusus, levi- densis,; Nautilus astacoides; Ammonites Jurensis, heterophyllus, subcarinatus, crassus, vortex, fibulatus, subarinatus, Lythensis, Roulbyensis, Beanii, striatulus ; Trigonia literata; Venus tenuis; Pholadomya gallina; Astacus rostratus. XI. Div. Ft. In. 2. We commence the second division with a band of hard Lias limestone, generally about three inches thick, but often interrupted, and in places swelling out into flattened nodules more than a foot in thickness. This may be called the first indurated band, and it appears to be very constant over extensive areas. Beneath this is 18 feet of dark blue shale, less produc- tive of alum, and with fewer fossils. It was in this bed that the first specimen of Teleo- saurus Chapmanni was found (1758) - - 18 3. We then come to a band of indurated shale, thin, uninterrupted, ferruginous, generally two inches thick, but thicker in places, passing gradually into ordinary shale be- neath, where we find Lingula venusta, and where Mr. Kershaw discovered Astacus (Ergon) Hartmanni. It is seen a little to the north of Whitby harbour, both in the cliff and on the beach, where it dips beneath the sea, and emerges not far from the north Nab at Saltwick, and forms a very distinct, red line in the cliff. Between this and the next indurated band, there are 18 feet of shale, in which the fossils of the upper divisions are very sparingly scattered, with Myacites rotundata - - 18 1. The third indurated band, which overlays the fourth division, is ferruginous and interrupted, forming large thin patches on the beach, with nodules of Lias limestone, both above and below, which contain Ammonites ovatus, and is known to collectors as the Ovatus band. It may be seen on the beach on the north side of the north Nab at Saltwick, and rises nearly to the top of it where the road crosses, and is a good line of demarcation over wide areas. Xll. Div. Ft. In. Between this band and the next, there are 18 feet of shale, and this may be considered the end of the Alum shale, as the shale be- neath is hard and unproductive of Alum - 18 The most characteristick fossils of this division are Belemnites curtus, dorsalis, and subtenuis in large masses, with A. ovatus. 5. The fourth indurated band, with which we a. commence the fifth division, consists, like the second, of hardened ferruginous shale, about four inches thick, hard at the top, and passing into ordinary shale beneath. It is first ob- served rising from the beach at the base of the Nab at Saltwick, towards the end of which it attains a considerable height, and afterwards dipping, it may be seen sweeping across the bay. It then rises into the cliff, where it forms a very distinct line, and is about twenty feet above high water under the Light-houses. Between this band and a line of large, flat, widely separated nodules of Lias limestone, there are ten feet of shale. The most charac- teristick fossil is a Belemnite which I name B. urbanus. b. Here we first come in sight of Ammonites Mulgravius, in large crushed examples, and descending twelve feet more, we come to a nodular bed where good examples of this fossil may be obtained 22 This lower part of our fifth division is comparatively rich in fossils. Belemnites tubularis, compressus, acuminatus, insequis-- triatus, politus, levis, subtenuis, dorsalis, pollex; Ammonites Mulgravius; abundance of crushed Inoceramus dubius ; Pachyphyllum peregrynurn. Xlll. Div. Ft. In. 6. From this line, not very well displayed, to the next indurated band, which caps the Jet Rock, there are twenty-four feet of hard, compact, bituminous shale, which forms flat scars on the beach - - - - - -240 It has yielded some good jet and many interesting fossils : The large Ichthyosaurus crassinianus, now in the Whitby Museum ; many Fishes, Gyrosteus mirabilis, Dapedius, Lepidotus, Ptycholepis, Pachycormus, Lepto- lepis ; Sepia with the ink-bag ; Belemnites trisulculosus, validus, robustus, obtusus ; Am- monites Mulgravius, crassulus, gracilis. Jet Rock. 7. Our seventh division is capped by a strong band, about four inches thick, very regular and continuous on the north of Whitby, forming a well denned line in the lower part of the cliffs ; but to the south it is much in- terrupted, and when washed by the sea, often takes the form of large millstones, very con- spicuous on the beach, sometimes incrusted with cone in cone coraloid. In general it consists of hard Lias limestone with a con- choidal fracture, offering considerable resist- ance to the sea, but in places it differs little from indurated shale. Beneath this band there is about twenty feet of very hard bituminous shale, called, by way of eminence, the Jet Rock. The whole is strongly impregnated with bitumen, which gives out a peculiar odour. It is full of nodules of fine Lias limestone, which generally contain fossils, and also mineral oil, at first a green liquid, which hardens into a kind of pitch by exposure to the atmosphere - - - - 20 It contains many of the fossils of the stratum above. Those most peculiar are Lepidotus XIV. Div. Ft. In. semiserratus, Ptycholepis Bollensis, Ammo- nites exaratus, often in large masses ; Am. elegans, Hildensis, nitidus ; Trigonolites Whit- byensis, Nerita buccinoides, neglecta. 8. This division is not separated from that above by any well denned line, but, unlike the Jet E-ock, it is soft and readily denuded by the sea, and in colour a dark grey. It is also dis- tinguished by an absence of nodules in its upper part, and the lower part is very soft and rotten. In the middle there is a seam about two feet thick with nodules containing Ammonites annulatus, constantly accompanied with Belemnites cylindricus. With these ex- ceptions, this division is exceedingly destitute of fossils. Below this seam we have the following section : Ft. In. Soft shale 10 Nodular band 3 Soft shale 4 Nodular band .. 03 Soft shale 4 Nodular band 03 Soft shale 1 6 Nodular band ... ... ... 04 Sulphurous rotten shale, with nu- merous broken Belemnites and other comminuted shells ... 36 24 1 40 Upper Lias at Whitby 194 Increasing to 220 feet in thickness at Nor- inanby Stye Batts, on the Hawsker shore. At Boulby, about twelve miles north of Whitby, it is 200 feet, and in some places it reaches 240 feet in thickness. In all places the increase or diminution is gradual. XV. MIDDLE LIAS. Ironstone Series. Syn. Kettlen-ess Beds, T. A B. The uppermost part of this series is well known as the Cleveland Ironstone, which is of great economical value in the north-east, but which becomes deteriorated to the south and west. It has its debased representatives at Normanby Stye Batts, and at another reef known as Peak Steel, on the south cheek of Robin Hood's Bay. The thickness of the Ironstone beds wrought at the Eston mines, is about 17 feet ; at Staithes six feet ; at Kettleness, at present, it is not worth working. The Ironstone beds wrought at the Grosmont mines are lower in the series. From the top of the Middle Lias to the Pecten bed it is 30 feet ; from thence to the Aviciila cygnipes bed it is 32 feet more. On the Hawsker shore the Avicula band is only nine inches in thickness, and instead of 62 feet, it is only 30 feet from the top, and at about the same distance to the north of Whitby, where it is exposed on the beach a little to the north of Old Nab, near Staithes. The Pecten band is probably d or e of the following section. The following is the Hawsker Bottoms section, com- mencing at a point called Nornianby Stye Batts, O. Sur. The same strata rise above the sea at a similar project- ing point, called Old Nab, near Staithes. A few feet of the same strata may be seen at the intervening Kettle- ness point. Div. Ft. In. a. Ironstone nodular band, 4 in.; dark blue shale, 2 ft. ; ironstone band, 3 in. ; indurated grey band, 1 ft. 3 in. ; sandy and micaceous shale, 5 ft. 6 in. 91 Belemnites insequalis, cylindricus; Ammo- nites spinatus, laboratus, subnodosus, Birdi j Turbo cyclostoma ; Cerithium liassicum, acri- culum ; Pecten sublsevis ; Modiola scalprum ; Corbula cardiodes ; Myacites costata ; Terebra- tula tetrahedra. XVI. Div. Ft. In. 6. Ironstone nodular band, 10 in. ; sandy and micaceous shale, with ironstone nodules, 5 ft. 6 in. 61 c. Ironstone nodular band, 6 in. ; blue shale, 1 ft. 1 6 Pecten sublsevis, major, much Dicotyledo- nous wood. This and the next are probably the Pecten seam of the Grosmont mines. d. Ironstone nodular band, 6 in. ; blue shale, 2 ft. 2 6 Myacites intermedia. e. Ironstone nodular band, -1 in.; blue shale, 2 ft. 6 in. - -. 2 10 Belemnites excavatus; Ammonites Haws- kerensis; Pecten planus ; Mytilus ensis. /. Ironstone nodular band, 6 in. j blue shale, 2 ft. 2 6 Among these thin bands we find various interesting fossils. Ammonites lenticular is, reticularis, vittatus, margaritatus ; Leda lon- gicaudata, complanata. g. Ironstone nodular band, 3 in. ; blue shale, 2 ft. 2 3 h. Ironstone nodular band, 6 in. ; blue shale, 2 ft., with patches of fossils - - - - - 2 6 i. Ironstone nodular band, 3 in. ; blue shale, 2 ft. 9 in. 30 fc. Ironstone nodular band, 9 in. A thin rotten seam of fossils, Pecten cygnipes, &c. The Avicula band of miners; seen also on the beach a little to the north of Old Nab near Staithes. Blue shale, 1 ft. 6 in. - - - 2 3 I. Ironstone nodular band, 3 in. ; blue shale, 1 ft. 6 in. Ammonites margaritatus - - 1 9 m. Ironstone nodular band, 6 in. ; blue shale, 15 ft'. 15 6 n. Ironstone band, 10 in. A thin, interrupted, fossiliferous band, Cardium truncatum. Blue shale, 10 ft. 10 10 o. Ferruginous band, 2 in., at the base of Clock- case Nab ; blue shale, 5 ft. - - - - 5 2 Belemnites cuspidatus; Ammonites cornu- copia, a large size. />' Ft. In. p. Sandy, micaceous, indurated shale; Cardium truncatum abundant ; a thin ferruginous band of comminuted fossils ; Belemnites laevigatus, retusus, atheticus; Pecten; micaceous sandy shale, with ironstone nodules interspersed, worn into, hillocks by the sea scouring the joints, 5 ft. - - - - - -50 Mytilus scalprum ; Corbula cardiodes ; Mya- cites levis ; Pholadomya gallina. q. Ironstone nodular band, 8 in. ; Dentalium band, 1 ft. 6 in., hard, micaceous, upper part full of Dentalium giganteum; beneath, small oysters ; Pecten planus ; Cardium truncatum ; Terebratula tetrahedra ; sandy shale, 3 ft . 10 in. 6 79 3 The strata of this series are very regular throughout the district, and may be taken at 80 feet, or a little more, in thickness. Staithes 85 feet. Hob Hill 80 feet. Sandy and Micaceous Beds. Syn. Staithes Beds, Y. A B. Marlstone, Phil. r. Massive sandstone, 6 ft., containing layers of oysters, forming a precipice on the beach. Coarse shale, 5 ft. It forms the base of Penny Nab, Staithes - - 11 Belemnites planulatus ; Ostrea tuuiidulosus ; Ophiura Milleri. s. Ironstone seam, 1 in. Oysters in thin layers, and sandy shale with Cardium truncatum abundant. Three indurations - - - 5 t. Sandstone, 3 ft. ; sandy and micaceous shale, 10ft. - - 13 Ammonites Clevelandicus, Bechii,bispicatus, nitescens. u. Ironstone nodules, 6 in. ; oyster band, 6 in.; sandy shale, 1 ft. ; oyster band, 1 in. ; sandy sandy shale, 1 ft. ' - - -'31 b XV111. Div. Ft. In. v. Oyster band, 4 in. ; coarse, light-coloured shale, 4 ft. 2 in. 46 w. Ironstone band, 4 in. ; sandy and micaceous shale, 11 ft. - - - - - - - 11 4 x. Ironstone nodules, 3 in., very f ossilif erous ; shaly sandstone, 4 ft., worn into channels on the beach by the sea scouring the joints - 4 3 Ammonites capricornus, Henleyi; Turbo undulatus, large ; Pecten ; Avicula Rosebury- ensis; Mytilus hippocampus; Cardium trun- catum. y. Ironstone band, 3 in. ; indurated band of large oysters, 3 in.; sandy shale, 6 ft., worn into irregularities on the beach by the sea - - 6 6 North point of Robin Hood's Bay, and base of Colburn Nab, Staithes. Thickness of the Arenaceous beds on the Hawsker shore - - - - - -58 8 Thickness of the Ironstone series - - - 79 3 Thickness of the Middle Lias south of Whitby 137 11 The average thickness of the Middle Lias in Yorkshire may be taken at about 150 feet or 160 feet. The Arenaceous beds vary much in thickness. Within a very short space, the beds r, s, i, are reduced to about 14 feet at Castle Chamber, and then swell out towards Bay Town, r forms the roof of the chamber, and u the floor. They increase in thickness northwards and are 72 feet thick at Staithes. LOWER LIAS. Ironstone Series. North Cheek of Eobin Hood's Bay. A great lithological change here takes place. We lose sight of the great Oyster and Sandy beds of the Arena- ceous series, and are introduced to a repetition of the thin dark-coloured muddy shales, and Ironstone bands of the Middle Lias, which must have been deposited in a tran- XIX. quil sea, allowing ferruginous precipitates or concretions . The bed of large Oysters., seen at the north point of Robin Hood's Bay and at the base of Colborn Nab, Staithes, forms a good line of demarcation. Die. Ft. In. a. Lias limestone nodules, 3 in. ; blue shale, 6 ft. 6 3 b. Lias limestone nodules, 3 in., containing Am- monites maculatus ; blue shale, 6 ft. - - 6 3 c. Indurated ferruginous band, 2 in.; ironstone nodules, 3 in. ; blue shale, 2 ft. 6 in. - - 2 11 Ammonites maculatus ; Gryphaea depressa. It also occurs at the base of Colborn Nab, Staithes. d. Ironstone nodules, 6 in. ; blue shale 14 it. - 14 6 e. Ironstone nodules, 3 in. ; blue shale, 8 ft. - 8 3 f . Ironstone nodules, 6 in. ; blue shale, 4 ft. 6 in. 5 g. Ironstone nodules, 6 in. ; blue shale, 4 ft. 6 in. 5 h. Interrupted ironstone band, 4 in. ; blue shale, 4 ft. 8 in. 50 i. Ironstone nodular band, 4 in.; blue shale, 3 ft. 8 in. 40 This and the next division are well charac- terized by a thin line of comminuted fossils which appears to be very constant, and may be seen on the beach where the strata rise at Skinningrove. These and the following down to t, are the chief repositories of fusiform and other inter- esting Belemnites. B. dens, elegans. k. Ironstone nodular band, 2 in. ; blue shale, 4 ft. 4 2 1. Ironstone nodular band, 3 in.; blue shale, 11 ft. 6 in. - 11 9 m. Ironstone nodular band, 2 in. ; blue shale, 3 ft. 3 2 n. Ironstone nodular band, 3 in. ; blue shale, 10 ft. 10 3 o. Ironstone nodular band, 2 in. j blue shale, 6 ft. 6 2 p. Ironstone nodular band, 2 in. ; blue shale, 3 ft. 3 2 q. Ironstone nodular band, 2 in. ; blue shale, 3 ft. 3 2 r. Ironstone nodular band, 4 in. ; blue shale, 8 ft. 8 4 s. Ironstone nodular band, 8 in* ; blue shale, 16 ft. 16 8 Belemnites microstylus ; Pecten defossus. Div. Ft. In. t. Ironstone nodules, 4 in. ; blue shale, 3 ft. - 3 4 Ammonites Loscombei, armatus, brevispina, and other armed varieties occur in these divisions. u. Ironstone nodules, 3 in. ; blue shale, 4 ft. - 4 3 v. Ironstone nodules, 6 in. ; blue shale, 4 ft. 2 in. 4 8 w. Indurated fossiliferous band, 4 in. ; blue shale, 4 ft. 6 in. 4 10 Pinna folium abundant ; Pholadornya trun- cata. Base of Huntcliff. One of the most persistent strata in the Lias, Scotland, &c. x. Ironstone nodular band, 6 in. ; blue shale, 8 ft. 8 6 y. Pyritous band, 3 in. ; very thin and interrupted, but full of interesting fossils. It rises above the beach a little to the north of Bay Town, and is high in the cliff at Peak. Blue shale, about 25 ft. - - 25 3 Ammonites Taylori, Jamesoni, subtriangu- laris, aculeatus, Huntoni, tubellus, rutilans, trivialis abundant. Turbo Youngi, concinnus ; Pecten punctatus, aheneus; Lima novem cos- tata ; Perna gerosa ; Myacites punctata, concava ; Terebratula hispidula, &c. z. Ironstone nodules, 3 in. ; blue shale, 6 ft. - 6 3 Ammonites tardecrescens. 180 10 INDURATED BANDS. Between Bay Town and Peak. These bands sweep round the bay in grand curves, dipping at an angle of about eight degrees to the north, then to the west, and on the south side of the bay, to the south. The beds near Bay Town contain many interesting small lenticular Ammonites, and have been distinguished by Tate and Blake as the Ammonites oxynotus group ; but I have never heard of this southern Ammonite being discovered in our strata, XXI. Dir. Ft. In. 1. Indurated band, 12 in.; blue shale, 4 ft. 5 Ammonites tubellus, Huntoni, trivialis. 2. Indurated band, 1 ft. 6 in. ; blue shale, 8 ft. 6 in. 10 Ammonites gagateus, raricostatus. 3. Indurated band, 4 in. blue shale, 6 ft.^ 6 4 4. Indurated band, 4 in. blue shale, 4 ft. 4 4 5. Indurated band, 2 in. blue shale, 2 ft. 2 2 6. Indurated band, 6 in. blue shale, 3 ft. 3 G Ammonites Eobinsoi li, Dennyi. 7. Indurated band, 5 in. blue shale, 3 ft. 3 5 8. Indurated band, 3 in. blue shale, 1 ft. 6 in. 1 9 9. Indurated band, 3 in. blue shale, 10 in. 1 1 10. -Indurated band, 2 in. blue shale, 1 ft. 5 in. 1 7 11. Indurated band, 3 in. blue shale, 2 ft. 2 in. 2 5 12. Indurated band, 1 ft. ; blue shale, 1 ft. 3 in. 2 3 13. Indurated band, 3 in. blue shale, 3 ft. 3 3 The following fossils occur in this locality, which is too often covered with sand : Belem- nites acutus; Ammonites Dennyi, aureus, gagateus, raricostatus,- integricostatus, arcig- erens, lens, E-obinsoni, flavus ; Gryphsea, Mac- cullochi. 14. A double indurated band, 1 ft. 3 in. ; blue shale, 1 ft. 6 in. * - - 2 9 This is a very good line of demarcation, which comes close up to the base of the cliff at Mill Beck, full of ramose bodies resembling marine plants, which appear to send their roots down into the shale beneath. This band is about 35 feet high in the cliff, at about half way between Stow Beck and Peak Road, where the strata attain their greatest elevation; it then descends to the beach at Peak Road, and continues to sink until it arrives at the great dislocation. Belemnites acutus ; Ammonites Buckii, Simpsoni. xxn. Die. Ft. In. 15. Indurated band, 4 in. ; blue shale 15 ft. - 15 4 16. Partially indurated band, 2 in. ; blue shale, 1 ft. 1 2 Ammonites obtusus, saggitarius, stellaris, planicostatus ; Cardinia; Hippopodium pon- derosum. 17. Partially indurated band, 2 in. j blue shale, 1 ft. 1 2 18. Partially indurated band, 2 in.; blue shale, 2 ft. 6 in. - 2 8 19. Partially indurated band, 2 in. ; blue shale, 4 ft. 4 2 20. Partially indurated band, 2 in. ; blue shale, 3 ft. 3 2 Base of the cliff covered with debris. 21. Partially indurated band, 2 in.; blue shale, 10 ft. or more - - 10 2 These partially indurated and interrupted bands do not form very satisfactory divisions ; so that at Stow Beck and Peak they can scarcely be distinguished, and flattish scars are formed on the beach; and the thickness of the intervening shales cannot be very accurately estimated. 22. Indurated band, 6 in., very hard ; blue shale, 6ft. - 6 6 23. Indurated band, 2 ft., in places separated into two 12 in. bands; blue shale, 3 ft. - - 5 Belemnites acutus; Ammonites stellaris, planicostatus ; Gryphsea incurva very abundant. 24. Two indurated bands, with a parting of shale, 6 in. ; blue shale, 1 ft. - - 1 G Belemnites acutus ; Ammonites semicostatus, acuticarinatus, Conybeari, Turneri, nodulosus, geometricus, angulatus, erugatus, Belcheri, Johnstoni. 25, Indurated band, 2 in. ; blue shale, 1 ft. - 1 2 26. Indurated band, 2 in. ; blue shale, 10 ft. - 10 2 Upper part very fossiliferous. 27. Indurated band, 12 in. Lumpy dark shale, reaching out 20 or 30 yards, broken up into deep holes, difficult to be traversed, and covered XX111. Ft. In. with Laminaria. No appearance of any more bands. Considering the dip, eight degrees ? the thickness must be considerable - - 10 ? Examined August 21st, 1868, during a very low ebb tide and a smooth sea. Aggregate of Indurated bands and Shale - - 121 10 Aggregate of Ironstone series - 180 10 Lower Lias exposed at Robin Hood's Bay - 302 8 According to this section there are about 660 feet of Lias exposed on the coast to the south of Whitby, and according to Tate and Blake's section of the Eedcar rocks, there are about 20 feet more of Lower Lias exposed in that locality, which are characterized by Ammonites Bucklandi, bisulcatus, angulatus, planorbis ; Ostrea liassica ; Cardinia Listeri ; Myacites crowcombei. Below these, they give sections from various localities and borings of Lower Lias strata about 30 feet still lower down, which consist of alternate beds of clay and limestone, known as the Pleuromya Limestone, charac- terized by compressed Ammonites planorbis, and Myacites crowcombei. This they consider the base of the Lias formation. Thus we have on an average : Upper Lias, 220 feet; Middle Lias, 160; and Lower Lias, 360 feet; making the thickness of the Lias in Yorkshire about 740 feet, and which may in some localities amount to 800 feet. Tate and Blake give 1281 feet as the whole thickness, which seems excessive. Below the Lias there are the Rhsetick beds, 15 feet in thickness ; succeeded by the Keupers of the New Red Sandstone series. This, with its associate Gypsum, may be seen near Wilton, at no great distance from Eston Nab ; where the Lias rises 630 feet above the sea. It may also be seen in the bed of the Leven, at the base of the lofty hills south of Stokesley. The whole thickness of the strata of East Yorkshire above the New Red Sandstone, may be taken at about 2,500 feet ; having a general rise towards the north-west of about 40 feet per mile. NOTES AND EXPLANATIONS. Sow. Sowerby's ff Mineral Conchology." Plates and Descriptions. Y. fy B. Young and Bird's "Geological Survey of the Yorkshire Coast." Plates and Descriptions. 1822-1828. Ph. Phillips 's "Illustrations of the Geology of York- shire/' Plates. 1835. Simp. The Author's Monograph. Descriptions, 1843. " Fossils of the Yorkshire Lias/' 1855. " Guide and Section of the Yorkshire Lias/' 1868. T. # B. Tate and Blake. "The Yorkshire Lias." Plates and Descriptions. 1876. Pal. Palaeontographical Society's Publications, Plates and Descriptions. E.H.B. Robin Hood's Bay. TVTT Tvn^rMo (rioo The numerals and small letters iyj_.j_j. iyj_.j_j. jjj.ivj.u.ifc; r -LJitio. _ . . . , , 3 ty* IT j T T _ Lower ; distinguish the different beds. Some errors in the names are corrected in the Index, and marked with an asterisk *. The greatest part of the Fossils described are in the Whitby Museum,, the rest are in the Museum of Economic Geology, in London. THE FOSSILS OF THE YORKSHIRE LIAS. IN considering the Fossils of the Yorkshire Lias, it would be very erroneous to suppose them to be scattered indiscriminately through the whole for- mation ; for few species range through any great thickness of strata. On the contrary, most of the species are confined to particular beds, and are scarcely to be found in those above or below them. The word fossil originally signified any substance dug out of the earth ; but in recent times, and especially in scientifick literature, it is restricted to substances which have been in a living state, and, having become buried in the earth, have undergone a mineralizing process, by which they have been greatly changed. Whilst this process of mineral- ization was going on, their general form, anatomical structure, and even their finest characteristick marks, are often wonderfully preserved, Fossils are never so perfect as recent species ; and their investigation is attended with greater B 2 difficulty; but they possess a higher interest, on account of their vast antiquitj^, and the wonderful changes which they prove to have taken place on the earth's surface during countless ages. The discovery of the remains of animals and plants buried deep in the earth, possessing all the essential characters of living 1 beings, has given a great impulse to the study of natural history in our times; and it is chiefly on the evidence disclosed by fossil remains, that there has been constructed the new, popular, and sublime science of Geology. For the classification of the vast variety of or- ganized beings which have inhabited the earth in every period of its history, many systems have been invented, which possess more or less merit ; but in drawing up a Descriptive Catalogue of the Fossils of the Yorkshire Lias, which are almost entirely the remains of animals, I have no hesitation in adopting the views of the late Baron Cuvier, which appear to me to be by far the most comprehensive, the simplest, and the most instructive of any which have been promulgated on the classification of animals. Whilst Cuvier's system, founded upon the strictest and most perfect anatomical investigations, embraces and unites both the systems of Aristotle and Lin- naeus, his principles of nomenclature seem to me the best calculated to rescue natural history from that confusion into which it has unhappily fallen. By adopting the comprehensive generick groups of Linnaeus as Genera, under which Species are to be united and named, thousands of names which now becloud and perplex natural history, might be ren- dered either very subordinate, or entirely swept away. And by adopting such Genera as those of Lamarck as Sub-genera or divisions of Genera, the Species can be more easily described and understood. Also, by this method, naturalists having different views of nomenclature might still understand each other. For whilst the followers of Cuvier and Lin- naeus would adopt the names of the more com- prehensive groups as the names of their Genera, others might prefer the names of the smaller groups for their generick names, as those of Lamarck ; yet both parties would understand each other; the Sub-genus being merely a division of the Genus. If, however, naturalists will go on, as they do, multiplying generick names of but little impor- tance in the great system of nature, and often worse than synonymous, the prediction of Cuvier will be verified, u That the advantages of the binominal nomenclature, so happily imagined by Linnaeus, will be lost," and men of general learning will in a great measure be excluded from pursuing the details of Natural History, the number of Genera being already far beyond any ordinary man's comprehension. Cuvier, following the views of the great ancient naturalist, Aristotle, considered all animals to be formed upon four distinct types, and therefore capable of being classed in four divisions, which he named Vertebrata, Mollmca, Articulata, and Radiata. The Vertebrate animals are such as have a back- bone, and framework of a skeleton, by which the softer parts are supported. The Mollusca are the soft animals, which have no such framework. The common snail is a familiar example of such an animal. Some of them are naked, others form shells for their protection and habitation. Such are the oyster, the mussel, and all other shell-fish. The Articulated animals are formed in a manner different from either of the foregoing divisions. The softer parts of many are protected by an outer crust, which is composed of various parts fitted and joined together. Such are all crabs and lobsters, which have a sort of external skeleton. Others are formed of numerous rings, united together; of these the common earthworm affords a familiar example. Besides all these, there is a vast number of animals which cannot be properly arranged under any of the foregoing divisions. As many of these are in the form of a star, spreading out arms in different directions, like rays, they have been united under the division Kadiata. Such, for example, is the star-fish. This division also comprehends an in- numerable multitude of creatures, many of which can scarcely be discerned with the naked eye, and others, though larger, differ but little from vegetables. VERTEBRATA. The vertebrate animals are arranged in three classes: the Mammalia, or such as suckle their young; Birds, Reptiles, and Fishes. The remains of vertebrate animals, hitherto discovered in the York- shire Lias, are entirely those of Reptiles and Fishes. EEPTILES.. Reptiles differ from the Mammalia in being all cold-blooded, and from Fishes in that they breathe the atmospherick air. The remains of seventeen species of Saurian Reptiles have been recorded as existing in the Yorkshire Lias, chiefly in the upper beds. Of these, only a few have been obtained in anything like a perfect state of preservation. They vary in length up to 30 feet, equal to the crocodiles of the present day. No remains of a decided land animal have been discovered in the Yorkshire Lias; but the remains of a species of crocodile, an animal generally am- phibious, and breathing the atmospherick air, along with other lizard-like animals, are by no means uncommon. Of the crocodile, or Teleosaurus, remains of two or three species have been discovered in our Lias, but the skeleton of only one has been ob- tained in anything like a state of good preservation. TELEOSAURUS. Their distinctive characters are legs for walking, ending in separated claws. 1. TELEOSAURUS CHAPMANNI, Konig Head with an excessively long, slender beak, gradually tapering to a narrow snout, where there is a sudden depression. The largest, and upon the whole, the most perfect specimen which has yet been obtained is now in the Whitby Museum, and was discovered in the Alum Shale of the Upper Lias at Saltwick, in 1824. A considerable portion of the beak* had been broken off previous to the discovery ; but the length of the remaining parts still measures 15 feet 6 inches ; so that we may suppose the whole length of the animal, when alive, to have been about 17 feet or 18 feet. The hind legs are very perfect, some of the claws still remaining. It is also covered in some places, both on the back and belly, with scales, similar to those of recent species, so there can be no doubt of its analogy with recent crocodiles ; especially with one which inhabits the Ganges, L. Gangetica, Linn. As this animal was fully and accurately described by the Rev. Dr. Young at the time of its discovery, and more recently by Professor Owen, along with other Saurian remains, in his valuable work on British Fossil Eeptiles, my remarks on this, and the other species of this order, will be very brief. The first specimen, of which we have any account, was discovered January, 1758, by Messrs. Chapman and Wooller, at the mouth of Whitby harbour. It was 12 feet long, and is described and figured in the Philosophical Transactions, and also in the Gentleman's Magazine of that period. Judging by the rude figures and the descrip- tions there given, there can be no doubt that it was the same species as that in the Museum, or one closely allied to it; but not a bone of it can be found. Another specimen, 15 feet long, was discovered seven or eight miles to the north of Whitby, in 1791. Another very perfect animal, but much smaller, was discovered near Whitby a few years ago, and is now in the British Museum. Many other remains, especially heads, have in late years been discovered, showing that crocodiles were by no means solitary in these regions, at some very remote period. Besides this there is another species. 2. T. BREVIOR, Owen. Several heads of this species have been discovered at various times, but were confounded with the last, from which it materially differs. The head is shorter in pro- portion, and instead of a depression at the end of the snout, there is an enlarged protuberance of an obovate form, whilst it also possesses more powerful teeth. The largest head I have seen is three feet long and fourteen inches wide across the skull, tapering to a little more than two inches near the muzzle. It was dug out of the alum pit at Kettleness, and is now in the British Museum. Many Crocodilian remains have been discovered from time to time, but nothing which has thrown much light on the subject. A phalangeal bone of the Streptospondylus, a closely allied genus, is in the Whitby Museum, and it may be expected that other remains of that animal may be dis- covered ; but the closing of the alum works is very much against the discovery of Saurian remains. All the fossil remains, both of animals and vege- tables, can be arranged under the same general heads as those of living species, indicating that there were the same laws and operations of nature in the most remote ages of our planet, as at the present day; but in their more subordinate parts and combinations they often differ from any crea- ture now in existence. Of all the strange forms of animal nature brought to light by geological research, our greatest naturalist, the Baron Cuvier, considered the 8 PLESIOSAURUS * c to have been the most singular, and in its characters, the most anomolous which had been discovered amid the ruins of a former world. To the head of a lizard it united the teeth of a croco- dile, a neck of enormous length, resembling the body of a serpent, a trunk and tail having the pro- portions of an ordinary quadruped, the ribs of a chameleon, and the paddles of a whale." The Plesiosaurus is readily distinguished from the rest of the Saurians by the excessive length of the neck ; and, upon a more particular examination, we find the vertebrae more like those of a land animal than those of a fish, being more closely fitted to each other with flat, or nearly flat, surfaces. By this structure of the back-bone, the body had greater strength, but less flexibility. Judging from the shortness of the tail, we may presume that the animal did not possess great power for rapid motion through the water. This defect was, however, in some measure, compensated by its large and powerful paddles, which, unlike those of the whale, were four in number. The paddles of all these Sau- rians are modifications of the arms and legs of other creatures, ending in five fingers and toes, and thus form an intermediate link between the mam- malia and fishes. The remains of eight or ten different species of Plesiosaurus have been extracted from the Lias in the neighbourhood of Whitby. The localities which have proved the most prolifick in such remains are Saltwick and Kettleness, where animals of this kind seem to have congregated, and probably, like the recent crocodile, basked on the mud banks, now hardened into shaly Lias. We notice 1. PLESIOSATJRUS HOMOLOSPONDYLUS, Owen. It is so named on account of the flat or close-fitting ends of the vertebrae ; but the complete skeleton is dis- tinguished by its small head and long neck. It has been well illustrated from specimens in the British and York Museums. There are 15 caudal vertebrae in the Whitby Museum, which were rescued from the rubbish of the alum pit at Saltwick. 2. P. GRANDIPENNIS, Owen. This has also a small head, with very large paddles ; and is now in the Cambridge Museum. A figure of this species, drawn at the time of its discovery (1840), was published in Reed's Guide to Whitby, and afterwards in Simpson's Lias Fossils. It has since been named P. niacropterus, apparently without any good reason ; and Mr. Blake also proposes to call it P. dubius. 3. P. CJELOSPONDYLUS, Owen. The only remains of this species I am acquainted with are 16 vertebrae in the Whitby Museum, from the rubbish of the alum pit at Saltwick. The distinctive character of these vertebrae is, that their uniting surfaces are more concave than is usual in this genus. 4. P. CRAMPTONI, Carte fy Bailey. This is a noble fossil, 22 feet 5 inches in length, with a powerful head, 3 feet 4 inches long. It has the peculiarity of having only four fingers in each paddle. It was extracted from Lord Normanby's alum pit, at 10 Kettleness, and presented by him to Sir Philip Crampton, and is now in the Dublin Museum. It is very like the next. 5. P. PROPINQUUS, Blake. The length of this animal is 15 feet, and the head is rather less in proportion than the last, being not quite one-sixth of -the whole length, and is about half the length of the neck. Only one of the paddles is perfect ; and it has the full complement of five fingers. It was named by Mr. Charlesworth P. macrocephalus, from which however it differs in several particulars. It has also been named by Professor Owen P. brachyspondylus. It was extracted from the Kettleness alum pit, and purchased for the Whitby Museum, where it is still preserved. 6. P. ZETLANDI, Phillips. This has been described as having a "head the most bulky, and the neck probably the shortest of all known species/' The length of the animal is about 19 feet ; the head 3 feet 6 inches, and the neck 4 feet 4 inches in length, and it possesses very large teeth. It is in the York Museum. 7. P. ROSTRATUS, Owen. P. LONGiROSTRis, BlaJce. The length is 15 feet 10 inches. The head, which is imperfect, measures 2 feet in length ; and the greatest breadth 8 inches, tapering to the snout, which is only If inches broad. The paddles are large. 8. P. BRACHYCEPHALUS, Owen. The short headed, of which little is known. Some vertebrae are in the York Museum. 9. P. RUGOSUS, Owen. Some vertebras from Whitby have received that name, from their rugosity. Professor Blake notices other remains in the ironstone mines at Eston. T. & B., p. 253. 11 ICHTHYOSAURUS. The Ichthyosaurus differs very materially from the Plesiosaurus, and, in the structure of its body, comes nearer to the class of Pishes. The neck -is short, and the tail long. The uniting surfaces of the vertebrae are deeply cupped, like those of Fishes, giving to the body great flexibility. Like the Plesi- osaurus, it had four paddles ; whilst the head, in its general outline, resembled that of the Dolphin. Its great peculiarity is the enormous magnitude of the orbit of the eye, measuring, in one example, four- teen inches across. The largest portion of the eye was protected by bony plates, which encompassed it all round, leaving an opening, or pupil, in the centre for the admission of light, which could be expanded or contracted at the pleasure of the animal. Also, by means of these sclerotic plates, the eye could be made more or less convex, so as to become either telescopic or microscopic, and thus enabled the animal to see objects at a great distance or near at hand; a structure of the eye, and a power of vision possessed by the Golden Eagle and some other birds of prey. The skin was smooth and destitute of scales. The remains of five or six species of Ichthyosaurus have been discovered in the Yorkshire Lias, but the skeletons of only three species are in any manner perfect. 12 1. ICHTHYOSAURUS ACUTIROSTRIS, Owen. Length of the head about four times its width across the eye ; snout long, slender, sharp pointed, and curving slightly downwards ; teeth moderately slender pointed, slightly bent inwards. This is by far the most common in our Lias. It may be known by the sharpness of the beak, and by the tri- angular form of the transverse section of the humerus and femur. 2. I. PLATYODON, 06. Length four times that of the head; length of the head about three times the breadth across the eye ; beak deeply concave before the eye, then tapering to an obtuse point, armed with numerous strong conical striated teeth flattened at the point ; lower jaw very strong, convex beneath ; the fore and hind paddles equal. Cervical and lembar vertebrae 45, tail 75 ; in all, about 120. Owen, Pal. pi. xxi., f. 1. A specimen in the Whitby Museum, extracted by Mr. Louis Hunton, from the Lofthouse alum, excavations, is 16 feet 8 inches in length. The cervical and lembar vertebrae are so displaced and concealed under the ribS as not to be counted. Length of head, 4 feet ; breadth across the eye, 14 inches ; length of body, 4 feet ; of tail, 8 feet 8 inches, with 86 vertebrae ; diameter of the largest 2f inches, and If inches in thickness; length of hind paddle, 20 inches, width 6 inches ; length of femur, 6 inches, width, 5 inches ; fore paddle, similar but imper- fect. 3. I. CRASSIMANUS, Owen. This noble fossil was extracted from the alum pit at Kettleness, and is now in the York Museum. It is nearly 30 feet long, and some of the vertebrae are 8 inches in diameter. It differs from P. platyodon in having the fore paddles larger than the hind paddles. Another, now in the Whitby Museum, is 25 feet long, and was extracted from the bed above the Jet Eock, at Hawsker. 13 4. I. TENUIROSTRIS, Cb. Some remains of this species are in the British Museum. 5. I. INTERMEDIUS, Cb. Some imperfect remains have been noticed. 6. I. LONGIROSTRIS or LATIFRONS, Blake. Some remains in the British Museum from Whitby. They have long, narrow snouts. Most of the saurian remains are from the Upper Lias. Some also occur in the main ironstone beds of the Middle Lias, and some in the Lower Lias, but very rare. FISHES. The fishes in our Lias are highly interesting, but they are comparatively rare and very imperfect. For a scientifick arrangement of fossil fishes we are principally indebted to Agassiz, the celebrated Swiss naturalist. His arrangement is founded on the scales, or external covering, and is well adapted for the investigation of fossils, because these parts are the best preserved. They may be arranged in two Orders : The Placoideans and the Ganoideans. OEDEE PLACOIDEI. The Placoideans are those which have hard enamelled plates on their skin, often of considerable dimensions ; whilst they are sometimes reduced to small points, such as we find on the skins of many Sharks, and the prickly, tooth-like tubercles on the skin of Rays. Messrs. Tate and Blake, in their very exhaustive work on the Yorkshire Lias, record the small 14 remains of only five species, which belong to three Genera : A crodus, Hybodus, and Notidamus. 1. Acrodus nobilis, Ag. " Several fine teeth in juxtaposition/' L.L., E.edcar. 2. A minimus., Ag. L.L. and Rhaetic. 1. Hybodus reticulatus, Ag. L.L.,, E/edcar. 2. H. minor, Ag. L.L., Redcar. 1. Notidamus amalthei, Op. M.L., Hawsker. Tooth in the Whitby Museum. OKDEK GANOIDEI. The Ganoideans are distinguished by their bright shining scales, which are of an angular form, and composed of horny or bony plates, covered with a thick plate of enamel. Eighteen species of this Order have been discovered in the Yorkshire Lias. They have been arranged in two Groups or Families : Lepidoides and Sauroides. FAMILY LEPIDOIDES. These are well distinguished by their large, im- bricated, rhomboidal scales, very thick, and coated with beautiful enamel. Tail either regularly forked or rounded. The most common in our Lias is: 1. LEPIDOTUS SEMISERRATUS, Ag. Head short, thick, mouth broad ; teeth slender, inflated near the points; body fusiform and lengthened; scales half serrated. ILL., 7, Whitby. 2. L. PECTINATTTS, Egerton. Of a small or moderate size, depth about one-third the length; scales with delicate radiating striations which serrate their posterior margins. U.L., 6, Whitby. 15 3. L. RUGOSUS, Ag. Head conical, tapering to a narrow mouth ; teeth short, strong, sharp, conical; bones and scales rugose. U.L., 7, Whitby Museum. 1. TETRAGONOLEPIS OVALIS, Ag. ^SCHMODUS, Eg. 1. SAURICTHYS APICALIS, Ag. Bhaetic. 1. DAPEDIUS MICANS, Ag. Body ovate, tail forked, fins large. There is in the Whitby Museum the impression of a fish which corresponds with Agassiz's figure, and many scattered scales which may belong to this species. U.L., 6, Whitby. 1. EUGNATHUS FASCICULATUS, Ag. I. GYROLEPIS ALBERTI, Ag. E-hsetic. FAMILY SAUKOIDES. The Sauroid, or Lizard-like fishes, which were so abundant in the earlier periods of our Earth's existence, have become nearly extinct. Only two genera remain, which inhabit fresh waters : the Lepidosteus or bony Pike, of the large American rivers, and the Polypterus in the Nile and Senegal. The Sauroid fishes of our Lias are small compared with those of an earlier period. Teeth conical, pointed, alternating with little teeth in a brush. Scales flat, rhomboidal, parallel on the body, which is entirely covered by them. 1. PTYCHOLEPIS BOLLENSIS, Ag. Length four times the depth ; tail forked ; one dorsal fin, one abdominal, one caulal ; scales longer than deep, longitudinally and irregularly striated or crinkled. Not uncommon. U.L., 6, Whitby. 16 1. PACHYCORMUS ACUTIROSTRIS, Ag. " Snout pointed ; teeth fine, very sharp/' Ag. 2. P. CURTUS, Ag. Length more than twice the depth, fusiform, head conical, mouth small. Not uncommon. U.L., 6, Whitby. 3. P. GRACILIS, Ag. " Near P. curtus, but more delicate ; tail with very fine rays, and broadly forked." York Museum. ILL. 6, Whitby. 4. P. LATIROSTRIS, Ag. "Very large, with short head and pointed snout." U.L., 6, Whitby. 5. P. LATUS, Ag. " Very large and oblong ; head short and small/" U.L. 6, Whitby. 6. P. MACROPTERUS, Ag . Head elongated, pectoral fin large. York Museum. Blake. ILL., 6, Whitby. 1. ASPIDORHYNCHUS ANGLICUS, Ag. Body very long, cylindrical ; tail regular ; upper jaw prolonged into a long beak. ILL., 6, Whitby. 1. BELONOSTOMUS ACUTUS, Ag. Many long, slender, sharp-toothed jaws frequently occur in U.L. 6, which may belong to this species or to the preceding. 1. LEPTOLEPIS SALTVICIENSIS, Simp. This little fish occurs in considerable numbers in the large lenticular nodules, a little above the Jet Eock, in the Upper Lias. Contrary to what occurs in most of our fishes, the external covering has perished, and the in- ternal skeleton only has been preserved. Professor Blake has given the following description : ff The pectoral, ventral, and anal fins are about the same size, and are at equal distances apart. The dorsal is rather large, and is situated opposite the interval between the anal and ventral. The vertebral column is ossified, and the tail 17 homocercal. The head is small,, and the teeth are com- paratively large, and lie apparently in clumps. Length 4 inches by f inch." U.L., 5a, Whitby. In connection with these, we may notice the occurrence of large spines belonging to the fins of some fish of this family, of which there are at least two species. The most remarkable of our Lias fishes, on account of its immense size, is the GYROSTEUS MIRABILIS, Ag. Large bones of this fish occur in the Upper Lias, chiefly in the bed above the Jet Rock. They were con- sidered by Agassiz to belong to some large Sauroid fish ; but not a single tooth, or scale, or vertebra has been discovered which could be referred to this animal ; and the remains, more recently, have been judged, with greater probability, to have been those of a fish closely allied to the Sturgeon, which has no teeth, and feeds by suction. U.L., 56. MOLLUSCA. The Molluscous animals have been divided into six classes : Cephalopoda, Pteropoda, Gasteropoda, Acephala, Brachiopoda, and Cirrhopoda. CEPHALOPODA. These are so named because they have the feet placed round the head. With these they crawl at the bottom of the sea, seize their prey and swim. A familiar example of a Cephalopodous animal is the Sepia or Cuttle-fish. They have been divided into several genera ; the principal which occur in C 18 our strata are Sepia, Belemnite, Nautilus, and Ammonite. Those which are destitute of an external shell form the genus Sepia, of Linnaeus, and to this modern research has added the Belemnite. SEPIA, Linn. This animal has a kind of shell or bone, which is often found in a fossil state ; and also a bag-, con- taining a black fluid, or ink, which it emits in time of danger. It is exceedingly interesting that ink- bags, in a fossil state, are occasionally found in our Lias, accompanied with a horny body, very much resembling, in structure, that of the recent Loligo. These bodies, and their accompanying ink-bags, we can have no doubt, belonged to that division of the Cephalopoda which have no external shell. The recent Sepia are also provided with horny beaks, like those of a Parrot, for crushing their prey ; but none of these have been discovered in our Lias, although they are not uncommon in the Lias at Lyme Regis. Of this genus we have several species. 1. SEPIA OBTUSALIS, Simp. Length of the bone about three times the width, a little wider at one end than at the other ; apex very obtuse; a keel between two furrows along the middle ; colour brown ; often covered with a thin, variously striated, black epidermis, which readily comes off. 19 They are found from two to seven inches long, and appear to have been comparatively stout. One of these, two inches long, has the ink-bag well preserved. Just above the bone, is a brown substance, probably copro- litick, and then the ink-bag, three inches long and one inch wide at the round end, where it is suddenly contracted into what looks like a neck a quarter of an inch wide. The bag, however, has been compressed, and the ink has been squeezed to one side. The bag has been thick, and probably horny, and is of a light brown colour. The whole is imbedded in compact Lias shale, and apparently water-worn by exposure on the beach. The upper part of the neck is gone, but a portion of the ink having been removed from the extremity of the remainder, the con- cave surface of a part of the interior of the bag may be seen, and the edge may be traced along one side of the ink, and around the base on the other side. Fragments of the bag may also be seen at a little distance from the main body of the ink, crushed together, and containing a film of ink between them. It is from the hard shale of the Upper Lias at Whitby, and is preserved in the Whitby Museum. The figure Mr. Blake has given of his Belemnoteuthis Leckenbii is so like the bone of this species, that it surely must be the same, T. & B. Yorks. Lias, pi. iv., f. 2. 2. S. CUSPIDATA, Simp. Triangular, five inches long and two inches broad at one end, tapering to a sharp point at the other ; an elevated triangular ridge or mid-rib the whole length ; epidermis striated logitudinally. The body appears to have been thin and flat; and they vary much in their proportional length to the width, some being much elongated. ILL., 6, Whitby, S. HATJSTRTJM, Simp. Triangular, with an obtusely rounded apex ; longitudinal, diverging striae, strong, unequal ; at a 20 little distance from the middle, a strong groove on either side ; many oblique striae. It appears to have been very thin and fragile,, and is seldom found perfect. The smaller end appears to have been hollow like a scoop. Length of example described, six inches, greatest width 2^ inches. ILL., 6, Whitby. I suppose this is the species figured by Mr. Blake under the name Geotenthis coreaceus. Quin. T. & B. Yorks. Lias, pi. iv., f. 1. S. INCOMPOSITA, Simp. Mr. Blake considers this to be a neural arch of a ver- tebra of the Gyrosteus mirabilis. Plate ii., f. 3. I may merely repeat what I said before on the subject ; Lias Fossils, page 21 : " Under this name I may notice a fossil, respecting the true nature of which I perhaps have no definite idea. It is about nine inches in length, and of a triangular form ; apex conical j base flatted, irregular, and unfinished." U.L., Whitby. I am disposed to place under the Genus Sepia TBIGONELLITES WHITBYENSIS, Simp. Some have imagined it to have been the operculum of an Ammonite ; but of this there does not appear to be any good evidence, and in all its characters it appears strongly to ally itself with the bone or pen of the Cuttle- fish. In what appears to be its natural state, its length is about the same as the width, with a triangular mid-rib ; the upper end square, with the angles rounded, the lower end obtusely rounded and diminished ; the striae are very numerous, fine, distinct, parallel with one side and lower end. It is generally found in two separate pieces, or with the pieces joined only at the broader end. Thinking that one of these pieces might be a valve of some shell, I gave the following description : " Excessively depressed, subtriangular, transverse ; two sides straight, forming a right angle ; base rounded at 21 both ends ; posterior end diminished ; disc with a groove near the longer straight side, increasing to the posterior end; very finely striated; one inch long, If inch wide. They are not uncommon in the Jet Rock, ILL., 7, where alone I have found them." BELEMNITES. The Belemnite is an exceedingly curious and interesting- fossil. On account of its pointed and dart-like form, it has been named Thunderbolt; and this idea has been strengthened by the abundance of pyrites often found at the thick end, which when struck with a hammer gives out a sulphurous odour. Kecent discoveries have now proved beyond all doubt, that the Belemnite has been enclosed in the body of a Cephalopodous animal, resembling the Sepia, or Cuttle-fish ; and it has also been proved, that, like this creature, some of the species, at least, possessed an ink-bag. Belemnites are exceedingly abundant in our Lias, and so variable that it is difficult to determine their species with anything like certainty. The fossil which we call the Belemnite, indepen- dent of the animal which formed it, consists of three principal parts: the Guard, the Case, and the Phragmocone. 1. The Guard, rostrum, or sheath, is generally of a conical form, terminating at the wider end in a hollow cone or Alveolus, which is the receptacle of the Phragmocone. 22 The substance of the Guard has the same struc- ture, and the same specifick gravity, as the shell of the recent Pinna. It is composed of an infinite number of fibres, radiating from a centre, and formed by concentrick lamellae, or depositions of calcareous matter, from the mantel of the animal, which had invested it on every side. These lamellae, or stages of growth, are well exhibited in polished sections of the Guard, whilst the exterior surface is often corrugated by the impressions of the mantel, and sometimes has a pearly or silky lustre. The sub- stance of the Guard becomes very much diminished where it invests the Phragmocone, but the external layer, or peristome, is continued far beyond it. 2. The Case. This is a very thin horny substance in the form of a cup, which lines the Alveolus, and and invests the Phragmocone, and being greatly extended beyond it, forms a larg*e anterior cham- ber, which contains the ink-bag and other viscera, and has been named the pro-ostracum. The Case is also continued in the opposite direction in a filamentary tract to the posterior apex of the Guard. This tract greatly resembles the pith of a tree, and around it have been deposited the numerous con- centrick layers of which the Guard is composed, and from which the fibres radiate as a centre. When the Phragmocone has been detached from the Guard, the Case may be seen covered with very delicate striae in systematick geometrical forms. 23 3. The Phragmocone, or conical part, which occupies the Alveolus, is transversely divided by thin horny plates, which are convex towards the apex, and separate it into narrow air-chambers. Attached to these, on the ventral side, there is a fine, strait tube, along* the whole length of the cone, called the Siphuncle. In many examples, it is filled with white calcarious spar, when it becomes beautifully con- spicuous. The apex of the Alveolus is generally turned more or less out of the centre of the Guard, the deposi- tion of the belemnitick matter from the Mantel having been more copious on one side than on the other. We may observe that the Mantel is the fleshy part which envelopes the whole. From what we know of the animal, it appears to have been long in proportion to the width, the Guard being little more than one-third the whole length. Whilst some of them have been very small, others have been very large, several feet in length, and must have been formidable enemies to fishes. The fleshy parts of all animals have perished ; but a very perfect specimen of a Belemnite has been dis- covered in the Lower Lias at Charnrnouth, where the whole outline of the animal could be traced. It has been fully and clearly described by Professor Huxley, and has thrown a great light on the struc- ture and nature of the Belemnite. The entire length 24 of this example, from the summit of the beak to the apex of the guard, is 12^ inches, whilst its greatest breadth does not exceed If inch. Around the beak there had sprung a number of arms 1-^ inch long, provided with numerous hooks for securing its prey. It is remarkable that the hooks are per- forated like the fangs of venomous serpents. The beak is horny, like that of other animals of this order, and is situated in the centre of the arms. The ink-bag is pear or flask-shaped, contracted into a narrow neck. The ink-bag and all the viscera are enclosed within the pro-ostracum, above the phragmocone, in the middle portion of the animal. Other examples, though less perfect as a whole, present the same characters. The Belemnite, so far as we know at present, first made its appearance during the formation of the lowest beds of Lias, and soon became exceedingly abundant in numbers, and of great variety. During . the Oolitic period there are examples of immense size, but it had greatly diminished, both in numbers and variety, and no true Belemnite has been dis- covered in European strata more recent than the Chalk ; but we hear that our friend, Professor Tate, has discovered a true Belemnite in Tertiary strata, in Australia. Fossils of a Beleinnitic character, however, occur in Tertiary strata in this country ; and the Orthoceras, a fossil very like the Belemnite, was abundant in very early geological times. 25 In arranging a Catalogue of Yorkshire Lias Bel- emnites, I have found it convenient to divide them into Upper, Middle, and Lower Lias Belemnites ; and I imagine this arrangement will assist in col- lecting them. I also think difference in time ought to be taken largely into account in determining species. As many have a great difficulty in understand- ing the nature of a Belemnite, I give the ac- companying figure, drawn in accordance with the above example, one-third the size. At the top are the arms with their little hooks; in the middle is the ink- bag ; and the lowest part represents the horny Belemnite with its phrag- niocone ; the whole invested by the mantle or OU fleshy part. The figure a a magnified view of a perforated hook. We may presume that the form of the animal would vary in accordance with the form of the guard. 26 UPPEK LIAS BELEMNITES. Slender and elongated. 1. BELEMNITES TUBULARIS; F. <$ B. Pal., pi. xiv., f. 36. Guard very long and slender, generally with a large portion towards the apex crushed flat, slightly increasing towards the alveolar region ; alveolus short, little expanded. The largest I have seen is about a foot in length and a quarter of an inch wide, gradually tapering to the trun- cated apex, which is about half the width of the other end. The flatted part exhibits nothing of the ordinary radiated structure, and varies very much in length. In some examples, three-quarters the length is flat ; in others, a very small portion only is flat, and in some I have observed an irregular thickening and flattening. It is supposed to have been tubular, or the inner part soft, the outer part hard, which has cracked by the superincum- bent pressure. In some examples the upper part of the guard is strongly striated, corrugated, and granulated. One variety, having these characters, but stouter, without any flattening, and ending in an obtuse apex, I named B. productus. Geo. Rep., p. 216 This species may be most conveniently obtained near the two Nabs at Saltwick, where it is by no means scarce, but it is found wherever the stratum 5& is exposed, from Peak to Eunswick. U.L., 5&. 2. B. COMPRESSUS, Y. 4* B. Stout, length of guard five times or more the width, one-third flatted, coarsely striated, or cor- rugated to the rounded apex ; transverse section irregularly ovate ; length five to seven inches. 27 This resembles the last in having the apical half crushed and flattened,, but is very much stouter. One example I got at Sandsend is three-quarters of an inch wide at the alveolar end, and after having tapered for more than half the length, is flattened, and spreads out like the head of a lance ; and this is more or less the character of the species. It is by no means uncommon in stratum 6, U.L. Young's name has the priority, and it represents a large, distinct species. 3. B. INJEQUISTRIATTJS, Simp. Pal., pi. xix., f. 48. Length of guard generally about six inches, six or seven times 'the width, regularly tapering, and sometimes curving towards the rounded apex, which is sometimes flatted, and with numerous strong strife and grooves about 1^ inch long, and smaller ones much longer ; alveolar part moderately expanding ; transverse section ovate. Not uncommon at Saltwick. The Sandsend specimens are stouter and straighter ; and one example is without grooves or striae. ILL., 6. 4. B. INCLUSUS, Simp. Length six times its greatest width, half that width near the apex, which is slightly compressed ; apex obtuse, eroded ; alveolus much expanding, extends far down the guard. U.L., 1, Whitby. 5. B. EROSUS, Simp. Long and rather slender, sides straight ; apex rough and unfinished, from whence proceed many slender grooves ; the surface, for half the length, is covered with long, irregular, distinct striae, or cor- rugations ; length eight inches, six times the width. U.L., 1, Peak. 28 This is closely allied to the last, but much stouter, especially in the apical half. It is also from a different bed. The mistake in assigning this and several others to the Lower Lias has arisen from the abutting of the Lower Lias against the uppermost beds of the Upper at the great Peak dislocation. 6. B. GLABER, Simp. The whole length 9 inches ; guard 5-| inches, width an inch and two-tenths, much flatted, tapering to a very obtuse apex, which is eroded and has a shallow groove ; transverse section very elliptical ; phragmocone protruding beyond the guard Scinches, and expanding to a width of two and two -tenths inches. U.L., 1, Peak. It is of a brown colour, and very smooth in its texture. The outer layers of the guard not reaching quite to the apex, gives that part an eroded appearance. It is well distinguished by its broad, flat appearance, and, judging from the matrix, I have no doubt that it is from the very uppermost bed of Lias. 7. B. LIMATUI/US, Simp. Conical, elongated, much compressed ; apex obtuse, with about five principal, deep, triangular furrows, and others smaller, and many distinct striae ; texture close and smooth ; length six inches, width of the base one inch. It was amongst the Yorkshire Lias Fossils, in the Scarborough Museum, and described by me in the G-eo. Eep., p. 216. I have now got a good specimen from the uppermost or cement stone nodular bed of the Upper Lias, at Whitby. The guard is eight inches long, and the greatest diameter of the cross section one inch. The guard, for 29 half the length,, maintains its stoutness, and then rather suddenly contracts,, and the portion towards the obtuse apex becomes attenuated and compressed. The trans- verse section, with the grooves and striae, are the same as in the Scarborough example. The part of the phragmo- cone protruding was unfortunately mislaid and lost. Another example in the Whitby Museum, which I suppose to be of the same species, has a rather crushed phragmocone expanding four inches beyond the guard to the width of full two inches, whilst the whole example is only nine inches in length. This has the sudden con- traction of the guard about the middle still more distinct. Blake refers them to B. insequistriatus, but they are much stouter, and the contraction at the middle of the guard is a strong character. U.L., 1, Whitby. I think it probable that the B. concavus of the first edition may be the apical half of the above species, but I repeat its characters : Length of guard about six times its greatest width, slightly depressed ; sides for about half its length from the apex, concave ; apex unfinished, with one wide groove and many narrow ones. 8. B. OPTATUS. There is in the Whitby Museum the apical half of some large Belemnite. It is nearly seven inches in length, and an inch in diameter at the thick end, slightly com- pressed into a regular ellipse. One side is quite straight,, the other rather convex, gradually tapering to a blunt,, eroded apex. It is very regular in the outline, and has the smoothness and density of structure so characteristick of the other long Belemnites of the uppermost bed of the Upper Lias. It is broken off nearly at the end of the alveolus, which is rather eccentrick. A perfect specimen is much desired. We may here place some elongated Belemnites which are highly characteristick of the Jet Eock and the stratum immediately above it ; and which some consider to be the B. tripartitus of Schlotheim, on account of the 30 apex being divided by three grooves. But as that name has been applied to very different species, I am at present disposed to retain the names I formerly gave them. 9. B. TRISULCULOSUS, Simp. Pal., pi. xi., f . 28. Length of guard seven inches, nine times its greatest width, subcylindrical for more than half its length, then, in tapering, one side being more convex than the other, the apex is thrown to one side; apex sharp, with three long, broad, shallow furrows ; transverse section irregularly ovate. Some have an additional fine triangular groove at the apex, others have the apex striated. The phragxnocone appears to be small. They occur both in the Jet Rock and in the stratum above. Saltwick and Sandsend, U.L., 6, 7. 10. B. DISTORTTJS, Simp. Pal., pi. xi., f. 29. Guard subcylindrical, length eight inches, nine or ten times its diameter; apex slender, bent to one side, with a strong groove on the concave side, which becomes double at the extremity ; two other principal grooves, and many small ones or striae ; phragmocone protruding beyond the guard, small. It is closely allied to the last, but more slender. Some are rather fusiform, the guard being diminished in thickness about the alveolar region ; others have the apex less bent, and the grooves shallower. It is more slender in proportion than B. subaduncatus, Voltz. U.L., 6, Whitby. 11. B. INCISUS, Simp. This is more slender, straight, and conical than the above, finely tapering to a finely pointed apex, from whence proceeds a deep, narrow, triangular groove, for 31 about one-fifth the length of the guard; deepest at a short distance from the apex; also two broad, shallow grooves of equal length at the apex. ILL., Whitby. 12. B. MULGRAVIUS. Length five inches, seven or eight times the width, two opposite sides much compressed, nearly parallel for two-thirds the length ; apex finely pro- duced, pointed, and with a long deep groove on the protuberant ventral side, and many long distinct striae on the opposite side, and a groove on the compressed sides; transverse section obovate. U.L., 6, Sandsend. Pal , pi. vi,, f. 16/., gives the general outline. There is also another with the guard rather depressed and the transverse section an ellipse. The apex is rather obtuse. It is smooth and regular, with little else to dis- tinguish it. Let us call it B. modestus. Length 5 inches. Another I cannot distinguish from B. pyramiformis of the Lower Lias. They are both from the Jet Bock, ILL., 7. 13. B. BITUMINOSUS. Conical, length five inches, five times its width, alveolus widely expanding, guard finely tapering to an acute and finely pointed apex ; apex grooved and numerously striated. ILL., 7, Saltwick and Sandsend. This is well distinguished from the other Jet B-ock Belenmites by its shorter and more conical form, and especially by the enlargement of the alveolus and phrag- mocone. Examples vary in respect of their grooves and striae. In one example the fine striae, with some inter- ruptions, are continued far up the guard. 32 14. B. DENSUS, Simp. Length of guard four inches, width six-tenths of an inch, subcylindrical, slightly compressed, of a fine dense texture ; apex obtuse, eroded. The whole length which remains is six inches ; the portion of the phragmocone protruding beyond the guard being two inches in length, and its greatest dia- meter 11 inch. U.L., 7. There is in the Whitby Museum the upper portion of a phragmocone seven inches long,, the diameter of the top three inches, at the bottom 1 inch. If we could imagine this fragment placed upon the above, the figure would closely agree with those given of Miller's B. elongatus. It is in a nodule from the Jet Rock. In the extensive workings of the Jet E-ock, portions of the phragmocone of some large Belemnite frequently occur, but no perfect example of such a Belemnite has been preserved. Large phragmocones, detached from the guards, sometimes occur, when the striations of the case are beautifully displayed. Mineral oil is not unfrequently found in the cells. 15. B. SUBSTRIATUS, Simp. Length 5^ inches, width seven-tenths of an inch, sub-conical, rather cylindrical, both sides of the guard equally convex, most towards the apex, smooth and regular; apex blunt, central, striated; transverse section circular. U.L., 6, Salt wick. It is of a brown colour, but less conical than B. teluni or spicatus, and too large to be B.le vis. Blake assimilates it to B. striolatus, but the strise are confined to the apex. 16. B. TELUM, Simp. Conical, rather depressed, length four inches, four times the width, sides nearly straight, gradually 33 tapering- to a somewhat attenuated but obtuse apex; apex central ; transverse section elliptical. U.L., 1, Whitby. Another example is more robust, with one side rather convex, and the apical portion strongly corrugated ; no striae or groove. Syn. B. Voltzii, Ph. Pal. pi. xvii., f . 45c?. 17. B. CINERETJS. Length five inches, five times the width, sides convex ; apex obtuse, without grooves or striae. U.L., 1, Whitby. It is of a grey colour and rough to the touch. A smaller example has two obsolete grooves at the apex. 18. B. SPICATUS, Simp. Conical, length five inches, five or six times the width ; transverse section circular ; apex central, very acute, finely pointed, a few striae, with two shallow grooves, and one long, narrow, concave, deep, widening upwards. U.L., 5, Whitby. Very slender. 19. B. SUBTENUIS, Simp. Pal. pi. x., f. 27. Length four inches, eight or nine times the width, slender, regularly tapering to a fine pointed apex ; apex with three long, shallow grooves, and finely striated. U.L., 4, 5, Whitby. This is a very abundant species in the middle of the Upper Lias, and varies much in the slenderness of the guard, and in respect to the grooves and striae at the apex ; the grooves and striae becoming obsolete. Var. (a.) Grooves obsolete ; apex not striated. (b.) Thicker in proportion ; apex not striated. D 34 20. B. DORSALIS, Ph. Pal. pi. x., f . 24. Like the last, but with a groove or slit in the alveolar region, concave on the grooved side ; apex finely pointed, seldom striated, grooves obsolete. Length 21 inches; generally less. It is most plentiful near the fourth indurated band of the Upper Lias, at Saltwick ; rare in the beds above. 21. B. TRIVIALIS, Simp. Pal. pi. x. Subconical, moderately stout, alveolus expand- ing ; apex rather obtuse, with numerous fine striae ; length two or three inches. U.L., 5. Intermediate between B. subtenuis and levis. 22. B. LENTUS, Simp. Very slender, sub-fusiform, length 3^ inches, nine times the width, finely tapering to the apex; apex with three long, deep, triangular grooves. ILL., Whitby. 23. B. TENTJIS, Simp. Slender, elongated, tapering towards both ends ; transverse section circular. U.L., 8, Hawsker. B. longiformis (Bl.) is its nearest ally, but it is the thickest in the middle. 24. B. EXIGUUS. Very slender, smooth and regular, gradually thickening from the alveolar part to near the apex, which is acute, and very sharply pointed U.L., 8, Hawsker. It is not to be confounded with B. microstylus, Ph. The two last are from a very rotten bed immediately above the Middle Lias, full of fragmentary fossils along with B. clavatus, longiformis, and others, too fragmentary for description. Further discoveries may be made in that bed at Hawsker and Kettleness. 35 Shorter and thicker in proportion. 25. B. EXPANSES, Simp. Cylindrical, or subfusiform, being contracted in the alveolar region, and then moderately expand- ing ; general length from two to four inches, seven times its diameter ; apex central, with two shall6w grooves on opposite sides, and another principal groove expanding into a wide convex area ; on the opposite side a few strise ; cross section circular. U.L., 1, Whitby. We may notice two principal varieties : Var. (a.) Apex elongated, and finely pointed. (b.) Apex very obtuse, groove large, deep, coarse. This last might be considered a very distinct species, but it has the characteristic!? groove only exaggerated. The formation of this groove I imagine has arisen from a peculiarity of the mantel not having deposited the belemnitick matter in that part. One would have thought that the groove would have been ventral, but judging from the crushing of the alveolus, it is on the right side. Something of this structure may be observed in B. rudis, Ph. Variety (a.) is very plentiful in the upper- most division of the Upper Lias, and I do not recollect finding it much below. 26. B. EEPANDUS, Simp. Subfusiform, much bent, convex on the grooved side ; apex pointed. U.L., 3. It has the characteristic^ groove of the last, and may be a variety of it. It is a good deal like Blake's fig. 9, pi. iv., but more curved. 27. B. LEVIS, Simp. Pal. x., f. 23. Length of guard three or. four inches, about five times it width, rather depressed, smooth and regular; 36 apex generally compressed, often striated, more or less obtusely pointed, sometimes with a flatted pro- cess. ILL., 56, Saltwick, Whitby. This species is plentiful about forty feet above the Jet Rock. Some are rather cylindrical, others more conical. The surface in places towards the smaller end is often finely and distinctly corrugated like leather. May not this be B. striolatus, Ph. ? Nearly all have one side of the guard more depressed than the other, which renders the transverse section irregularly ovate. 28. B. APTUS. This has the same general form as the last, but with a long, deep groove on one side proceeding from the apex. It differs from B. incisus in being more cylindrical, and in the apex being rather obtuse. Length four inches. The lower portion is rather bent to one side. U.L., 56. It is not badly represented by Pal. pi. x., f. 27. 29. B. PINQUIS. Tumid, length four inches, four times the width, sides regularly convex ; apex obtuse with a rather large foramen, and on both sides a very flat, long, broad groove; transverse section circular or slightly ovate. One example five inches long, five times the width, has many fine striae diverging from the apex on the ventral side. A smaller example has a strong, shallow groove at the apex on the ventral side, and a triangular groove on two opposite sides. They are all of a dark blue colour, and very smooth and soft to the touch. ILL., 2, Whitby. 30. B. ROSTRATUS. Length three inches, six times the width, sub- cylindrical, apical portion elongated, like the bill of 37 a bird, obtusely pointed, three long, deep furrows, and many striae. U.L., 4, Whitby. 31. B. WOOLLERI. Length five inches, five times the width, much depressed, two opposite sides being much flatted, gradually tapering ; apex elongated, acute, from whence proceed along the two more rounded sides a keel between two long, triangular furrows, with many shorter striae. ILL., 5, High Whitby. Some examples are less flatted, and the apical part less drawn out, and thus graduate into the more robust varieties of B. levis. I name this in memory of Mr. Wooller, who, when engineer of Whitby Piers and Harbour, along with Mr. Chapman, in 1758, discovered the first known example of Teleosaurus Chapmanni, and described and figured the same, though roughly, in the Philosophical Transactions, vol. 50. The observations there made show that Wooller was far ahead of the age in which he lived. 32. B. ACUMINATUS, Simp. Pal. pi. ix., f. 22. Length 2^ inches, five times its diameter, cylin- drical for nearly its whole length, then suddenly ends in a sharp point, more or less produced ; trans- verse section circular or slightly ovate ; grooves, if any, at the apex very obscure. ILL., 5, Whitby. 33. B. CYLINDBICUS, Simp. Pal. pi. xx., f . 52. Cylindrical for the greatest part of the length, transverse section circular ; length five inches, from five to seven times the diameter; apex rather obtusely pointed. U.L., 8. The general rounded form is constant, and for the most part very cylindrical, but some incline to the conical, whilst others, being slightly contracted in the alveolar region, become somewhat fusiform. The apex is some^ times rather finely pointed, and with two or three slight grooves. In one example it is also finely striated. It has a considerable range of strata. It occurs sparingly in the uppermost beds of the Lower Lias, more common in the Middle Lias, and is very plentiful, and the most perfect, in the lowest bed of the Upper Lias, where it accompanies Am. annulatus over wide areas, which, with the exception of an imperfect Nautilus, and the frag- mentary remains in the rotten bed immediately above the Middle Lias, are the only fossils I have been able to detect in that stratum. 34. B. ATHLETICUS, Simp. Conical, with the outline gently and regularly curved; length 4 inches, about four times the greatest diameter ; transverse section circular ; apex obtuse. U.L., 1, Peak, R.H. Bay. This is a strong, coarse species, with little to charac- terize it, except its general form. It is more conical than the last, and of a grey colour and coarse texture. It was brought to us as from the Lower Lias, but I have no doubt it is from the uppermost bed of the Upper Lias, where Blake places it. 35. B. VULGABIS, F. B. Pal. pi. xvi., f. 40, 41. Robust, subcylindrical ; length four or five times its width, outline most convex near the obtusely pointed apex, irregularly and slightly compressed on two opposite sides; apex inclined to one side, with two and sometimes three grooves; general length from six to eight inches. U.L., 1, 2. 39 It is very plentiful in the uppermost strata of the Upper Lias, and is rather variable, the smaller examples being rather conical, approaching to B. spicatue. The phragniocone is often well preserved, extending consider- ably beyond the guard, and not unfrequently exhibiting; the siphuncle like a white line. 36. B. CURTUS, Simp. Very thick, short, and conical. It occurs in the shale below the third indurated band. It is generally regarded as a mere variety of the last, but it is sufficiently distinguished by its very short conical form, and by the phragniocone being always rotten. In this it also differs from the next. Both the above are of a brown colour. U.L., 4. 37. B. UBBANUS. Conical, general length three or four inches, about four times the width, expanding much at the alveolar part ; transverse section ovate ; apex central, acute, with three shallow grooves. ILL., 5. This is more finely and regularly formed than B. vul- garis. Some are rather inclined to be subcylindrical in the upper part, but in all the apical portion is finely taper and pointed. In one very taper example, the apex, besides the grooves, is finely striated. It approaches B. regularis (Ph.). Pal. pi. xv., f. 38Z. It is very cha- racteristick of the upper part of the fifth division of the Upper Lias at Saltwick, and almost confined to it. It may be well to observe that B. validus and robustus occur in the lower part of this division, and their young may be mistaken for this species, but they have the apex somewhat out of the centre. 38. B. POLITUS, Simp. Robust, subcylindrical, rather fusiform, being slightly contracted in the alveolar region, and tumid towards the apex ; length 3^ inches, five times the 40 width; transverse section circular; apex short, obtuse, ending in a small blunt point, with two shallow grooves on one side. U.L., 5, High Whitby. Pound also in the same bed in Cleveland by Mr. R. Tate. Geo. Rep., p. 216. It is of a dark colour, smooth and regular, as if turned in a lathe. The phragmocone appears to have been small. It is much too long to be mistaken for the young of B. pollex, and the little blunt point at the apex bears no resemblance to the apex of B. acuininatus. 39. B. POLLEX, Simp. Pal. pi. ix, f. 20. Subcylindrical, length 3^ inches, width 1 inch, one side rather flatted ; apex very obtuse, with a short irregular groove. U.L., 5. 40. B. BOBUSTUS, Simp. Pal. pi. v., f. 14. Conical, length of guard 5| inches, three times its width, with a strong wide groove on two oppo- site sides the whole length ; apex obtuse, turned to one side. U.L., 5, Whitby, Hawsker. This species is well figured by Phillips, but I think he has done very wrong to change the name, especially as he had both the published description and the labelled specimen, which is in the Whitby Museum, to go by. The phragmocone, in a very crushed state, spreads out far beyond the guard. In. the smaller examples which I have found, the upper part was so rotten as not to be preserved. 41. B. OBTUSTJS, Simp. Subcylindrical, rather flatted on two opposite sides, length of guard five inches, four times the width, with a shallow groove or depression on one 41 side towards the alveolar end; apex obtuse, central, with four short, broad, shallow grooves. U.L., 5, Whitby. On one side of the apex the groove is sharper and deeper than on the other. Phragmocone small. The central position of the apex distinguishes it most from the kindred forms. It is also shorter in proportion than the next, and the apex more obtuse. 42. B. VALIDUS, Simp. T. & B., pi. iii., f. 4. Cylindrical, with a shallow groove on one side the whole length, deepest in the alveolar region ; transverse section circular; apex eccentrick, obtusely pointed ; length six inches, six times the diameter. ILL., 5. 43. B. LEVIDENSIS, Simp. T. & B., pi. iii., f. 3. Depressed, regularly tapering to about half the width, wide at the base ; apex obtuse ; texture coarse; length three inches, three times its greatest width ; an obsolete groove or flattening at the apex on one side. U.L., 1, Whitby. Var. (a.) Less taper, rather cylindrical, with two long deep grooves from the apex. (6.) More robust, with two short wide grooves at the very obtuse apex. (c.) Length 3 inches, three times the width, much depressed; apex broadish, obtuse, with a short broad groove on the dorsal side. The outline resembles that of B. pollex. The apex of all is very blunt, and has a large foramen. Colour grey, and texture coarse. I very much doubt whether Mr. Blake's example is identical with any of these varieties. 42 44. B. DACTYLUS. Subquadrate, of nearly the same thickness the whole length; length 3J inches, four times the width, sides nearly parallel, one side occupied by a wide shallow groove, or flatted space, the opposite side rounded ; apex very obtuse, with a large fora- men; transverse section subquadrate. U.L., 1, Whitby. It is of a soft light grey colour, and has the appear- ance of a very thick clumsy finger. It is much more robust than the continental B. digitalis, and the trans- verse section more quadrate. The next is still of the finger form, but widely sepa- rated in time from the above, and seems to have a family relation with B. levis. 45. B. DIGITTJ8. Subcylindrical, much depressed on one side; apex obtuse, with a very sharp ridge between two narrow furrows in the end ; length 3^ inches, four times the breadth ; of a brown colour. U.L., 56, Whitby. I may notice here the apical portions of two Belemnites of kindred form, which I found in the Am. Mulgravius seam at Saltwick. (a.) Cylindrical, depressed ; apex obtuse, with a deep triangular groove, and some strong striae on one of the more convex sides ; transverse section ovate ; length two inches, containing the end of the phragmocone. (&.) Less depressed ; apex with a broad groove on one side. ILL., 56. 46. B. CABIN ATUS, Sirup. Conical, slightly depressed, a strong irregularly striated rib, or keel between two furrows the whole 43 length of the guard, with many other slight furrows towards the apex, which is obtusely rounded, and less than half the width of the other end ; length 2-| inches, five times the width. ILL., 5, Salt wick. It was discovered' by Mr. Beckles, and is probably in his possession. MIDDLE LIAS BELEMNITES. 47. B. IN.&QUALIS, Simp. Length 3^ inches, about four times the width > subconical, alveolar region moderately expanding; apex central, pointed, with two or three depressions- or broad furrows; apex of phragmocone much inclined to the more convex side. Geo. Rep., p. 216. 1865. It is very minierous in the uppermost beds of the ironstone series of the Middle Lias,, at Hawsker and Kettleness ; and it also occurs in the beds below. It is subject to much variety. We may notice the following: Var. (a.) Longer in proportion, and tapers more finely to the apex. (b.) Subcylindrical, apex obtuse. (c.) B. ferreus. Simp. Short, thick; apex obtuse, with a little point drawn out like a nipple, difficult to extract without fracture. Kettle- ness. All this must remind one of what has been said of B. breviformis. Pal. pi. iv. 48. B. RUDIS, Ph. Pal. pi. xvi., f . 42. Length three inches, four times the width ; apex obtuse, bent to one side, without grooves or striae; apex of alveolus much inclined to one side. M.L.,. Ironstone, Kettleness. 44 If I am right respecting B. rudis (Ph.), the belemnitick matter is much wanting on one side of the apex. In this it resembles B. expansus. 49. B. TERES.. Length four inches, six times the width, tapering to a slender apex; transverse section elliptical ; apex central, with two narrow grooves. M.L.,p, Hawsker. This and the next are closely allied to B. elegans. 50. B. LEPTOS. Conical, transverse section circular, length 2^ inches, six times the diameter; apex elongated, finely pointed, faintly grooved. M.L., o, Hawsker. Intermediate between the last and B. araris. 51. B. LJEVIGATUS, Simp Length four inches, six or seven times its greatest width, depressed, sides nearly straight, tapering- little ; transverse section elliptical ; apex broad, truncated, two obsolete grooves, foramen large. M.L., />, Hawsker. Geo. Rep. If the above name be inadmissible, it may be called B. complanatus. From the same bed, and with nearly the same characters, I have a robust example, coarse in texture and of a grey colour, which may be an overgrown B.lsevigatus, but I am disposed to name it 52. B. GRANDvEVUS. Length four inches, five times the width, trans- verse section rather quadrate. -53. B. PLANULATUS. Conical, length five inches, five times its width, much depressed towards the apex, sides rather 45 convex, alveolar part moderately expanding ; apex blunt, flatted, wide obsolete grooves ; in some the apex is narrower; transverse section elliptical. M.L., r, Hawsker. 54. B. ARENACEUS. Conical, stout, length 4^ inches, nearly five times- the diameter ; transverse section circular ; apex obtuse. M.L., ^?, Hawsker. It greatly resembles B. athleticus, but it is too widely separated in time to be that species. 55. B. LONGICONUS. Conical, length of guard four inches, about four or five times its width, depressed ; alveolar region wide ; apex obtusely pointed ; transverse section ovate ; alveolus central, reaching far down the guard. M.L., e, Hawsker. The chief character of this Belemnite is the great length of the alveolus and included phragmocone^ reaching within one-third of the N apex. 56. B. RETUSUS. Under this head I propose to consider some Belem- nitick forms which occur in a thin ferruginous seam in, the division p of the Middle Lias, on the Hawsker shore, full of fragmentary fossils. Subconical, with the sides regularly convex, transverse section circular ; apex hemispherical. The specimen described is four inches in length, four times its greatest diameter,, very smooth and regular as if turned in a lathe, without furrows or striae. I observe in this example, and also in another, that the alveolar part, at least, one-half of it, terminates abruptly, and is rounded over inwardly. 46 There is much difference in the sleiiderness of the guard. The length of some is six times the diameter. I have a fragment three inches in length, and only four- tenths of an inch in diameter, and this does not reach the alveolus, which is wanting. It reminds one of Xiphoteuthis elongata. M.L., p, Hawsker. I have another example more cylindrical and robust, with the apex very obtuse, foramen considerable. M.L., /,-, Hawsker. Pal. pi. xv., f . 37^, may be taken as the general form. 57. B. PESSULUS. A cylinder through its whole length, with a very obtuse rounded apex, length 2^- inches, eight times its diameter ; greatest part of the alveolus wanting. M.L., p, Hawsker. 58. B. LONQIFOBMIS, Blake. PL iv., f. 8. Fusiform, lance shaped, much depressed ; length four inches, eight or nine times its width ; apex obtuse. M.L., z,^, Hawsker. I have four specimens varying from three to four inches in length, which I found in the Middle Lias on the Hawsker shore. They are all stout with obsolete grooves or depressions at the apex, and the alveolar part expanding moderately. 59. B. DEMISSUS. Length two inches, very smooth and taper, rather depressed ; apex blunt. It occurs in the rotten bed immediately above the Middle Lias, and in some beds below. Through want of character, I am unable to associate it with any other Belemnite. It is more elongated and slender than B. acutus. M.L., Hawsker. 47 LOWER LIAS BELEMNITES. 60. B. ELEGUNS, Simp. Pal. pi. xx., f. 50. Subfusiform, length of guard from three to five inches, seven or eight times the width, expanding but little at the base, gently swelling in the middle, and elegantly tapering to the apex, which is central ; at the apex, on one side, there are two deepish grooves of moderate length, and on the other side several coarse striae ; alveolus central, small ; trans- verse section circular. L.L. Ironstone -Series, north cheek of R.H. Bay. Since publishing the above description, I have collected a great many, ranging through nearly all the upper beds of the Lower Lias, from the bed 6, of my section, down to x, but they are the most plentiful about the bed Jc. They are subject to some variety. In some the apex is sharp, in others rather blunt. They also vary much in their proportional thickness. One fine example which I possess, five inches long, is eight-tenths of an inch diameter in the middle, contracted by one-eighth of an inch in the alveolar region, and slightly concave in the apical region. L.L., k. The most constant characters are the circular section and the more or less lengthening of the apical region. 61. B. ATTENUATUS. Length five inches, eight or nine times the width, regularly tapering to a fine, obtusely pointed apex; transverse section circular. L.L., >, R.H. Bay. This is far more slender and elongated than any variety of B. elegans. The sides of the guard are but slightly convex, smooth and regular. I have two from a lower part of the series r and $e, which are rather stouter, main- taining their thickness more towards the apex. In all the alveolus expands moderately. 48 62. B. ACUS. Length of guard five inches, eight times the width, regularly tapering to a fine rounded apex, cut by a long, deep triangular groove; transverse section circular. L.L., z, R.H. Bay. It differs chiefly from the last by the long groove in the apical region. It is also stouter in the upper part. I have two examples from the same beds which I might associate with either of the above, but they are shorter in proportion, rather cylindrical, and the alveolar portion expands more. One of them has a long, obsolete groove from the apex. 63. B. SCOLOPS. Cylindrical, very smooth and regular, length five inches, about eight times the width, tapering but little to a rather blunt apex ; apex central ; trans- verse section circular ; alveolar part little expanded. L.L., wz, R.H. Bay. This is so like the bill of a woodcock that it needs little more description. They differ slightly in thickness, and on the lower portion of one there is a long, faint groove or depression. 64. B. OBLONGUS. Cylindrical, length three inches, five times the width ; transverse section circular ; apex obtusely pointed. L.L., v, R.H. Bay. It closely resembles some varieties of B. elegans, but the apical portion is short, and consequently less acute. Two examples are rather flatted on one side, and so approach the next. One of them strongly resembles B. levis. Some are rather conical. 49 65. B. PYRAMIFOBMIS. Length four inches, seven times the width, taper- ing with a gentle curve to a rather obtnse, central apex; a broad shallow groove or depression along the whole length of the guard ; transverse section irregularly ovate. L.L., wz, R.H. Bay. The groove or depression is the chief character, and is constant. One example is rather fusiform,, with the groove stronger. 66. B. PERFORATUS, Simp. SYN., B. ASPERGILLUM, Blake. Length four inches, five or six times the greatest width, sides concave, width over the alveolus twice that at the apex ; apex truncate, hollow ; transverse section ovate. L.L., s, R.H. Bay. Geo. Rep. p. 216. 67. B. TURRIS, Simp. Length four inches, five times the width, rather flatted on one side, sides nearly parallel for two- thirds the length, apical region drawn out to a point, and with three broadish grooves. The alve- olus expands but little; transverse section ovate. L.L., R.H. Bay. Geo. Rep., p. 216. They occur in all the beds from L.L., y, up to the arenaceous beds M.L. The length of the apical portion of the guard is its principal character, in which it resembles B. Woolleri. In some it is shorter, and graduates in the next. In most the groves are obsolete or wanting. It is a rather robust species. 68. B. TRUNCULUS. Subcylindrical, short, thick, length two inches, four times the width ; transverse section circular, or with one side rather flatted; apical portion E 50 obtuse, but finely pointed. L.L., Ironstone Series, R.H. Bay. They occur in all the beds of the upper division of the Lower Lias on the north cheek of R.H. Bay, but the apical part is often eroded. I have one example from the seventh indurated band which may be a variety of B. penicillatus, Sow. Pal. pi. i. 69. B. CTTSPIDALUS. Very cylindrical for the greater part of the length, length three inches, five times the diameter; trans- verse section circular; apical region elongated, of double curviture, finely drawn out and acutely pointed. No grooves or striae. L.L., Ironstone Series, R.H. Bay. They differ in the length of the apical region, in which however it is always longer than in B. acuminatus. 70. B. DELICATTJ8. Very slender and conical, the apical half of the guard very finely striated; length two inches, five times the diameter. L.L., &, R.H. Bay. If it had been in the Upper Lias, I should have placed it under B. subtenuis. It differs chiefly from the next in its striated apex. 71. B. ARARIS, Blake. Conical, slightly fusiform, finely taper to an acute apex, an obsolete groove or depression on one side of the guard; transverse section circular; length two inches, six times the width. L.L., &, R.H. Bay. Of these fine smooth-pointed Belemnites some are much thicker in proportion. A fine specimen Mr. Blake kindly sent me is much more conical and finer pointed than his figure pi. iv.,-f. 1, Yorks. Lias. 51 The following is Mr. Blake's description : " Guard short, delicate, very slightly fusiform, with no apical, and only faint lateral lines ; section rather angular, not depressed ; length two inches, which is six times its breadth/' Shorter and thicker. 72. B. ACUTTJS, Miller. Pal. pi. i., f. 3. Very acutely conical, length 2^ inches, four or five times the width, apex central, sharply pointed, without grooves or striae; alveolar region much expanding. They are subject to great variety, if, indeed, they are all the same species. In many examples the guard is much depressed. Some have also an obsolete, broad groove along the whole length, with the transverse sec- tion very elliptical ; in others the section is circular. The alveolus extends half down the guard, with the apex and filament central. The sides of the phragmocone are concave, corresponding with the alveolar part of the guard. They are common to all the indurated bands of the Lower Lias, at R.H. Bay. 73. B. DEPRESSUS, Simp. SYN., B. INTUNDIBULUS, Ph. Pal. pi. i., f. 3. Much depressed, length of guard about four or five times its width, widened at the base, the sides somewhat parallel, apex moderately pointed ; trans- verse section an elongated ellipse. L.L., R.H. Bay. 74. B. INFUNDIBULUS. The name B. infundibulus might be appropriated to a large triangular Belemnite which is almost entirely occupied by the alveolus. It occurs in the lowest beds of Lias in R.H. Bay, but so rotten as not to be preserved. 52 It is probably the same as noticed by Mr. Blake in the Lowest Lias at Redcar. Yorks. Lias, page 327. I have a part of one from L.L., 23, R.H. Bay. 75. B. CONICUS, Simp. A cone, length 2 inches, three times the diame- ter, transverse section circular ; alveolus large ; apex eroded. L.L., R.H. Bay. A portion of the guard of a very much larger example, having the same proportions, is in the Whitby Museum, and was from the Lower Lias at Redcar. 76. B. DENS, Simp. Pal. pi. ii., f. 6. Length of guard 1 inch, not twice the width, much depressed, sides straight, finely striated lon- gitudinally, or corrugated, and roughened with small tubercles most towards the blunt apex. I found it in the upper part of the Lower Lias about the middle of the north cheek of Robin Hood's Bay. Another, discovered by the Rev. Dr. Cookson in the same locality, did not show the same ornamentation, but was equally compressed. 77. B. PALLIATUS, Dum. Blake, pi. iv., f. 4. Under this name Mr. Blake has given the following description of two examples from the L.L., R.H. Bay. " A very remarkable form in which the alveolus is very large, and the guard very thin. The end of the guard has a triangular section and slightly recurved apex; there are two dorso-lateral depressions, and an irregu- larity on the ventral side. The whole is conical, with the sides concave, the angle of the cone being about thirty degrees. Length 1 inch, which is twice its greatest breadth. "The phragmocone occupies four-fifths of the whole length, the septa are numerous, and it is eccentrick, lying 53 nearer one side of the triangle, opposite to the direction in which the apex is curved. "It differs from B. calcar by the concave sides and triangular section, and is not so robust ; and from B. dens, by the want also of the peculiar ornamentation." 78. B. CALCAR, Ph. Pal. pi. ii., f. 5. I supposed the little article Phillips calls B. calcar might be an immature B. dens, where the alveolus occupies nearly the whole of the interior of the guard. Fusiform. 79. B. SCABROSUS, Simp. Pal. pi. xx., f. 51. Fusiform, length seven inches, fourteen times its greatest width, very much roughened and granulated about the alveolar region ; alveolus moderately ex- panded, transverse section circular ; apical region elongated, obtusely pointed with three long grooves. I obtained this fine specimen at the middle of the north cheek of Eobin Hood's Bay, L.L., i. It has been beau- tifully figured by Phillips. 80. B. SPADIX ARI, Simp. Fusiform; length of guard four inches, greatest diameter a quarter of an inch, least diameter one- eighth of an inch ; transverse section of club circular, of alveolar region irregularly angular, arising from long irregular ridges and depressions in that region; apex obtuse; alveolus small. L.L., R.H. Bay. This is well distinguished from the rest of the fusiform group by the great length and slenderness of the shank which connects the alveolar region with the club. I have seen only two examples, the one now described in the Whitby Museum, the other in the British. They were both from the Lower Lias on the north cheek of E-.H. Bay. 54 81. B. MICBOSLYLUS, Ph. Pal. pi., f. 31. Very slender and delicate, length If inch, greatest diameter one-eighth of an inch, least one- tenth, gradually thickening towards the rather blunt apex, transverse section at the apical part circular, at the alveolar octagonal. L.L., s, R.H. Bay. 82. B. FUSTEOLUS, Simp. Pal. pi. iii., f. 7. Guard much contracted in the alveolar region, then gradually and moderately swelling out into a lengthened club with an acute apex; length 2-| inches, eight or nine times the greatest diameter; transverse section of the club circular, of the alveo- lus octagonal ; alveolus small, moderately expanding. L.L., y, R.H. Bay. The depressions or grooves in the alveolar region are rather irregular. In the more typical examples there is a distinct groove running down into the club. I have collected them from all the beds on the north cheek of R.H. Bay from bed b to No. 2 indurated band. The alveolar part is generally wanting. 83. B. CLAVATUS, Simp. Guard contracted in diameter at the alveolar region, then gradually swelling into a club, with an obtuse apex. L.L., R.H. Bay. I am much at a loss to determine what is really in- tended by the above name of authors. What I take to be our B. clavatus is a rather short, thick kind, about two inches long plentiful in the Lower Lias, and occasional in the Middle, but the alveolar part generally wanting. It resembles the next. 55 84. B. CHARMOUTHENSIS, Blake. PI. iv., f. 5. Length If inch, four times the diameter of the club, contracted in the alveolar region, which is multangular with elevations and depressions ; apex obtusely pointed with a very distinct foramen. L.L., K.H. Bay. Mr. Blake, who kindly sent me a specimen he collected from the Lower Lias at K.H. Bay,, says : "The part near the alveolus is quadrangular, and the apex of the guard is obtuse." Yorks. Lias, p. 317. Beds between the Lias and the Oolite. Blea-Wyke, Peak. B. ALVEOLATUS, Simp. Syn. ? B. INORNATUS, Ph. Pal. pi. xviii., f . 46. Short, thick, conical ; length 3| inches, width across the alveolus an inch, tapering with a gentle curve to a rather obtuse apex ; transverse section elliptical. Phillips's figure is more elongated, and the apex is grooved. B. PROCUSTJS, Simp. General form of the last, but the apical region much flatted ; apex broad, wedge-shaped, with two short,, strong grooves. Mackie's Geo. and Nat. Rep., p. 215. 1865. B. MILLERI, Ph. Pal. pi. xviii., f. 19. Cylindrical for the greater part of the length, then tapering to an obtuse apex ; length three inches, width four-tenths of an inch. I obtained them in a bed about fourteen feet above the Lias at Blea-Wyke. 56 NAUTILUS. The fossil Nautilus, which has laid buried in our rocks for countless ages, is similar in every respect to the shell of the common Nautilus, which now inhabits the great Indian Ocean and the adjoining seas ; so we can have no doubt, that the creature, which formed it for its habitation, was like those now living. The shell of the living Nautilus is comparatively light, and is divided into air-cham- bers by shelly plates or partitions called septa. Through the centre of these, a tube passes, called the siphuncle, and to which it is firmly attached. The animal resides in the outer cell, which is very spacious. In general form the animal resembles the Cuttle-fish. It is provided with thirty-six arms, or tentacles, which it can throw out at plea- sure, or retract into its cell. With these arms it walks on the bottom of the sea, and seizes its prey, the shell being lighter than the water, rising above it. By expanding its arms, and drawing its body partly out of its cell, it can ascend to the surface, and by withdrawing them, descend to the bottom. The siphuncle is also of use in regulating the animal's motions. For the tube being pliant, when the animal forces into it a certain fluid, it swells out on all sides into the chambers, thus rendering the shell so much heavier. But when the creature wishes to lighten the shell, it with- daws the fluid, and the tube collapses by the 57 expansion of the air in the chambers. Like the Sepia, it is provided with a horny beak resembling that of a parrot, with which it crushes crabs and molluscous animals, on which it lives. The fossil Nautilus, being- a heavy stony mass, may appear to be a very different thing" from the light hollow shell of the recent Nautilus ; but on an attentive examination it will be found that the only difference is, that the interior of the fossil has been filled with stony matter, and the shell has undergone a mineralizing process. When cut through the middle, and polished, besides shewing the septa, the siphuncle is often beautifully displayed. It will be seen that this interesting apparatus, like that of the recent Nau- tilus, is situated near the middle of the septa, where it is contracted into a narrow neck, and then swells out between each septum, giving the idea of a row of connected beads, gradually dimi- nishing in size towards the interior. When the animal was perishing 1 , the mud and earthy sub- stances in which the shell became imbedded, en- tered the siphuncle, and filled it up ; but there being no intermediate communication between the exterior and the air-chambers, which form the principal part of the cavity of the shell, they are found either hollow, or as is generally the case, filled with carbonate of lime, and such other sub- stances as have passed through the pores of the 58 shell, or the membranous siphuncle. These sub- stances, for the most part, are crystallized. In not a few cases, however, the siphuncular mem- brane has given way, and then the black muddy matter of the Lias has entered the hollow spaces, or chambers, which intervene between the septa. We may presume, that the remains of the Nautilus, preserved in the strata, bear only a small proportion to the numbers which then existed. For on the death of the animal of the recent Nautilus, it remains for some time at the bottom. But when the fleshy matter has decayed, the shell by its great buoyancy rises, and floats on the surface of the sea ; and is ultimately washed ashore, and destroyed by the waves. It is only when the outer cell, and the siphuncle get filled with earthy matter that the shell can become imbedded. So it has been with the fossil Nautilus. The same remarks may be applied to the Am- monites. Generic Characters. Shell univalve, involute, chambered ; septa plain, concave towards the mouth ; siphuncle passing nearly through the centre of the septa. 1. NAUTILUS ASTACOIDES, Y. fy B. Outer whorl ventricose; inner volutions rapidly diminishing, concealed ; umbilicus small ; striae lon- gitudinal, coarse, often obsolete. 59 The common Nautilus of the Upper Lias is undoubtedly the one Young named N. astacoides. It often attains to a considerable size. There is a fine specimen in the Whitby Museum, eleven inches in diameter, and eight inches thick. The shell is thin, and of a dark brown colour, but it is seldom preserved. The cast is smooth and shining, displaying the curved edges of the septa, which give it the appearance of the joints of the lobster's tail. It is well known amongst collectors as the Lobster- tail Nautilus. As the various chambers are often held together merely by the stony matter, which has filled the siphuncle, they are often readily dislocated, so as to shew in a very instructive manner the structure of the whole. In some specimens a slight elevated line may be seen, passing along the back of the whorls, as in Sowerby^s N. lineatus, but this is by no means a constant character. I may here give a description of one which may be a variety of this. 2. Umbilicus wider than common, longitudinal striae numerous, strong, zigzag, and waving, equal to the in- tervening flattish spaces, crossed by numerous fine, faint, transverse striae, and many more distinct lines of growth, which bend strongly from the aperture in passing over the back ; cast smooth ; diameter four inches. It might be named N. reticulatus. Mr. Blake suggests this may be a variety of N. striatus, Sow., but the striae are very different. 3. N. YOUNGI. N. ASTACOIDES, Simp. Back flatted ; strise transverse, obsolete, bend from the aperture in passing over the back. Mr. Blake suggests that this may be N. intermedius, Sow., but the transverse striae forbid it. 4. N. ANNTJLARIS, Ph. N. UNDULATUS, Y. $ -# Rather depressed, umbilicus rather wide; radii broad, obtuse, prominent, slightly waving, obsolete on the back; shell thick; longitudinal striae strong, 60 distinct; sides and back regularly convex, inner margin of the whorl quickly rounded; diameter 2 inches, width across the aperture 1-| inch. This may be called thick, but by no means ventricose, as is usual in this genus; and the whorls appear to diminish little towards the interior ; but the inner volu- tions are wanting. The umbilicus is rather wide, and the sides slope but little. It is well distinguished by the short, obtuse radii, or undulations on the side of the whorl, and by its thick shell. It was first described and named by Young, who says it was from the alum shale, but does not say from what particular bed. Young named it N. undulatus, but as Sowerby had previously given that name to another, I adopt that given by Phillips. Whitby Museum. 5. N. HETEROGENUS, Simp. Outer whorl rather ventricose, sides and back regularly convex, inner margin quickly rounded, aperture transverse ; inner volution half exposed ; umbilicus wide; shell thick, decussated with coarse, obsolete, longitudinal and transverse striae, which vanish towards the aperture, where there are some irregular tubercles ; diameter two inches. In this example there is a strong peculiarity. For besides the usual central siphuncle, there is what appears to be another, along the inner margin of the whorl ; but this, no doubt, is only a hollow spur passing from one septum to another. It is in the Whitby Museum, and was previously in Mr. Belcher's collection. The matrix indicates the L. Lias. 6. N. ARARIS, Dum., BlaJce. This has been noticed as occurring in the upper half of the Lower Lias at Robin Hood's Bay. "It is distin- guished by the aperture becoming narrower towards the front before making the convexity, and by the obliquity of the septa." No good example has been obtained. 61 AMMONITES. The Ammonite, the Cornu Ammonis of the an* cients, and the Snakestone of more modern times,, is now well known to be an extinct genus of shells, found buried in the strata over a large portion of the temperate regions of the northern hemisphere. After a careful examination of the structure of the shell, and of all the circumstances connected with it, which have come under our observation, there can be no doubt, that the animal which formed it was, in its general nature, like that of the recent Nautilus. In this opinion all naturalists of the present day concur ; but it is a matter of doubt, whether the animal was enclosed in the shell, as in the recent Nautilus pompifcux, or whether the shell was enclosed in the fleshy part of the animal, as in the Nautilus spirula. The thinness and delicacy of the shell, and the small space allowed for the animal within the shell, and other circumstances lead to the belief, that the mantel of the animal enclosed the whole of the shell. In respect to the shell, they differ; for whilst the Nautilus has the siphuncle passing through the middle of the septa, the siphuncle of the Am- monite passes along the back. In the Nautilus,, the septa are plane, and concave to the mouth ; whilst in the Ammonite the septa are convex to the mouth, and their edges ramify in numerous, foliations and meanderings, which are beautifully 62 displayed where the shell happens to be removed. Ammonites have existed from very remote geo- logical periods, but it was during the formation of the Lias and Oolite, that they appeared in the greatest numbers and variety. They then began to decline, and became extinct with the chalk. Generic Characters. Shell univalve, involute, chambered ; septa angulated or waving ; siphuncle passing along the back. The Ammonite constitutes so noble, and well- defined a genus, that it cannot be divided into sub-genera with any degree of usefulness or pro- priety. For the better recognition and classification of the species, we will, as before, consider them as forming certain artificial groups, with some degree of laxity. I. Those without a dorsal keel or furrow. II. With a dorsal keel. III. A keel between two furrows on the back. IV. A dorsal furrow only. I. Without a dorsal keel or furrow. (a.) yo spines. 1. A. HETEROPHYLLUS, Sow., pi. Inner volutions concealed, outer whorl rather more than half the diameter of the shell ; umbilicus small ; striae numerous, annular, diverging, rather 63 flatted, separated by concave spaces ; aperture ovate ; diameter from an inch to sixteen inches. This Ammonite is found in every bed of the Upper Lias ; but those specimens which are obtained from the upper part of this division are the largest. The striated shell is thin, and when removed, the varied angular and rounded forms of the septa are displayed, which give to the cast a beautiful foliated appearance. On the outer whorl. of some large specimens maybe observed straight, obtuse radii, which spread out like a fan, and become obsolete before reaching the .back ; but in the smaller specimens, these are scarcely discernible. Var. With the striae distant. 2. A. EASINGTONENSIS. Inner volutions concealed, outer whorl tumid, rather more than half the diameter, with a line along the middle of the side, and a slightly concave band within it ; umbilicus deep ; striae numerous, annular, diverging, distinct, fine, rounded, sepa- rated by sharp grooves ; aperture ovate ; diameter 4^ inches. This greatly resembles A. heterophyllus ; the whorls are more tumid, and the striae are closely united, and finely rounded ; and on the inner half of the whorls there is a slightly concave space, and a line as if formed by the bending of the shell, in the same way as a line is often formed by the bending of writing paper. In the same block, there is a young shell, which has this char- acteristick line and depression. It is from the Jet Rock at Boulby ; upon a slab containing a great number of A. exaratus. I am not able to see the septa. 3. A. LABRATUS, $imp. , Inner volutions concealed, outer whorl nearly 64 two thirds the diameter ; umbilicus small with an elevated rim ; striae numerous, fine, slightly fim- briated or roughened ; aperture ovate ; diameter 2^ inches. This also greatly resembles A. heterophyllus, but it has a rim round the umbilicus, and the septa are more simple and of a different form. Specimen imperfect. 4. A. PEREGRINUS, Simp A fragment with a finely rounded back equal to a semi- circle, then a sudden depression on the side, a flat space, and a shallow umbilicus ; siphuncle well displayed where the shell is wanting ; transverse striae numerous, flat, in places nearly obsolete ; diameter three inches. 5. A. ANTIQUATUS, Simp. A fragment, deeply indented by the succeeding whorl, with numerous, irregular, obsolete ribs, or undulations ; and in many places may be observed numerous fine, transverse striae, crossed by faint, distant, longitudinal striss ; but little of the shell remains : aperture ovate, resembling that of A. heterophyllus, but the outer whorl has been much narrower ; diameter eight or nine inches. I have seen a larger fragment from the Lower Lias at Eedcar. 6. A. LOSCOMBEI, Sow. PL clxxxiii. A. AMBIGUTJS, Simp. Much depressed ; volutions four, inner ones eight-tenths concealed, outer whorl more than half the diameter ; radii twice bent, numerous, faint aperture ovate ; diameter 2^ inches. The markings on the shell, which is very thin, differ very little from those on the cast. L.L., w, E.H. Bay, Huntcliff. 65 7. A. ERRATUS, Simp. Much depressed ; volutions four, inner ones eight- tenths concealed, outer whorl half the diameter, sides flatted ; radii twice bent, unequal, pass over the back ; aperture ovate ; diameter an inch and four-tenths. This ammonite reminds one of A. elegans or A. exaratus ; but it is entirely destitute of a keel. The shell is thin and of a greyish colour, and where it is absent the cast is black and shining. Jet Rock, U.L., Whitby. 8. A. SUBCARINATUS, Y. Sf B. Inner volutions concealed, outer whorl half the diameter, flatted on the back ; radii straight, obtuse, irregular, nearly obsolete ; striae very numerous, fine, irregular, annular, diverging ; aperture ovate ; diameter four inches. ILL., 1, Whitby. This species is well charaterised by an elevated line along the middle of the back. The striae resemble fine hairs, which unite in places and then separate, and occasionally split in two. 9. A. FABRICATES. Rather tumid ; inner volutions concealed, outer whorl more than half the diameter ; umbilicus large ; radii on the inner part of the whorl broad, flattish, obsolete on the rounded back ; striae nu- merous, annular, fine, fimbriated ; aperture ovate ; diameter half an inch. Probably from the Jet Rock. 10. A. PBRSONATUS, Bean's MSS. Simp. Volutions four or five, exposed, outer whorl one-third the diameter ; sides gently rounded, back F 66 rather angular with a slightly elevated line or obsolete keel ; radii obtuse, irregular, inclining backwards, nearly obsolete towards the aperture, obsolete on the back ; transverse strige obsolete, cast smooth ; aperture ovate ; diameter 1 inch. Not the young of A. subcarinatus. L.L., ind. band,, 26, E.H. Bay. 11. A. DENNYI, Simp. Volutions three, inner ones half concealed, outer whorl about half the diameter, sides flatted, back obscurely triangular or round ; radii few, nearly obsolete ; sulci or constrictions regular, small, distant, straight, diverging, distinct on the inner margin of the whorl, obsolete on the back ; aper- ture sub-quadrate or ovate ; diameter half an inch. Considering its small size, it is rather a thick species. The constrictions are generally obsolete on the back, but in some places they are visible : they are then observed to make a sudden bend towards the aperture. It is smooth and shining, and of a bronze colour. L.L., ind. band, 13, E.H. Bay. Var. Without constrictions. 12. A. ARCTUS, Simp. This greatly resembles the last, but the outer whorl is narrower; the back is rounded; it has a few obscure annular radii, but no constrictions ; it occurs along with the last. 13. A. NANUS, Simp. Volutions several, inner ones three-quarters con- cealed, outer whorl less than half the diameter, with deep constrictions on its inner part passing 67 over the rounded back ; aperture ovate ; diameter quarter of an inch. This is a cast and greatly resembles A. Benny i, but the outer whorl is narrower, and the ramifications of the septa are much more deeply lobed. Probably from the Lower Lias. 14. A. ILLATUS, Simp. Volutions four or five, much exposed ; radii strong, straight, not equal to the intervening con- cave spaces; aperture ovate; diameter 1J inch. The outer whorl is considerably more than one-fifth the diameter 3 there is something like an imperfect keel, but the back is rather water-worn ; the radii on the inner whorls have a triangular appearance, ending in a sharp point; shell roughish, with obsolete transverse strise. L.L., R.H. Bay. 15. A. SOCTALIS, Simp. T. & B., pi. vii., f, 6. Volutions several, exposed, outer whorl . two- fifths the diameter ; radii irregular, diverging, pass unaltered over the back ; striae fine, longitudinal ; aperture rather ovate ; diameter four inches, L.L. , R.H. Bay. 16. A. INVOLTJTUS, Simp. Volutions seven, inner ones quarter concealed, outer whorl two-fifths the diameter, sides rather depressed, inner margin full and rounded; radii obtuse, bend towards the aperture in passing over the back ; aperture ovate ; diameter 3| inches. The radii of the cast are nearly obsolete ; the shell, where it exists, is smooth, and without strise ; the radii in general pass over the back undivided; but in the intervening furrows, may be seen, in many places, strise 68 or the rudiments of other radii. The ramifications of the septa are exceedingly numerous, intricate, and pointed on the outer whorls, crowding the entire surface. L.L. 17. A. JUBENSIS, Zeit. Pal. Ixxiv., f . 3. A. GUBEBNATOB, Simp. Volutions four or five, inner ones quarter con- cealed ; outer whorl not quite half the diameter, inner margin prominent, suddenly rounded ; aper- ture ovate ; diameter 3 inches. U.L., 1, Peak. This is a smooth bright shell, without radii or striae. In the rapid diminution of the whorls it resembles A. fimbriatus, but the prominence of the inner margin of the whorls, and the partial concealment of the inner ones, at once distinguish it. 18. A. FIMBBIATUS, Sow: PL 164. Volutions four or five, rapidly diminishing, ex- posed, covered with numerous undulating, annular fimbriated striae; outer whorl not half the diameter; aperture ovate ; diameter 4 inches. ILL., 6, 7. This is one of the most handsome shells found on our coast. It is by no means rare, and often reaches a large size. On the inner whorls may sometimes be observed obsolete radii, and also a few constrictions, but its most distinguishing character is its fringed striae, caused by numerous concentrick striae crossing the other. It is not uncommon to find Orbecula reflera attached to the shell. It is Young's A. cornucopia, but as Sowerby's name has priority I have given Young's name to another. I have a part of the outer whorl of a similar form ; but the striae are nearly obsolete. It was in stratum s of the Lower Lias at R.H. Bay. It is noticed by Mr. Blake, as occurring in the same bed at Huntcliff. It is so far 69 separated from Sowerby's shell that it can scarcely be the same species and may be named A. senex. A fragment of an outer whorl of an Ammonite which I found in bed s of the Lower Lias at the north cheek of Eobin Hood's Bay,, which may have been four or five inches in diameter, belongs to this group. It is tumid, the inner margin of the whorl full and quickly rounded, the outer part ovate. It has the same slender annular striee, but little of the shell remains, and the cast is smooth. It may belong to this species, but there is A. lineatus. Sch. I have observed in the ironstone bands at Hawsker Bottoms, a small Ammonite, which has a strong resem- blance to the one now described. The whorls are natter, and I am not able to see the fimbriated striae. I am therefore unable to say whether it be a distinct species, or the young of A. fimbriatus. 19. A. CORNUCOPIA, Simp. Pal. pi. Ixxiii. Very similar to the last, but a much coarser shell ; the striae are scarcely fimbriated ; and the aperture is round, or transverse. M.L.^ 0, Hawsker. It is generally of a large size, and is obtained from a bed lower in the series than the last. Both naturalists and fossilists consider it a distinct species. There are in the Whitby Museum two good examples of this fossil twelve inches in diameter, and I discovered one of equal size, but imperfect at the base of clock case. Nab, Hawsker Shore. 20. A TENTJICOSTATTTS, T fy S. Volutions six, exposed, rapidly diminishing ; outer whorl two-fifths the diameter ; radii very numerous, slender, annular; aperture ovate ; diame- ter 2^ inches. M.L., o, Haweker. 70 The form of the whorls of this Ammonite strongly re- sembles the last. It is distinguished by its very slender hair-like radii, which are entirely destitute of fimbrise. 21 A. rAsciATUS, Simp. Depressed ; volutions exposed ; outer whorl more than one-third the diameter; radii annular, nearly obsolete ; striae annular, separated by flat or slightly concave spaces ; aperture ovate ; dia- meter 1 inch. U.L., v, 7. The cast of the inside is smooth, with very obsolete radii, or annular swellings, towards the aperture ; the striae resemble narrow thin strips of paper, laid on so as to show one edge ; the aperture is nearly a very regular ellipse of but little eccentricity. The inner whorls of the only specimen I have seen are defective. I found it ia the Jet Rock at Hawsker Bottoms. 22. A. NITIDUS, T. $ B. A. BALHEALUS, Ph. Volutions three or four, rapidly diminishing, ex- posed ; on the outer whorl are numerous, irregular, slender, annular lines, or rings, which are nearly obsolete on the inner margin; aperture circular; diameter 1 inch. ILL., 7. This beautiful shining little Ammonite is from the Jet Rock on the Hawsker shore, where it is not very un- common. The rings, or radii, are very irregular, even on the same specimen ; sometimes prominent, at other times nearly obsolete. 23. A. ANGUIFOBMIS, Simp. Volutions five or six, exposed ; radii straight, very obtuse, nearly obsolete on the back and inner whorls ; transverse striae irregular, faint ; aperture 71 circular ; diameter one inch and seven-tenths. L.L., ironstone bands, R.H. Bay. The inner whorls of this species are very slender and delicate, but the outer whorl is rather coarse. Many specimens have a row of small tubercles on the outer margin of the whorls, but this is not a constant cha- racter. With a strong magnifier may be seen faint longitudinal striae, in places merely fimbriating or dotting the transverse striae. 24. A. TUBELLTJS, Simp. Volutions five, exposed ; rapidly diminishing', smooth, gradually rounded ; radii few, obsolete ; aperture ovate, enlarged ; diameter three-eighths of an inch. L.L., z. This is the most beautiful thing which I have seen of the kind, with its golden, shining, attenuated whorls just touching one another, and its trumpet-shaped mouth. The edges of the septa are very simple, con- sisting of three slightly indented lobes, which bend towards the aperture on each side of the whorl. The enlargement of the mouth shows them to be full-grown specimens. I have seen several with tubercles, and stronger radii, near the aperture. They are found on the beach close to Bay-town. 25. A. ERUGATUS, F. fy B. Depressed ; volutions six, exposed, back rounded ; radii straight, obtuse, nearly obsolete on the outer whorls ; striae diverging, aperture ovate ; diameter 1-J- inch. Although the radii are distinct on the inner whorls^ and the striae still remain on the outer whorls, this is, nevertheless, nearly a smooth species. It is from the Lower Lias at Robin Hood's Bay. It not unfrequently 72 occurs in a semi-transparent state, when the waving septa are beautifully displayed. 26. A. RUTILANS, Bean's MSS. Simp. Depressed ; volutions six, inner ones but little concealed ; outer whorl rather more than one-third the diameter ; sides regularly rounded ; radii obtuse on the inner whorls ; more numerous and nearly obsolete on the outer whorl ; aperture ovate ; diameter If inch. L.L., y. Var. With small sharp tubercles on the inner whorls. On the inner whorls the back is triangular, but on the outer whorls it is rounded ; where the shell remains it is quite smooth and destitute of striae, but in general it is wanting, when the edges of the septa are beautifully displayed ; on the inner whorls the lobes are very plane, but on the outer whorls they become more serrated, shooting out lengthened fingers, until they occupy the whole surface. This shell is of a fine yellow colour, and is by no means uncommon in a thin brassy bed or layer in the Lower Lias at Eobin Hood's Bay, which is also rich in other fossils. 27. A. BELCHEBI, Simp. Pal. pi. xv., f. 7. Volutions six or seven, exposed, rather flat on the sides, back rounded ; radii straight, prominent, obtuse, obsolete on the back, separated by concave spaces ; aperture squarish ; diameter 1^ inch. A cast, L.L., R.H. Bay. 28. A. JOHNSTONI, Sow. PI. ccccxlix. This greatly resembles the last. The ribs are less prominent and the back rather angular. It is from the very lowest beds of Lias at Eedcar. Dr. Wright has figured several kindred forms. Pal. pis. xv., xvi. L.L., 23. 73 29. A. CONVOLUTUS, Simp. Volutions five, exposed ; radii strong, waving, rather obliquely inclined towards the aperture, ob- solete on the back and the inner whorls ; aperture round ; diameter- sixth-tenths of an inch. L.L., E.H. Bay. 30. A. RESUPINATUS, Simp. Volutions five, exposed ; radii on the outer whorls sharp, prominent, bend from the aperture, separated by wide concave spaces, form sharp points on the outer margin of the whorl, nearly obsolete on the back, absent on the inner whorls ; striae numerous, distinct, rather bent ; shell thick ; aperture quad- rate ; ' diameter one inch. This species is smooth and shining, both on the cast and where the shell remains. The block from whence it was extracted is in the Whitby Museum, and was pro- cured from the Lower Lias at Eobin Hood's Bay. Ind. 23. 31. A. EXORTTJS, Simp Volutions five, exposed, outer whorl more than a quarter the diameter ; radii prominent, strong, annular, separated by concave spaces ; aperture sub-quadrate ; diameter one inch and three-tenths. The aperture is nearly square, and on the outer angles of the whorls the radii in places have slight tubercles. Mr. Clarkson's Col. L.L. j R.H. Bay. 32. A. TRIVIALIS, Bean's MSB. Simp. Volutions five, exposed, outer whorl one-third the diameter; radii numerous, sharp, slender, diverging, 74 form obtuse angles on the back ; diameter three- quarters of an inch. This beautiful little ammonite is from the Lower Lias, and, like several others from those beds, it is of a fine bronze colour. This, together with the elegance of the whorls and radii, render it one of the most beautiful of our ammonites. On the inner whorls the radii are very close, and on the outer whorls they are gradually more and more separated by flattish spaces ; the aperture becomes more and more quadrate, and the radii, before passing over the back, form small tubercles. On some the radii are strong and prominent, others have the outer whorl nearly smooth ; indeed the varieties are so numerous that they can scarcely be defined. L.L., x, R.H. Bay, Saltburn. 33. A. EIPLEYI, Simp. Volutions five or six, exposed ; radii straight, diverging, obtuse, bent towards the aperture in passing over the back, where they are obsolete ; a row of minute tubercles on the outer margin of the whorls ; aperture quadrate ; diameter six-tenths of an inch. L.L., R.H. Bay. 34. A. AUBEUS, - Volutions five, exposed, outer whorl a quarter the diameter ; radii numerous, straight, sharp, equal to the intervening concave spaces, orna- mented with two rows of flattened tubercles ; back ronnded, nearly plane ; aperture sub -quadrate ; diameter one inch. L.L., R.H. Bay. This resembles A. Eipleyi, but the outer whorl is narrower, and the radii are much sharper, and more 75 prominent, and have two rows of tubercles j the ramifications of the septa are very delicate, rounded, and numerous. 35. A. PLANICOSTATUS, Sow. PL Ixxiii. Volutions five, exposed; radii slender, prominent, on the back bend towards the aperture, separated by flattish spaces, aperture nearly circular. The older specimens have knobs near the aperture. L.L., 22, R.H. Bay. They are rather plentiful in the shale beneath the A. stellaris bed, but the middle whorls are often want- ing. They are more slender than the southern examples, if indeed they are the same species. 36. A. DIVEBSTJS, Simp. This species is closely allied to the next, and at pre- sent is very rare. I have seen only a portion of the two outer whorls. The radii on the outer whorl are more distant and much sharper than in A. gagateus. They have, also, two rows of small tubercles towards the mid- dle of the whorl, and are separated by flattish concave spaces. The radii on the inner whorl are still more distant, and are blunter, aperture circular; diameter 2 inches. 37. A. GAGATEUS, F. # B. Volutions six, exposed, inner margin of the whorls rather prominent ; radii prominent, annular, separated by concave spaces; aperture roundish, rather transverse ; diameter If inch. The radii pass over the back with very little altera- tion, or very slightly flatted. The shell, which is gene- rally wanting, is roughish, and the cast is often black and shining. L.L., 13, R.H. Bay. 76 38. A. NEGLECTUS, Simp. Volutions seven or eight, exposed ; radii prominent, separated by widish concave spaces, slightly bend towards the aperture on the back near an elevated line or imperfect keel; aperture circular; diameter If inch. The shell is rough, wth a few annular striae. It is more depressed than A. gagateus, which it much re- sembles. L.L., E.H. Bay. 39. A. LURIDTTS, Simp. Thickish ; volutions five, exposed, outer whorl more than a quarter the diameter ; radii sharpish, strong, annular, rather depressed on the back, where they bend towards the aperture, separated by widish spaces ; a few annular striae ; aperture little more than a semicircle ; diameter If inch. The whorls of this Ammonite diminish very little in width, forming a shallow umbilicus. The shell is thick, and formed of several layers, of a brown colour. Mr. Leckenby's Col. 40. A. INTEGRICOSTATTJS, Simp. This resembles A. gagateus, but it is more de- pressed, and the whorls are more slender, very prominent on the back, and separated by wide con- cave spaces ; the aperture is about a semicircle. The outer whorls of this Ammonite are rather abun- dant in a bed a little to the south of Bay-town ; but the inner whorls are so decomposed as not to admit of description. 41. A. VITREUS, Simp. Volutions seven, exposed, central ones quite 77 smooth ; radii on the remainder numerous, pro- minent, sharp, slightly bend towards the aperture, where there is a flattish space, separated by con- cave spaces,; shell smooth, glassy, and cracked; aperture round ; diameter three-quarters of an inch. L.L. Inner whorl very delicate ; outer ones stronger than in A. arcigerens. 42. A. CEREUS, Simp. Volutions six, exposed, outer whorl nearly a quarter the diameter ; radii very prominent on the sides, nearly obsolete on the back, separated by rather wide concave spaces ; aperture ovate, trans- verse ; diameter nine-tenths of an inch. Shell smooth and bright, with a few striae, colour light-brown. L.L., R. H. Bay. 43. A. ARCIGERENS, PH. Volutions six, exposed, slender ; radii prominent, meet in very obtuse angles on the back, separated by concave spaces ; aperture circular ; diameter three-quarters of an inch. This may be easily distinguished from any of the fol- lowing by the slenderness of the whorls. Var. Radii nearly obsolete on the back. L.L., E.H. Bay. 44. A. OMISSUS, Simp. Volutions five, exposed, outer whorl more than one-third the diameter ; radii numerous, prominent, sharp, separated by concave spaces, suddenly bend towards the aperture in passing over the back ;. 78 aperture roundish ; diameter one and two -tenths of an inch. This may be distinguished from A. defossus by the inner whorls being more slender and numerous, and by their having more numerous and finer radii. It is from the same beds as the last. 45.. A. FiGULiNUS, Simp. This also has sharp radii, strongly bent towards the aperture on the back ; but the whorls are much stronger, and the radii separated by wider and deeper concave spaces ; the aperture between the radii would be cir- cular, but if taken in a line through the radii, it would be many-sided, for the outline from the inner edge of the whorl is first convex, then, for a short space, it be- comes concave, so as to form two angles on the side of the whorl ; it then undulates across the back, where the radii seem as if rubbed up with the finger in a plastic state. 46. A. DEFOSSUS, Bean's MSB. Simp. Volutions five or six, exposed ; radii prominent, sharp, straight, suddenly bend towards the aper- ture in passing over the back, where they are much flatted ; intervening spaces flattish ; striated ; aper- ture quadrate ; diameter If inch. This has long been confounded with the next, which it much resembles. As it occurs so frequently in this form, there can be little doubt that it is a distinct species. It may readily be distinguished from the last by the flatted back, which in some places is even concave. The whorls are less numerous than in A. arcigerens. L.L., d, K.H. Bay. 47. A. CAPBICOBNUS, Schlotheim. As this name has been applied in a loose way to a number of species which have strong, prominent, annu- lar ribs, I retain Young's name for the next, and confine 79 this to a variety with sharper ribs, and deeper concave spaces, which is rather plentiful in the ironstone band, x, M.L., Hawsker. 48. A. MACULATUS, F. 4" -B. Pal. pi. xxxiv., xxxv. Volutions six, exposed ; radii prominent, annular, obtuse, separated by wide concave furrows, rather flatted on the back ; striated ; aperture circular ; diameter 3^ inch. This shell is obtained from the uppermost beds of the Lower Lias, and is often spotted with whitish, a character which it receives from the rock in which it is imbedded. In some specimens I have observed the outer whorl to be greatly enlarged, but I still consider them as the same species. 49. A. JAMESONI, Sow. PI. dlv. Volutions five or six, much exposed ; outer whorl one-third the diameter; radii annular, rather sharp, slightly flatted on the back, where they turn towards the aperture, not equal to the intervening concave spaces ; shell irregularly and transversely striated ; cast smooth; aperture ovate; diameter 2^ inches. L.L., g, R.H. Bay. This comes the nearest to A. Jamesoni of any I have seen. Where the shell remains, the radii are more obtuse, and in the older specimens there is an elevated line on the back, amounting almost to a keel. 50. A. SAGITTARIUS, Blake. PI. vii., f. 2. Volutions four or five, inner whorls but little con- cealed, outer whorl one-third the diameter; radii sharp, prominent, not equal to the concave spaces; striae in the direction of the radii ; aperture ovate ; diameter 2^ inches. 80 This has been reckoned a variety of A. Jamesoni, but I agree with Mr. Blake in making it a different species. Very seldom more than the outer whorls remain, which are strong. The radii are but slightly bent towards the ovate aperture., and meet on a rounded elevation, or im- perfect keel on the back, where they become obsolete. In some examples the radii, before reaching the back, form small tubercles. The outer whorls are very plenti- ful at the indurated band, No. 16, L. Lias, E.H. Bay. 51. A. CBENULARIS, Ph. G. Y., pi. xii, f. 22. Whorls rapidly diminishing, inner ones slightly concealed, outer whorl nearly half the diameter ; radii straight, rather slender, prominent, unequal, pass over the back, where they are rather flatted ; aperture elliptical ; diameter 3J inches. L.L. I possess only a fragment of this ammonite, which is, however, highly characteristick. The curvature of the sides is rather greater near the inner margin of the whorl, from whence proceed more than one-half the radii ; the rest commence about the middle of the whorl, and they all have a strong resemblance to pieces of cord laid on. The sides of the whorl become less convex near the aperture, which is a somewhat eccentrick ellipse. 52. A. CHARMASSEI, D'Orb. A fragment sent me by Mr. Tate as a variety of this species from the Lower Lias at E-edcar. Much depressed, whorl broad, flat; radii numerous, round, broader than the intervening concave spaces, gently bend to the aperture. Specimen very imperfect. It may be a variety of the last. 53. A. JEQUALIS, Simp. Outer whorl nearly one -third the diameter, inner margin prominent ; radii equal, bend towards the 81 aperture on the outer part of the whorl, nearly obsolete on the middle of the back, not equal to the intervening spaces ; aperture ovate ; diameter 1 inch. A cast with the centre broken; probably from the Lower Lias. The following species,, to the end of the section, have all a family resemblance to A. communis : Whorls narrow, exposed, with numerous slender, an- nular ribs, which generally split in two on the back. 54. A. ANNULATUS, Sow. PL ccxxii. Volutions seven or eight, exposed ; radii numerous, slender, annular ; aperture circular ; diameter 3^ inches. ILL., 8. This differs chiefly from A. communis in having a greater number of whorls, and in the radii being more slender, and in often passing over the rounded back un- divided, like rings. As the round nodules in which these are contained readily split when struck with a hammer so as to display the fossil, and can be closed up without much shewing the fracture, they are known amongst collectors by the name of Jack in the Box. 55. A. ANNULIFERUS, Simp. Radii obtuse, on the outer whorl separated by narrow grooves, split in two, then pass straight over the back, where they are nearly obsolete ; aperture an ellipse, in- dented by the succeeding whorl. 56. A. SEMICELATUS, Simp. Depressed ; volutions seven or eight, inner ones nearly half concealed, outer whorl more than one- fourth the diameter, inner margin depressed, de- pressed near the back ; radii annular, pass nearly G 82 straight over the back, rounded, fine, numerous, equal to the intervening concave furrows, double in number on the back ; aperture ovate ; diameter 3^ inches. ILL. The form of the radii and the smoothness of the cast render this species very like a compressed variety of A. anmilatus ; but it may be distinguished by the greater width of the outer whorl, partly concealing the inner ones, as well as by its more depressed form. On the inner whorls the inner margin is prominent ; radii regular, distinct, split in two near the back, flatted, separated by concave spaces ; radii of the cast round the aperture ovate. 57. A. ATHLETICUS, Simp. This resembles A. communis, but is more robust ; the ribs are sharper, and more elevated, some split in two on the outer margin of the whorl, others pass over the back undivided ; inner margin of the whorls prominent ; aper- ture ovate ; diameter four inches. M.L., Hawsker. 58. A. VEKMIS, Simp. Volutions slender j radii nearly obsolete on the outer whorl; aperture nearly round. Jet rock. 59. A. COMMUNIS, Sow. PL cvii. Volutions seven, much exposed, outer whorl less than one-fourth the diameter; radii numerous, an- nular, split in two near the back, distinct, not quite equal to the intervening concave spaces; aperture ovate; diameter three inches. U.L., 1. The foliations of the septa are not crowded nor intri- cate ; besides the dorsal lobe, which points from the aperture with two fingers, on the sides of the whorls there are two principal lobes pointing towards the aper- ture, with serratures by no means deep, and which are 83 rather rounded ; again, there are three principal lobes,, which point in the opposite direction ; the middle lobe has three long points or fingers, of which the middle one is the longest; they are all accompanied with smaller serratures, but subject to much modification. As far as I have been able to observe, this is the gen- eral form of the septa also of A. fibulatus, and all the kindred ammonites. This is one of the most abundant fossils of the coast, and it appears to be confined to the Upper Lias. They are extracted from round nodules, which, at one time, literally paved some parts of the beach near Whitby ; and a cart-load might have been obtained in a short time. The great demand for these nodules, for the manufacture of Roman cement, has of late rendered them less abundant. As this is the most common species, and the most easily obtained, its value in the market is greatly depreciated. On this account many are rubbed down on one side, and polished, and wrought up into ornaments. By this means their internal struc- ture is beautifully displayed, and in this respect, they are equal to the rarest species. The siphuncle, as in all ammonites, passes along the back, but is very seldom discernible. And as it does not appear that there has been any communication with the exterior and the internal chambers, by means of this apparatus, the cham- bers have been filled by infiltration of carbonate of lime, and other substances, through the pores of the shell.* These substances may be seen deposited in layers around the inner surface of each chamber, until the whole has * In some species of ammonites, especially the larger, the process of infiltration has been arrested, so that when cut open they are found empty, affording a beautiful illustration of the structure of the shell. The interior surface of these hollow chambers are often coated with beautiful crystals, shooting in various directions. Some from the Jet Kock have the cavities filled with a green kind of oil, which, by exposure to the atmostphere, hardens into a black pitch, that burns with a crackling noise. 84 been filled up. In general the chambers become gra- dually larger as they approach the aperture ; but what is very singular, in some specimens, near the aperture, may be observed a long chamber filled with the same substance as the rest. Some have considered this as the last chamber, where the animal has resided at the time of its death ; but in all the specimens which I have examined, I have found it enclosed by a septum, and the last chamber filled with the dark substance of the Lias. Under the general name A. communis, no doubt there are comprehended many different species, the distinctive characters of which have been lost in the process of petrifaction. Without pretending to say which are species, and which only varieties, to some forms we may give par- ticular names, and others we may leave under the name of A. communis. After examining a great number, I find to be most numerous Var. (a.) Sides of the whorls depressed, inner angle prominent ; aperture ovate. These may be again thus divided : 1. Radii and intervening spaces equal. 2. Intervening spaces wider. 3. With tubercles on the outer margin of the whorl. The next in point of numbers is Var. (6.) Whorl narrower, sides tumid, aperture circular. Under this variety we may reckon 1. A. ANGULATUS, SOW. In general character this differs nothing from A. communis, except that it has the inner angle of the whorls truncated; thus a flattish or concave groove is formed along the inner margin of the whorls. This, however, is by no means a constant character ; for this angular part is frequently to be found only on a small portion of the whorls, and often only on one side. This character may some- times be observed on A. fibulatus. 85 2. This has the inner margin of the whorls prominent, and, like A. angulatus, the siphuncle is in general clearly displayed ; and as, like A. angulatus, it has the inner margin of the whorls prominent, where they are not truncated by the characteristick groove, I am led to think that these two species or varieties are identical. 3. This agrees with the last in having the siphuncle clearly displayed, like a white line along the back, and in the inner margin of the whorls being promi- nent ; but the radii on the outer whorl bend from the aperture, and meet undivided at an angle on the back. I have seen only one specimen in this way, and as this singularity exists only on the outer whorl, it may possibly have arisen from some accidental cause. 4. With the outer whorl suddenly enlarged. Var. (c.) Inner margin of the whorl prominent, spaces between the radii widish, aperture subquadrate. Var. (d.) Whorls slender, radii often pass over the back undivided. Var. (e.) Umbilicus shallow ; aperture ovate ; diameter 2^ inches. Probably a distinct species. 1. Much depressed, radii slender, aperture still more ovate; an elegant variety or species. It may be named A. attenuatus. It is not uncommon in the Upper Lias, at Peak. 60. A. GRACILIS, Simp. Volutions six, exposed, slender, sides rather flatted ; radii regular, distinct ; aperture sub- quadrate ; diameter three-quarters of an inch. Jet Rock, U.L. These are found in masses, and are best distinguished by the slenderness of the whorls. They are generally casts, and where the shell remains, it is of a brown colour. In examining a great many of these, I generally found a chamber near the aperture, of great length, and often hollow. 86 61. A. DELICATUS, Simp. Bean's MSS. Eadii sharper and more ' slender than in the last, and the inner whorls generally wanting. ILL. 62. A. INCRASSATTJS, Simp. Very similar to the next,, but the radii terminate on the outer margin of the whorls in sharp tubercles,, from whence proceed numerous striae, or the back is nearly smooth. ILL. 63. A. CRASSULUS, Simp. This possesses the same precision and elegance of workmanship as A. gracilis, but the whorls are much stronger and thicker, and the inner ones more concealed ; radii distinct on the back ; diameter seldom exceeds one inch. ILL., 6, Hunton, Geo. Tr., 1836. Var. (a.) Depressed. Yar. (&.) Depressed ; radii flatted. 64. A. cRASsus, Y. # B. This has nearly the same characters as A. comniunis, but it is much thicker, and more robust, with a deep umbilicus. The radii are round, but a part of the shell often comes off, then they appear flat. I am not aware that it is ever found along with A. cominunis, but lower in the series; diameter four inches. II. L., 1. 65. A. CRASSOIDES, Simp. This is still thicker in proportion, the inner whorls are rather concealed, and there is a row of tubercles on the middle of the whorls ; the aperture is transverse, and it is altogether a more elegant shell than the last. Jet Kock, ILL. 66. A CRASSULOSUS, Simp. Thickish ; outer whorl less than one-third the diameter ; radii smooth, strong, prominent, distinct, separated by widish concave spaces, split in two near the back, and bend towards the aperture ; aperture half of a regular ellipse; diameter three inches. 87 This differs chiefly from the communis or crassus type by the prominence of the radii and their wider inter- vening spaces. The shell is thick, and the whole form, gives the idea of strength. The middle is imperfect. It appears to be from the hard iron bands of fhe Middle Lias. 67. A. CKASSESCENS, Simp. Thickish ; volutions six, exposed, outer whorl more than a quarter the diameter ; radii obtuse, split in two over the back, on the inner whorls armed with tubercles, or short spines; aperture circular, rather transverse ; diameter 2 inches. The radii of this ammonite resembles in general that of A. communis, bending slightly towards the aperture in passing over the back. The outer whorls diminish very little, but the inner ones form a rather deep um- bilicus. Inner margin of the whorl not depressed, as in A. crassus, but very sharply rounded. 68. A. CE.ASSIBUNDUS, Simp. Thickish ; volutions seven or eight, much ex- posed ; outer whorl more than a quarter the diameter ; radii annular, prominent, rounded, scarcely equal to the intervening concave spaces ; aperture semi- circular, or ovate ; diameter 2-J inches. This is more depressed than the last, and, like it, the outer whorls diminish but little in thickness, rendering the umbilicus deep in proportion to its width. The sides are slightly flatted near the inner margin, which is sharply rounded ; the radii sometimes pass over the entire- whorl undivided, often cease when having passed over the back, or unite with other radii, so as to become in- terlaced together. Mr. Clarkson's col. 69. A. CRASSIFACTUS, Simp. Thick ; volutions six, inner ones one-half con- 88 cealed, outer whorl nearly one-third the diameter, sides and back regularly rounded ; radii numerous, fine, regular, annular, distinct, rounded, flat on the cast, split in two in passing over the back, equal to the intervening concave spaces ; aperture more than a semicircle ; diameter 2-^ inches. This may be at once distinguished from A. crassus by the fineness of the radii. In this respect it resembles A. Crosbeyi, but differs from this and all other kindred ammonites in having the radii of the cast flat ; these appearing as if formed merely by the excavation of the very distinct and concave grooves. They occur, but rarely, in the lower part of the Jet Rock in the Upper Lias. The specimen now described, like many others from the same bed, contains mineral oil. 70. A. CRASSIUSCTJLUS, Simp. Volutions six, exposed, outer whorl one-third the diameter ; radii strong, annular, obtuse, split in two on the back, nearly equal to the intervening concave furrows, on the inner whorls fibulate ; aperture circular ; diameter 1 inch. This is a very bright and shining species ; of a brown colour, and whitish in the middle. The radii are stronger and more obtuse than in any of the kindred species ; they very seldom pass entire over the whole whorl, for each alternate one splitting in two near the back, unites with a different one on the other side of the whorl, so that they all become interlaced together. It is moderately thick, and the aperture is nearly a correct segment of a circle. Judging from the matrix, it is from the hard bands of the Middle Lias. 71. A. CBASSIUSCULOSUS, Simp. Thickish; volutions six or seven, outer whorl 89 one -fourth the diameter, neatly rounded ; radii strong-, prominent, obtuse, split in two on the back; aperture transverse ; diameter If inch. This is a very neat and slender species or variety, inter- mediate between A. crassus and A. crassulus. It is from the Jet Rock of the Lias. There is another in the same beds, which resembles it in the slenderness of the whorls, but the aperture is circular. 72. A. FOVEATUS, Simp. Thick; volutions six, well exposed, outer whorl one-third the diameter, sides and back rounded ; umbilicus deep; radii annular, split in two before they pass over the back, strong-, scarce equal to the intervening concave furrows; aperture transverse; diameter 1 inch. U.L. In general form this ammonite resembles A. subarmatus, but quite free from spines and tubercles, and the whorls diminish much more rapidly than in A. crassus, forming a deeper and larger umbilicus. The shell, where it remains, is of a light-brown colour, aud very smooth and shining ; the radii are rounded, but on the cast they are flatted, especially on the back. The ramifications of the septa are obtusely pointed, and by no means so crowded as in many species. 73. A. FONTICULUS, Simp. Thick; volutions seven, inner ones nearly half concealed, outer whorl less than one-third the diameter, sides quickly and regularly rounded; umbilicus deep ; radii obtuse, split in two or three near the back, on the inner whorls show a row of flatted bases of tubercles. U.L. 90 74. A. PUTEOLUS, Simp. Thick ; inner volutions three-quarters concealed ; diameter 2\ inches. U.L. The whorls are more inflated, the inner angles more rounded, the umbilicus deeper, and the radii less numerous than in the last. Whitl^y Museum. 75. A. CROSBEYI, Simp. Thickish; volutions four, inner ones half con- cealed; radii numerous, slender, annular, generally split in two in passing over the back ; inner margin of the whorls slightly rounded, and overhanging the next; aperture one-half of a regular ellipse: diameter three inches. 76. A. ANDERSONI, Simp. Volutions five or six, inner ones quarter concealed, outer whorl less than one-third the diameter ; radii numerous, slender, annular, rounded, separated by deep concave grooves; aperture one-half of a regular ellipse; diameter 2^ inches. In some places the radii pass over the back undivided and unaltered, sometimes with a short one intervening, and in other places they regularly divide into two in the middle of the whorl. The specimen is somewhat distorted. (&.) Armed with spines or distinct tubercles. 77. A. FIBULATUS, Sow. PL ccccvii. Volutions six, exposed, rounded on the back; radii numerous, united in pairs by a small knob near the outer margin of the whorl, then split into two or three on the back; aperture rather quadrate; diameter 2^ inches. 91 The most obvious character of this ammonite is the uniting of the radii by knobs, like a button and loop. In some specimens this style is remarkably uniform ; in most there occur knobs, each united with only one rib; in others three ribs may be seen united in one knob. It is rather plentiful in the alum shale, but by no means so much so as A. communis, which in general form it resembles. It also sometimes has the inner angle of the whorls truncated, as in A. angulatus, Sow. Var. Knobs more distant, aperture round. 78. A. TURRICULATUS, Simp. Volutions six or seven, much exposed, outer whorl a quarter the diameter, sides depressed, inner margin prominent, sharply rounded ; radii numerous, fine, annular, pass over the back undivided, with short ones there frequently introduced, on the outer edge of the whorls a row of tubercles or short knobs at intervals of five or six radii ; aperture sub-quadrate ; diameter 2^ inches. U.L. This is rather a robust shell. The radii are fibulated at the tubercles, and nearly obsolete at the aperture. Syn. A. Davaei, Y. and B. 79. A. ANDREW, Simp. Volutions six or seven, exposed, outer whorl nearly a quarter the diameter ; radii numerous, prominent, form knobs near the outer margin of the whorls, then split into two or three on the back ; aperture subquadrate ; diameter 2^ inches. Towards the aperture, alternate radii are introduced, without knobs, and at length the knobs become entirely obsolete. U.L. 80. A. OBSOLETUS, Simp. Much depressed ; volutions five, exposed, outer 92 whorl less than a third the diameter, sides flatted, inner margin suddenly rounded ; radii numerous, straight, nearly obsolete, terminate in a row of small tubercles on the outer margin ; diameter 4J inches. L.L. 14, R.H. Bay. The radii are very regular, formed merely by a slight groove. I have seen several, probably of this species, quite flatted. They are figured by T. & B., pi. vii., f. 1. 81. A SUBARMATUS. Sow. PI. CCCCVlL Thickish ; volutions six or seven, exposed ; radii rise up in short spines near the outer margin of the whorls, then split into two or three on the rounded back, and bend towards the aperture ; aperture transverse ; diameter 2 inches. As the outer whorl of the larger specimens increases but little in thickness, the aperture then is scarcely transverse, and the general form approaches near to that of A. fibulatus, from which it is best distinguished by its coarse radii and larger knobs. It, however, varies much in the prominences of the radii. In some specimens they are grooved, or in the button and loop style. It varies also in the length of the spines, and in the depth of the umbilicus. ILL. 1. 82. A. SEMIARMATUS, Simp. Inner whorls like the last, but the outer whorl wants both the knobs and radii ; aperture half of an ellipse. 83. A. VORTEX, Simp. Volutions six or seven, exposed, outer whorl one- fourth the diameter ; radii numerous, annular, split in two near the back, where there is a row of tuber- cles, and pass directly over without bending towards 93 the aperture ; aperture subquadrate, transverse ; diameter three inches, and I have seen one much larger inner whorl, imperfect. U.L., 1, Whitby. This resembles some varieties of A. subarmatus, having two radii connected with each tubercle, in the button and loop style ; the tubercles, however, are more distant, there being on the outer whorl two radii interposed be- tween those connected with the tubercles. The inner edge of the whorls is also more rounded, forming a deep groove at the suture, and the umbilicus is not so deep, the outer whorl having nearly the same size throughout* The inner side of the whorls is but little indented by the succeeding ones. The radii, which on the inner whorls are strong and rounded, 'and equal to the intervening concave spaces, become depressed and nearly obsolete towards the aperture. Where the shell has been removed there is displayed a very strong siphuncle, without any apparent constrictions. The ramifications of the septa are numerous and pointed, differing very much from those observed in A. subarmatus. 84. A. VOUTICELLUS, Simp. Volutions six or seven, exposed, outer whorl quarter the diameter; radii annular, obtuse, equal to the intervening concave spaces, alternate radii form a tubercle near the outer margin of the whorl,, then split in two, and pass directly across the back ; aperture subquadrate; diameter 1^ inch. This is a much more slender and depressed species than the last. Another, rather thicker, with the radii on the inner whorls more distant, each having a small tubercle on the outer margin of the whorls, may, for the present, be placed here as Var. (a.) 94 85. A. IGNOTTTS, Simp. Volutions nearly a quarter concealed, outer whorl nearly one-third the diameter, sides flattish; radii numerous, obtuse, equal to the intervening- concave spaces, slightly curved towards the aperture, form a row of tubercles on the outer margin of the whorl, then pass undivided over the rounded back; aperture elliptical ; diameter 2J inches. L.L., y, R.H. Bay. 86. A. SINUATUS, Simp. Volutions exposed, outer whorl one-third the diameter, sides convex ; radii obtuse, separated by rather wide concave spaces, commence on the inner margin, slightly incline towards the aperture, and then in the opposite direction, form a row of tuber- cles on the outer margin, nearly obsolete on the back ; aperture ovate or subquadrate ; diameter 4^ inches. A fragment, L.L., R.H. Bay. 87. A. MARSHALLANI, Simp. Volutions six, exposed, outer whorl more than one-third the diameter ; umbilicus nearly equal to the diameter ; radii prominent, strong, rise up into blunt knobs on the outer margin of the whorls, then split into several on the flatly-rounded back ; aper- ture transverse ; diameter seven-eights of an inch. L.L., y, R.H. Bay. 88. A. RETUSUS, Simp. Rather depressed ; volutions six, exposed ; radii 95 obtuse, annular, split in two in passing over the rounded back, in the middle of which they have a slight bend towards the aperture, sometimes obso- lete on the inner whorls ; on the outer whorls, towards the outer margin, an irregular row of tubercles ; aperture nearly round, rather transverse ; diameter two inches. L.L., #, E.H. Bay. The shell, which is seldom preserved, is thin, and with- out striae ; the tubercles are strong and pointed, and come off with the shell, leaving their flatted bases on the cast. The ramifications of the septa, with their fingered and bushy lobes, are more numerous than in the last. 89. A. VALIDUS, Simp. Volutions six, exposed, outer whorl one-third the diameter ; radii strong, ccarse, annular, wider than the intervening spaces, split in two or three on the back, armed with a row of broad tubercles on the outer margin of the whorls ; aperture circular ; diameter 3 inches. L.L., ?/, R.H. Bay. This is a much coarser ammonite than the last, with fewer whorls, and stronger radii, which become almost obsolete towards the aperture ; there are the same large flat scars of the tubercles, and the ramifications of the septa are the same. 90. A. DECTJSSATTTS, Bean's MSB. Simp. Volutions six, inner ones one -fourth concealed ; umbilicus deep ; radii on the inner whorls prominent, each terminating in a distinct knob or tubercle, on the outer whorl, faint, numerous, annular, split in two or three on the back ; tubercles distant, nearly obsolete; decussated by fine, longitudinal, and 96 transverse striae ; aperture circular ; diameter three inches. L.L., ?/, E.H. Bay. . The outer whorl of this ammonite is rather stronger than that of A. crassus, which it much resembles. In the cast, the surface is beautifully adorned by the sharp- pointed ramifications of the septa, which crowd the whole surface. The inner whorls have the characters of A. Marshallani. This fine specimen is in the valuable collection of Mr. Bean, of Scarborough. 91. A. MUTATUS, Simp. Volutions six, inner ones one-fourth concealed, outer whorl one-third the diameter ; radii on the inner whorls strong, obtuse, ending in a distinct knob or tubercle, on part of the outer whorl nu- merous, fine, irregular, annular; aperture an ellipse; diameter one inch and eight-tenths. This is a smooth, neat ammonite, of a greyish colour. Several of the radii on the inner whorls have a slight groove, running into the knobs ; in some places the grooves go past the knobs, and form additional radii, without knobs ; the radii on the outer part of the outer whorl, in places, are little more than annular striae, and the tubercles become obsolete. It appears to be from the Lower Lias. Mr. Clarkson's collection. 92. A. OWENENSIS, Simp. Volutions five or six, exposed, outer whorl more than one -third the diameter; radii rather distant, straight, distinct,- slender, armed with a row of tubercles near the outer margin, obsolete on the back and on the inner whorls ; aperture round ; diameter one inch. 97 The whorls diminish rather rapidly; and, in some specimens, the radii are very distant. The cast is very smooth and neat. L.L., R.H. Bay. 93. A. ARMATUS, Sow. PL xcv. Volutions six or seven, exposed, outer whorl more than a third the diameter ; radii strong, ter- minating on the outer margin of the whorls in a row of short, strong spines ; inner whorls striated, four or five striae are gathered into each spine ; these are divided into three on the back, one or two annular strife between the spines, striae obso- lete towards the aperture ; aperture nearly round ; diameter five inches. L.L. , R.H. Bay. I have now got a fair specimen of Sowerby's A. armatus, which has caused so much trouble to naturalists. The very central whorls are imperfect, but there is sufficient to show that they are plane, or. nearly so; the succeeding whorls have the characters exhibited in Sowerby's figure. Where the spines have been knocked off, there remain also the oval discs. The siphuncle is also displayed. In places where the striae have 'become obsolete, towards the aperture, the shell has a roughened and granulated appearance. Most of these armed varie- ties occur in the lower part of ironstone series on the north cheek of E.H. Bay, and also at Boulby and Huntcliff. It would seem that when Mr. Sfcrangeways visited Whitby, this species was plentiful ; but the specimen I have now described is the only one I have seen ; and the one I formerly took to be A. armatus,, Sow., I believe to be a different species, which we may name A. miles. 94. A. MILES, Simp. Volutions six, exposed, slender ; radii separated by rather wide spaces, terminate near the back in H 98 long pointed spines ; striae numerous, undulating-, annular ; aperture roundish ; diameter 3 J inches. This is a smooth and more elegant species than the last ; the spines are more distant, and there cannot be reckoned more than two or three striae on each spine. The sides of the outer whorl are often rather flattened, and the spines being long and slender, are very generally knocked off. Inner volutions striated., but without spines or radii. L.L., v., E.H. Bay. 95. A. HASTATUS, F. # B. Volutions six or seven, exposed, sides regularly rounded, tumid, towards the aperture excavated between the spines, back rounded ; a row of long spines on the outer edge of the whorls, nearly perpendicular, spines round on the inner whorls, rather angular on the outer whorl, striated ; aper- ture transverse, ovate ; diameter six inches. The shell is rough, with coarse, obsolete strise. Spines sometimes occur two inches in length, but they can never be perfectly extracted from the matrix. L.L., E.H. Bay. 96. A. SPICATUS, Simp. Pal., pi. xxix. Volutions nine, exposed, outer whorl more than one -fifth the diameter, inner edge prominent, back rounded, sides flattish ; radii on the inner whorls numerous, more distant and stronger on the outer, end in strong spines on the outer edge of the whorls, pointing outwards ; spines strong, annular, often with a single groove ; transverse striae on the inner whorls, and on the back, numerous, 99 obsolete on the outer whorls ; aperture transverse, rounded, or subquadrate ; diameter 7-J- inches. This is one of the species noticed by Young, as ap- proaching near to A. armatus, Sow. It is, however, a coarser species, and beside other characters, the outer whorls are narrower in proportion, the radii more dis- tant and stronger, and the spines become very powerful, separated by deep concavities. L.L. 97. A. SUBTEJANGTTLARIS, T. fy B. Volutions eight, exposed ; radii very obtuse, bent most near the inner margin of the whorl, terminate on the outer edge in a row of strong knobs ; diameter twelve inches. The aperture of this species differs in form very materially in different parts of the same specimen ; at the extremity of the outer whorl of the largest specimens it is triangular, with the apex truncated, and the base outward ; it then becomes almost square ; in the inner whorls it is transverse and elliptical ; so that the whorls are separated by a deep channel. This species is by no means uncommon in the pyritous bed near Bay-town ; but the specimens are so crushed and distorted, that I have not seen a perfect one. 98. A. ACULEATTTS, Simp. Volutions six, exposed ; obsoletely radiated ; armed with a row of moderate, pointed spines ; striaB numerous, undulating, annular ; aperture cir- cular ; diameter ten inches. Brassy-bed, L.L, K.H. Bay. The edges of the septa are exceedingly fine and in- tricate ; some are pointed, others are rounded, crowding the whole surface of the whorls with their delicate meanderings. They vary much in the length and number of the spines. 100 99. A. ARMIGKER, Simp. Volutions seven, exposed, outer whorl one-fifth the diameter ; radii bend from the aperture on the inner edge of the whorl, then proceed in a straight direction to the outer edge, where they end in a row of knobs, equal to the intervening furrows ; aperture quadrate ; diameter twelve inches. L.L., R.H. Bay. 100. A. HAMILTONI, Simp. Volutions eight or nine, exposed ; radii numerous, bend slightly towards the aperture, on the outer whorls, strong, obtuse, equal to the concave spaces between ; on the inner whorls, fine, armed with a row of strong spines along the outer margin of the whorls, nearly obsolete on the back ; aperture quadrate ; diameter seventeen inches. This noble fossil is in the Whitby Museum,, and is the largest Ammonite I have seen in our Lias ; but notwith- standing its large size, it still retains the elegance which so highly characterizes the fossils of that formation. It was found in the Lower Lias at Robin Hood's Bay, at a very low tide ; but in what particular bed I am unable to say. Probably about the stratum t. The part to- wards the aperture is much depressed. The spines on the outer whorl I judge to have been three-quarters of an inch long ; those on the inner whorls strongly resemble those of A. aculeatus ; the greater number and slender- ness of the whorls, however, clearly distinguish it from that species. There is in the Whitby Museum the outer whorl of this species, seventeen inches in diameter, where the part towards the aperture becomes much depressed, so 101 as to render the aperture an elongated ellipse, with very diminished spines. There is a large, but very imperfect example in the Scarborough Museum. 101. A. MAMMILLATUS, Simp. Volutions five or six, exposed, with one row of distant mammillae, or obtuse spines ; radii annular, on the inner whorls prominent, separated by rather wide concave spaces, on the outer whorls, nearly obsolete; striated; aperture circular ; diameter four inches. L.L., R.H. Bay. This is at present a rare species ; the cast is smooth and striated, but ohe shell is rough. The ramifications of the septa are not very numerous, but rather deeply serrated. 102. A. NATIVUS, Simp. Volutions six, exposed ; outer whorl more than one-third the diameter, inner margin rounded, pro- minent, slightly overhanging the succeeding one ; radii obtuse, irregular, more numerous on the outer whorl, annular, a row of blunt tubercles on the outer half of the whorl,, more distinct towards the aperture, the radii connected with the tubercles split in two on the back, between these are from one to three radii which pass over the back undi- vided ; aperture circular ; diameter two inches, L.L., R.H. Bay. As far as I can judge, the shell is smooth. The rami- fications of the septa are very numerous, delicate, and angular, occupying nearly the whole whorl. This speci- men, and a fragment of a larger one, are much cracked, and very fragile, arising apparently from the abundant pyrites they contain. 102 Two rows of Spines. 103. A. PETRICOSUS, Simp. Volutions five or six, exposed ; radii numerous, obtuse, larger than the intervening spaces, obsolete on the back ; aperture nearly round ; diameter three-quarters of an inch. L.L., R.H. Bay. The radii terminate at both ends in round, flatted spaces, as if knobs had been worn off. Some indistinct striae may be observed on the back, which almost seem fimbriated. The ramifications of the septa are numerous, slender, and sometimes pointed, covering the whole surface of the shell. Mr. CharlesworWs Col. 104. A. BIRCHII, Sow. PL cclxvii. Volutions six or seven, exposed ; radii prominent, armed with two rows of short pointed spines ; striae annular, fimbriated ; aperture roundish, rather transverse ; diameter 3^ inches. The ramifications of the septa of this ammonite are sharply pointed, and not so crowded as in some species ; all the specimens which I have seen were in Mr. Bean's Museum, and were obtained from the Lower Lias. Outer whorl 7 inches, in the Scarborough Museum. I have obtained portions of whorls about L.L., 16, E.H. Bay. 105. A. BISPICATTJS, Simp. Volutions five, exposed, outer one one-third the diameter, back rounded, two rows of strong spines along the sides of the whorls ; shell coarsely striated transversely ; cast smooth ; aperture roundish ; diameter 10J inches. A very coarse shell. Judging from the character of the matrix, it is from an arenaceous bed of the Middle Lias above the Lower Lias. Hawsker. 103 106. A. SCORESBYI, Simp. Volutions six or seven, exposed ; radii prominent on the sides, with two rows of blunt tubercles, obsolete on the back and on the inner margin of the whorls, nearly equal to the concave spaces between them; striae obsolete, annular, fringed; aperture circular ; diameter eight inches. L.L., R.H. Bay. This is principally distinguished from A. Birchii by the smallness of the tubercles. 107. A. BREVISPINA, Sow., pi. dlvi. Volutions five or six, exposed ; radii numerous, straight, obsolete on the back; armed with two rows of small sharp spines near either margin of the whorl; aperture roundish ; diameter 1^ inch. L.L.,, R.H. Bay. In the larger specimens the spines become obsolete on the outer whorls, and the radii strong and prominent,, passing over the back. It appears to have been a very tender shell, and is seldom found perfect. Outer whorls occur five inches in diameter. 108. A. TENUISPINA, Simp. Volutions five, exposed, outer whorl less than one-third the diameter ; radii numerous, straight, terminate on both sides of the whorl in a sharp point, forming two rows of spines; back slightly rounded ; aperture quadrate ; diameter half an inch. L.L., R.H. Bay. On the back of this ammonite may be seen, in places., some indistinct transverse striae ; and, occasionally, the radii are also continued over it. The shell has been 104 obliterated, and the ramifications of the septa, thus displayed, are very numerous, and often pointed. Mr. Charlesworth/s Col. 109. A. HETEROGENES, Y. fy B. Pal. pi. xxxv.-vi. Volutions five or six, exposed, thick near the mouth ; radii annular, obtuse, separated by widish concave furrows ; flatted on the back, on a part of the outer whorl, numerous, fine, split over the back, and armed with two rows of small spines ; aperture roundish ; diameter four inches. L.L., c. This is a most singular ammonite ; for whilst the inner whorls cannot be distinguished from those of A. maculatus, towards the aperture the shell becomes greatly enlarged, the radii gradually become finer, until they are nearly obsolete, and about half the outer whorl is armed with two rows of short spines, like those on A. Henleyi. It occurs in the same beds with A. maculatus. 110. A. BECHII, Sow., pi. cclxxx. Very ventricose; inner whorls two-thirds con- cealed, outer whorl more than one-half the diameter, inner margin rounded ; radii numerous, obtuse, annular, crossed by numerous concentric striae, armed with two rows of short spines; aperture ovate ; diameter eight inches ; thickness five inches. M.L.,#, Hawsker, R.H. Bay. This ammonite may be readily distinguished by its thickness, in which respect it exceeds all the rest ; the radii are separated by flattish spaces; they are also flattened, and resemble narrow bands, which in general pass undivided over the rounded back, but sometimes they split in two. 105 111. A. BISPICATUS, Simp. Volutions five, exposed, outer one one-third the diameter, rounded, two rows of strong spines along the side of the whorls ; shells coarsely striated transversely; cast smooth; aperture roundish; diameter 10^ inches. A very coarse shell. I got my description from a speci- men in a dealer's shop. It was said to be from the Lower Lias at E.H. Bay. I suspect it is from the lowest beds of Middle Lias. 112. A. HENLEYI, Sow., pi. clxxii. Pal. pi. xli. Thick ; volutions six, inner whorls half concealed, outer whorl half the diameter, armed on the sides with two rows of short spines ; radii numerous, irregular, separated by flattish concave furrows, often united at the knobs; longitudinally striated; aperture roundish or heptangular; diameter seven inches. The outer whorl is much less than in the last, and the inner ones more exposed. It is altogether a much coarser shell. It is flatted or depressed between the spines., which gives the aperture an angular form. Syn. A. heptangularis, Y. & B. This is from one of the beds which unite the Middle with the Lower Lias at E..H. Bay. 113. A. TAYLORI, Sow. PL dxiv. A. CORNTTTUS, Simp. Volutions five, exposed, rather rapidly diminish- ing, outer whorl two-fifths the diameter ; radii annular, very prominent, slender, separated by rather wide concave spaces ; two rows of blunt tubercles on the back ; shell coarse and cracked ; aperture circular ; diameter two inches. L.L., y, R.H. Bay. 106 This beautiful, highly characteristic, and rare species,, is from the lower beds of lias at Robin Hood's Bay ; it might have been associated with A. maculatus, but the two prominences on the back, which suggest the idea of horns, render it necessary to unite it with the armed ones. It differs from that species, also, in the slender- ness of the ribs, and in the more rapid diminution of the whorls. On the back of a young specimen, five-eighths of an inch in diameter, there are four rows of tubercles, two of which become obsolete near the aperture. 114. A. QUADBICORNUTUS, Simp. Volutions four or five, exposed, outer whorl more than one-third the diameter; radii annular, very prominent, rounded, slender, separated by wide concave spaces, armed with four rows of strong, blunt spines on the back; shell thick, striated transversely ; aperture round ; diameter two inches. L.L., R.H. Bay. Whether it is possible that this can be merely a variety of the last or not, I would not take upon me to say. The whorls are less inflated, the ribs more prominent, and the spines in general strongly developed, especially those on the middle of the back ; and I believe it is from a differ- ent bed ; but one of the radii, I observe, is in every respect like those of A. Taylori. If it is^not a distinct species, it is certainly a very interesting variety, and worthy of a separate description. Whitby Museum. II. With a keel on the back. (a.) Outer whorl broad. 115. A. ELEGANS, F. 4" -B Volutions four or five, inner ones six-tenths con- cealed, outer whorl rather more than one-third the diameter, inner edge sloping or concave ; radii twice 107 bent, faint; keel sharp, prominent, entire; aperture triangular ; diameter three inches. ILL., 7. This elegant shell is rather abundant in the Jet Eock . and hard shale of the Upper Lias ; the shell is thin, and both it and the cast are smooth and shining. About one- eighth of an inch from the inner edge of the whorl is a concentric line, in some specimens distinct, in others obsolete. The inner edge of the whorls of this group being deeply indented by the succeding whorls, the apertures have more or less the shape of arrow heads. There is one which comes so near to this, that I am at a loss to determine whether it is a variety or a distinct species. The outer whorl is narrower, the inner whorls more exposed, and the sides of the whorls more regularly rounded ; in other respects it agrees, and is from the same beds. 116. A. EXARATUS, F. 4* B. Pal. pi. Ixii. Volutions five, inner ones two-thirds concealed, outer whorl not quite half the diameter ; radii numerous, distinct, uniform, twice bent; keel sharp, entire ; aperture triangular, or rather ovate ; diame- ter 3-^ inches. U.L., 7. In general form this ammonite resembles the last ; but the radii are much more regular and distinct, and have a greater curvature; it differs from A. Mulgravius, in the sides of the whorls being rounded in the middle, and in having the inner margin sloping. This species is rather abundant in the Jet Rock. 117. A. ELEGANTULTJS, T. 8{ B. I can regard this only as the young of the last ; for although the radii are not nearly so distinct as in the older shells, yet, after placing a number of different sizes alongside of each other, they passed into each other by imperceptible gradations. Like other young shells, they appear to have been of a gregarious nature, and are 108 found in great numbers, crowded together in the flattened nodular bands of lias limestone, which occur in the Jet Rock. U.L., 7. Syn. A. sigmifer, Ph. Along with these sometimes occurs one of a similar form, but distinguished by the crowded foliations of the septa, which are rounded. If it should not prove to be the young of some known species, it might be named 118. A. MULTIFOLIATUS, Simp. 119. A. RUGATULUS, Simp. Radii on the inner margin of the whorls straight, regular, distant, separated by wide flat spaces, sigmoidal on the outer half of the whorls, with short ones irregularly introduced ; longitudinal irregular striae, or corrugations, between the ribs ; keel round, depressed ; aperture ovate ; diameter one inch. U.L. 120. A. MULGBAVITTS, T. $ B. Volutions five, inner ones one-third concealed, outer ones more than one-third the diameter, with a concentric depression in the middle; inner mar gin an acute angle ; radii numerous, nearly straight, and diverging to the middle of the whorl, then suddenly bend from the aperture, and then gradually bend towards it ; keel sharp, entire ; aperture ovate ; diameter nine inches. U.L., 5b. The radii of this, and some of the neighbouring species, resemble reaping hooks ; the radii in this makes a longer bend towards the aperture than in the rest, and they are marked with a small triangular groove, which is not seen on the cast ; it may be readily dis- tinguished from A. excavatus, which it much resembles, by the inner margin of the whorls hanging over the 109 succeeding ones. It often attains a large size, and is obtained from the hard shale of the Upper Lias, 56. This is certainly not A. serpentinus, if the figures given by authors of that species be correct. 121. A. LYTHENSIS, Y. fy B. Volutions four or five, inner ones nearly con- cealed, outer whorl more than one-half the diameter, thick near the inner margin, which is rectangular ; radii twice bent, rather prominent near the back ; keel thick ; aperture ovate ; diameter four inches. ILL., 1, Peak. The whorls of this shell are more concealed than in A. elegans, the radii are stronger, and it is not so much depressed ; the shell also is rough, which gives it rather an inelegant appearance ; the interior edge of each whorl, as Young and Bird observe, being rectangular, the central part appears like a small round pit, with perpendicular sides. 122. A. BOULBIENSIS, F. 4- B. Nearly the same characters as the last, from which it may be distinguished by a small concave space on each side of the keel, and by the inner edge of the whorl sloping, so as to render the umbilicus a small hemis- pherical depression ; whilst that of the last is perpendi- cular ; there is also often a slightly elevated rim around part of the umbilicus. Both these are from the alum shale, at Peak. The edges of the septa shew very in- tricate and crowded foliations ; diameter two inches. U.L., 1. 123. A. SIMILIS, Simp. This greatly resembles the last, especially in the size and form of the umbilicus, but it is thicker towards the back, and it wants the concave part near the keel. The keel is slender, and easily knocked off, when the back 110 appears regularly rounded. This last circumstance strongly convinces me that it is a distinct species ; for this is a structure entirely different from what is ob- served in A. Boulbiensis, and the succeeding one, where the keel is wedged-shaped, with a slight groove on each side, and not otherwise separated from the sides of the whorl. It occurs with A. elegans, exaratus, &c., in the Jet Rock along the Hawsker coast ; diameter 1} inch. U.L., 7. 124. A. COMPACTILIS, Simp. Much depressed ; inner volutions nearly con- cealed, outer whorl more than one-half the diameter; radii waving, nearly obsolete ; obsoletely striated ; keel rounded, entire ; aperture acutely triangular, or ovate ; diameter 1^ inch. ILL., 7. This, like Boulbiensis, and the next, has the keel formed by a slight groove on either side, and some specimens have a faint rim round the small umbilicus ; but it is a much more depressed and elegant species than A. Boulbiensis. The foliations of the septa are also very different, being far more delicate and numerous, crowding the whole surface with their ramifications ; one set of lobes touching, or nearly touching one another. I can count six principal lobes between the keel and the margin of the whorl. 125. A. LECTUS, Simp. Much depressed ; volutions four or five, inner ones nearly concealed, outer whorl more than one- half the diameter ; radii waving, nearly obsolete ; striae numerous, waving ; keel slightly crenulated ; aperture acutely triangular, or ovate ; diameter 1 inch. ILL., 7, Ill The sides of the whorls are regularly convex, as in A. ovatus ; the keel is slightly crenated by the radii passing over it, and is little more than the sharp edge of the back, with a slight groove on each side. In this respect it resembles A. Boulbiensis ; but the inner margin of the whorls is much depressed, so as to leave but a very shallow umbilicus. 126. A. SUBCONCAVUS, Y. Sf B. Volutions five, inner ones much concealed, outer whorl one-half the diameter, inner margin sloping ; radii twice bent, sometimes united in pairs, most prominent near the back ; keel prominent, entire ; aperture triangular, or ovate ; diameter 2 inches. U.L., 6. This is not so depressed as A. Boulbiensis, the radii are more prominent, and the inner whorls are not quite so much concealed, leaving a larger umbilicus ; the whorls, too, are thicker near the back, which renders the aperture rather ovate. In two specimens before me, the shell appears very thick, but in a larger one (three inches diameter), it is moderate. 127. A. DENOTATUS, Simp. Pal. pi. vi., f. 1. Volutions five or six, inner whorls three-quarters concealed, outer whorl less than one-half the diameter, inner margin rounded, outer part de- pressed ; radii straight for about three-quarters the width of the whorl, then suddenly bend towards the aperture, where they become obsolete, terminate abruptly at a flattish groove, which relieves the sides of the whorl from the keel ; which is promi- nent, sharp, entire ; aperture ovate ; diameter six inches. L.L. Mr. Leckenby's Col. 112 128. A. OVATUS, F # B. Volutions five, inner ones about one -half con- cealed, outer whorl about one-third the diameter ; radii twice bent, faint, or obsolete ; striae delicate, numerous, waving ; keel sharp, entire ; aperture ovate ; diameter 7^ inches. U.L., 4. This species varies both in the breadth of the outer whorl, and in the exposure of the inner whorls ; in some specimens the side of the whorl is a very regular curve, but in others the inner margin is rather elevated, and quickly rounded. It is found in a nodular band, near the first Nab at Saltwick, and in other places where the bed is exposed. 129. A. OVATULUS, Simp. Nearly the same characters, but the outer whorl much broader. It cannot be the young of the last, as it occurs in a bed lower in the series, along with A. ele- gant ulus ; diameter 1^ inch. U.L., 7. 130. A. OBLIQUATUS, Y. fy B. Volutions five, inner ones one-half concealed, outer whorl one-third the diameter ; radii nearly straight, then bend towards the aperture ; keel sharp, slender, prominent, entire ; aperture ovate ; diameter eight inches. ILL. These two species in general appearance greatly re- semble each other, but they may be at once distinguished by the edges of the septa ; for whilst those of A. ovatus, shew a serrated waving, with a space between, those of this species occupy nearly the whole surface with their intricate foliations ; the shell is smooth and without striae, and the radii on the inner whorls are often pro- minent. There are two fine specimens of this species in the Whitby Museum, one eight inches in diameter, the other shews the fine foliations of the septa. 113 131. A. BEANIL, Simp. Volutions four or five, inner ones much concealed, outer whorl nearly one-half the diameter, sides flattish, with a row of tubercles along" the inner margin ; radii twice bent ; aperture ovate ; dia- meter four inches. ILL., 1, Peak. This may be readily distinguished from the rest which have sigmoidal radii, by the row of tubercles on the inner margin of the whorl. I have now got a specimen more than seven inches in diameter, with the outer whorl narrower in proportion, and the inner whorls less concealed ; the keel is very prominent, thin, entire, and rounded on the edge, easily knocked off, when the siphuncle is clearly displayed. The ramifications of the septa are very fine and numerous, and often pointed. 132. A. FABALIS, Simp. Inner volutions one-third concealed, outer whorl one-third the diameter, regularly convex ; radii, distinct, rounded, equal to the intervening concave spaces, proceed from a row of tubercles on the inner margin of the whorl, where they are united in pairs, sigmoidal, bend towards the aperture on the back; keel rounded, depressed; aperture ovate; diameter 5J inches. The outer whorl is narrower than in A. Beanii, and the radii much more strongly marked. 133. A. PHILLIPSII, Simp. Inner volutions much concealed, outer whorl two-fifths the diameter ; thin near the back, thick at the inner margin, which is irregular with tuber- cles or swellings ; radii unequal, nearly straight, I 114 then bend towards the aperture ; keel sharp, prominent, entire ; aperture triangular ; diameter 2 inches. U.L., 1, Peak. 134. A. RETICULARIS, Simp. Volutions five, inner ones more than three- quarters concealed, outer whorl one-half the dia- meter, most convex on the outer half ; transverse striae numerous, fine, waving, crossing numerous fine longitudinal striae ; keel or back rounded, and slightly crenated by the striae ; aperture triangular, or slightly ovate ; diameter 2 inches. M.L., e, Hawsker. This conies 'near to A. lenticularis, but the outer half of the whorl is thicker. It is from the iron-stone beds of the Middle Lias, along with A. Hawskerensis. 135. A. CONJUNCTIVUS, Simp. This greatly resembles the last ; the keel is the sharp edge of the back,, and it has the fine diverging striae, but it wants the longitudinal striae ; it occurs in the same beds; diameter about an inch. Some specimens are thicker, and approach A. volutus. I may also be allowed to notice here another little shell, of frequent occurrence in the same beds, which I would call, 136. A. FERRUGINEUS, Simp. The sides of the whorls are regularly convex, with the inner margin truncated ; the radii are sigmoidal and regular, but nearly obsolete. M.L., Ironstone. 137. A. LENTICULARIS, T. fy B. Very much depressed ; inner whorls nearly con- cealed, outer whorl more than one-half the diameter, sides very slightly convex, thinning to a sharp edge at the back, umbilicus small, with upright 115 sides ; striae radiating, faint, and slightly waving ; keel slightly crenated ; aperture acutely triangular ; diameter 3 inches. M.L., e. This approaches very near to Sowerby's A. discus,, but it has a small portion of the inner whorls exposed. On account of the sharpness of the back and its strong resemblance to a cutting instrument, it is popularly known by the name of razor-back. It is not very uncom- mon in the ironstone bands of the Middle Lias ; but on account of its thinness, it is with difficulty extracted from the matrix. 138. A. SIMPSONI, Bean's M88. f Simp. Pal. pi. xlvii., f . 4. Much depressed; volutions four or five, inner ones seven-eighths concealed, outer whorl one- half the diameter, sides undulating, inner margin rounded ; radii nearly obsolete on the outer whorl, bend towards the aperture ; striae diverging, nume- rous, and delicate; keel sharp, prominent; aperture acutely triangular ; diameter six inches. L.L., 15, R.H. Bay. This ammonite, which Mr. Bean has been pleased to call A. Simpsoni, is from the Lower Lias shale at Eobin Hood's Bay; the whorls swell out in thickness towards the inner margin, which is finely rounded, whilst the part near the keel is slightly concave; in the older specimens the radii are scarcely discernible. 139. A. COMPLANATUS, Sow. ? Inner volutions concealed, outer whorl more than one-half the diameter, sides rounded ; radii nume- rous, slender, diverging, straight for two-thirds the breadth of the whorl, then turn gently towards 116 the aperture, unequal ; keel slender, entire ; aper- ture triangular; diameter Scinches. L.L., y, R.H. Bay. At the first sight, this has the appearance of a com- pressed specimen of A. heterophyllus, but a closer inspection shows it to be a very different shell; the slender radii diverge beautifully from the centre, and towards the outer margin of the whorl are separated by short ones, all terminating near a very slightly elevated keel j in the direction of the radii may also be seen very delicate striae. If, as some think, this be different from Sowerby's shell, it may be named A. complanosus. Whitby Museum. 140. A. LENS, Simp. Volutions three or four, inner ones nearly con- cealed, outer whorl more than one-half the diameter, regularly convex ; radii nearly obsolete, waving ; keel very slender, sharp, prominent, crenated, concave on each side ; aperture a very elongated ellipse ; diameter one inch. L.L., RJEL Bay. A cast of a bronze colour ; lobes of the septa numerous, rounded, and finely serrated. Mr. Clarkson's Col. 141. A. LEPTOPHYLLUS, Simp. Inner volutions nearly concealed, outer whorl more than half the diameter, inner angle perpen- dicular to the regularly and flatly convex sides ; umbilicus a small deep pit ; radii sigmoidal, nearly obsolete, entirely so on the inner margin of the whorl ; keel relieved from the thin edge of the back by slight furrows ; aperture triangular, or ovate ; diameter 3 inches. 117 A cast having the whole surface ornamented with the very numerous and delicate foliations of the septa. The lobes looking towards the aperture are rounded, and finely serrated ; those looking from the aperture pointed with long delicate fingers. Apparently from the M. or L.L. Scarborough Museum. 142. A. POLYPHYLLUS, Simp. Much depressed ; volutions five, inner ones very little exposed, outer whorl one-half the diameter, inner margin rounded, sides convex, then concave ; back thin ; radii obtuse, depressed, waving ; keel sharp, much elevated ; aperture triangular ; diame- ter 3| inches. L.L., R.IL, Bay. This ammonite is distinguished by the great number and regularity of the foliations of the septa, which ornament the whole surface of the whorls by their meanderings ; the inner edge of the whorls are rounded, and the thin back is greatly produced, so as easily to be knocked off. The radii in general are nearly obsolete towards the inner margin of the whorl, and become gradually more distinct towards the backj but a fine specimen in the possession of Mr. Bean is entirely with- out radii. 143. A. MARGARITATTJS, Mont. A. STOKESi, Simp. Pal. pi. liii. Volutions five, inner ones two-thirds concealed ; outer whorl nearly one-half the diameter, sides gently rounded ; radii distinct near the inner margin of the whorls, obsolete towards the keel ; delicately striated ; keel strongly crenated ; aper- ture triangular ; diameter six inches. M.L., Iron- stone bands, Hawsker. The diverging striae are very distinct on the inner margin of the whorls, and there are also obsolete concentrick lines or striae crossing these; it may be 118 principally distinguished from the next by the keel, which resembles a twisted rope running along the back. I have seen two specimens which agree with this,, but which have, on the inner whorls, rather distant spines. 144. A. CLEVELANDICUS, T. fy B. Much depressed ; whorls five or six, more than one-half concealed, sides regularly convex, inner margin rounded; radii numerous, flat, nearly straight, then turn to the aperture ; keel the acute angle of the back, crenated by the radii ; aperture saggitate ; diameter 6^- inches. M.L., , Hawsker. This has nearly the same specific characters as the last. In general the radii are almost obsolete near the inner margin of the whorls, and are often rather promi- nent near the keel, where they slightly bend towards the aperture ; the keel is strongly crenated by the radii passing over it, but it has not the cord-like form which distinguishes the last ; the edges of the septa shew them- selves in minute, intricate, and crowded foliations, spread over the whole surface of the whorl ; diameter seven inches. I have a young shell (one inch diameter), which has nearly the same characters as the larger one, but the radii are the most prominent near the inner margin of the whorl ; under such variety, the form of the keel seems to be the most certain character for distinguishing this from the last. No striae. 145. A. DEPRESSUS, Simp. Very much depressed ; volutions four or five, inner ones nearly half concealed, outer whorl one- half the diameter, sides flatted ; radii on the inner whorls straight, prominent, equal to the spaces between, obsolete on the outer whorls ; striated ; keel strongly crenated ; diameter two inches. 119 This ammonite is the most depressed of any I have seen., not even excepting A. lenticular is. The inner- whorls diminishing very little in thickness, it has a very shallow umbilicus ; the keel has the cord-like ap- pearance observed in A. margaritatus, of which I once supposed it to be a variety ; but on account of its very depressed form, and the absence of radii from the outer whorl, I am obliged to consider it a distinct species. It also resembles some varieties of A. Clevelandicus, but the septa are much more distant, and their ramifications much more simple, a circumstance which 'shews it to be a distinct species. 146. A. VITTATUS, Y. and B. Volutions four or five, inner ones slightly con- cealed, outer whorl one-third the diameter ; back rounded ; radii straight, prominent, diverging, end in a small sharp tubercle ; keel prominent ; strongly crenated ; aperture triangular ; diameter one inch. This is a shining species, and always occurs of small size ; it might be mistaken for the young of A. Stokesi, but the radii occupy the whole of the disc, and the tubercles shew it to be a distinct species. In some specimens the radii are stronger, and separated by wider grooves than usual. It is rather abundant in the iron bands on the Hawsker shore. M.L. 147. A. HUNTONI, Simp. Much depressed ; volutions three or four, inner ones three-quarters concealed, outer whorl one- half the diameter, gradually thinning to the keel ; radii sigmoidal, obsolete ; with distant deep con- strictions ; aperture acutely triangular ; diameter six-tenths of an inch. L.L., ?/, E.H. Bay. This is easily confounded with the inner volutions of 120 A. Robinsoni, but it is more depressed, and the con- strictions are nearly straight. The shell is very thin, and faintly radiated or striated. 148. A. ROBINSONI, Simp. Volutions four, inner ones nearly concealed, outer whorl more than one-half the diameter, back rounded ; radii slightly waving, nearly obsolete ; keel blunt ; aperture acutely triangular or ovate ; diameter seven-tenths of an inch. L.L., 13. This beautiful little ammonite is from the lowest beds of Lias at Eobin Hood's Bay. The sides of the whorls are regularly convex, the inner margin is slightly ele- vated above the succeeding whorl; the keel is merely the thin edge of the back, which is rounded, but without the groove on each side, as occurs in A. lectus. The inner whorls frequently have waving constrictions. It is peculiarly distinguished by the regular and beautiful ramifications of the septa, which crowd the sides of the whorls. I can count six principal, deeply-serrated ramifications, or lobes, from the inner margin of the whorl to the back. 149. A. SIMPLEX, Simp. Volutions four or five, inner ones much concealed, outer whorl less than one-half the diameter ; radii flat, and nearly obsolete ; keel blunt ; aperture acutely triangular, or ovate ; diameter three-quarters of an inch. L.L., R.H. Bay. In external form, this differs little from A. Robinsoni ; but the ramifications of the septa are much more simple, and altogether so different, that I am compelled to con- sider it a distinct species. Mr. Charlesworth's Col. 150. A. RETENTUS, Simp. Inner volutions nearly concealed, outer whorl 121 more than one-half the diameter, sides regularly rounded ; radii waving-, nearly obsolete ; keel prominent, sharp, entire ; aperture acutely trian- gular, or ovate ; diameter nine-tenths of an inch. L.L., R.H. Bay. This is a cast, and, like many others from the Lower Lias, is of a bronze colour; the ramifications of the septa are very numerous, those on the inner margin of the whorl are mere serrations. It may be readily dis- tinguished from A. Eobinsoni by its prominent keel, and from the next, by its small umbilicus. Mr. Clarkson's Col. 151. A. BUCKII, Simp. Volutions three or four, inner ones one-half con- cealed, outer whorl not one-half the diameter ; radii broad, flat, waving, distinct near the inner margin of the whorl, obsolete towards the keel ; keel prominent, sharp ; aperture triangular, or ovate ; diameter half an inch. L.L., Ind. b, 15, K.H. Bay. In the prominence of the keel, and in the general form of the whorls, this ammonite resembles A. Simpsoni, but the outer whorl is narrower, the inner margin is more quickly rounded, and the foliations of the septa are very simple, and obtuse ; the shell is rough, and the cast is smooth and shining. These small ammonites, which occur in the Lower Lias, are by no means to be considered as the young of the larger species; their definite and elaborate forms being a certain indication of age and slow growth. In this respect they are strongly contrasted with the irregularity of A. elegantulus, and other shells, which are so abundant in the Upper Lias. 122 Var. (a.) Radii more numerous, and being continued irregularly on the back, the keel becomes crenated. Var. (6.) Whorls more tumid ; keel sharp, prominent, entire, with a portion of the whorl on either side concave. Probably a distinct species. 152. A. DEJECTUS, Simp. Volutions four, inner ones one-quarter concealed, outer whorl not one-third the diameter ; radii separated by wide spaces, bend from the aperture, obsolete towards the back ; keel indistinct, coarsely crenated; aperture ovate; diameter half an inch. LL., R.H. Bay. There is something about this ammonite which creates a suspicion that, after all, it may be a variety of A. Buckii ; but the keel is so much depressed, and the general form so different, that one would scarcely think it possible. Mr. Charlesworth's Col. 153. A. ALIENUS, Simp. Volutions four or five, inner ones one-half con- cealed, outer whorl not one-half the diameter ; umbilicus shallow ; radii rather numerous, waving, flattened, equal to the furrows between, nearly obsolete towards the keel ; keel not prominent ; aperture ovate ; diameter six-tenths of an inch. L.L., R.H. Bay. This species is rather variable. In one example the outer whorl is narrower, and the keel, towards the mouth, becomes obliterated, and some of the radii pass over the rounded back. In two smaller specimens, the radii are nearly obsolete, so that they resemble what we might suppose to be the young of A. ovatus, which I believe is never found in the Lower Lias. They how- ever all agree in the foliations of the septa being much more simple than usual. Mr. Charles wort h's Col. 123 154. A. FLAVUS, i Volutions three or four, inner ones three-quarters concealed, outer whorl not one-half the diameter ; keel obtuse ; aperture ovate ; diameter three- quarters of an inch. This is not quite so much depressed as the last, and the inner whorls diminish very little in thickness ; it is quite plane, without radii or striae ; the shell is cracked ; the septa are more distant than in the last, and the lobes are less serrated, and not so numerous. It is also from the Lower Lias at Eobin Hood's Bay, and has a light metallic hue. 155. A. LIMATUS, Simp. This greatly resembles the last, but the whorls diminish more in thickness, leaving a larger umbilicus ; there are also a few obsolete radii. It is entirely a cast, and of a brown colour. L.L., R.H. Bay. 156. A. VOLUTTJS, Simp. Volutions four, inner ones one-half concealed, outer whorl not one-half the diameter ; radii faint, obtuse, waving ; keel obtuse, slightly crenated ; aperture ovate ; diameter half an inch. M.L., Hawsker. Merely taking a side view of this shell, it very much resembles A. fimbriatus ; the sides of the whorls are finely rounded, and the keel is merely the thin back ; cast is smooth and shining, and the foliations of the septa are, for the most, obtuse. Another, which I judge to be of the same species, has the shell striated. They occur in the marlstone. 157. A. ALTERNATUS, Simp. Volutions four or five, inner ones one-third con- cealed, sides flatted, a row of obtuse depressions 124 near the inner margin, which is sloping-, outer whorl two-fifths the diameter ; radii numerous, twice bent ; keel sharp, entire ; aperture acutely triangular ; diameter three inches. U.L., 7. This ammonite may be easily distinguished from A. elegans, A. exaratus, and others of a similar form., by the depressions upon the inner margin of the whorls, as as well as by the less breadth of the outer whorl, and by its being thicker towards the back ; also, where the shell remains, there may be observed very slender radii in the furrows ; on which account it has received the above name. (6.) Outer whorl narrower. 158. A. RUDIS, Simp. Volutions four or five, inner ones one-fifth con- cealed ; radii strong, straight, then turn towards the aperture, equal to the concave spaces between ; aperture roundish ; diameter 2^ inches. U.L. This is an extremely rugged shell ; the outer whorls are only slightly indented by the succeeding ones. Near the inner margin of the whorls are coarse, irregular swellings, from whence proceed two radii, which are occasionally separated by other radii, but with the great- est irregularity. I have seen only one specimen, the shell of which is thick, the keel broken off, and the siphuncle is well displayed. 159. A. STRIATULTJS, Sow. PL ccccxxi. Volutions five, inner ones one-fifth concealed, outer whorl one-third the diameter of the shell; radii twice bent ; striae numerous in the direction of the radii ; keel obtuse, entire ; aperture ovate ; diameter 2 inches. ILL., 1, Peak. This smooth and elegant shell is from the Upper Lias 125 at Peak, where it is found in some abundance. The sides of the whorls are gently rounded, as in A. ovatus. On some specimens the radii are nearly obsolete, in others they are rather prominent, gradually increasing in strength from the inner margin, and turn towards the aperture in passing over the back ; the beautiful striae observed on the shell is not seen on the cast, which is smooth and shining. 160. A. NITESCENS, Y. Sf B. Pal. pi. xlix., f. 1. Volutions six, inner ones very little concealed; radii faint on the inner margin of the whorls, twice bent, form a row of blunt tubercles in passing over the back ; keel obtuse ; aperture ovate ; diameter three inches. M.L., , Hawsker. Var. Radii more prominent. This greatly resembles the last, and is, like it, striated ; but the ramifications of the septa are much more acute and intricate; which show it at once to be a different species. It occurs in the marlstone beds, which are im- mediately above the Lower Lias ; but it is by no means plentiful. 161. A. MACDONNELLI, Portlock; T. $ B., pi. v., f. 8. Much depressed ; volutions eight, little con- cealed, outer whorl one-quarter the diameter, sides regularly and flatly rounded ; striae very numerous, slightly bend to the aperture ; keel sharp, entire ; aperture saggitate ; diameter If inch. Upper half of the L.L. This was very kindly sent me by Mr. Blake from Water, where it appears to be abundant. It is much more delicate than A. striatulus. 162. A. VETUBTUS, Simp. Volutions five, inner ones nearly half concealed. 126 outer whorl one-third the diameter ; radii straight, obtuse, nearly obsolete on the inner whorls; keel an obtuse angle; aperture ovate; diameter one inch and one -tenth. The shell is roughish, the cast smooth, and the folia- tions of the septa simple. In general form it comes near to the more depressed varieties of A. striatulus, but the whorls are numerous, and the shell is without striae. I believe it is from the Lower Lias at E.H. Bay. Mr. Clarkson's Col. 163. A. SIPHUNCULARIS, Simp. Volutions four, exposed ; radii straight, strong, obtuse, separated by narrow furrows ; siphuncle on the back equal to half the breadth of the whorl ; diameter six-tenths of an inch. L.L., R.H. Bay, This is a most singular species, the keel being formed of a very distinct tube. In one specimen part of the tube has been broken off, and the radii are seen to pass over the back, strongly resembling those of A. macula tus. The cast is smooth and the shell rough. 164. A. RADIATUS, Simp. Volutions five, inner ones one-third concealed, outer whorl not quite one-half the diameter, sides rounded ; radii straight, numerous, sharp, regular, delicate, bend towards the aperture near the back ; the keel slender, rather rounded, furrows distinct ; aperture ovate ; diameter three-quarters of an inch. L.L., R,H. Bay. This is an exceedingly beautiful and well-defined species ; the radii are all as if drawn with geometrical exactness, those near the aperture slightly waving, absent in the centre ; the keel and all its parts have the greatest 127 regularity. I have seen five or six, all small and uni- form, and entirely unlike the young of A. geometricus, Bucklandi, or any other species. 165. A. REGULARIS, Simp. Volutions four, inner ones one -half concealed, outer whorl more than one-third the diameter, with the sides rounded ; radii numerous, regular, straight, bend towards the aperture near the keel ; keel depressed ; aperture acutely triangular, or ovate ; diameter one inch and two-tenths. This ammonite is much more depressed than A. geo- metricus, the outer whorl is wider, and the radii are obtuse, and less numerous; the shell is roughish, and without striae. I believe it is from the Lower Lias at E.H. Bay. Mr. Clarkson's Col. 166. A. GEOMETRICUS, Ph. Volutions four or five, exposed ; radii slender, very regular and distinct, straight, suddenly turn towards the aperture on the back ; keel slender, entire; aperture ovate ; diameter l inch. M.L., Hawsker. The radii of this shell are extremely regular ; it differs from A. subnodosus, chiefly in the more regular convexity of the sides of the whorls, and in the absence of tubercles on the exterior part of the radii ; on some specimens, however, I have seen a few tubercles like those always observed on A. subnodosus ; but as these occur only occasionally, I shall consider it a distinct species. III. Keel between two furrows, (a.) Furrows slight. 167. A. SPINATUS. Volutions five or six, inner ones more than one- quarter concealed, outer whorl one-third the 128 diameter, sides flat, and nearly parallel with each other, inner edge rounded ; radii straight, promi- nent, end in a knob on the back, turn at a right angle towards the aperture, not equal to the intervening concave furrows; keel slender, rounded; furrows on either side slight ; aperture rectangular ; diameter five inches. M.L., a, Hawsker. The radii are most prominent on the outer margin of the whorls where they often form a knob, and where they are separated by deeper furrows. The radii, espe- cially on the inner whorls are much more numerous, plain and regular than in A. Hawskerensis with which it has been confounded. In one sent me by Mr. Tate from the Cleveland mines the radii are not so numerous, and the aperture is rather ovate. Another, which I suppose we must place under this name, has a square aperture, the keel having been de- pressed into a mere crenated line. 168. A. ELABORATUS. Depressed ; volutions six, exposed, prominent on the rounded inner margin, outer whorl less than one-third the diameter, pinched towards the back ; radii strong, sharp, regular, tending to form tuber- cles on both margins, suddenly turn towards the aperture on the back, separated by deep concave grooves ; keel much depressed, sharp, smooth ; aperture quadrate ; diameter two inches. M.L., a, Hawsker. This belongs to the A. spinatus family, and is from the uppermost bed of the Middle Lias on the Hawsker shore. It is highly finished, and well distinguished from A. 129 solitarius, by the prominence of the inner margin of the whorls, and the smooth keel. From the ribs rising on both margins a slight hollow or groove is formed along the side of the whorl. Whitby Museum, No. 302. 169. A. EXASCIATUS, Simp. Volutions five, inner ones nearly one-half con- cealed, outer whorl more than one-third the diameter, inner margin prominent ; radii straight, terminate in a tubercle near the outer margin, separated by rather wide concave spaces ; keel rounded, distinct ; aperture subquadrate, or ovate ; diameter 2^ inches. In the form of the radii, this ammonite resembles A. nodosus, and, in its coarseness and general appearance* A. Hawskerensis ; but the back is triangular, and with- out furrows near the keel. It is from the ironstone beds of the Middle Lias. 170. A. SUBNODOSUS, Y. 4" -B- Volutions five or six, inner ones one-quarter concealed, outer whorl one-third the diameter ; radii straight for two -thirds their length, then a small tubercle, a sharp turn towards the aperture and the keel, another tubercle, then turn towards the aperture ; keel crenated ; aperture subquadrate, or ovate ; diameter 1^ inch. M.L., Hawsker. This is intermediate between the last and the following species ; it is a much more elegant shell than the next, and the radii are more numerous, regular, and less prominent. In some specimens the radii are still closer, and the characteristic tubercles become nearly obsolete, until it can scarcely be distinguished from A. geome- tricus. K 130 171. A. HAWSKERENSIS, F. fy B. Volutions five, inner ones very slightly concealed ; radii prominent, sharp, separated by wide spaces, straight on the sides, suddenly turn towards the aperture on the back ; striated ; keel faintly cre- nated ; aperture subquadrate ; diameter 3 inches. M.L., e, Hawsker. This approaches very closely to Sowerby^s A. multi- costatus, but differs in the form of the aperture, the present one being wider near the next whorl than to- wards the keel; it is also more depressed. It is not uncommon in the ironstone bands. There are several varieties. One,, in which the straight part of the radii terminate in a tubercle ; another, which has two tubercles, as in the last ; another, which has knobs also on the inner margin of the whorls. A very elegant variety, if not a distinct species, with a row of tubercles on the inner margin, and the sides more parallel. 172. A. TRANSFORMATUS, Simp. Volutions five, exposed, outer whorl one-third the diameter ; radii strong, prominent, sharp, sepa- rated by rather wide concave spaces, nearly obsolete on the back, straight until they reach the outer margin of the whorls, where, on the last whorl, they form a slight knob, and suddenly bend to- wards the aperture ; keel much depressed, furrows on either side slight ; aperture quadrate ; diameter 1^ inch. The inner whorls of this species are destitute of any dorsal keel or furrow, and have a good deal the character* of A. arcigerens, though by no means so numerous and 131 slender; but as they increase in size, they have gradually formed upon the back a distinct elevated line, which ultimately becomes a depressed but distinct keel between two slight furrows j the radii towards the aperture be- come stronger, and form distinct knobs on the outer margin of the whorl, when they greatly resemble those of A. Hawskerensis. I have now seen a good number of specimens, which have been obtained from lias boulders in the alluvium on the Holderness coast, and some also from the Lower Lias at E.H. Bay. 173. A. MULTICOSTATUS, Sow. PL ccccliv. Volutions five, exposed ; radii numerous, promi- nent, straight ; keel depressed ; furrows on either side slight ; aperture nearly square ; diameter four inches. L.L. It principally differs from A. Hawskerensis, in being much thicker, the radii more numerous, the keel entire, or but slightly crenated. The shell is smooth and with- out striae, enlarges much towards the aperture, and the sides of the whorls are rather rounded j there appears to have been tubercles on the outer margin : I see a very prominent one, and others appear to have been broken off. This specimen is in the Leeds Museum, The sides in Sowerby's figure are much natter, and the grooves on either side deeper ; but his specimen was much larger (fourteen inches diameter, and between three and four inches thick). 174. A. BIBDI, Simp. Volutions five, exposed ; radii very prominent, sharp, separated by large concave spaces, nearly straight, then make a slight turn from the aperture, and form a tubercle, make another turn towards the aperture on the back, where they become 132 obsolete ; keel very small ; grooves on either side nearly obsolete ; aperture quadrate ; diameter two inches. The radii on the rounded inner edge of the whorls are nearly obsolete, then become gradually more and more prominent, until they reach the outer edge, where the groove which separates them is very deep. From the very feruginous appearance of this specimen, I judge it to be from the ironstone bands. 175. A. OBTUSUS, Sow. PL clxvii. Volutions five, inner ones one-third concealed, outer whorl one-third the diameter ; radii obtuse, prominent, regularly bend towards the aperture; keel blunt, much depressed ; furrows on each side nearly obsolete ; aperture ovate ; diameter 3 inches. L.L., 22, E.H. Bay. The shell of this species is rough, and the cast smooth and shining ; the radii, where the shell is not removed, are like cords laid on, and are not equal to the concave spaces between ; on the cast they are sharper, and not so prominent. (&.) Furrows distinct. 176. A. ROTIFORMIS, Sow., ccccliii. Pal. pi. vii., f. 1. Volutions six, exposed; radii numerous, equal, prominent, straight nearly the whole length, then suddenly bend towards the aperture; a row of tubercles near the outer margin of the whorls; a deep furrow on each side of a low, rounded keel ; aperture quadrate ; diameter five inches. This has a strong resemblance to A. Hawskerensis ; its distinguishing character is the plane keel and the deep furrows. The only one I have seen is in Mr. Bean's collection. 133 177. A. SOLITARIUS, Simp. Volutions five, exposed, outer whorl one-third the diameter of the shell, sides flatted ; radii numerous, equal, prominent, nearly straight to the outer margin of the whorl, then suddenly bend towards the aperture, equal to the intervening con- cave spaces ; keel rounded, strongly crenated, the furrows on either side nearly obsolete; aperture oblong quadrate ; diameter 1-J- inch. L.L., R.H. Bay. On the inner whorls of this ammonite may be seen a row of tubercles at a short distance from the outer margin. The shell, as far as it can be observed, appears very thin, and quite smooth and shining ; but very little of it remains, and the cast is roughish, exhibiting the ramifications of the septa rather rounded, and very numerous, covering nearly the whole surface of the shell with their meanderings. 178. A. SEMICOSTATUS, T. Sf B. Volutions five or six, exposed ; radii sharp, promi- nent, separated by concave spaces; delicately striated ; keel entire, between two distinct furrows ; aperture subquadrate ; diameter two inches. L.L., 25, R.H. Bay. This often occurs in large masses. In general the inner whorls are destitute of radii, but it is a variable species ; in some the radii are distant and much curved towards the aperture ; in others the sides of the whorls are very convex, and the keel without furrows. 179. A. ACUTICARINATUS, Simp. Volutions seven or eight, exposed ; radii separated by concave spaces, sharp, faint on the inner margin, gradually increasing towards the keel, where they 134 suddenly turn towards the mouth; keel slender, sharp, prominent, entire; aperture ovate; diameter 2 inohes. L.L., 25, K.H. Bay. This greatly resembles A. semicostatus, but the sides of the whorls are more rounded, the keel sharper and more prominent, and without any distinct furrow on either side. I formerly named this shell A. Youngi ; but I was after- wards reminded that another from the Speton clay (A. rotula, Sow.) had been named A. Youngi, by Mr. Bean, and described by Young previous to the publication of Sowerby's description. 180. A. ATJREOLUS, Simp. Volutions eight, exposed, outer whorl less than a quarter the diameter, sides regularly rounded ; radii numerous, nearly straight, sharp, not equal to the intervening concave furrows, terminate on the outer margin of the whorl ; keel rounded, depressed be- tween two slight furrows ; aperture roundish ; diameter one inch. L.L., 15, R.H. Bay. This ammonite, on the side, greatly resembles A. aureus, and the radii in places have a tendency to form two slight tubercles. The cast is smooth and of a golden colour. The shell is thin, smooth, and brownish, without any appearance of striae ; the ramifications of the septa are very simple and distant, at irregular intervals of two or three radii. On comparing a description I wrote of a specimen I received of Mr. Bean, labelled A. finitimis, I find it identical with the above. I also believe that Blake's A. spiratissimus is the same as my A. aureolus. They are all from the same bed, and are strongly marked to the very centre. 181. A. MULTANFRACTUS, Simp. Volutions seven or eight, exposed ; radii of the 135 cast sharp, bend slightly towards the aperture ; keel rounded, much depressed, furrows on either side shallow ; aperture ovate ; diameter 2| inches. L.L., 25, R.H. Bay. This comes near to A. semicostatus, but the sides are more regularly convex, and the keel and furrows are nearly obsolete. The little of the shell which remains appears wrinkled and coarse, and irregular striae crenu- late the keel. The septa are rather distant, being clearly separated by each alternate rib ; the radii on the innermost whorls split in two near the inner margin, and are strongly marked to the very centre. The innermost whorls are more slender in proportion than the outer whorls. 182. A. VALIDANFRACTTJS, Simp. Volutions, five or six, exposed ; outer whorl ,one- quarter the diameter ; radii of the cast sharp, straight, strong, prominent, form tubercles on the outer margin, then bend towards the aperture and terminate abruptly near a depressed rounded keel and two slight furrows, not equal to the wide concave spaces ; aperture roundish ; diameter 2 inches. L.L., 25, R.H. Bay. This is a strong robust species. The little of the shell which remains is of a dark colour without striae. 183. A. TURNEKI, Sow, pi. cccclii. Pal. pi. xii. Volutions five or six, inner ones half concealed, outer whorl more than one-third the diameter, sides flatted ; radii numerous, regular, bend towards the aperture, not equal to the intervening concave spaces ; dorsal furrows very distinct ; keel entire ; 136 aperture oblong subquadrate ; diameter 2 inches. L.L., 24, R.H. Bay. The little of the shell that remains is rough,, and with- out striae ; and the cast is smooth. The ramifications of the septa are numerous and rounded, but by no means so deeply indented as may often be observed. 184. A. IMPENDENS, r. <. B. Pal. pi. xxii. Volutions four or five, inner ones three-fourths concealed, outer whorl two fifths the diameter, slightly convex, inner margin overhanging the next whorl; radii prominent, straight, turn suddenly towards the aperture near the back ; keel very prominent, furrows on either side large ; aperture triangular; diameter three inches. L.L., 16, R.H. Bay. The radii on the whorls of this species vary much in their distance from each other in different specimens ; in some they are numerous, in others rather distant, and are separated by flat spaces. The inner edge of the whorls overhangs, and the outer edge is terminated rather abruptly by the groove on the side of the keel. 185. A. CONYBEARI, Sow. PI. cxxxi. Volutions many, exposed, sides rather inflated, outer whorl rather less than one-quarter the dia- meter ; ribs prominent, rounded, numerous, curve towards the aperture, equal to the rather angular spaces ; keel prominent, plane, betweeen two strong furrows ; aperture subquadrate. L.L., 24, Redcar, and R.H. Bay. 186. A. TARDECRESCENS, BlaJce, pi. v., f. 5. Much depressed ; volutions seven or eight, 137 exposed, sides flatly rounded, inner margin blunt, outer whorl one-fifth the diameter ; radii numerous, straight, or but slightly waving, bend suddenly to the aperture on the back, equal to the separating concave spaces, scarcely striated; keel smooth, furrows on each side distinct ; aperture subquadrate ; diameter 3 inches. In the first edition of this work, I took it as a variety of A. Conybeari, but I agree with Mr. Blake in con- sidering it a distinct species. It occurs in a nodular bed L.L. 2. of my section, on the beach near the town of R.H. Bay. 187. A. TENELLUS, Simp. Much depressed; volutions five, inner ones three- quarters concealed, outer whorl less than half the diameter ; radii separated by widish spaces, straight, turn suddenly towards the aperture near the back ; striae, or lines of growth, numerous, fine, beautifully sharp and distinct upon the keel, which they finely crenate; keel prominent, round, relieved from the sides of the whorl by a concavity; aperture tri- angular or ovate ; diameter 2| inches. L.L., R.H. Bay. This is a more elegant species than the last ; the radii are less prominent, and the groove on the side of the keel much natter. 188. A. STELLARIS, Sow., pi. xciii. Syn. A. BUCKLANDI, Simp. Volutions five, inner ones a quarter concealed, outer whorl one-third the diameter, thinnest near the back, sides rather convex, inner margin rounded, 138 overhangs the next whorl ; radii nearly straight as far as the outer margin, then bend towards the aperture, obtuse, equal to the intervening furrows, nearly obsolete towards the aperture; keel obtuse; aperture quadrate; diameter 12 inches. L.L., 23. This is one of the largest species of ammonites which occurs in our lias, and is. not uncommon in the lowest beds at E.H. Bay. Different specimens vary much in the strength of the radii, and, in the very large ones, the radii sometimes become nearly obsolete towards the aper- ture ; the inner edge of the whorl is rounded in such a manner as to expose the next whorl, which it overhangs ; the keel is often smooth, but in some specimens it is crenated. 189. A. BUCKLANDI, Sow., pi. cxxx. Pal. ]S1. 1. The A. Bucklandi of the Whitby dealers is the A. stellaris, Sow. It appears from Tate and Blake that the true A. Bucklandi occurs in a lower bed at Eedcar. Sowerby describes his shell as having five volutions wholly exposed and the aperture quadrate ; radii large and obtuse. 190. A. BISULCATU8, Bing. I have only a fragment sent me by Mr. Tate. The radii are like those of A. stellaris, the aperture square with the angles rounded. L.L., Eedcar. 191. A. BROOKI, Sow., pi. cxc. Pal. pi. vi., f. 4. In the Whitby Museum, there is a fragment from the Lower Lias at E.H. Bay, which I suppose to have be- longed to Sowerby 's A. Brooki. The radii are more bent, and the sides of the whorls are more rounded than in A. stellaris ; the aperture is transverse ; diameter of aperture three inches by 3 inches. 192. A. NODTTLOSUS, F. 4* B- Pal. pi. vi., f. 2. Volutions five, inner ones about one-fifth con- cealed, outer whorl about one-third the diameter, 139 sides flat ; radii separated by flattish concave spaces, straight to the outer margin of the whorls, where there is a row of tubercles, then turn to- wards the aperture ; keel crenated, grooves on each side distinct ; aperture subquadrate ; diameter two inches. This is from the lower beds of Lias at E.H. Bay ; the radii are only slightly elevated, and slender. The shell is thickish, and of a light-brown colour. The characters by which this ammonite is described, are nearly the same as those of A. subnodosus, but it belongs to a different family widely separated in time, and must be considered a different species. There is, in the Whitby Museum, the outer whorl of an ammonite, from the Lower . Lias at Robin Hood's Bay, 13^ inches in diameter. It has straight radii terminating near the angular back in blunt knobs ; the keel, and the deep furrows on its side, are well denned ; the aperture is oblong, and widest at the inner part of the whorls. 193. A. SAUZEANUS. Mr. Blake has sent me an ammonite under this name from beyond Slow-beck, E.H. Bay, one inch diameter, volutions six, innermost ones plain, slightly concealed, outer whorl more than one-third the diameter, inflated ; ribs obtuse, short, prominent, with blunt tubercles on the outer margin, separated by rather wide concave spaces ; back rounded with a slight rising or incipient keel ; shell smooth. Some of the ribs incline from the aperture which has induced Mr. Blake to associate it with A. resupenatus. Aperture ovate. I have two examples, an inch and four-tenths dia- meter, from the same locality, L.L., band 24, which greatly resemble the above, but they have a smooth keel between the distinct furrows. The ribs slightly incline from the aperture, and in some places split in two, so that one rib unites with two tubercles. 140 194. A. BIFRONS, Brug. Syn. A. WALCOTTII, Sow. Volutions five or six, inner ones one-fourth con- cealed, inner edge of the whorls nearly plane, rounded, or rather angular, then a broadish, shal- low, concentric furrow or depression, from whence proceed obtuse, crooked radii, separated by widish concave spaces; keel entire, furrow on each side large ; aperture oblong quadrate; diameter 6^ inches. This may readily be distinguished by the groove run- ning along the side of the whorls, and by the short, obtuse radii. On the inner whorls, however, the groove often becomes obsolete, and then the radii commence on the inner margin of the whorl ; the shell is thick and coarse, and the cast is smooth. In extracting the shell from the matrix, the keel often comes off, and then the siphuncle is beautifully displayed with constrictions at short intervals. This is one of the most abundant shells in the uppermost part of the Upper Lias. 195. A. HILDENSIS, Simp. Of the same size and type as the last ; but the back of the outer whorl is obtusely triangular. It is of frequent occurrence in the jet-rock, where A. bifrons is never found. 196. A. LEVISONI, Simp. Volutions five, inner ones but little concealed, outer whorl one-third the diameter, inner edge rounded ; radii sigmoidal, obtuse, equal to the in- tervening concave spaces ; keel entire, furrow on either side distinct; aperture ovate; diameter 1| in. 197. A. LATESCENS, Simp. Depressed ; volutions four or five, inner ones half concealed, outer whorl two-fifths the diameter, sides 141 regularly rounded ; radii waving, the last bend is towards the aperture, obtuse, distinct on the outer margin, on the inner whorls distant and nearly obso- lete ; keel sharpish, entire, furrows on either side distinct ; aperture ovate ; diameter l inch. The breadth of the whorls, the regular convexity of their sides, and the form of the radii, give this ammonite a strong resemblance to A. striatulus ; but it is destitute of striae, and has a distinct furrow on each side of the keel. 198. A. PINGUIS, Simp. Thickish ; volutions five or six, inner ones half concealed, outer whorl less than half the diameter, inner margin nearly perpendicular, sides regularly rounded; radii numerous, waving, strongest on the outer half of the whorl ; keel plane, obtuse, between two distinct furrows ; aperture ovate ; diameter 1| inch. This is much thicker than the last, and the radii more numerous ; the keel also appears to be constructed in a different way, so as to be knocked off with the shell ; whilst in A. latescens it remains perfect where the shell has been removed. It is of a brown colour, and shining. It is from the jet-rock of the Upper Lias. Mr. Clarkson's collection. IV. With a dorsal furrow only. 199. A. ANGTJLATUS, Sch. Syn. A. EEDCARENSIS, Y. fy B. Volutions five or six, inner ones, half concealed, outer whorl rather more than one-third the diameter ; radii prominent, diverging, straight along the sides of the whorl, then suddenly bend towards the aperture near the back, where they are terminated 142 by a narrow smooth space or furrow; aperture triangular, or subquadrate ; diameter three inches. The radii proceed from the inner margin of the whorls, and have the appearance of coarse plaits; the prominent angles on the back, and the absence of a keel, render this a highly characteristick species; the sides of the whorls are slightly convex, and the inner edge quickly rounded. It is very variable. I have a fragment of a specimen, twice as thick as some, and with coarse and irregular radii. I leave it at present as a variety. L.L., 26. 200. A. SULCATUS, Simp. Volutions much concealed, outer whorl nearly half the diameter ; radii strong on the inner margin of the whorl, then split in two or three, faint, twice bent ; an angular furrow on the back ; aperture triangular ; diameter three-eighths of an inch. This interesting little ammonite may be readily dis- tinguished from the rest by the angular furrow on the back, which is very distinct on the outer whorls, and becomes a mere line on the inner ones. It, like a great many other small and beautiful species, is from the lower beds of lias at Robin Hood's Bay. MALFORMATIONS. I may notice several malformations, which came under my observation all at once : Two specimens of A. elegan- tulus, which are in the form of a dish, with an ill-formed keel near the hollow side; one is 1 inch in diameter, the other three-quarter inch. Three more, which may be of the same species, are also hollow on one side, and round on the other ; the back is thin and rounded, and an imperfect keel is formed on the hollow side of the whorl. The inner whorls are more concealed than is generally the case in A. elegantulus, and the radii are less distinct. They are all from the Jet Rock. 143 There is also another, which I suppose to be A. Haws- kerensis ; on one side it has the characteristick radii of that species, but on the other they are nearly obsolete, and their place supplied with an imperfect crenated keel. The inner whorls differ nothing from the ordinary forms of this species. GASTEEOPODA. The animals which inhabit these shells, are so named, because they walk on their stomach. The common garden snail, and the periwinkle of our shores, are familiar examples. The muddy beds of Lias have been very un- favourable to the existence of these creatures, and in the previous edition of this work, I could not make out more than fifteen species. But Messrs. Tate and Blake, by their enthusiastick labours in the main bed of ironstone, in the Middle Lias at Eston, in the Tees valley, and more especially in the lowest beds of the Lower Lias, in that region, have recently brought up the number of species to eighty-four. To these we have added a few more. We may first notice the Trochoid or Turbinated shells. They feed on vegetables. Genus Trochus, Linn. The top-shaped shells. These have more or less a quadrangular aperture. Of many species noticed by Profr. Tate, as found by him in the Yorkshire Lias, no examples could be found in the collection he deposited in the Museum of Economic Geology in London, on leaving for Australia. I give the names to assist future researches. 144 Those with a slit in the outer margin, are called Pleurotomaria. Some have the base umbilicate as in Solarium, in others it is imperf orate. Trochus proper. 1. TROCHUS THETIS, Mun., Tate. Spire conical, height one-quarter of an inch, equal to the width of the flatted base, apex pointed ; whorls four or five, sides flatted, the spiral strise tuberculated by coarse lines of growth. L.L., w, North cheek of R.H. Bay, Huntcliff, &c. 2. T. REDCABENSIS, Tate, T. $ B., pi. x., f. 14. Whorls six, deeply channelled at the suture, decorated with three strong spiral strise ; height of spire two-tenths of an inch ; diameter of the concentrically striated base two-tenths of an inch. Lowest beds of Lias at Redcar. 3. T. EOBIGUS, Tate, T. $ B., pi. x., f. 3. Whorls six, with the shell angular, shewing a central line ; cast of interior, smooth, round ; length of spire three -tenths of an inch ; width three-twentieths of an inch. L.L., upper part of the indurated bands, R.H. Bay. Pleurotomaria. A slit in the aperture. 4. T. ANQLICUS, Sow. Syn. SIMILIS, Sow. Turriculated, base umbilicate, flatly rounded, and strongly striated, width nearly equal to the height of the spire; whorls five, rhomboidal, very strongly crenated on the edge, a keel in the middle 145 between two furrows, coarsely, spirally, and longi- tudinally striated; length two inches. The whorls of the cast are rounded; and entirely smooth. It is from the lowest beds of the Lower Lias, R.H. Bay ; Redcar. 5. T. PUSILLUS, Simp. Length three-quarters of an inch, equal to the width, base rounded ; five rounded tumid whorls, last whorl large, having on the middle a rounded keel between two concave furrows, the lower furrow the larger. A cast, with a small bit of the shell at the base strongly striated. L.L., w, E..H. Bay. 6. T. PROCERUS, D'Orb, Tate, T. & B., pi. ix., f. 24. Whorls seven or eight, rhomboidal, concentrically and transversely striated, with a groove on the angle, height one and three-quarters of an inch, width seven-tenths of an inch ; base protuberant, con- centrically striated. L.L., w, R.H. Bay. This is a very beautiful and well-defined species, the transverse striae are the most distinct on the upper whorls, and are oblique. 7. T. FOVEOLATUS, Desl., Tate, T. $ B., pi. ix., f. 2. Whorls five, strongly, concentrically, and trans- versely striated ; on the upper whorls deeply grooved. M.L., ironstone, Staithes. 8. T. HELICINOIDES, Ro., Tate, T, $ B., pi. x., f. 7. Ovate, turriculated, width of base three-quarters of an inch, equal to the height, apex obtuse, base convex, with 16 strong T concentrick striae, inter- vening spaces wider towards the centre ; whorls L 146 five, subquadrate, lower edge rounded, then a con- cave band with six spiral striae and a narrow groove on the upper margin, then a broad concave band, and a narrow elevated sutural band ; the whole shell is decussated by spiral, and longitudinal, wav- ing striae. Uppermost part of the M.L., Hawsker. 9. T. TECTARIUS, Tate, T. Sf B., pi. ix., f . 26. Whorls five, rather angular; upper side sloping, with a distinct groove on its lower edge ; lower side concave, coarsely and concentrically striated ; height of spire seven-tenths of an inch, width of base five- tenths of an inch. Lowest Lias, Redcar. In another example the whorls are rhomboidal and spire pointed. 10. T. UNDOSUS, Des., Tate, T. $ B., pi. ix., f. 1. This I have not seen. It is from the ironstone at Eston, and is very similar to T. Anglicus. 11. T. CONCAVUS, Martin, Tate, T. Sf B., pi. ix., f. 27. Whorls four, the cast much inflated, flatted in the middle concentrically striated ; height three- tenths of an inch, width two-tenths of an inch. Lowest Lias, Redcar. 12. T. RUSTICTJS, Des., Tate. This has not been preserved in Tate's collection. It occurs in the Cleveland Main Ironstone bed, and is three inches in diameter, but so imperfectly preserved as not to admit of particular description. Tate assimi- lates it to T. Anglicus. 13. T. BASILICUS, C. # D., Tate. Very similar to T. Anglicus, but of small size, umbi- licus wide. Lowest Lias, Eedcar. 147 14. T. HENNOCQUI, Ter., Tate. Whorls five, flattish, concentrically, and irregu- larly striated ; base flattish, margin rounded ; height two inches and seven -tenths, equal to the width. Lowest Lias, Redcar. 15. T. OBESULUS, Tate, T. & B. f pi. x., f. 6. Whorls four, rounded, concentrically striated; apex obtuse ; base flattish, umbilicate, concentri- cally striated, height one inch, equal to the width. Lowest Lias, Market Weighton. Helicina, or those which approach in form to the Helix. 16. T. EXPANSTJS, Sow. Syn. HELIX CIRROIDEA, Y. & B. Spire much depressed, acuminate, base deeply umbilicate ; whorls five or six, last one large, lower part rounded, upper part concave, then a ridge, concave at the suture ; striae spiral, numerous,, fine, distinct, often waving, crossed by lines of growth ; aperture gibbous ; width of the base one inch. Cast smooth and shining, in which state Young com- pares it with Helis ericetorum. It has had various names. Sowerby first named it Helicina expansa. It it is closely allied to Pleurotomaria. Uppermost part of the Middle Lias at Hawsker, Eston, &c. 17. T. CONSOBRINUS, Tate, T. & B., pi. x., f . 2. Spire very much depressed, acute ; whorls five, last one large, lower part rounded, upper part concave with a rounded rim at the suture ; dia- meter one inch. M.L., a. This is well distinguished from the last by its having no striae, as well as by the greater flatness of the spire. 148 It is from the main ironstone bands at Eston. Tate says it is marked with curved transverse lines. 18. T. SOLABIOIDES, Sow ., pi. cclxxiii. ; T. & B., pi. x., f . 2. Spire very much depressed, base rounded, with a depressed central area ; whorls five or six, upper part with a large concave channel ; apex acute ; spiral striae obsolete ; diameter three-quarters of an inch. This is even more discoid than either of the above. Lowest beds of Lower Lias at Eedcar. 19. T. R6TELL,aEFORMis, Dun., Tate. No example, and / very doubtful. Lowest Lias, E-edcar. 20. T. NUCLERES, Ter., Tate. No example, and very doubtful. Lowest Lias, Cliff. Solarium ; Tate's Discohelix. 21. T. OPPELI, Ma., Tate, T. $ B., pi. x., f. 8. Discoid, much depressed, whorls six, smooth, diameter three-tenths of an inch. Lowest Lias, Eedcar. 22. T. LIASINUS, Dunks., Tate. L.L. No example. 23. T. STRIATUS, Pic., Tate, T. fy B., pi. ix., f. 8, 9. Much depressed, whorls five or six, exposed ; ribs numerous, pass over the back ; diameter two- tenths of an inch. Lowest Lias, Redcar. 24. T. ARATTJS, Tate, T. $ B.,, pi. ix., f. 5. Whorls four; transverse ribs, numerous, distinct, pass over the back undivided ; aperture transverse ; diameter quarter of an inch. M.L., Saltburn, &c. This is well distinguished from the next by the ribs. On one specimen I observe some obsolete spiral striae. The spire is scarcely so much depressed as in the next. 149 25. T. BELLTTLUS, Tate. Whorls four, with very fine, numerous, spiral striae, crossed by lines of growth, amounting in some places to ribs ; aperture very transverse, lunate ; diameter one-fifth of an inch. The back is regularly convex, and the spire is so much depressed that it might be taken for an ammonite. Lower beds of Middle Lias at Staithes. 26. T. SEMICLAUSUS, Tate, T. & B., pi. ix., f. 14. < ' Shell small globose ; spire sunk, base convex, umbi- licus narrow, not exposing the inner whorls ; whorls four, convex, embracing, ornamented with numerous, fine, flexuous threads; diameter and height one-tenth of an inch." Tate. L.L., 27, Eedcar. Genus Turbo, Linn. There is no well-defined line of separation between the genera Trochus and Turbo. In general the former has a quadrate aperture and the whorls more angular. The latter has the aperture more rounded and the spire more perfectly and regularly turbinated. In some species it is greatly lengthened. Spire short. Turbo proper. 1. T. SOLARIUM, Pic., Tate, T. $ B., pi. ix., f . 16. Height scarcely equal to the width ; whorls four, rounded, smooth, channelled at the suture; diame- ter of the base quarter of an inch. L.L., Redcar. 2. T. LATILABRUS, 8tol. t Tate, T. fy B., pi. ix., f. 15. Whorls five, quickly rounded, apex obtuse ; last whorl half the spire ; height of spire three-tenths of an inch, scarcely equal to the width of the base. M.L., a, Eston. 150 3. T. LINEATUS, Moor, Tate, T. & B., pi. ix., f. 20. Whorls six, rounded, with numerous, strong spiral striae ; last whorl about half the length of the spire, which is seven -tenths of an inch ; dia- meter of base five-tenths of an inch. M.L , a, Upleatham. 4. T. RETICULATUS, Moor, Tate. Depressed, four rather angular whorls, with reticulated striae ; base convex, striated, diameter four-tenths of an inch, height of spire three-tenths of an inch. L.L., 16, Redcar. 5. T. WILSONI, Tate, T. fr B., pi. x., f. 5. Depressed; Whorls four, convex, spiral striae fine; base convex, umbilicate, concentrically striated ; width two-tenths of an inch, equal to the length of the spire. L.L., 16, Redcar. 6. T. CYCLOSTOMA, Benz., Tate, T. j- B., pi. ix., f. 19, 20. Conical ; whorls five, rounded below, upper part rather flatted, channelled at the suture ; apex acute ; spiral striae numerous, distinct, reticulated by trans- verse lines of growth ; height of spire three-eighths of an inch, greater than the width. M.L., a, and ILL., 8, Hawsker, &c. 7. T. TUKBINATUS, Moor, Tate. Conical, height three-eighths of an inch, greater than the breadth ; apex acute ; base rounded, umbilicate ; whorls five, regularly rounded. M.L., dj Eston. 151 8. T. ACICULUS, Stol., Tate, T. & B., pi. ix., f. 22. Mr. Tate says this differs from T. turbinatus, but I cannot see on what his opinion is founded. All my specimens are from Mr. Tate. 9. T. PHILEMON, D'Orb, Tate, T. $ B., pi. ix., f. 25. Spire much depressed ; base umbilicate, crimped, breadth one-eighth of an inch, greater than the height ; whorls four, smooth, flatted, last whorl with a spiral groove on the edge. Lowest beds of L.L., at Redcar. 10. T. TENTHS, T. fr P. Tate. Whorls three, turriculated, last whorl large, height of spire one-tenth of an inch. Lowest beds of Lias, Foxton. Littorina, shore shells. 11. T. NANUS, Martin, Tate, T. fr B., pi. ix., f. 17. Ovate, whorls four, convex, with about eighteen strong longitudinal ribs, crossed by very fine, faint spiral striae, height of spire two -tenths of an inch, greater than the width. L.L., Redcar. 12. T. SORDIDTJS, Tate, T. fr B., pi. x., f. 19. Conical, height one-fourth of an inch, equal to the width, base imperf orate, striated in the middle, whorls five, rather inflated, convex, smooth or obscurely and spirally striated. Lowest beds of Lias at Redcar. 13. T. ELEGANS, Huns., Tate, T. & B. y pi. ix., f. 30. Conical, height one-third of an inch, width at the base one-fifth of an inch ; base convex, imper- forate, concentric striae, strong, reticulated ; apex obtusely pointed ; whorls seven, with two strong 152 spiral ribs in the middle and a smaller one above, deeply channelled at the suture, spiral striae numerous, distinct, reticulated, interrupted. L.L., Redcar, &c. 14. T. CHAPTTISI, T. & P., Tate, T. & E., pi. ix., f. 29. No example. <( Whorls angulated, sub-imbricating,, with granular ribs." L.L., 23, Redcar. Tate. 15. T. SELECTUS, C. & V., Tate. Whorls six or seven, flat, with a strong elevated ridge on the lower part, imbricating, longitudinally striated ; base convex, strongly and concentrically striated, width six-tenths of an inch ; height of spire one inch. L.L., Marsk. 16. T. ACUMINATUS, C. & D., Tate, T. minute ; total length one-sixth of an inch." L.L., 27, Cliff. 40. T. BEBTHAUDI, Dum., Tate. Whorls ten or eleven, rather inflated, with numerous varices or strong striae. L.L., 25, Eedcar. 41. T. UNICINGULATUS, Ter., Tate. Many whorls, slightly inflated, smooth. L.L., 26, Redcar. 42. T. CABUSENSIS, D'Orb, Tate, L.L., w, E.H. Bay. No example. 158 43. T. FOVEOLATUS, Tate, T. & B., pi. ix., f. 12. I have no example. The following is Tate's des- cription : " Shell conical, elongated ; whorls twelve, nearly flat, or slightly convex, separated by a narrow, but well denned suture ; the anterior whorls with thicker cortse, but separated into granular nodulations by trans- verse sulci." L.L., w, Ayton. 44. T. SEMITECTUS, Tate, T. fy B., pi. ix., f. 23. Whorls nine, flatly covex, longitudinally striated ; length four-tenths of an inch, diameter of base two-tenths of an inch. M.L., a, Eston, &c. This can scarcely be placed amongst those which have the spire elongated. 45. T. COLLENOTI, T. & P., Tate. Whorls seven, rounded, smooth, a depressed plica or varix on the body whorl continued to the apex where the number is increased ; apex obtuse, height of spire less than three times the width, three-tenths of an inch. L.L., R.H. Bay. Genus Nerita, Linn. Spire very short, last whorl large. Nerita proper. 1. N. ALTERNANS, Tate. T. Sf B., pi. x., f. 16. Much depressed ; whorls three, last whorls very large, strongly striated spirally, with a fine strias between the larger, crossed by numerous lines of growth ; width of the mouth seven-tenths by six- tenths of an inch ; height of spire three-tenths of an inch. M.L., a, Eston. Natica. 2. N. BUCCINOIDES, Y. $ B. T. & B., pi. ix., f. 11. Spire depressed; height 1^ inch, equal to the 159 width; whorls five or six, turriculated, convex; last whorl very large, base and side convex, upper margin angular, a broad concave band to the suture which is slightly channelled, covered by fine reticu- lated and punctured striae. U.L., 5, Whitby. 3. N. NEGLECTA, Simp. Syn. MINUTA ? A minute species, having nearly the same form as the last. It is ornamented with -exceedingly fine, unequal, hair-like spiral striae, to be seen only under a powerful lens. Cast of interior smooth. Found in the greatest profusion in a band above the Jet Rock, reminding one of the vast number of small turbinated shell which may be seen devouring the laminaria at very low tides. U.L., 6, Whitby, &c. 4. N. FUSCA. Of the same form as N. buccinoides, but entirely smooth, and the whorls seem to imbricate. It is of a lightish brown colour. U.L., Whitby. 5. N. PURPUROIDES, Tate. T. & B., pi. x., f. 13. No example. Tate describes it as "ovately globose, pyriform, spire oblique, whorls few, body whorl angulated medially, posterior half concave, anterior part convex; surface covered with flexuous lines and rugose ; length one and seven-twelfths of an inch, greatest breadth one and one- twelfth of an inch. The following small shells probably belong to the Genus Tornatella, Lamark, and which Mr. Tate places under the Sub-genus Actasonina. 1. TORNATELLA MARGIN AT A, Simp. Whorls four, turriculated, last whorl two-thirds the whole length, with a ridge or elevated line on 160 the upper margin, subcylindrical ; length of spire one-fourth of an inch. L.L., v, R.H. Bay. 2. T. SINEMUNENSIS, Martin, Tate. No example. L.L., E/edcar. 3. T. FRAGILIS, Dun., Tate. Whorls four, turriculated, last whorl subcylin- drical, smooth, upper margin sharply defined, three- fourths the length ; length one-seventh of an inch. L.L., 13, R.H. Bay, Redcar, &c. 4. T. CHRYSALIS, Tate, T. pi. xii., f. 3. Equivalve, subequilateral, transverse, ovate ; beaks small, recurved, approximate ; disc smooth ; transverse striae numerous, fine, unequal ; width nearly an inch. Like a Cyclas, or ventricose Tellina ; and there is a small fold or faint depression at the base of the posterior side. Hard bands M.L., Hawsker, &c. Genus Tellina. Generally inequivalve and com- pressed. 1. TELLINA FABALIS, Simp. T. $r B., pi. xii, f. 5. Ovate, depressed, equivalve, inequilateral ; con- centrick striae numerous, fine ; obsolete striae radiate 206 from the beaks ; width four-tenths of an inch, depth three -tenths of an inch. M.L., a, Hawsker, &c. 2. T. TENTHS, K. $ D., Venus. T. CYCLIFORMIS, Simp. Suborbicular or ovate ; rather tumid at the beaks ; transverse striae or lines of growth numerous, fine, distinct. A neat, shining little shell, like a Cyclas, from the uppermost beds of Lias at Peak, where it is rather plentiful. 3. T. STRIATA, Simp. Ovate, transverse; concentrick striae, numerous, with stronger lines of growth, rough ; width three- quarters of an inch. L.L. 4. T. CARDINOIDES, Tate. T. fy B., pi. xvi., f. 8. " Ovate-trapezoid, subinequilateral, subventricose, concentrically ridged ; rounded in front, posterially subtruncated ; ventral margin curved; umbones small, intermedial, subacute; lamellae very small, escutcheon linear." 5. T. PUMILA, Mun., Tate. M.L., a, Hawsker. No example. 6. T. SUBGLOBOSUM, Tate. ( Unicardium) . Ventricose, beaks small, incurved, approximate ; anterior side boldly rounded, short ; posterior side the wider, diminished; concentrick striae numerous. M.L., a, Redcar. 7. T. GBOCIANA, Br., Tate. No example. Thracia. 8. T. GLABBA, Ag., Tate. Ovate, much depressed, transverse ; anterior side 207 the shorter, sharply carinated ; posterior side rather expanded; base con vex; disc smooth, with unequally elevated ribs of growth, the whole covered with very numerous, fine, concentrick striae; width an inch. ILL., Whitby. Closely allied with T. striata. Tancredia. 9. T. DIONVILLENSIS, Ter., Tate, T. & B., pi. xiv., f. 12. Rather inflated, width twice the depth ; posterior side the longer, elliptical, slope convex ; anterior side excavated under the beaks, then produced in a para- bolick curve; angle at the beaks more than a right angle ; base convex. U.L., 5&, Salt wick. Mr. Tate gives the following notice of this specimen , Hawsker. 8. M. MEDI^VA, Simp. Subtriaugular, ventricose, transverse ; anterior side very short, obtuse ; posterior side long, obtusely pointed ; base convex ; beaks recurved ; areola larg*e, cordate. L.L., R.H. Bay. This has many of the characters of the last, but quite smooth ; the anterior side is short er, and very obtuse ; the posterior end is narrower. There is also a broad, slight, longitudinal depression or constriction from the beaks. 9. M. PUNCTATA, Simp. T. fy B., pi. xiv., f. 10. Subtriangular, transverse ; beaks approximate, incurved ; anterior side short, angular, with a broad longitudinal constriction ; posterior side elongated ; transverse striae numerous, dotted, or reticulated. This is rather a large shell. With a lens may be observed numerous fine dots, which, in places, run into each other longitudinally. It it from the pyritous band in the Lower Lias at R.H. Bay, so rich in other fossils. A bit has been broken off the posterior end. 10. M. DONACIFORMIS, Ph. Subtriangular, transverse; beaks incurved, con- tiguous ; anterior side short, rounded, with a longitudinal plait or depression ; posterior side elongated, depressed ; base convex ; transverse striae obsolete. This is one of the most abundant shells in the upper part of the Upper Lias ; but it is seldom found perfect. 214 It appears to have burrowed in the mud,, the sharp side being generally found uppermost. The largest specimens are about 2 inches wide,, and 1 inch long. Some are much depressed, others are ventricose, and the constriction nearly obsolete. 11. M. ROTUNDATA, Ph. Ovate, ventricose, transverse, anterior side short, boldly rounded ; posterior side rounded, attenuated ; posterior slope convex from the beaks ; base con- vex ; beaks incurved, contiguous ; areola deep, transverse, reniform ; width two inches, depth 1J inch, thickness an inch and one-eighth. It occurs very sparingly in the uppermost divisions of the Upper Lias, along with the last. The front of some is less regularly convex, being protruded towards the base. ILL., 1, 2. Whitby. 12. M. INTERMEDIA, Simp. Ovate, transverse ; anterior side short, regularly convex ; posterior side elongated, rounded, rather concave, behind the beaks ; base convex ; beaks rather small, contiguous ; areola narrow ; striae numerous, regular, granulated, transverse; width 2^ inches, depth 1^ inch, thickness seven-eighth of an inch. This is rather an elegantly shaped species, in some the striae amount to ribs. They also vary in the length and depth of the posterior end. They are rather abun- dant in the main ironstone beds of the Middle Lias. 13. M. FERRUGINEA, Simp. Ovate, inaequivalve, inequilateral, rather de- pressed about the beaks ; anterior side rounded, 215 little excavated under the beaks ; posterior side the longer, rounded, slope convex ; base convex. This is a very ovate shell, the beaks being a. little elevated. A smooth cast. It comes nearest, to M. intermedia. Width 3 inches, depth seven-eighth of an inch, thickness an inch and one-eighth. Ironstone bands of the Middle Lias, Grosinont. 14. M. LEVIS, Simp. Ovate ; beaks incurved, small; areola beneath, small ; anterior side short, tumid, rounded ; pos- terior side elongated, rounded, depressed ; base convex ; transverse striae irregular, granulated ; cast smooth ; width 2 inches, depth 1-^ inch. This is an abundant shell in the middle of the Middle Lias ; stratum p of my section. They are very regular, but some are more ventricose, when they approach to M. rotundata. 15. M. SUBTRUNCATA, Simp. Anterior side shorter than in the last, and the posterior side more depressed and attenuated. From the same bed. M.L.,^>. 16. M. MACULATA, Simp. Subquadrate ; anterior side short ; posterior side depressed, truncate ; base convex. Lowest beds of Middle Lias. The length of this species is greater in proportion to the width than is usual in this genus. The shell is thin, and spotted with white, and has many irregular undu- lations and lines of growth. Mr. Tate has comprehended under this species, M. sebachii, but his figure pi. xiii., f. 3., indicates a much longer posterior side. The example he has sent me has fine striae crossing each other in various directions. 216 17. M. OVATA, Tate's MSS. Ovate, rather ventricose, nearly equilateral ; anterior side the shorter, and more obtuse, both convex ; base convex ; beaks small, incurved ; roughly striated. L.L., R.H. Bay. 18. ./EQUALIS, Simp. Subgequilateral, posterior side the longer, anterior side much produced towards the base, convex ; beaks prominent ; middle of the side flatted, trans- versely and obsoletely striated. ILL., Whit by. 19. M. CONCAVA, Simp. Depressed, subtriangular, anterior side short, angular ; posterior side long ; base more or less concave ; width two inches, depth 1^ inch. Pyritous band. L.L., ?/, R.H., Bay. It much resembles a depressed variety of M. donaci- forinis. 20. M. LIASINA, Sch., Tate. Very transverse ; anterior side short, rounded ; posterior side elongated, little diminished, rounded ; base convex ; beaks depressed ; coucentrick striae fine, smooth ; width two inches and three-eighths, depth an inch and one -eighth. Lowest beds of Lias at Redcar. One sent me by Mr. Tate, very much resembles the preceding one, with the concave base. 21. M. CRASSA, Ag., Tate. Ovate, ventricose, transverse ; anterior side short, bluntly rounded ; posterior side tumid, convex ; 217 base flatly convex r line behind the beaks con- cave; width an inch and seven -eighths, depth an inch and one-eighth. Lower Lias, 23, Redcar. 22. M. GALATHEA, Ag., Tate. Subtriangular, tumid on the anterior part, trans- verse; anterior side short, boldly rounded, posterior side elongated, depressed and attenuated ; base and posterior slope nearly straight. L.L., 23, Redcar. 23. M. MTJNDULA, Tate, T. $ B., pi. xii., f. 11. Depressed, ovate ; width nearly twice the depth, subequilateral, anterior side the shorter, both ends rounded, and of equal width ; base flatly convex ; beaks small, depressed ; smoothly and concentrically striated. A handsomely shaped shell,, from the lowest beds of Middle Lias. Huntcliff, Staithes, &c. 24. M. CONCINNA, Tate, T. fy B., pi. xi., f. 1. Much depressed, width about twice the depth, both ends rounded ; base flatly convex ; anterior side the shorter ; beaks small, contiguous ; striated and granulated. M.L., a, Eston. 25. M. CONTRACTA, Simp., T. fy B., pi. xvi.., f. 9. Equivalve, for half the width sub-cylindrical ; anterior side very short, obtuse ; posterior side angular ; width more than twice the length ; width 1^ inch, length seven-tenths of an inch, thickness seven-tenths of an inch. U L., Whitby. 26. M. LUNULATA, Tate, T. $ B., pi. xii., f. 10. ff Transversely ovate, very oblique, umbones approxi- 218 mate, small, incurved, pointed, anterior esclmcheon large, cordate ; anterior side short, truncated j posterior rounded and attenuated ; transverse strise numerous, irregular." Tate says that it is my Pholadoniya rostrata. M.L. 27. M. DUNKERI, Ter. y Tate. Widely ovate, with obsolete transverse strise ; anterior side rather attenuated, rounded ; posterior side much the larger, expanded ; base convex ; width one inch and seven-tenths, depth eight-tenths of an inch. L.L., 27. 28. M. GIBBOSA, Eth. L.L., Eedcar. No example. 29. M. SUBL^EVIS, Tate, T. & B., pi. xii., f. 6. " Shell subtrigonal, ventricose, thin, slightly inequilateral ; urnbones inflated, depressed and involute, nearly central ; anterior side rounded, posterior side truncated, attenuated ; front margin much curved, lunule broad, shallow ; surface with fine, and closely arranged ridges of growth ; acute anteriority ; depressed on the posterior side ; breadth 3| inches, height three inches, thickness nearly two inches." 30. M. VENTRICOSA, Simp. Subtriangular, subequivalve, ventricose ; anterior side short, obtuse ; posterior side sharp and cutting., ovate ; beaks approximate, recurved, from whence proceed to the base a broad, rather oblique de- pression ; transverse striae obsolete ; length one- inch ; width 1^ inch. L.L., R.H. Bay. 219 Sanguinolaria. 31. M. ELEGANS., Ph. Ovate, depressed, transverse ; posterior side the- longer ; transverse striae coarse. 32. M. VETUSTA, Ph. Trapezoid, transverse ; anterior side short ; pos- terior side enlarged ; transverse plaits lamellar. L.L., R.H. Bay. Genus Mya, Linn. Open at both ends. Hinge variable. 1. MYA ANTIQUA, Simp. Trapezoid, depressed, transverse, posterior side the longer, both ends boldly rounded ; base a little convex ; beaks incurved, wide ; transverse ribs nearly straight in the middle, curving round the ends ; shell thin, scaly ; width 3 inches, depth 1-J- inch. The hinge is not well displayed. There is another smaller valve imperfect on the same nodule, along with Am. Hawskerensis. Upper bed of Ironstone M.L., Hawsker Bottoms. 2. M. ^QUILATERALIS, Simp. Subequilateral, very transverse ; beaks small r incurved ; area behind the beaks very wide and spreading ; anterior end attenuated, rounded, pos- terior end imperfect ; width 2^ inches, depth three-quarters of an inch, width across the beaks three-quarters of an inch ; shell transversely and numerously striated. 220 Probably from the Lower Lias, with Lima novem- costata. 3. M. HISPIDA, Simp. Very inequilateral, very transverse ; posterior side much produced, slightly curved upwards, upper and lower sides nearly parallel ; transversely striated, and covered over with fine points ; width nearly four times the length. M.L., Ironstone bands, Hawsker Bottoms. This is so transverse, that it has a good deal the ap- pearance of a blade of a knife ; but rather tumid about the beaks. 4. M. LITERATA, Sow., pi. CCXXiv. Ovate, subequilateral, posterior side the longer ; beaks approximate ; striae meeting in the middle of the disc at an acute angle, form the letter V. L.L., K.H. Bay. 5. M. ELONGATA, Eomer, Tate. Subrectangular, very transverse, anterior side short, rounded, posterior side elongated, beaks small, incurved ; upper and lower sides nearly parallel ; transversely striated ; width 2 inches, depth one inch. L.L., ?/, R.H. Bay. 6. CONCINNA, Tate, T. $ B., pi. xi., f. 1. Rather depressed, anterior side the shorter, boldly rounded more than a semicircle, posterior side the narrower, rounded, base flatly convex ; beaks small; width two inches and three-tenths, depth one inch. M.L., , Eston. 221 7. M. LONGA, Bur., Tate, T. Sf B. f pi. xi., f. 11. Ovate, anterior side much the shorter, full and boldly convex ; posterior side narrower, convex ; line behind the hinge concave ; beaks large, trans- versely striated ; length four inches, depth two inches. M.L., a, Eston. Genus Pholadomya. Intermediate between My a and Pholas, as the name indicates. Anterior side, for the most part, ventricose, with ribs radiating from the beaks ; posterior side depressed. Rather common in the Lower Lias. 1. PHOLADOMYA CONCINNA, Simp. Ovate, transverse ; beaks strong, obtuse ; an- terior side short, obtuse ; posterior side produced, depressed, angular ; base convex ; transverse striee numerous, distinct, unequal ; width twice the length. A handsome shell from the L.L., 23, E-.H. Bay. 2. P. AMBiGUAj Sow, pi. ccxxii. Syn. P. PRODUCTA,, Simp. Subrhomboidal, transverse ; anterior side short, rounded ; posterior side produced, rounded, gaping ; beaks small ; oblique ribs radiating from the beak, obsolete ; transverse ribs obsolete ; width four inches, length 2 inches. M.L. 3. P. RECURVA, Simp. Ovate, transverse, beaks incurved, approximate over a deepish posterior sinus, or channel ; anterior 222 side short, obtusely rounded ; posterior side lengthened, diminished, slightly recurved ; base convex ; transverse striae irregular ; six or seven ribs diverging from the beaks, indistinctly muri- cated ; width three inches ; depth one inch and seven-eighths ; thickness 1^ inch. Ironstone bands, M.L., Hawsker. 4. P. SIMPSONI, Tate, T. fy B., pi. xii., f. 1. Syn. P. GIBBOSA, Simp. Oblique, transverse, gibbous ; beaks approximate, incurved, prominent, obtuse ; anterior side very .short, obtuse ; posterior side recurved, attenuated ; about eight or nine muricated ribs diverging from the beak ; coarsely, transversely striated ; width 2^ inches, depth two inches, thickness across the beaks 1 inch. M.L., a, Hawsker. Mr. Tate has given the following description of this shell : " Shell ovately triangular, the ventral margin much arched and strongly incurved behind the umbones ; umbones nearly terminal, and incurved, obtuse ; es- cutcheon very large; surface ornamented with about seven oblique diverging and nodulous ribs, and with concentrick folds and striae/' P. 399. 5. P. DECORATA, Ziet., Tate. Yentricose, transverse ; anterior side short, boldly rounded ; posterior side obtuse, rounded ; base con- vex; upper side concave; beaks short, incurved, contiguous ; decorated with numerous transverse strige, and about ten slightly muricated diverg- ing ribs ; width 3| inches ; depth three inches ; 223 thickness two inches and three-eighths. L.L., ?/, Huntcliff, &c. 6. P. LUNATA, Simp. Gibbous, transverse ; beaks very large, incurved, contiguous, obtuse ; anterior side obtuse ; posterior -side large, depressed, rounded ; transverse strise fine, numerous, distinct ; longitudinal striae on the beaks only. The anterior side, base, and posterior side a regular curve ; width five inches, length 3-J- inches. M.L., a, Hawsker. Mr. Tate's description : " Transversely oval, elongated ; .umbones gibbous, very large, ante-medial ; anterior side produced, inflated ; margin regularly rounded, front margin much curved ; posterior side attenuated, elon- gated, obtusely pointed ; dorsal line deeply incurved behind the umbones. Surface ornamented with three faint oblique ribs, and concentrick rugse and strise. Distinguished by its elongated form, few ribs, and the deep saddle-like depression behind the umbones. " Another very like this . in general form, occurs in the Lower Lias at Robin Hood's Bay. It is less deep in the anterior half, and broader and more compressed in the posterior. With the exception of a few obsolete radii on the beaks, it is without ribs or strise ; width four inches and seven-eighths, depth 2| inches, thickness one inch and seven-eighths. It may be named P. selenata. .7. P. LJEVIS, Simp. Triangular, transverse; anterior side ventricose; posterior side acutely triangular, much compressed ; base convex ; beaks moderate, incurved, contiguous ; areola beneath, small ; width three inches, depth two inches: thickness an inch and four-tenths at 224 the anterior side; transverse strise obsolete; shell coarse and scaly. M.L., ironstone, Hawsker. 8. P. OBTTJSALIS. Rhomboidal, ventricose, transverse; anterior side short, obtuse, oblique, curving regularly with the convex base; beaks small, approximate, incurved over a small areola; width 1 inch; depth nearly the same. M.L., p, Hawsker. 9. P. GLABRA, Ag., Tate. Subquadrate or ovate, ventricose; anterior side boldly convex; base slightly convex; beaks con- tiguous, rounded ; concentrically ribbed on the upper part, and with about seven obsolete ribs radiating from the beak; conceritrick stria? numerous, fine. Lowest beds of Lias at Redcar and R.H. Bay. 10. P. COSTATA, Simp. Sub-rhomboidal, ovate ; beaks incurved, obtuse ; areola very large, cordate, with two or three obsolete ribs ; about nine oblique, diverging ribs on the disc, separated by widish concave furrows ; transverse striae coarse, irregular. M.L. 11. P. GALLINA, Simp. Sub-rhomboidal or ovate, ventricose ; beaks con- tiguous, incurved, pointed, small, oblique ; anterior side very short ; areola very large, impressed, cordate, divided by a prominent keel ; posterior slope convex ; base convex ; length and breadth about l inch. M.L., jt>, Hawsker. 225 12. P. ROSTELLATA, Simp. Transverse, ovate, very oblique ; beaks incurved, pointed, very oblique ; anterior side short, oblique, with a sharp process, or keel beneath the beaks ; posterior side long, rounded ; . transverse striae numerous, irregular ; width nearly equal to the length. M.L. With the exception of the process in the front, it corresponds with Phillips' figure of P. obliquata. PL xiii., f. 15., Yorks. 13. P. ROSTRATA, Simp. Subquadrate ; beaks contiguous, small, incurved, pointed, projecting over the front ; areola large, cordate, keeled towards the base ; anterior side truncate, nearly a right angle with the line of the hinge ; base and posterior side rounded. M.L., s. 14. P. SCUTULATA. Subtriangular ; anterior side truncate, forming a large, flat, heart-shaped shield, with a keel towards the base, and two or three coarse ribs on the outer edge, with numerous, concentrick striae ; beaks much elongated, incurved, with a cutting edge, contiguous, with a concavity behind ; posterior side circular, much compressed ; base convex ; three or four coarse, muricated, trans- versely striated ribs, diverging from the beaks ; width one inch and five-eighths, depth one inch and seven-eighths, breadth across the shield one inch and three-eighths. L.L., R.H. Bay. Q 226 Longer than wide. 15, P. ELONGATA, Simp. Ovate, ventricose ; beaks long 1 , contiguous ; posterior side angular; indistinctly striated ; length If inch, width l inch. L.L., R.H. Bay. Another four inches long, and two inches wide, may be the same. 16, P. TRUNCATA, Simp. Ventricose, beaks long, contiguous ; anterior side truncated ; areola large, cordate ; posterior side short ; transverse stride numerous ; four longitu- dinal ribs, diverging from the beaks ; length 3^- inches, width 2^- inches. L.L., R.H. Bay. Much resembling the last. 17, P. ANTIQUATA, Simp. Triangular, oblique, ventricose ; anterior and posterior sides flat ; longitudinally and transversely striated ; length 3^ inches, width two inches. This is by no means uncommon in the Lower Lias, at Peak ; but the characters are generally much obliterated. BRACHIOPODA. Instead of a foot, two fleshy arms. Genus Lingula. An oblong", nearly equivalved compressed shell, resembling a little tongue. 1. LINGULA VENTJSTA, Simp. Length twice the width, narrowest at the hinge, ovate ; beak small, near the margin ; concentrick lines of growth, or striae, numerous, faint ; length three-tenths of an inch. 227 This is an exceedingly neat, shining, little shell; shewing only one valve on a piece of lias limestone. Where a part of the shell has been removed,, the cast of the interior is equally smooth and shining. ILL. Since writing this description,, I have found them rather plentiful in the shale , a little below the second indurated band, ILL., but not so perfect. 2. L. SACCULUS, C. fy D., Tale. Ovate, beak rather tumid, and pointed. Mr. Tate compares this with L. Beanii, which occurs in the inferior Oolite, immediately above the Lias. L. Beanii, more pointed towards the apex, is ovate, oblong ; shell thick, of a light blue colour. L. sacculus, subovate, shell thin, and black-blue. A few specimens are recorded from the uppermost beds of the Middle Lias. M.L., a. Genus Terebratula. Valves unequal ; beak per- forated. 1. TEREBRATULA PUNCTATA, Sow., pi. xiv. Ovate, elongated, and acutely triangular at the beaks, moderately gibbous, smooth, with a few concentrick lines of growth near the base; base rounded. This has passed for T. ornithocephala ; but there is no flattened or truncated part at the base, which distin- guishes that shell ; neither has it the three diverging lines at the beak, as in T. trilineata, Y. & B. M.L. 2. T. HISPIDULA, Simp. Ovate, beaks wide; both valves flattened at the base, and very slightly on one side ; the whole covered with exceedingly numerous, fine, micro- scopic points. L.L., ?/, R.H. Bay. In general form, this comes very near to T. ornitho- cephala ; but, when examined with a lens, it is found to 228 be covered with exceedingly fine points, resembling the skin of a shark. It occurs both in the Middle and Lower Lias. The largest I have seen is about three-quarters of an inch leng. Those from the Lower Lias are of a brassy hue. The former has the base regularly rounded,, without the flattening in the middle ; though both are covered with the minute points. They may possibly be distinct species. 3. T. RESUPINATA, Sow., pi. cl. T. Sf B., pi. xv., f. 12, 13. Three sided, sharply pointed at both ends; length greater than the width, the larger valve convex, the other with a deep broad furrow ; concentrically striated. Common in the Eston ironstone mines. M.L., a. Rhynconella. 4. T. TETRAHEDRA, Sow., pi. Ixxxiii. Subglobular, four-sided; beak of the longer valve pointed, incurved, a deep broad depression, or chan- nel, in the middle of the valve, curved inwards at the base, containing about four angular ribs, and about four on either side; beak of the smaller valve obtuse, incurved beneath the other, an elevation in the middle corresponding to the depression in the other valve, containing about four more sharp ribs on either side. These are exceedingly common, forming large masses in the marly beds of the middle lias ; but they can seldom be obtained with the shell on. They present great variety., from the typical form with the deep central depression in the larger valve, to those where it has almost been obliterated, and the shell has become much depressed, and regularly radiated over the whole surface. 229 5. T. TRIPLICATA, Ph. Geo. Yorks. Obscurely four-sided ; larger valve with a deep middle depression, containing two sharp ribs, and two or three more on each side ; the smaller valve much inflated, with three sharp ribs in the middle, and three more on each side. M.L., Hawsker. It may possibly be a variety of T. tetrahedra. 6. T. LINEATA, T. 4- B. T.fr B., pi. xv., f. 21, 22, 23. ' ' It differs from T. tetrahedra not only in being smaller but in having only two elevated plaits at the base, and a sunk line on the lesser valve, running from the beak to the groove between these plaits/' Young. 7. T. BIDENS, Ph. Triangular ; the larger valve with a deep concave groove occupying the whole side, containing one strong rib down the middle, bounded on either side by a strait edge ; the smaller valve smooth and inflated below the beak, two short elevated ribs or teeth at the base, and two plicae on either side. L.L., R. H. Bay. 8. T. ACUTA, Sow., pi. cli. Subtriangular, length rather more than the width ; larger valve with a deep smooth depression or groove the whole length ; the other valve with one large groove and two or three small ribs on either side. M.L., Hawsker. It differs chiefly from the last by having only one tooth at the base. They are both sharply defined species, and have no connection with any variety of T. tetrahedra. 230 9. T. VARIABILIS, Sch., Tate. Triangular, base convex, often depressed, with from seven to nine coarse ribs on each valve; beak very small, foramen circular. L.L., #, R. II. Bay. 10. T. MUNDULA, Simp. Deltoid, regular, transverse ; beak of the larger valve pointed, incurved, either side of which is concave and excavated ; middle of valve with a broad depression, containing five or six rounded ribs, and five or six on either side ; the smaller valve has about eighteen rounded ribs, and the middle is but little elevated, and turns quickly over, so as to make the rounded base appear truncated in the middle. M.L., y, R, H. Bay. Although this has a good deal the shape of some varieties of T. tetrahedra, yet its neat form, its being transverse, and more excavated on the sides of the beaks, and from the smaller valve bending over in the middle to meet the depression in the other ; and being also from the lower lias, where, as far as I know, T. tetrahedra does not occur, I consider it a distinct species. In the round- ness of the ribs, it also appears to differ from T. media. Another specimen has the middle depression in the larger valve deeper. Mr. Tate identifies it with T. plicatissima, and also allies it with T. Juransis, but the examples he sent me of T. plicatissima are depressed, ribs sharply angular, and the excavations on the sides of the beaks are wanting. 11. T. CALCICOSTA, Quen., Tate. T. $ B., pi. xv., f. 10. Mr. Tate associates this with the preceding species, and describes it as " Triangular obovate, with an elevated mesial fold carrying two or three plaits bordered on each 231 side by two or three equally strong folds, all of which proceed to the unibo. The beaks are large and erect j and the foramen is elongated." It is a coarse, rather irregular species, with coarse lamellar plaits of growth towards the base. M.L., Huntcliff, &c. 12. T. SUBCONCINNA, Ddv., Tate. T. fy B., pi. xv., f . 18. Ovate, depressed beak broad, elongated; base convex ; larger valve with about fourteen smooth diverging ribs ; length four-tenths of an inch ; width three-tenths of an inch. L.L., ?/, Huntcliff. 13. T. CAPITULATA, Tate. T. fy B., pi. xv., f. 24. Subtri angular, or ovate ; larger valve with a deep groove at the base, containing from three to five plaits, with two or three on either side ; beak small ; the other valve tumid, plaited. M.L., ironstone, Eston. It is a neat little shell. Mr. Tate gives the following description of this new species. " Shell ovate-triangular, slightly transverse, with an elevated angular mesial fold, anterior third of the shell plaited ; two to four (usually three) plaits in the mesial fold, and about five on each lateral area ; the umbones gibbous. Beak thick, small, suberect. The shell never attains any considerable size." 14. T. BIMOSA, Von Buch, Tate. Obovate, three plaits in the centre and four or five on either side ; beak flatted. L.L., y, Huntcliff. 15. T. FURCILLATA, Von Buck, Tate. Ovate, angular towards the small beak, three plaits in the centre at the base, five or six on each side. L.L., y, Huntcliff. 232 16. T. COMPRESSA, T. Sf B. T. FODINALIS, Tate. T. 4* B., pi. xv., f. 16. Ovate, rather transverse, depressed ; sides and base regularly convex ; dorsal valve convex, the wing-s moderately elevated ; the other valve convex, tumid at the beak; beak small, incurved; both valves covered with about twenty fine, equal ribs, concentrically striated. M.L., ironstone. This well-defined species corresponds with the descrip- tion Young gives of his T. compressa. "The beaks smooth, and the whole margin plaited, in an unbroken series of twenty or twenty-two small plaits. The margin rises at the base, not abruptly, as in T. tetrahedra, but with a gentle undulation." Young's specimen was from the Oolite. 17. T. BOUCHARDI, Davidson, Tate. Mr. Tate describes it as having "" usually three plaits on the depressed mesial fold, flanked on each side by ten, which extend nearly to the umbonal region. The beaks are small, acute and erect. Its numerous ribs and sub- globose shape serve to distinguish it." Genus Spirifer, Sow. Beaks imperforate. Two spiral cones in the interior. 1. SPIRIFER WALCOTTI, Sow., pi. ccclxxvii. Circular, rather tumid ; hinge-line about half the width ; beaks prominent, approximate ; on the smaller valve the middle fold about one-third the width, prominent, four smaller obtuse ribs on either side, a few longitudinal striae, concentrick striae, or lines of growth, irregular ; on the larger valve, a broad central furrow, five or six obtuse ribs on either side, longitudinally striated; length 1-J- inches. 233 2. S. ROSTRATUS, Sch., Tate. Width seven-tenths of an inch, equal to the length, with a deep, concave mesial depression ; no ribs, beak much elongated, rather small, excavated on either side. The larger valve only. L.L., 27. 3. S. LIASSICUS, Simp. Tumid, more than a semicircle ; hinge-line less than the width ; sinus concave ; beaks depressed, rather distant ; a broad, nearly obsolete, fold on the middle of the smaller valve, and a corresponding wide concave furrow on the larger valve ; width eight-tenths of an inch. L.L., R. H. Bay. 4. S. RECENTIOR, Simp. Width twice the length, minutely rugose; hinge- line nearly the whole width ; beaks much depressed, distant ; sinus triangular, slightly concave, finely striated ; on the smaller valve, thirteen strong ribs, equal to the intervening concave spaces, the middle one largest; in the middle of the larger valve, a deep wide furrow, with seven strong ribs on either side ; width nine-tenths of an inch. On a portion of the sinus 'may be observed reticulated striae ; the rest of the shell is roughened with minute prominences, greatly resembling the skin of the shark. L.L., R. H. Bay. Mr. Tate makes these two last only varieties of S. Walcotti, but, besides other characters, they have the hinge-line much wider ; the beaks widely separated, small, and depressed; the sinus, or area, large. S. recentior is remarkable for its width. 234 5. S. SIGNIENSIS, Bur. } Tate. T. fy B., pi. xv., f. 7. Width one inch, length eight -tenths of an inch ; base convex, medial depression deep, triangular, with nine angular ribs on each side, imbricated by plates of growth ; beak wide ; hinge-line nearly the width of the shell. M.L., c. 6. S. OXYPTERUS, Bur., Tate, T. fr B., pi. xv., f. 8. Width greater than the depth ; a deep furrow in the middle of the larger valve, and five strong ribs on each side ; on the other valve a strong central lobe, with five ribs on each side ; beak not much incurved. L.L., ?/, Huntcliff. 7. S. VERUCOSUS, Tate's MSS. Width greater than the depth ; a deep central furrow from the beak to the base, with five or six ribs on each side ; a central lobe and ribs to correspond on the other valve ; the whole rough with pointed granules. L.L., w, B. H. Bay. Genus Orbicula. 1. ORBICULA REFLEXA, Sow., pi. dvi. Base ovate, height more than half the length, apex a little out of the centre ; radii nearly obsolete ; length half an inch. This shell is of frequent occurence in the Upper Lias, and often attached to other shells, especially to Ammonites fimbricatus. It often happens that the lower valve only remains, which has the appearance of a very small oyster. 2. O. HOLDENI, Tate. Apex central, concentrick ridges well marked. L.L., Marske. 235 ARTICULATA. The Articulated Animals have been distributed into four Classes. The Annelides, or Red-blooded Worms. The Crustacea. The Arachnida, or Spiders* The Insects. ANNELIDES. The Annelides, of which the common Earth Worm is a familiar example, are composed of numerous- rings united together. They are soft animals, and almost all, with few exceptions, live in water, and seek protection by burrowing in mud. All such have perished without leaving any traces of their existence. Others agglutinate grains of sand, and other earthy matter, and form hard cases in which they live. Of these we have many examples pre- served in our strata. Some secrete a calcareous substance, with which they form a sort of tubular shell. Of these we have the remains of two Genera in our strata, Serpula and Dentalium. Genus Serpula, Linn. These, in their living state, are amongst the most beautiful objects in nature. The tubes, which they form for their habitation, have not the regularity of those of the Dentalium. They are often twisted about stones and other hard substances ; and some fabricate their tubes by agglutinating mud or any other suitable substances. The muddy state of the Upper Lias appears to 236 have been very unfavourable to their existence, and their remains are very rare. I have a thin plate of Jet which has on it a number of short Serpulse. Ditrypa. These approach closely to Dentalium. 1. SERPULA CAPITATA., Ph., T. $* B., pi. xi., f. 8. Nearly straight, with irregular, rugose rings; aperture irregular. L.L. 2. S. GLOBICEPS, Quen., Tate, T. fy B., pi. xii, f. 2. Much curved, smooth, with well separated, rounded rings; aperture circular. L.L., 27, Redcar. 3. S. CIRCINATA, Tate, T. fy B., pi. xiv., f. 11. The smaller end convolute, ending in a straight smooth tube; aperture circular. L.L., 15, R.H. Bay. 4. S. QUINQU-ESULCATA, Mun., Tate. A semicircle, with an angular aperture. L.L., R. H. Bay. Serpula proper. 5. S. SOCIALIS, Gold, Tate. Branched, smooth ; aperture circular. L.L., 27, Redcar. 6. S. LIMAX, Gold, Tate. Much curved; aperture angular. L.L., 27, Redcar. 7. S. LITUIFORMIS, Mun., Tate. A wreath of four diminishing coils, partially cor- rugated ; aperture circular ; diameter of coil two- tenths of an inch, equal to the height. 8. S. DEFLEXA, Ph. Geo. Yorks., pi. xi., f. 26. Many, varied, smooth convolutions. L.L., R. H. Bay. 237 Genus Dentalium, Linn. These have a shell in the form of an elongated cone, more or less bent, and open at both ends, and may be compared to an elephant's tusk in miniature. 1. DENTALIUM GIGANTETJM, Ph., T. Sf B., pi. ix., f. 10. Large, smooth, and moderately bent ; aperture ovate ; length 3^ inches, diameter a quarter of an inch. It is very abundant in the lowest stratum (q) of the Iron- stone series of the Middle Lias at Hawsker, Staithes, &c. 2. D. ETALENSE, T. &? P., Tate, T. $ B., pi. ix., f. 13. Very slender, smooth, no striae, nearly straight; aperture circular. Mr. Tate has kindly sent me several examples of this species from the lowest beds of Lias at Redcar. The length of the largest is 1.2 inch, diameter .075 inch. 3. D. ARCUATUM. Slender, smooth, bright, no striae, much curved, especially towards the posterior end ; posterior part finely attenuated; aperture circular, or obscurely pentagonal ; length 11 inch, greatest diameter one- eighth of an inch. This agrees very much with the last, except in its great curvature, and in being stronger. I found several on a piece of shale, all much arcuated, but not equally so. L.L.., s, north cheek of E. H. Bay. 4. D. ELONGATUM, Mun., Tate, T. <$f B., pi. ix., f . 28. Long, slender, and nearly straight, with some obsolete concentrick rings, or distant striae ; aperture circular ; length 3^ inches, diameter one-eighth of an inch. M.L., a, Hawsker. 238 5. D, LIMATULUM, Tate, T. & B., pi. x., f. 18. Slightly carved, with very fine, acute, transverse, rather oblique ribs or elevated lines'; aperture ovate, tapering to a fine point. Lowest beds of Lias, Kedcar. 6. D. LIASSICUM,, Moor, Tate. " Cylindrical, longitudinally striated." ILL., 8. Tate. CEUSTACEA. No remains of short-tailed Crabs (Cancer} have been discovered in the Yorkshire Lias. They all belong to the long-tailed. (Astacus). They are comparatively small, resembling the Prawns rather than the Lobsters. Their remains are rare, and very fragmentary ; and are chiefly found in the uppermost beds of Lias. 1. ASTACTJS HARTMANI, Meyer. (Ergon). This rare and interesting fossil was discovered by J. W. Kershaw, Esq., F.G.S., in the second Indu- rated band of the Upper Lias at Salt wick, along with Lingula venusta. I have since torn up much of this band in search of it, but without success. Mr. Blake places it under the sub-genus Ergon, which has the carapace very broad, and with very deep lateral incisions. The carapace of this speci- men, however, has not been preserved ; and Mr. Blake seems to depend for specifick characters on the caudal plates, which are broad, with a central ridge ; and the edges are rounded. Claws narrow and small. 239 Some think it to be A. Barrowviensis. 2. A. WILLIAMSONI, Simp. Carapace robust, roughened with numerous tuber- cles ; rostrum long ; joints of the abdomen nearly smooth ; first pair of legs very long, and strongly tuberculated ; claws of the pincers slender. Syn. A. rostratus, Simp. I find that under this name I have described the joints of the abdomen as nearly smooth^ whilst A. Williamsoni is described as having seven rugose plates with smooth constrictions at the joints, and the ridges at the front of the carapace less elevated. Probably they are the same species. I think the specimens were in Mr. Bean's collection, from the Lower Lias at E-. H. Bay. . 3. A. L^SVIGATUS, Simp., Bean. Carapace and abdomen smooth, slender. Two claws (hands) in a separate nodule, probably of this species, have the last joint inflated; a few distant tubercles ; claws of the pincers rather wide at the base. Upper Lias. 4. A. BANKSII, Simp., Bean. Carapace broad, channelled with many wrinkles ; tubercles numerous, small. A robust species. L.L., E. H. Bay. Bean's col. ENTOMOSTRAC.ZE. Of these Mr. Blake has described seventeen species, chiefly from the very lowest beds of Lias. They are numerous and important as instruments of geological research; but they are very tiny things, and for the present we must leave them to the microscopist. INSECTA. The only remains of Insects discovered in our Lias are a wing-case of a beetle, and two Neuropterous wings. 240 RADIATA. Genus Asterias. Star- Fish. 1. ASTERIAS MEDIA, Simp. A. CARINATA, Wright. Pal., pi. ii, f. 1. With five triangular rays, resembling* the common A. rubens. Scarbro' Museum. 2. A. MURCHISONI, Williamson. A. POLYNEMIA, Simp. With about twenty triangular pointed rays ; diameter nine inches ; central disc one inch. An impression upon a very frail marly substance, from the Middle Lias. Scarbro' Museum, 3. A. HASTINGS, Forbes. M.L., Staithes. 4. A. OPHINUROIDES, Wright. Pal., pi. v., f. 1. Ophiv.ra. Rays long and slender. Snake tail. 5. A. MILLERI, Ph. Five strong, imbricated rays, with the scales in three rows ; disc pentagonal. Rather common, but seldom perfect, in the sandy beds of the M.L. 6. A. GRACILIS, Simp. A. CARINATA, Wr. Pal., pi. xvi. f. 1. Five slender rays ; disc round. It very much resembles O. texurata, Lam. M.L., Scarbro" Museum. I have seen a great number on a slab of Lias, very similar. 7. A. MURRAVII, Forbes. M.L., Staithes. 8. A. COLUMBA, Tate, T. & B., xvi., f. 1. Pentacrinus. 1. PENTACRINUS CAPUT-MEDUS^E, Miller. Joints of column strongly pentangular, with 241 articulating surfaces pentapetalous, ovate, striated markings. L.L., R. II. Bay. Probably this is the same as P. tuber culatus. There is in the Whitby Museum a fine slab of Pentacrinites with very numerous delicate arms, but no stem. I suppose they must have been the heads of this species. I procured a smaller slab of the same for Mr. Bean, which is pro- bably in the Bean collection in the British Museum. They were from the Lower Lias at Eobin Hood's Bay. 2. P. BRIAREUS, Miller. Joints of column, pentangular, alternately larger and smaller ; pentapetalous, striated, articulating surfaces nearly linear. U.L., Saltwick. 3. P. BASALTIFORMIS, Miller. Column neat and slender ; joints of a uniform size and thickness. L.L., R. H. Bay. 4. P. GRACILIS, Charlesworth. Stem with a few small side branches ; head with seven or more long branches, which at length bifurcate. M.L., Staithes. Echinus. Sea Hedgehog or Urchin. 1. ECHINUS ANTIQUUS, Simp. In the Scarbro' Museum, there is a crushed portion of an Echinus, with some of the spines attached, but broken. The shell is covered with tubercles, and also strongly mammillated, with a depressed circular channel for the reception of the spines. The spines are smooth, have a broad, thin base, and probably were pointed. M.L., Skinningrove. 2. E. OBSOLETUS, Simp. In the same Museum, there is a spine like the one figured by Phillips, pi. xiii, f. 17. Base a truncated cone, K 242 toothed ; it then swells into a knob, and diminishes, then the appearance of a joint ; all this occupies one quarter the length ; the rest regularly tapers. 8. E. EDWARDSII, Wright. CORALS. THERE are very few Corals in the Yorkshire Lias, and these are confined to the lowest beds. Mr. Blake notices three species. 1. MONTLIVALTIA HAiMEi, C. <$f D., Blake. Button-shaped, depressed, numerous muricated rays proceeding from the central pit. Rays beneath finely decussated by concentrick striae. 2. M. GUETTARDI, Slain, BlaTce. Button -shaped, turreted, concentrick rings and striae coarse, irregular. 8. M. POLYMORFHA, T. fy P., Blake. 1. SEPTASTRJEA EXCAVATA, Fr., Blake. 1. GALEOLANA SOCIALIS, Tate. VEGETABLES. WOOD is found plentifully in all the^beds of Lias, but always in a fragmentary state ; lying in the direction of the strata, and often bruised and compressed. Some of it appears to be monocotyle- donous ; but the greater part is dicotyledonous and 243 coniferous ; and, when cut into thin slices, and fixed on glass, its structure can be beautifully observed. There can be no doubt that large quantities of vegetable matter have been deposited in the Lias, which have entirely perished. The only distinct plant, which I have observed, is 1. ARAUCARITES PEREGRINUS, Lind. & Hut. Pinnate ; pinnulae broad at the base, curving and tapering upwards, accuminate, thickly set on the rachis. It is not uncommon in the upper part of the jet-rock, at Saltwick. Syn. Pachyphyllum. In various beds of the Lias, 4 and especially in a bed in the Lower Lias, near Mill-beck, at Robin Hood's Bay, may be observed, numerous branching, cylindrical bodies, which we must consider as having been Marine Plants. Their organic structure is , clear enough, but we can determine nothing respecting their species. The casts of a long cylindrical Marine Plant, abundant in the uppermost bed of the Middle Lias, near Staithes, noticed by Young & Bird "as bearing a striking resemblance to the stalks of the common Tangle " has been named by Mr. Tate, 2. CHORDOPHYLLITES CICATRICOSUS, T. & B., pi. xiv., f. 9, 244 MINERALS. THE most important minerals which occur in the Yorkshire Lias are Iron and Jet. IKON enters largely into all the strata, but more abundantly into the Middle and Upper portions of the Lower Lias. It occurs generally in thin seams, associated with organick remains, to which it appears to have been attracted. The most important deposit of iron is in the oyster beds at the top of the Middle Lias, in Cleveland, where the ironstone beds amount to from nine to seventeen feet in thickness, yielding from thirty to thirty-two per cent, of metallick iron. These beds soon become deteriorated, both to the south and west, so as to be scarcely recognizable. The other deposit of economick value is in the Esk valley, near Whitby, and consists of two beds, lower in the order of the strata than those of Cleve- land. These beds also deteriorate, and thin out both to the north and south. At Grosrnont, where they are wrought, the upper beds are about three feet in thickness, and the lower nearly the same ; yielding about the same per cent, in iron as those of Cleveland. JET. The stratum from which the hard or most valu- able Jet is extracted, is a bed in the Upper Lias, about twenty feet thick, called by way of eminence the Jet Rock. It is about J40 or 150 feet from the 245 top of the Lias formation, and about 50 feet above the main bed of ironstone. Much good jet has also been occasionally found in the shales above the jet rock, and also in the bed beneath, and even in the main bed of ironstone in the Middle Lias ; but it is only .in the jet rock that the miner carries on any systematick operations. This bed extends from the sea cliffs to its western outcrop in the the vale of Cleveland, and from Robin Hood's Bay to the mouth of the Tees. Jet lies parallel with the plane of the strata, in flattened, detached masses of various form and magnitude ; the larger are about ten or twelve feet long, twelve or eighteen inches wide, and from three inches to a mere film in thickness. One famous mass was reported to be twenty feet long by six feet wide, and in places three inches thick; but masses approaching at all to such dimensions are exceedingly rare. In extracting the jet from the rock, it is generally broken into small pieces, but occasionally some are obtained three or four feet long by about a foot wide. The best Whitby jet has a conchoidal fracture, gives a brown streak, takes a beautiful deep, velvet- black polish, is highly elect rick, rather lighter than coal, its specifick gravity being 1.238 ; it is com- bustible, and burns with a light greenish flame, and strong bituminous odour. It varies much in hard- ness and tenacity, some pieces being very brittle 246 and difficult to work, while other pieces possess much elasticity. It has been very generally concluded that jet is of ligneous origin, but this opinion is supported neither by chemical analysis, nor microscopic inves- tigation ; and, now that the material is better known, the weight of evidence is decidedly against it. It is not unlikely that vegetable matter may have become jet, for we find wood, and the scales of fishes, converted into something like it ; but it is far more probable, that the best jet is an aggre- gation of bituminous matter, which abounds in the jet rock of the Lias. Mr. Louis Hunt on, of the Lofthouse Alum Works, states in the Geological " Transactions" for 1836, " that when a small heap of this rock was calcined at the works, the melted bitumen and sulphur flowed in flaming streams." It is also well known that petroleum or mineral oil frequently occurs in the cells of belemuites and ammonites, and in cavities of nodules in the jet rock, which at first is a greenish liquid, but when exposed to the air soon hardens into a kind of pitch, which burns with a crackling flame. It is not improbable that the bitumen itself may have had a vegetable origin, as coniferous wood abounds in the Lias, and the leaves of Araucarites are frequent in the strata above. 247 INDEX. Those marked thus * indicate corrections made in Page VERTEBKATA ... 5 Hybodus REPTILES ... 5 minor reticulatus Ichthyosaurus . . . acutirostris ... crassimanus ... intermedius . . . ... 11 ... 12 ... 12 ... 13 Lepidotus pectinatus ... semiserratus longirostris ... platyodon . . . tenuirostris ... ... 13 ... 12 ... 13 rugosus Leptolepis Saltviciensis Notidamus Plesiosaurus . . . ... 8 amalthei brachycephalus cselospondylus Cramptoni . . . ... 10 ... 9 ... 9 Pachycormus . . . acutirostris curtus grandipennis homolospondylus ... 9 ... 9 gracilis latirostris ... propinquus . . . ... 10 latus rostratus ... 10 i n macropterus rugosus Zetland! Teleosaurus brevior ... Chapmanni ... ... 10 ... 10 ... 5 ... 7 ... 6 Ptycholepis . . . Bollensis . . . Sauricthys apicalis Tetragonolepis FISHES ... 13 ovalis Acrodus ... 14 minimus ... 14 MOLLUSC A... nobilis ... 14 CEPHALOPODA Aspidorhyncus ... 16 Ammonites . . . anglicus ... 16 aculeatus . . . Belonostomus ... 16 acuticarinatus acutus ... 16 asqualis Dapedius ... 15 alienus micans ... 15 alternatus ... Eugnathus ... 15 Andrese fasciculatus ... 15 Andersoni ... Gyrolepis ... 15 anguiformis Alberti ... 15 angulatus ... Gyrosteus ... 17 annulatus . . . mirabilis ... 17 annuliferus Page .. 14 ,. 14 .. 14 .. 14 .. 14 .. 14 .. 15 ... 16 .. 16 .. 14 .. 14 .. 16 .. 16 .. 16 .. 16 .. 16 .. 16 .. 16 .. 15 .. 15 .. 15 .. 15 .. 15 .. 15 .. 17 .. 17 .. 61 .. 99 .. 133 .. 80 .. 122 .. 123 .. 91 .. 90 .. 70 .. 84 .. 81 81 248 Ammonites _ -"^j-' Ammonites ,~ antiquatus ... ... 64 decussatus . . . ... 95 arcigerens ... ... 77 def ossus ... 78 arctus ... 66 dejectus ... 122 armatus ... 97 delicatus . . . ... 86 sirmiger ... 100 Dennyi ... 86 athleticus . . . ... 82 denotatus . . . ... Ill attemiatus . . . ... 85 depressus . . . ... 118 aureolus ... 134 diversus ... 75 aureus ... 74 Easingtonensis ... 63 Beanii ... 113 elaboratus ... ... 128 Bechii ... 104 elegans ... 106 Belcheri ... 72 elegantulus ... 107 bif rons ... 140 erratus ... 65 Birchii ... 102 erugatus ... 71 Birdi ... 131 exaratus ... 107 bispicatus . . . ... 105 exasciatus ... ... 129 bisulcatus ... ... 138 exortus ... 73 Boulbiensis ... 109 f abalis ... 113 brevispina ... ... 103 fabricatus ... ... 65 Brooki ... 138 f asciatus ... 70 Bucki ... 121 ferrugineus ... 114 Bucklandi ... ... 138 fibulatus ... 90 oapricornus ... 78 figulinus ... 78 cereus .. 77 fiinbriatus ... ... 68 Charmassei... ... 80 flavus ... 123 Clevelandicus ... 118 fonticulus ... ... 89 communis ... ... 82 f oveatus ... 89 compactilis... ... 110 gagateus . . . ... 75 complanatus ? ... 115 geonietricus ... 127 conjunctivus ... 114 gracilis ... 85 convolutus ... ... 73 Hamiltoni ... ... 100 Conybeari ... ... 136 hastatus ... 98 cornucopia . . . ... 69 Hawskerensis ... 130 crassescens... ... 87 Henleyi ... 105 crassibundus ... 87 heterogenes ... 104 crassifactus ... 87 heterophyllus ... 62 crassiusculosus ... 88 Hildensis . . . ... 140 crassiusculus ... 88 Huntoni ... 119 crassoides . . . ... 86 ignofrus ... 94 crassulosus . . . ... 86 illatus ... 67 crassulus . . . ... 86 impendens . . . ... 136 crassus ... 86 incrassatus... ... 86 crenularis ... ... 80 involutus . . . ... 67 Crosbeyi . . . ... 90 integricostatus ... 76 Ammonites Jamesoni ... Johnstoni ... jurensis Sabratus latescens . . . lectus lens ... lenticularis leptophyllus Levisoni limatus loscombei . . . luridus Lythensis ... Macdonnelli maculatus ... mammillatus margaritatus Marshallani miles Mulgravius multanfractus multicostatus multifoliatus mutatus nanus nativus neglectus ... nitescens . . . iiitidus nodulosus . . . obliquatus ... obtusus obsoletus . . . omissus ovatulus ovatus Owensis - peregrinus . . . personatus . . . petricosus ... Phillipsii ... pinguis planicostatus 249 Page Page Ammonites 79 .. 72 polyphyllus puteolus . 117 ... 90 .. 68 quadricornutus ... 106 .. 63 radiatus ... 126 .. 140 Redearensis ... 141 .. 110 regularis . . . ... 127 .. 116 resupinatus ... 73 .. 114 retentus ... 120 .. 116 reticularis ... ... 114 .. 140 retusus ... 94 .. 123 Ripleyi ... 74 .. 64 Kobinsoni ... ... 120 .. 76 rotiformis ... ... 132 .. 109 rudis ... 124 .. 125 rugatulus . . . ... 108 .. 79 rutilans ... 72 .. 101 Sagittarius . . . ... 73 .. 117 sauzeanus ... ... 139 .. 94 Scoresbyi . . . ... 103 .. 97 semiarmatus ... 92 .. 108 semicelatus ... 81 .. 134 senricostatus ... 133 .. 131 similis ... 109 .. 108 simplex ... 120 ... 96 Simpsoni . . . ... 115 ... 66 sinuatus ... 94 ... 101 siphuncularis ... 126 .. 76 socialis ... 67 .. 125 solitaries . . . ... 133 .. 70 spicatus ... 98 .. 138 spinatus ... 127 ..112 stellaris ... ... 137 .. 132 striatulus ... ... 124 .. 91 subarmatus ... 92 .. 77 subcarinatus ... 65 .. 112 subconcavus ... Ill .. 112 subnodosus... ... 129 .. 96 subtriangularis ... 99 ... 64 sulcatus ... 142 .. 65 tardecrescens ... 136 .. 102 Taylori ... 105 .. 113 tenellus ... 137 .. 141 tenuicostatus ... 69 .. 75 temiispina ... ... 103 250 Ammonites .rage Belemnites rage transformatus ... 130 dorsalis ... 34 trivialis ... 73 elegans ... 47 tubellus ... 71 erosus ... 27 Turner! ... 135 exiguus ... 34 turriculatus ... 91 expansus ... 35 validanfractus ... 135 f erreus ... 43 validus ... 95 fusteolus ... ... 54 vermis ... 82 glaber ... 28 vetustus ... 125 grandee vus... ... 44 vitreus ... 76 inaequalis . . . ... 43 vittatus ... 119 insequistriatus ... 27 volutus ... 123 incisus ... 30 vorticellus ... ... 93 inclusus ... 27 vortex ... 92 infundibulus ... 51 Belemnites . . . ... 21 laevigatus . . . ... 44 acuminatus ... 37 lentus ... 34 acus... ... 48 leptos ... 44 acutus ... 51 levidensis . . . ... 41 alveolatus ... ... 55 limatulus . . . ... 28 aptus ... 36 levis... ... 35 araris ... 50 longiconus ... ... 45 arenaceous . . . ... 45 longiformis ... 46 athleticus ... ... 38 *microstylus ... 54 attenuatus . . . ... 47 Milleri ... 55 bituminosus ... 31 Mulgravius ... 31 calcar ... 53 oblongus . . . ... 48 carinatus . . . ... 42 obtusus ... 40 charmouthensis ... 55 optatus ... 29 cinereus ... 33 palliatus ... 52 clavatus ... 54 perforatus ... ... 49 compressus... ... 26 pessulus ... 46 concavus ... ... 29 *pinguis ... 36 conicus ... 52 planulatus . . . ... 44 curtus ... 39 politus ... 39 *cuspidatus ... ... 50 pollex ... 40 cylindricus... ... 37 procusus ... 55 dactylus ... 42 pyramiformis ... 49 delicatus . . . ... 50 repandus . . . ... 35 dens ... 52 retusus ... 45 densus ... 32 robustus ... 40 demissus . . . ... 46 rostratus . . . ... 36 depressus . . . ... 51 rudis ... 43 digitus ... 42 scabrosus ... ... 53 distortus ... ... 30 scollops ... 48 251 Page Page Beleninites Nerita ... 158 Spadix- Ari . . . ... 53 alternans ... ... 158 spicatus ... 33 Natica ... 158 substriatus... ... 32 buccinoides ... 158 sub tenuis . . . ... 33 fusca ... 159 telum ... 32 neglecta ... 159 tenuis ... 34 purpuroides ... 159 teres trisulculosus trivialis ... 44 ... 30 ... 34 Tornatella chrysalis . . . f raff ilis ... 159 ... 160 ... 160 truneulus . . . ... 49 ilminsterensis ... 160 tubularis . . . turris urbanus ... 26 ... 49 ... 39 marginata ... pulla *sinemuriensis ... 159 ... 160 ... 160 validus ... 41 vulgaris ... 38 Trochus ... 143 Woolleri ... ... 37 Anglicus ... ... 144 Nautilus ... 56 aratus ... 148 annularis . . . ... 59 basilicus ... 146 araris ... 60 bellulus ... 149 astacoides . . . ... 58 concavus . . . ... 146 heterogenus ... 60 consobrinus ... 147 Youngi ... 59 18 expansus . . . *foveatus ... 147 ... 145 cuspidata . . . haustrum . . . incomposita obtusalis Trigonolites ... Whitbyensis '.'.'. 19 ... 19 ... 20 ... 18 ... 20 ... 20 Helicina helicinoides Hennocqui . . . *liassinus *nucleus obesulus oppeli ... 147 ... 145 ... 147 ... 148 ... 148 ... 147 ... 148 GASTEROPODA ... 143 Pleurotomaria procerus ... 144 ... 145 Buccinum nitidum ... 161 ... 161 pusillus Redcarensis ... 145 ... 144 Cerithium ... 161 Eobigus .. 144 acriculum . . . ... 162 *rotelliformis . ... 148 armatum . . . ... 162 rusticus ... 146 aureum ... 161 semiclausus ... 149 gratum ... 162 solarioides ... ... 148 liassicum . . . ... 162 Solarium ... ... 148 quadrilineatuin ... 162 striatus ... 148 semele ... 162 tectarius . . . ... 146 spiratum . . . ... 162 Thetis ... 144 Slatteri ... 161 undosus ... 146 252 Page Page Turbo ... 149 Turbo *aculus ... 157 undulatus ... ... 153 aciculus ... 151 unicingulatus ... 153 acuxninatus ... 152 Wilsoni ... 150 adductus . . . ... 153 Youngi ... 156 aureus .,. 155 Zenkeni ... 155 Berthaudi ... Blainvillei . . . ... 157 ... 156 ACEPHALA ... 163 carucensis ... ... 157 Anomia ... 177 Chapuisi ... 152 alpina . . ... 177 citharella . . . ... 157 ferruginea ... ... 177 cingendus ... ... 154 numismalis ... 177 Clevelandicus ... 154 Placuna ... 177 Collenoti . . . ... 15s striatula ... 177 concinnus . . . ... 153 Area ... ... 185 conspersus ... ... 154 Buckmani ... ... 187 cyclostoma . . . ... 150 *Clevelandica ... 186 def ossus .. 155 complanata ... 190 *Dunkeri ... 155 cordata ... 188 elegans ... 151 Cucullcea ... 185 f erreus ... 156 cuspidata . . . ... 187 foveolatus ... ... 158 cymbula ... 189 Guadryanus ... 153 dura ... ... 190 imbricatus... . . 152 expansa ... 186 latilabrus . . . ... 149 Heberti ... 189 lineatus ... 150 hetangiensis ... 187 Littorina ... ... 151 incrassata ... ... 185 Morencyanus ... 155 intermedia . . . ... 185 nanus ... 151 liassina ... 187 Nireus ... 154 longicaudata ... 190 nuda ... 157 Leda ... 188 Phasianella ... 155 minor ... 189 Philemon . . . ... 151 navicula ... 188 regularis . . . ... 155 navis ... 188 reticulatus . . . ... 150 obtusalis . . . ... 186 rugosus ... 153 ovum ... 188 selectus ... 152 pulchella . . . ... 186 semitectus ... ... 158 pulla ... 186 solarium ... 149 Eenevierei . . . ... 191 solidulus . . . subovalis . . . ... 192 sordidus "'. 151 telliseformis ... 192 tenuis ... 151 tenuistriata ... 191 transversus . . . ... 157 texturata ... ... 191 turbinatus ... ... 150 v-scripta ... 191 Turritella . . . ... 155 Zieteni ... 189 253 Page Page Avicula ... 180 Hippopodium .., 198 Bronni ... 184 ponderosum ... 198 calva ... 183 gigas ... 198 contorta ... 184 Inoceramus ... 179 crescens ... 182 Isocardia ... 198 cygnipes . . . ... 181 bombax ... 200 echinata ... 183 cuculata ... 200 minima ... 183 Cypricardia ... 200 nitescens . . . ... 182 gibbosa ... 200 Pattersoni ... ... 183 laevis ... 198 papyria ... 184 nitida ... 199 Eoseburiensis ... 181 petricosa ... 199 *substriata . . . ... 182 regularis . . . ... 200 *tuniidula ... 182 securii'ormis ... 200 Cardinia ... 200 sublsevis .,. 199 antiqua ... 201 Lima ... ... 173 attenuata . . . ... 203 acuticosta ... ... 176 costata ... 201 Blakeana . . . ... 176 concinna . . . ... 202 Eucharis ... ... 175 crassissima... ... 203 excavata ... 176 crassiuscula ... 202 gigantea ... ... 175 delicata ... 201 Hermanni ... ... 173 Deshaysesi . . . ... 203 hettangensis ... 175 Desoudini ... ... 203 irregularis ... ... 173 Listeri ... 201 Juliana ... 177 inembranacea ... 202 Limcea ... 176 ovalis ... 203 multicostata ... 174 Cardium ... 203 novemcostata ... 174 bituminosum ... 204 pectinoides... ... 174 globosum . . . ... 205 pectinoidea ... 174 Heberti ... ... 204 punctata . . . ... 175 multicostatuin ... 204 succincta ... - ... 174 Philippianuni ... 204 Terquemi . . . ... 175 sub str iatulum ... 205 Mya ... ... 219 triangulare ... 205 sequilateralis ... 219 truncatum ... ... 204 antiqua ... 219 Chamacea ... 198 concinna ... 220 Corbis ... ... 205 elongata ... 220 unif ormis , . . ... 205 hispida ... 220 Corbula ... 208 literata - ... ... 220 sequivalvis . . . ... 209 ' longa ... 221 cardioides ... ... 208 Myacites ... 210 deltoidea . . . ... 209 sequalis ... 216 subglobosa . . . ... 209 bituminosa ... 211 Crenatula ... 179 concava ... 216 254 Myacites concinna contracta . . . Page ... 217 ... 217 Mytilus pygmseus ... rusticus Page ... 195 ... 197 costata crassa crowcombeia ... 210 ... 216 ... 212 scalprum . . . siliqua similis ... 194 ... 194 ... 197 donaciformis ... 213 subcancellatu s ... 195 dubia ... 211 Thiollierei ... ... 196 Dunkeri ... 218 Ostrea ... ... 164 elegans ferruginea ... galathea . . . gibbosa granata intermedia . . . ... 219 ... 214 ... 217 ... 218 ... 212 ... 214 arcuata concinna depressa Gryphcea inilata laeviuscula .... ... 166 ... 164 ... 167 ... 166 ... 164 ... 165 levis liassina ... 215 ... 216 laganiformis liassica ... 166 ... 165 lunulata ... 217 Macullochi . . ... 167 maculata . . . ... 215 orbicularis . . . ... 167 mediseva ... 213 patellaeformis ... 164 mundula ... ... 217 Saltviciensis ... 164 ovata punctata ... rotundata . . . ... 216 ... 213 ... 214 serniplicata... sportella subauricularis ... 165 ... 165 ... 165 Sanguinolaria scabrosa ... 219 ... 212 submargaritacea tumidulosa... ... 165 ... 164 sublevis subtriangularis subtruncata ... 218 ... 211 ... 215 ungula Pecten aheneus ... 164 ... 167 ... 169 ventricosa ... ... 218 calvus ... 172 vetusta ... 219 def ossus 170 Mytilus aviothensis... ... 193 ... 194 dichotomus discif orinis . . . ... 169 ... 172 *bifasciatus . . . ... 196 Hinnites ... 173 cuneatus . . . ... 193 interstinctus ... 169 curvatus ensis ... 194 ... 194 lohberigensis lunularis . . . ... 171 ... 171 Hillanus ... 196 major ... 168 Hillanoides ... 196 multicostatus ... 170 hippocampus Ifievis *minimus Modiolus Myoconcha ... numismalis *psilonoti ... 197 ... 195 ... 196 ... 194 ... 197 ... 196 ... 197 papyraceus... planus pollux pulchellus ... pumillus ... punctatus . . . punctatissimus ... 173 ... 172 ... 171 ... 171 ... 172 ... 171 ... 170 255 Page Page Pecten Spondylus ... 178 reticularis ... ... 171 calvus ... 178 rudis ... 169 intus-striatus ... 178 sublaevis ... ... 168 liassinus ... 178 substriatus... ... 172 Plicatula ... 178 textilis ... 171 spinosus ... 178 textorius . . . ... 170 Tellina ... 205 *Thioellieri ... ... 170 apicistria . . . ... 208 turnidus ... 173 bioliensis . . . ... 208 Perna ... ... 178 cardinoides ... 206 serosa ... 180 cycliformis... ... 206 cincta ... 180 dionvillensis ... 207 Crenatula ... ... 179 fabalis ... 205 dubia ... 179 glabra ... 206 Gervillia ... 180 grociana ... 206 Hagenovii ... ... 180 longicostata ... 207 infraliassica ... 178 lucida ... 208 Inoceramus . . . ... 179 o vata . , 207 pinnaeformis ... 180 pumila ... 206 *quadrata . . . ... 178 striata ... 206 Simpson! . . . ... 179 *subglobosa . . . ... 206 substriata ... ... 180 Tancredia . . . ... 207- ventricosa ... ... 179 tenuis ... 206 Pinna ... 184 Trigonia ... 192 folium ... 1S4 lingonensis ... 193 Hartmanni... ... 184 literata ... 192 spathulata ... ... 184 modesta ... 193 Pholadomya ... ... 221 Venus ... ... 208 ambigua ... 221 cingulata ... ... 208 antiquata . . . ... 226 obsoleta ... 208 concinna ... 221 Oppeli ... 208 costata ... 224 rugata ... 208 decorata ... 222 striato-sulcata ... 208 elongata ... 226 BRACHIOPODA ... 226 gallina ... 224 Lingula ... 226 glabra ... 224 sacculus ... 227 Isevis ... 223 venusta ... 226 lunata ... 223 Orblcula ... 234 obtusalis . . . ... 224 Holdeni ... 234 recurva ... 221 renexa ... 234 rostellata . . . ... 225 Spirif er ... 232 rostrata ... 225 liassicus ... 233 scutulata . . . ... 225 oxypterus ... ... 234 Simpson! . . . ... 222 recentior . . , ... 233 truncata ... 226 rostratus ... ... 233 256 Spirifer Page Page signiensis . . . ... 234 Astacus ... 238 verucosus . . . ... 234 Banksii ... 239 Walcotti ... ... 232 Hartmani . . . ... 238 Terebratula . . . ... 227 Isevigatus ... ... 239 acuta ... 229 Williamson! ... 232 bidens ... 229 INSECTA ... 239 Bouchard! ... ... 232 calcicosta . . . ... 230 EADIATA ... ... 240 capitulata ... ... 231 Asterias ... 240 compressa ... ... 232 Columba . . . ... 240 f urcillata . . . ... 231 gracilis ... 240 hispidula . . . ... 227 Hastingise ... ... 240 lineata ... 229 media ... 240 inundula ... 230 Milleri ... 240 plicatissima ... 230 Murchisoni ... 240 punctata ... 227 Murravii ... 240 resupinata . . . ... 228 Ophiura ... 240 Rhynconella ... 228 *Ophiuroides ... 240 rimosa :.. 231 rubens ... 240 subconcinna ..: 231 Pentacrinus . . ... 240 tetrahedra . . . ... 228 basaltiformis ... 241 triplicata . . . ... 229 briareus ... 241 variabilis . . . ... 230 caput-medusae ... 240 gracilis ... 241 ARTICULATA ... 235 Echinus ... 241 ANNELIDES ... ... 235 antiquus ... 241 Dentalium ... 237 Edwardsii ... ... 242 arcuatum . . . ... 237 obsoletus . . . ... 241 elongatum ... ... 237 CORALS ... 242 etalense ... 237 Galeolana ... 242 giganteuni . . . ... 237 socialis ... 242 liassicuin . . . ... 238 Montlivaltia ... 242 limatulurn ... ... 238 Guettardi ... ... 242 Serpula ... 235 Haimei ... 242 capitata ... 236 polymorpha ... 242 circinata . . . ... 236 Septastrsea ... 242 *deplexa ... 236 excavata ... 242 globiceps . . . ... 236 PLANTS ... 243 limax lituif ormis . . . quinquesulcata socialis ... 236 ... 236 ... 236 ... 236 Araucarites . . . peregrinus . . . Chordophyllites cicatricosus ... 243 ... 243 ... 243 ... 243 CRUSTACEA ... ... 238 MINERALS ... ... 244 FORTH AND SON, PRINTERS. WHITBY. A ! -114 DAY USE RETURN TO DBBfFROM WHICH BORROWED EARTH SCIENCES L1BRARV This book is due on the last date stamped below, or on the date to which renewed. Renewed books are subject to immediate recall. but JAW ?005 SUBJECT TO RECALL DUE JAN 2 i 2005 SUBJECT TO RECALL IMMEDIATELY RFC'H BIOS r ~* - * T r 01 Kn,^'Q General Library 'Sffiffio&S? v"*^ 10 '