Smithsonian Institution Libraries Purchased from the CULLMAN ENDOWMENT / ) , V'CU- : . i ■ ■ ■ THE 1 MINERAL CONCHOLOGY OF GREAT BRITAIN; OR COLOURED FIGURES AND DESCRIPTIONS OF THOSE REMAINS OF TESTACEOUS ANIMALS OR Shells, WHICH HAVE BEEN PRESERVED AT VARIOUS TIMES AND DEPTHS IN the earth. By JAMES SOWERBY, F.L.S. G.S. W.S. HONORARY MEMBER OF THE PHYSICAL SOCIETY OF GOTTINGEN, OF THE SOCIETY OF JENA, &C. CONTINUED BY JAMES D. C. SOWERBY, F.L.S. Z.S. &c. Many, O Lord my God, are thy wonderful works which thou hast done ; they cannot be reckoned up in order to thee : if I would declare and speak of them, they are more than can be numbered. — Psalm xl. 5. VOL. VI. LONDON: PRINTED BY RICHARD TAYLOR, RED LION COURT, FLEET STREET J And sold by J. D. C. and C. E. Sowerby, No. 2, Mead Place, Lambeth ; G. B. Sowerby, 156, Regent Street; Longman and Co., and Sherwood and Co., Paternoster-row; &c. MDCCCXX1X. - s ' ~ ■ INDEX TO VOL. VI. Se,9 fr/z ■G - s*- >V £*f ' Tab. Page. Ammonites Bakeriae 570/.1 &2 134 Benettianus . 539 77 Beudanti. See “Corrections.” brevispina ..556/. 2 106 Catillus 564/. 2 123 cinctus 564/. 1 122 complanatus . 569/. 1 133 curvatus .... 579/ 2 154 denarius 540/ 1 78 elegans .... 162 falcatus ....579/ 1 153 Gowerianus .549/2 94 HiPtanum} 5l4/-2 24 Jamesoni ... 555/ 1 105 laevigatus ... 570/ 3 135 fem^<«S(Sel-?549/ , 93 liguinus) S J lataecosta ... 556/ 1 106 Murchisonae . 550 95 navicularis .. 555/ 2 105 planulatus ..570/5 136 rhotomagensis 515 25 Rotula 570/4 136 See “Corrections.” spinosus ....540/2 78 Sutherlandiae 563 121 Taylori 514/1 23 tetrammatus . 587 /. 2 166 undatus 569/ 2 134 Woollgari . . 587 / 1 165 Ampullaria helicoides522 / 2 40 nobilis 522 /. 1 39 Ancylus elegans 533 64 Argonauta 173 Astarte bipartita . . 521 / 3 38 imbricata . . 521 /. 1 37 nitida 521/2 37 oblonga .... 521 /. 4 38 orbicularis ..520/2 35 striata 520 /. 1 35 tellinoides 9 Avicula lanceolata .512/1 17 ovata 512 / 2 18 in Greeia-sand 158 Baculites anceps . . 185 Faujasii .... 592 / 1 186 obliquatus .. 592 / 2&3 186 ovata 186 vertebralis. . 185,186 Tab. Page. Belemnues^ab- } B90/.2,3&9 179 acutus . . . . . 590/7, 8& 10 180 attenuatus . . 589/ 2 176 compressus . . , 590 / 4 182 ellipticus . . . 182 elongatus. . . . . 590/ 1 178 Gigas 182 granulatus . . 600/ 3&5 207 lanceolatus . 600/ 8&9 208 minimus . . . . 589/ 1 175 mucronatus . 600/.l,2,4,6&7 205 penicillatus . 590/ 5&6 181 pistilliformis 589 / 3 177 Beloptera 171 anomala ... . 591 f. 2 184 belemnitoidea 591 /. 3 183 sepioidea . . , . 591/1 183 Buccinum acutum . 566/1 127 breve ..... 566 /. 3 128 imbricatum. . 566/ 2 127 spinosum. . . . 566/ 4 128 Bulimus conicus . . . . 61 Camerina 74 Cardium alaeforme . 552 f.2 100,132 decussatum. . 552/ 1 99 dissimile . . . . 553 / 2 101 hibernicum , . 552/ 3 100 striatulum . . 553/ 1 101 truncatum . . 553/ 3 102 Carinaria 173 Chama 218,219 Corbis laevis 580 156 Corbula elegans. . . . 572/ 1 139 obscura .... 572/5 140 rotundata ..572/ 4 140 striatula S72/.2&3 139 Cyclas pulcher .... 527 / 1 51,202 medius 527 / 2 membranaceus527 / 3 Discina Emarginula (s. Fis- surella) clathrata scalaris }519/. 51 52 3 33 . 519 /3&4 34 tricarinata .. 519/2 34 Exogyra conica .... 605 /. 1 — 3 219 eostata {Say) 218 digitata . . . .. 218 haliotoidea. . 218 laevigata .... 605 / 4 220 INDEX TO VOL. VI. Tab. Page. Exogyra plicata . . . 218 ,219 recurvata . . . 218 ,219 undata 605 /. 5 220 Fistulana 48 Fusus alveolatus. . . . 525/ 1 45 cancellatus . . 525/ 2 45 Galeolaria 198 Gastrochaena con- } torta ) 526/ 2 50 tortuosa . . . . 526/ 1 49 Gevvillia acuta . . . . 510/ 5 15 aviculoides . . 511 16 solenoides .. 510/1 — 4 14, 32 GryphaeaMaccul-^ 547/1_3 gg minuta 547 /. 4 90 canaliculata., 218 Hamites Gigas . . . . 593/ 2 188 grandis . 593 / 1 187 Hinnites Cortesyi.. , 209 Dubuissoni . . . 601 210 Inoceramus Cripsii. 161 digitatus . . . , . 604/ 2 215 dubius 584 f. 3 162 gryphaeoides .584 f. 1 161 involutus. . . . . 583 160 latus 582/ l 159 picfus . 604/ l 215 striatus . . . . , 582/2 160 tenuis 161 vetustus 584/ 2 162 Isocardia Cor . . . . 516/ 2 27 similis . 516/ 1 27 ventricosa . 28 Lenticulites 73 radians . . . 76 Limnea columellaris 528 / 2 53 maxima . . . • 528/. 1 53 pyramidalis .528/3 54 Lithodomus 141 Lucina antiquata . . 557/ 2 108 crassa . 557/3 108 mitis . 557 /. 1 107 Lutraria carinifera . 534/ 2 66 oblata . 534/3 66 striata . 534/ 1 65 Megalodon cucul-4 latus J ■ 568 132 Melania attenuata . 52 subulata . . . 41 tricarinata . 52 Melanopsis brevis . '. 523/ 2 42 carinata . . . . 523/ 1 41,51 Murex angustatus . . 531 /. 1 57 Tab. Page. Murex Harpula 578/. 5 152 Smithii 578/. 1—3 151 tuberosus ... 578/. 4 152 Mya angustata .... 531 /. 1 57,59 Antiquorum . 59 arenaria 58 glycimeris . . 211 labiosa 57,61 plana 57,61,202 Pullus 531/. 2 58 subangulata . 57 Mytilus affinis 532 /. 1 59 Brardii ....532/ 1 60,202 pellucidus . . 59 polymorphic 60,61,202 striated 51 Nautilus 173 Comptoni. .. 74 excavatus ... 529/ 1 55 hexagonus . . 529 /. 2 55 polygonalis . . 530 56 sulcatus .... 571 / 1&2 137 Woodwardii 571/3 138 Nuculaamygdaloides554/ 4 104 deltoidea. . . . 554/ 1 103 inflata 554/ 2 103 undulata. . . . 554/ 3 104 Nummulites 73 Nummularia Comp- ) ~ . toni ) elegans 538 /. 2 76 laevigata .... 538/ 1 75 variolaria ..538/ 3 76 Ocythoe 173 Orbicula granulata . 506/ 3&4 6 HUmPhrana}606/'2 5 norvegica . . 5 reflexa 50 6/ 1 4 Orthocera cincta ..588/3 168 fusiformis . . 588 / I3f2 167 Pachymya Gigas . . 504, 505 2 Paludina carinifera 509/ 3 12 elongata 509/ 1&2 11 lenta 30 Panopsea Faujas .. 602 212 gibbosa (vol. 1. t. 42) 211 intermedia (vol. i. t.76. vol. v. t.419,/2. & vol. vi.) t. 602. / 4. p. 212. plicata(vol. v. ^.419, /.3.) 21 1 Pecten annulatus .. 542/ 1 80 carinatus. ... 575/4 145 complanatus. 586 164 dentatus 574/ 1 143 INDEX TO VOL. VI Tab. Page. Peeten duplicatus . . 57 5/. 1 — 3 145 grandis 585 163 granosus .... 574/2 144 Jacobaeus .. 163,164 maximus . . . 163, 164 obsoletus. 541 79 plebeius Lam. 146 plicatus ....574/. 3 144 Princeps .... 542 / 2 80 Pusio 209 reconditus . . 575/.5&6 146 smooth, in Lias 17 smooth, in Oolite 9 sulcatus .... 146 vagans 543 /.3 — 5 82 vimineus . . . . 543/.1&2 81 Petricola laminosa 573 142 Pholadomya acu- ? 546/ 1&2 88 ti-costata ^ J aequalis ....546/. 3 88 ambigua .... 86 angustata . . 86 deltoidea .... 86 fidicula (lirata bis) 86 lirata 86 margaritacea 86 Murchisoni . . 545 87 obtusa 86 ovalis 86 producta .... 86 Pholas compressa . . 603 213 prisca 581 157 of France.... 213 Pileopsis tubifer . . 607 / 4 224 vetusta 607 /.I — 3,223 Plagiostoma con- ) „ centrica 3 ' 1 116 duplicata ..559/. 3 114 elongata 559/. 2 113 Planorbis rotundatus 53 Pollicipes maximus 606/3—6,222 reflex us ....606/ 8 222 sulcatus 606/ 1, 2 & 7 221 Potamidesventri-4 .. __ cosusj- 41’S9 Producta calva .... 560/2 — 6 1 15 costata 560/ 115 hemisphferica 561 117 personata .. 117 scabricula .. 117 scotica 117 Rissoa acuta 609 /. 2 230 duplicata .. 609/4 230 laevis 609 / 1 229 Tab. Page. Rissoa obliquata . . . 609 / 3 230 Rostellariae 22 Rostellaria com-l 55g „ m positaj J Parkinsoni . 558/ 3 102 Pes Pellecani558/. 1 109 Sanguinolariagib-? 548/ 3 g, bosa ) J undulata 548 /.1&2 91 Scalaria acuta 577 /. 2 149 frondosa .. .577/ 1 149 interrupta .. 577/ 3 149 reticulata . . 577 /. 5 150 semicostata. . 577/ 6 150 (plicata, Des Hayes) undosa 577/ 4 150 Sepia 171 Serpula 51, 197 ampullacea. . 597/1 — 5 199 antiquata .. 598/4 202 articulata ..599/ 4 204 Carineila ...598/2 201 compressa .. 598/ 3 201 fluctuata. . . . 608/ 5 228 granulafa . . 597 / 7&S 200 Macropus . . 597 /. 6 200 obtusa 608/ 8 228 Plexus 598/ 1 201 quadraEf runcinata . . 608 /. 6 227 rustica ...... 599 /. 3 203 sulcata 608 f. 1&2 225 tenuis 598/ 5 202 tetragona .. 599/ 1&2 203 triangulata. . 608/ 7 227 tricarinata. . 608/ 3&4 226 vertebralis .. 599/ 5 204 Solarium canali- ) - culatum J-S24/1 43 plicatum 524/ 2 44 Spirifer octoplicatus 562/ 2—4 120 triangularis.. 562 /5&6 120 undulatus .. 562/ 1 119 Spirorbis 197, 200 Spirula 171 Terebratula Fla- ) _ R„ bell ula ) 535 /• 1 bT furcata 535 / 2 67 Gibbsiana .. 537/ 4 72 hemisphaerica 5 36/ 1 69 Mantelliana.. 537 / 5 72 oblonga 535/ 4—6 68 orbicularis . . 535 / 3 68 Pisum ...... 536/ 6^7 70 INDEX TO VOL. VI. Tab. Page. Terebratula 5l6 f x 147 recta) rigida 536 f. 2 69 rostrata . ...537/1 &2 71 striatula .... 53 6/3 — 5 69 truncata .... 537 /. 3 71 variabilis. . . 576/2 — 5 148 Thetis major 513/1 — 4 20 minor 513/.5&6 21 Trigonia angulata . . 508/ 1 9 cuspidata . . 507 /.4&5 8 imbricata . . 507 f. 2&3 8 nodosa 507/ 1 7 Pullus 508 /.2&3 10 rugosa 117 spectabilis . . 544 183 Turbo obtusus .... 551/ 2 97 Terebra . . . . 110 Tiara 551/1 97 Turritella abbreviata565 /. 2 125 costata . 565/4 126 excavata ) ( concava ) ) * .565/ 5 126 gran ul ata . . 565/ 1 125 Tab. Page, Turritella Tere- 1 bra j 565/3 126,110 Unio aduncus . 595 / 2 190 antiquus ... . 594/3- •5 190 batava .. . . 29 compressus . ,. 594/ 2 189 cordiformis. . 595/ 1 191 Pictorum... 29 porrectus . 594/ 1 189 Solandri . . , .. 517 29 Venus caperata . . , ..518/1 31 Faba . . . . . . 567 f. 3 129 ovalis . . . . , .. 567 /.I &2 129 parva .. 518/4- -6 32 Vermetus bogno- > riensis j 596/1- -3 194 concinnus , .. 596/ 5 195 polygonalis . . tumidus .... Vennicularia 1 (Vermetus) J Vermilia Vivipara 596/ 6 196 596/ 4 195 193 198, 200, 225 CORRECTIONS AND OBSERVATIONS. Page 5, last line, for Oxford, read Kimmeridge. 6, et seq. Obs. Ancliffe is otherwise called Hanckley, it is in the parish of Westwood in Wiltshire. 17, line 19 et passim, for Lyas, read Lias. 34, to Emargintjla scalaris, add fig. 4. 41, line 15 et passim, fur Melanea, read Melania. 51, line 18, for carinatus, read carinata. 63, add a comma after Ancylijs. 69, line 5, after numerous, add granulated. line 9, add the striae become smooth by age. 93, line 1 ,/or laevigatus, read Selliguinus. Add Syn. A. Selliguinus ? Cuvier Brongniart Env. de Baris, 394 t. 7./. I . Obs. — Our fossil is between A. Selliguinus and A. Beudanti of Brongniart: the latter is not uncommon at Folkstone, and varies much,— may they not all be one species ? lol; kS line but 2, \f°r Brambury> read Braambury. 157, line 1 ,/or priscus, read prisca. 166, line 1 ,/or tetrammata, read tetrammatus. 185, last line but 1, dele lower beds of. Obs. — It appears that the Baculites Faujasii is from the upper Chalk. 191, line 5 from the bottom, for renders, read render. 193, line 13, for Trachelepodous, read Trachelipodous. 213, line 4 from the bottom, for priscus, read prisca. 226, for Turritella concava, read Turritella excavata, and add Syn. Cerithium excavatum, Cuvier fy Brongniart , Env. de Paris , 399, t. 9./. 10. Obs. — We had published this as a Turritella before we observed that Brongniart had given it as a Cerithium : we retain our generic name, which Brongniart seems inclined to think may be right. ♦ . . ■ ■ ' « " ' : ■ ) i: J i r : , 1 PACHYMYA*. Gen. Char, Shell bivalved, transversely elongated, very thick, sub-bilobate, with the beaks near the anterior f extremity. Ligament partly im- mersed, attached to prominent processes or fulcra. A strong analogy exists between this genus and Mo« diola, evinced by the position of the beaks, the elongated form of the valves, and the partial separation of the an- terior portion into an imperfect lobe. But a closer in- spection shows that it is rather related to Cypricardiaand several other genera which have a comparatively short ligament, and that, fixed upon a strong prominent part of the shell within the edge, not linear and affixed to nar*- row edges, as in most of those thin shells that are allied to Mytilus. The great thickness of the valves, their depth, and the ridge that crosses them obliquely, help to distinguish this from other genera, independently of the hinge teeth, which we regret not having seen. It is probable that several fossils hitherto described as Modiolae will, when better known, prove to belong to this genus. * From 7 rot,ixps ( crassus ) and Mya, another genus which this resembles. f We purpose in this volume to use the terms anterior and posterior in their correct sense, as pointed out by the situation of the mouth of the animal. Vol. VI. 2 PACHYMYA Gigas. TAB. DIV. and DV. Spec. Char A gibbose heavy shell, above twice as wide as long ; the thickness also exceeds the length. It is slightly curved, with parallel edges. The anterior extremity is small, rounded ; the posterior, rather truncated : they are both close. The valves are rendered obliquely boat-shaped by a ridge that runs from the beaks to the lower extremity of the posterior edge ; the surface is smooth except to- wards the margin, where it is formed of the imbricated edges of laminae. We are indebted to the zeal and kindness of H. T. De la Beche, Esq. for the opportunity of representing this extraordinary shell : it is from the Chalk with quartzose grains at Dowlands, the lowest part of the Chalk for- mation in the vicinity of Lyme Regis. The generic name suggested by Mr. De la Beche ex- presses a slight resemblance which the shell has to some species of the Linnean genus Mya. 504. <505. | I 3 ORBICULA Lamarck. (Discina, Lamarck.) Gen. Char*. Bivalve, inequivalve, nearly orbi- cular, compressed, fixed ; upper valve patelli- form, with 4 internal muscular impressions, two rather large and approximating near the cen- tre, and two smaller and more distant, placed near the posterior margin. Lower valve flat, with corresponding muscular impressions and a rather obtuse process placed at the inner end of a fissure near the centre. Hinge none.” The animal has two ciliated arms or tentacula, and adheres by a muscle or ligament which passes through the fissure.” Little can be added to the above detailed Gen. Cha- racter. The shells that compose the genus are thin and rather coriaceous. The animals contained in them are analogous to those of Terebratulae and other Branchio- poda ; but the foot or byssus, instead of passing through the beak of one valve as in Terebratula, and being in- closed in a tube, passes through the disk and spreads im- mediately upon the stone it is attached to. Two recent species are known ; they are described, in the thirteenth volume of the Linnean Transactions, by my brother : and we have now the pleasure of adding three fossil ones, two of them from the collection pur- chased by him from the late Mr. G. Humphries, whose merits and penetration have unfortunately been rendered of little service to the scientific world. * Trans. Linn. Soc. vol. 13. p« 466. 4 ORBICULA reflexa. TAB. mi.— Jig. 1. Spec. Char. Shell subelliptical,, most pointed to- wards the back, polished ; upper valve rather convex, with the vertex near the posterior mar- gin ; lower valve flat with a nearly central ver- tex, the margin reflected ; sinus for the byssus large, elongated. Syn. Orbicula reflexa. G. B. Soiverby , Zoological Journal , v. 2. p. 321. Although a great part of the lower valve is flat, yet the portion behind the focus or apex is concave, be- ing gradually bent inwards towards the sinus, which ex- tends from the focus to the margin, and terminates where that begins to be reflected. The upper valve co- vers the reflected edge of the lower, in the same way that the upper valve covers or incloses the other in the genus Produeta, Both valves are smooth and very thin ; and, the lower especially, beautifully marked with con- centric lines and zones of a light colour : they seem to have contained a large portion of animal matter, and are very fragile, easily dividing into very thin, translucent laminae. We cannot discover any traces of impressions of muscles or ligaments, yet we do not doubt the pro- priety of placing this species in the same genus with the recent ones. A number of these curious shells were found in one or two broken Clay Ironstone nodules, buried, — with 506. 5 many hundred unknown shells and numerous marks of a scientific mind, — in Mr. Humphries’s collection, which had been for many years unopened when my brother pur- chased it and disclosed its riches. It is remarkable that both valves should always be found, and no substance ac- companying them to which they may have been attach- ed : but this is partly accounted for by the nature of the attachment, which would fail upon the death of the ani- mal, and by the elastic texture of the valves, which, as one is inclosed in or grasped by the other, would still hold together. We know of but one other specimen ; it is a single individual attached to Nucula Ovum : both are filled with indurated clay. It is in the cabinet of John Hogg, jun., Esq., who obtained it near Whitby, from the Alum Clay. ORBICULA Humphriesiana. TAB. DVI .—Jig. 2. Spec. Char. Conical, orbicular, marked with di- verging strise ; apex elevated, rather excentric, obtuse. Much resembling the O. norvegica ; but it is a higher and more regular cone, is more deeply striated, and thicker. We do not know the lower valve. Found attached to Ostrea deltoidea (M. C. 1 1 1.) in Mr. Humphries’s collection, with a label marked u Collin- son’s Sale, at Langford’s.” We suspect it to come from the Oxford Clay at Shotover Hill. 6 ORBICULA granulata. TAB. mi.— jigs. 3 and 4. Spec. Char. Conical, orbicular, marked with gra- nulated radii ; apex elevated. A more elevated and regular cone than even the last : but the sides are rather rounded ; the diverging lines are elevated, and rendered granular by the lines of growth. We have not seen the other valve. This shell had passed for a Patella, but its orbicular form gave rise to some doubts : and we now venture to place it under the genus Orbicula, in consequence of its strong resemblance to the last species. From the Ancliffe Oolite in the collection of the Rev. G. Cookson. Fig. 4 is an enlarged view. 7 TRIGONIA nodosa. TAB. DVII.— -^g*. 1. Spec. Char. Obovate, depressed ; anterior part covered with rows of large knobs., a portion of the posterior part plain ; superior edge straight. A large rather depressed species : two or three rows of slightly elevated tubercles extend from the beaks to- wards the posterior margin, which is truncated irregu- larly : from that row of tubercles which passes over the disk, 8 or 10 others extend obliquely over the whole of the anterior portion. Much resembling T. daedalea (M. C. 88.) ; but it is larger, and the tubercles are less numerous, and do not cover the posterior portion. Casts of the insides have been preserved in Mr. Sowerby’s Museum since 1815 s they were found in the Green-sand at Hythe in Kent. 8 TRIGONIA imbricata. TAB. DVII. —Jigs. 2 and 3. Spec. Char. Transversely oblong, depressed ; with 5 or 6 concentric, dentated, subimbricated keels upon the rounded anterior side ; posterior side obliquely truncated, ribbed. The carinae upon the surface of this little shell resem- ble terraces one above the other ; each is divided into 4 or 5 angular lobes. Imperfect specimens of this Trigonia occur in the Rev. Mr. Cookson’s collection of AnclifFe fossils. Fig. 3 is enlarged. TRIGONIA cuspidata. TAB. DVII.— figs. 4 and 5. Spec. Char. Obovate, depressed, ribbed ; poste- rior side truncated, its lower angle pointed ; ribs concentric, with projecting angles where they pass unto the posterior side. A delicate, slender shell. It has, in place of the keel (which in several other species runs from the beak to the lower angle of the posterior edge), only produced angles of the ribs, the last of which forms a strong point at the lower extremity of the truncation. The hinge teeth are unusually long. From the AnclifFe Oolite, w ith the last. Fig. 5. a magnified representation. So 8 9 TRXGONIA angulata. TAB. mill.— jig. 1. Spec. Char. Transversely elongated,, convex ; pos- terior side produced, truncated, transversely striated, bounded by a crenulated line ; the remainder ornamented with nodose ridges bent at right angles as they pass over the middle. Syn. Trigonia clavellata var. Min. Conch, t. 87. lower jigures . Vol. i.p. 197. Upon the posterior side are not only transverse striae, but there is generally a crenulated ridge in the middle of it ; the crenulations upon this and also upon the bounding lines are often elevated into small spines. The curvature, like the letter S,of the concentric ridges,which are sometimes divided into distinct tubercles, and at other times continuous, is a strong and constant charac- ter. The portion above the anterior side (correspond- ing with the lunette in other shells, but very large in this) is smooth. The breadth seldom exceeds an inch and a half. An excellent specimen lately lent us by our good friend Thomas Meade, Esq. has shown this to be a dis- tinct species, which the imperfect specimens formerly figured were not sufficient for. It is from B re wham near Nunney. The accompanying shells are Astarte elegans (M. C. 137.), an unpublished one, resembling a Tellina, and, at the back of the mass, fragments of a smooth Pecten. 10 TRIGONIA Pullus. TAB. mill.— jigs. 2 and 3. Spec. Char. Obovato-triangular, with transverse smooth ribs ; posterior side obliquely trun- cated, marked with several crenulated ridges and bounded by a strong crenulated keel ; lu- nette large,, regularly striated across. This so nearly resembles T.costata(M.C.tab.85.), that it is doubtful whether it may not be the young state : the only marked difference, except size, is the regular some- what curved set of elevated lines that cross the lunette at right angles with the edge of the shell, in place of irregular lines of growth ; the form is not quite so an- gular, and the ridge that separates the posterior side pro- jects beyond the edge. I am not acquainted with the locality of the specimen fig. 2, but it is evidently from the same kind of stone as the smaller ones, fig. 3, which are from Ancliffe. There is in the Green-sandstone at Hythe in Kent, a Trigonia much resembling T. costata ; but the speci- mens that have come into our hands are too imperfect to describe, or even to distinguish : it appears to have fewer ribs. soy. 11 PALUDINA elongata. (Gen. Yivipara, Yol. i. p. 75.) TAB. DIX.— figs. 1 and 2. Spec. Char. Ovato-lanceolate, smooth ; volutions 5, convex ; aperture elongated. Well distinguished from the other species of Paludina by its great length, which equals twice the diameter : it resembles the recent species common in fresh water every where (Helix tentaculata Linn.), but is larger and even longer in proportion than that is. When Yivipara Fluviorum (Paludina vivipara of La- marck) was published in Mineral Conchology, it was not known that fresh-water formations were to be found be- low the Chalk ; nevertheless the probability of one was pointed out by that shell. The existence of several spe- cies of Paludina, of bivalved shells belonging to the fresh-water genus Cyrena, and of Cypris, in the strata between the Green-sand and the Portland Rock, indicate this range to be of fresh-water origin. (See Dr. Fitton’s paper in the Ann. of Phil. vol. viii. N. S. p. 379; and Mi- neral Conchology, vol. v. p. 138. tab. 485. Cypris.) Dr. Fitton has favoured us with specimens out of the Weald Clay, in hard ferruginous clay (u Clay-Iron- stone”), from Compton Grange Chine in the Isle of Wight. Most generally only the cast of the shells re- mains, but in that selected for representation the shell is preserved (fig. 2.): it is accompanied with Cyrena and Cypris. The same shell also occurs less perfect in la- minated Clay and in u irregular concretional masses of hard calcareous grit in the latter the shells are often filled with sulphate of barytes. We have taken fig. 1. from a mass of Limestone, upon the surface of which the shells are tolerably per- fect, although within they appear to be crushed (a cir- 12 cumstance that, however curious and difficult to account for, is not uncommon), and from some detached indivi- duals that were collected at East Peckham in Kent by J. B. Dorient, Esq. Although we cannot detect the Cy- pris among these, we suppose they come from the beds of Limestone subordinate to the Weald Clay : some fragments of the fibrous carbonate of lime resembling “ Curl” mentioned by Dr. Fitton (p. 374, note) occur with them. PALUDINA carinifera. TAB. DIX- fig. 3 . Spec. Char. Ovato-conical, smooth ; volutions 4, convex, the upper two bounded by a linear keel at the lower edge. Not much longer than wide, and rather blunt ; the thread that runs round the sutures of the two upper whorls is a strong character. From one of the upper beds of Purbeck Limestone. In the interior of the mass the shells are more complete- ly crushed than in that from East Peckham just men- tioned : it contains fragments of some bivalve. The insulated figure is taken from parts of several in- viduals. In the Sandstone at Hollington near Hastings, and in other parts of the Hastings Sands, there occurs a Paludina of nearly the same proportions as the one before us ; but as we have only seen casts, we cannot determine the species. 13 GERVILLIA, Defiance. Gen. Char. An unequal-valved, unequal-sided bi- valve,, oblique, much elongated ; beaks near the anterior extremity ; hinge long ; divided into several pits„ and furnished with many, more or less lam ell i form, teeth ; one muscular im- pression in each valve. A genus nearly related to Perna. The species upon which it is founded has nearly parallel edges ; but seve- ral others that possess the same characters in the hinge, are ovate, and more or less taper towards the extremi- ties. The hinge consists in a long transverse area, con- taining 3 or more shallow hollows destined to receive the ligament ; about the inner edge of this area are a number of irregular interlocking lamellar teeth, varying in their direction and size in different parts of the same hinge and in different species ; those placed towards the anterior extremity are, in the type of the genus, small and longitudinal ; the others long and transverse : in other species they are all either oblique or transverse. The casts of the typical species indicate a shell that gapes at one if not at both extremities ; the other species are close. The shell in all is thick, and probably consists chiefly of pearl. Mons. Defrance established this genus in the Diction - naire des Sciences Naturelles , from casts discovered by Mons. de Gerville,— -in commemoration of whom he has named it, and thus done honour to a Naturalist whose zeal and urbanity justly merit it. — Other species have been added to it by Mons. Eudes-Deslonchamps, in conse- quence of the resemblance in their hinges. Hereafter these will form at least a sub-genus. 14 GERVILLIA solenoides. TAB. D X.—Jigs. 1 to 4. Spec. Char. Transversely much elongated,, depress- ed,, smooth ; edges parallel ; anterior extre- mity truncated^ open; teeth of the hinge nu- merous,, variously disposed. Syn. Gervillie solenoide. Def ranee, Diet. desScienc. Nat. 18. p. 503. cahier 16. pi. 18./. 4. Gervillia solenoides. Eudes-Deslonchamps, Mem . de la So c . Linn .duCalvados, 1 824 .p . 1 29 . A long, narrow, slightly curved shell ; the hinge con- tains about four depressions for the reception of the li- gament : the teeth within are irregular and linear ; those on the anterior extremity are most elevated and placed perpendicular to the hinge line ; the others are in the same direction with it, and often curved : the anterior ex- tremity appears to be open, perhaps for a byssus ; the other we have not seen. The shell is at least eight times as wide as it is long. Many imperfect casts of this extremely curious shell were collected in 1818 at Shanklin Chine in the Isle of Wight by my father, in the lowest ferruginous beds of the Green-sand (fig. 2. and 3.); and immediately identified with casts from Normandy, which he had received from his highly valued correspondent Mons. de Gerville. The discovery of the same fossil, with a portion of the shell preserved (fig. 1.), in the lowest beds of Green-sand near Lyme Regis, by H. T. De la Beche, Esq., has induced me to figure it ; and for illustration I have added two figures taken from specimens picked up at Fresville by Mons. de Gerville (fig. 4.). Many of the fossils which ac- company the same rock with this in Normandy, are un- known in any English stratum ; others correspond with those of the Green-sand ; and some with Chalk fossils, — a circumstance that may give rise to much speculation. 3.70. 15 GERVILLIA ? acuta, TAB, D X.—fig. 5. Spec. Char. Ovate-lanceolate,, oblique,, narrow, de- pressed, slightly curved ; anterior extremity acute ; teeth in the hinge variously disposed. Externally this shell exhibits a few lines of growth ; it is comparatively thin s its width (the longest measure from the two extremities) is four times its length ; the anterior portion is rather remarkably attenuated, the other extremity is rounded. Found in a calcareous sand-stone at Colly weston, by the late Lady Wilson. We have not been able to ascertain whether this have any hollows in the area of the hinge destined for the ligament, as that part is not visible in the specimen, al- though there are four or five casts of the inside, and one or two of the outside upon it. The thinness of the shell would lead us to think it an Avicula, were not the teeth so large, and differently placed. 16 GERVILL1A aviculoides. (Perna aviculoides. Min . Conch, tab. 66.) TAB. DXI. Spec. Char.* Obliquely ovate-lanceolate, curved ; both extremities pointed ; hinge line nearly half the length of the shell ; hinge teeth few, similarly disposed. Distinguished from G. per- noides of Mons. Deslonchamps above quoted, by its more pointed form. At the request of several friends, and for the purpose of further illustrating this species, we have given a second plate of it. It belongs to that division of the genus in which the lamellar teeth of the hinge are all nearly in the same direction. Fig. 1. is from a remarkably fine speci- men in the cabinet of our kind friend J.Vine, Esq. It exhibits the opposite valve to those figured on tab. 66. Fig. 2. is a portion of the hinge with two lamellae. Fig. 3. shows a front view of both valves, in which their differ- ence is seen, one having a shallow furrow along it, which the other wants. These three specimens are from the Shanklin Sand. Fig. 4. is a cast of the inside, picked up on Shotover Hill, Oxford ; it shows the muscular im- pression and several of the points of attachment of the mantle. Fig. 5. the cast of the hinge nearly perfect, taken out of one of the same masses that produced the Gervil- lia solenoides. Similar casts are met with in Parham Park, but not, I believe, accompanied with the G. sole- noides. They are mentioned by Mr.Mantell(p. 74. n. 17.). Mr. De la Beche has found the same species in the lowest strata of Green-sand near Lyme. Hence it should ap- pear that it is a constant attendant upon that formation. * This will supply the place of the one formerly given. V'«v 1 512. ' 17 AVICULA lanceolata. TAB. DXII.—^g*. 1. Spec. Char. Transversely linear-lanceolate, com- pressed ; posterior wing large, obtuse-angled ; anterior wing minute, pointed. Six times as wide as long, very flat ; the beaks are very near the anterior extremity ; the posterior extremity is narrow and blunt ; the posterior wing extends about one third the width of the shell : it is in no part distinct, but runs along the superior edge ; its two edges, one of which is a continuation of the hinge line, meet at a very obtuse angle. A very remarkably formed shell (if in fact it be a shell) strongly resembling the external bony appendages to the abdominal fins of several fishes : the manner in which the pair is displayed strongly favours this resemblance, and is by no means common among fossil shells. Figured from a specimen in the cabinet of H. T. De la Beche, Esq., who found it in the Blue-Lyas ofLyme Regis, Dorsetshire. The shell is imposed upon a plate consisting of per- pendicular fibres, of grey carbonate of lime, imbedded between the laminae of the slaty clay that composes a great part of the Lyas stratum. It is accompanied by a small Pecten. 18 AVICULA ovata. TAB. DXII.-; -fig.2. Spec. Char. Transversely ovate,, convex ; poste- rior side elongated, blunt ; hinge line long, forming part of the posterior wing, which is not distinct. A slightly curved shell, much approaching in form to a Gervillia ; the hinge line occupies more than half the width of the shell : the wings do not project beyond it, but are rectangular, and raised upon the upper edge of the shell ; the beaks are rather prominent. This may easily be taken for a short variety of Gervil- lia acuta (tab. 510.): but we can detect no indications of lamellar teeth or cavities in the hinge. It is a species that connects the two genera. A very abundant shell in the Stonesfield Slate. 19 THETIS * Gen. Char. An equivalved subequilateral bivalve ; more or less orbicular, and convex ; ligament marginal ; 3 or 4 small acuminated teeth about the hinge ; the line of attachment of the mantle ? has a deep sinus extending nearly to the beak; muscular impressions rounded, small, distant from the hinge. Ligament external* This genus bears some resemblance to Mactra; but the ligament is not internal, nor are there any remote teeth. It also comes near to Tellina, but its margin is not curved laterally. The shell is thin, with small incurved beaks : the leading feature is a line within, which, taking an irre- gular sweep from the anterior muscular impression over the middle of the valve, turns suddenly up, almost to the beak, then bends down again in a nearly parallel direc- tion for some distance, and at last proceeds to the pos- terior impression. This line has much the appearance of the mark'formed by the attachment of the mantle ; but the sipus in it is so remarkably directed that we are led to doubt, more especially as we have only observed fos- sil examples. There is no lunette or other external mark, the surface being nearly smooth and plain. The teeth about the hinge are unequal : the two interior ones are largest, conical, and slightly curved ; the other two, if there be more than one, are small. The fossils composing this genus have been referred to Venus, but are totally distinct. * The elegant symmetry in the form of the shells of this genus render it worthy of the name of this beautiful Sea Nymph. 20 THETIS major. TAB. DXIII. —Jigs. 1. to 4. Spec. Char. Convex,, orbicular ; posterior edge rather angular ; beaks small. Often two inches wide, and nearly as much long ; ex- tremely thin : the surface is plain and smooth, except numerous longitudinal rows of very minute rising punc- tums, probably epidermis : the beaks are small, sharp, and curved close together. The size and a less degree of convexity are almost the only points in which this differs from the following. The most perfect specimens we have met with, were col- lected at Blackdown, in 18 12, by Miss E. Hill ; they are siliceous casts imbedded in Sandstone, and do not appear to have undergone any violence, as they are regular and precisely similar in shape. (See fig. 1.) The same species is very abundant in the soft micaceous Sandstone near Devizes, where there are only casts, which, in common with the other fossils of that place, are much and various- ly distorted (figs. 2. 3. &4.). For these we are under obligations to Miss Gent. It occurs also at Earlstoke. 513. 21 THETIS minor. TAB. DXIXL —Jigs. 5 and 6. Spec. Char. Gibbose, wider than long ; posterior edge rounded. Syn. Venus. Mantell,GeoL of Sussex, p. 73. no. 12. Generally about an inch wide, but sometimes nearly an inch and a half : it is more convex and has larger beaks than the preceding species ; the surface has the same kind of punctums, but they are very seldom to be traced in the circumstances under which the individuals are commonly presented to us. An immense number of very perfect casts of this neat shell occur in the hard ferruginous masses of the lower Green-sand at Parham Park in Sussex, and Shanklin Chine in the Isle of Wight. Specimens from the former spot have long been in Mr. Sowerby’s Museum, where they were deposited by G. Mantell, Esq. ; those from the latter place (fig. 6.) were collected by my father himself, in 1818. H.T. DelaBeche Esq. has also discovered it in the lowest Green-sand near Lyme Regis, where the earthy matter of the shell still remains (fig. 5.) ; but the shells 22 are often much distorted. They are in all these places ac» companied by various other shells, especially by Trigonia aliformis and two unpublished species of Rostellaria, which, as far as the very imperfect fragments hitherto obtained will indicate, are nearer allied to the R. Pes Pelicani, than they are to R. Parkinsoni. Since the Plate was engraved, we have met with a beautiful white individual of this species, from Black- down, in which the short, cylindrical, external ligament is very neatly cast in Silex. J24, 23 AMMONITES Taylori. TAB. DXI V.—Jig. 1. Spec. Char. Discoid,, radiated ; inner whorls ex- posed ; radii about 12, with one large spini- form tubercle upon each side of the front, and one or two slight elevations on the rounded sides of the whorls; aperture nearly round. Aperture rather transverse, not quite one-third of the diameter of the shell long : there are about three whorls ; the inner ones are small, but almost wholly exposed to view. Found in a water- worn mass of indurated Clay ap- proaching Ironstone, and containing Blende, in Hap- pisbury Cliff, where it was probably alluvial. For the use of the specimen I am indebted to R. Tay- lor, Esq., of Norwich, whose assiduity in collecting and drawing the fossils of the Cotswold Hills, and other Geological researches, have induced me to yield to friendly inclinations in commemorating his name. 24 AMMONITES Hippocastanum. TAB. DXIV — fig. 2. Spec. Char. Gibbose, umbilicated, radiated, spi- nose ; inner whorls almost concealed ; radii ten or more, unequal, much elevated, each fur- nished with three tubercles upon the front, and most of them with two obtuse spines upon each side ; aperture transversely obovate. Distinguished from A. rhotomagensis by the convex- ity of the sides of the whorls, the small number and thick- ness of the radii, and the size of the spiniform tubercles ; the thickness equals two-thirds of the diameter at least. At first sight this fossil has a very striking appearance, although upon examination it is found to be very nearly allied to the following. The specimen is in the cabinet of H. T. De la Beche, Esq., who discovered it at Dowlands, in the same Chalk (replete with large grains of Quartz and Green-sand,) which produced the Pachymya (tab. 504.). We have a small specimen from near Rouen, also containing parti- cles of Green-sand, but no conspicuous grains of Quartz. We have named it from its resemblance to the thorny capsule of the Horse-chestnut. S1& 25 AMMONITES rhotomagensis. TAB. DXV. Spec. Char. Discoid, radiated, umbilicated ; inner whorls partly concealed ; radii about 20, fur- nished with three short tubercles upon the front, and two more or less elevated upon each side ; whorls thick, with flattish sides ; aper- ture oblong. Syn. Am. rhotomagensis. Cuv. $$Brongn. Env. de Paris , p. 83. t. 6./. 2. Am. sussexiensis. Mantell , Geol. of Sussex, p. 114. t. 20. f. 2. and t.Ql.fig. 10. In the centre of the rounded front of this Ammonite is a row of tubercles, one placed upon each rib ; on each side of this is another similar row : these, toge- ther with the flattened sides and wide umbilicus, are the distinguishing characters ; the other two rows of tubercles are very variable, the outer one often ri- sing into obtuse spines. When these tubercles are in- conspicuous, it bears a strong resemblance to A. Man- 26 telli (tab. 176.) ; when they are large it comes still nearer to A. Hippocastanum, which may possibly be only a re- markable variety of it. Mr. Mantell observes, “ it varies from a few inches to a foot in diameter.” Very abundant, but less so than A. varians (tab. 55.), in the lowest Chalk and Chalk Marl of Sussex, Wilt- shire, &c., as at Hamsey, Bidcomb, and Rouen. It is an unfortunate circumstance that two names should have been given to this Ammonite from its loca- lities, and proves the impropriety of such names for fos- sils ; — we retain that which we suppose to be the oldest. . SM. 27 ISOCARDIA similis. TAB. DXYI. —Jig. 1. Spec. Char. Transversely rather oblong*, ventri- cose, slightly flattened; anterior side small, turned a little up ; edge of the base nearly straight. A large strong shell, which differs from the recent Iso- cardia Cor only in having a straighter edge to the base, a larger anterior side, and a slight flatness of the middle of the disk. The base line being straight, makes it rather wider than long. Found at Sandgate near Margate, in the upper Green- sand. It consists of the original calcareous matter of the shell somewhat loosened in its texture. ISOCARDIA Cor ? TAB. DXYI. —fig. 2. From the small fragments that are sometimes found of an Isocardia in the Suffolk Crag, we are able to draw no other conclusion, than that they belong to the same spe- 28 cies which still inhabits the sea; but until nearly whole individuals are met with, it would not be just to speak too positively : for although several other of the Crag- shells correspond with recent species, we must not be too hasty in supposing shells from distant parts to have been mixed accidentally with the Crag. Most, if not all the other shells that agree with recent ones, are such as may still be found on the neighbouring shores ; while the nearest habitat of the Chama Cor is the Irish coast. There are found near Verona, and in other places abroad, casts in limestone of an Isocardia resembling the Cor, but more ventricose, shorter, and smaller. Such probably occur in England, perhaps even at Heddington in Oxfordshire (see Plott’s Oxfordshire, page 127) ; but we have not met with any specimen of which we know the locality. We propose to call it I. ventricosa. 29 UNIO Solan dri. TAB. DXVIL Spec. Char. Transversely oblong-ovate,, slightly arched, rather compressed, thin ; both extre- mities obtuse ; beaks small, rugose ; hinge slender. Syn. Mya Pictorum. Brander , 95 ? Exactly twice as wide as long ; the posterior extre- mity is rather square and more compressed than the other ; the superior and inferior edges are parallel and a little arched ; the beaks are slightly waved or rugose. This beautifully pearly shell resembles the Unio ba- tava of Lamarck, but is more compressed : it differs from U. Pictorum of the same author in the square form of the posterior extremity, and from both in being a little curved. It appears from the cast that the mus- cular impressions are not deep, and there is only a small space left for the hinge, the teeth of which we have not been able to extricate ; the general contour of the shell, its rugose umbones, and brilliant pearl are so charac- teristic of the genus Unio, that even if the hinge were 30 never to be seen, no one would doubt the propriety of re- ferring* it to it : added to this, it occurs among decidedly fresh-water shells, such as Paludina lenta (M. C. /. 31.) in sandy clay in the lower freshwater formation of Hord- well. Brander’s fig. 95. does not accord in form with the shell before us : but as he has referred it to Mya Picto- rum of Linnaeus, and as we know of no other shell found at Hordwell at all resembling it, it is probable that his figure was taken from a specimen so mutilated as to give a very different idea of the shell, to that he had formed by observing a number of individuals. The shells themselves are exceedingly fragile, and the earth they are imbedded in so loose, that it is not often a cast can be preserved tolerably entire ; so that his specimen might be much broken before it was drawn #. We are indebted to the zeal and perseverance of our kind friend Charles Lyell, juu., Esq. for the knowledge of this Unio, which we consider a valuable addition to the list of freshwater fossils. It occurs in abundance, but it required much care to save two or three speci- mens. The several fossils formerly published as Uniones require reconsidering before they can be established in the situation assigned them ; for they present characters and occur under circumstances not compatible with the habits of that genus, or not fully explained. * The only way to keep the shells is to soak them in gum- water soon after they are picked up, first drying them care- fully. VENUS caperata. TAB. DXVIII. —Jig. ]. Spec. Char. Orbicular, rather depressed,, covered with small, rounded, concentric ridges ; lu- nette cordiform, inconspicuous. A nearly lenticular shell, but rather most gibbose near the umbones ; the concentric ridges are numerous, sharply defined, rounded, and equal to the spaces be- tween them. The hinge has a large tooth under the lunette in one valve, and in the other a laminated tooth within the posterior slope, besides those under the beaks. These teeth occur also in other species, and will serve, if not to distinguish a genus, to characterize a section. Found replaced by silex on Blackdown many years ago by Miss Hill : the same has lately been observed by Mr. De la Beche in the vicinity of Lyme, along with the Gervillia (tab. 510.), in the lowest beds of the Green- sand, where, although not only the earthy part of the shell but also the fibrous portion of the ligament are still remaining in a firm stone, the individuals are fre- quently as much distorted as the casts of shells gene- rally are in the loose sand near Devizes. Figs. 1. and 3. represent Blackdown specimens; and fig. 2. is from a distorted one in the cabinet of H. T. De la Beche, Esq. — it shows a portion of the ligament. VENUS parva. TAB. DXVIII. —Jigs. 4, 5 and 6. Spec. Char. Transversely obovate, rather convex^ smooth ; lunette narrow. This species is very nearly orbicular; its form is so simple that it is not easy to describe how it differs from shells of other genera with which it is associated, al- though an accurate eye will readily observe it even when its hinge is not discoverable,— the degree of its convexity and evenness of its surface are the most ob- vious marks of distinction ; it is less convex, and has besides a larger hinge than Thetis minor (tab. 513.), but is more convex and smoother than another shell (pro- bably a Lucina) that also occurs with it. The hinge, as far as can be learnt from casts, is similar to that of V. caperata above described. Abundant in the lower beds of Green-sand at Parham Park*, Shanklin Chine, and near Lyme. * By accident, the only specimens of the ferruginous stone from Parham Park containing casts of Gervillia solenoides (tab. 510.) had been mislaid; and in consequence it was observed on page 16, that in Parham Park, Gervillia aviculoides (tab. 511.) is u not accompanied with the O. kolenoides.” S3 EMARG1NULA? s. PISSURELLA ? claihrata. TAB. DXI X.—jig. 1. Spec. Char. An elevated curved cone ; sides coarsely reticulated ; longitudinal ribs about six on each side, and one central, which is split more than half way down from the apex ; base oval ; apex bent almost down to the base. This little shell has the general form of Fissurella reti- culata, but is more curved : it is however in all probabi- lity generically distinct, for we have not met with a spe- cimen that has a notch in the margin ; on the contrary, the central rib is split for a considerable distance from the apex ; but as this does not appear to be perforated, but is acute, the propriety of referring the species to Emarginula is doubtful. 34 EMARGINULA tricarinata. TAB DXIX.- fig. 2. Spec. Char. Conical, with the apex bent down ; surface marked with three principal and se- veral lesser ribs, the spaces between them nearly smooth ; base oblong. The three ribs upon the posterior portion of this Emar- ginula are very prominent ; the middle one is divided by the marginal fissure, which gradually filling up as the shell grows, leaves a striated surface in the centre of it. EMARGINULA scalaris. TAB. DXIX.— /g\ 3. Spec. Char. Conical, ribbed ; apex excentric ; ribs many, connected by numerous cross lines ; base obovate. Almost upright, the apex being very litttle bent for- ward ; the ribs are equal, and the central one divided into two by the fissure in the margin. These are all from the Ancliffe Oolite. They all so much resemble each other, and are so small, that al- though there might be some doubts respecting the genus of the first, it did not seem desirable to place them upon separate plates. 35 ASTARTE striata. TAB. D XX,— fig. 1. Spec. Char. Lenticular, transversely striated ; lu- nette ovate, flat, deeply sunk, shell thick. A very round shell, with small close beaks, and very numerous, regular, rounded furrows, or impressed striae ; the edge is obtuse, and probably entire. Drawn from a Chalcedony cast sent me from Black™ down. ASTARTE orbicularis. TAB. D XX.— fig. 2. Spec. Char. Lenticular, rather gibbose, concen- trically furrowed ; furrows small ; posterior surface plaited with an angle at its edge ; lu- nette elongated, very deep. The convexity of this shell is rather greatest towards the beaks ; the lunette is deeply sunk, and composed of two planes that meet at an acute angle in its middle ; the shell is very thick, and has elongated crenulations with- in its edge. Our specimens are from the Hampton Quarry near Bath : the shells are replaced by crystallized carbonate of lime, which has also retained the impression of the external ligament : they are imbedded in Oolite. . . ' . . ' : >, ' .. - . ? ‘ i ‘ ' ■ i 3Z1 37 ASTARTE imbricata. TAB. DXXI. —Jig. 1. Spec. Char. Cordate, orbicular, largely imbricated, convex; tooth in the left valve beneath the lunette small ; lunette elongated, flat ; hinge line arched ; edge finely crenulated. The surface is marked with about eight ridges one above the other, in the manner of tiles : these may possibly be exposed by wear, but their small number is remarkable. ASTARTE nitida. TAB. DXXI .—Jig. 2. Spec. Char. Transversely obovate, angular above, rather depressed, minutely sulcated near the beaks, the rest even ; beaks pointed ; lunette lanceolate ; edge crenated. Somewhat variable in form, the beaks being more pro- duced and nearer to one side in some specimens than in others : all the varieties agree in being minutely and neatly sulcated around the beaks, while the rest of the surface is smooth and even ; the whole surface is regu- larly convex. 38 ASTARTE bipartita,, TAB. DXXL —jig. 3. Spec. Char. Obcordate, gibbose ; six or eight large undulations upon a flat space near the beak, the rest of the surface even ; beaks acute ; edge toothed. The peculiar character of this shell is, that part of its surface is much flatter than the rest, and upon this por- tion are a few concentric waves, the rest of the surface being even and convex ; the whole often appears dis- torted. In some specimens the two parts are not so distinctly marked : such are readily distinguishable from the last species by the size of the undulations, and the large, short, concave and smooth lunette. ASTARTE oblonga. TAB. DXXI. —fig. 4. Spec. Char. Transversely oblong, convex; surface largely waved ; beaks small ; lunette cordate, pointed, concave ; edge crenated. More depressed, much wider, and differently formed about the beaks than the last, the young state of which it might be supposed to resemble ; the beaks are not very prominent. These four species of Astarte occur rather abundantly in the Suffolk Crag: the first and last appear to be the least common. S22. 39 AMPULLARIA nobilis. TAB DXXII. —Jig. 1. Spec. Char. Subglobose„ smooth ; spire conical, composed of a few convex whorls ; base very convex,, not umbilicate ; aperture elliptical^ sublunate^ pointed above. A magnificent although a simple formed fossil : there is a boldness in its contour that renders it handsome, and at the same time gives it a character very different from fossils in general. The shell does not appear to have been thick : it was externally slightly waved in the direction of the lines of growth ; the spire is pointed, composed of about five whorls, and occupying one third the length of the shell : the aperture appears to be per- fectly longitudinal, and equals half the entire length. One of the products of that only recently explored mine of fossil shells, the Black Rock of Queen’s County in Ireland. The substance of the shell is partly con« verted into calcareous spar, but principally almost in- corporated with the black limestone. 40 AMPULLARIA helicoides. TAB DXXll.—jig. 2. Spec. Char. Almost discoid^ smooth ; spire very shorty blunt ; whorls nearly blended,, round ; base umbilicated ; aperture oblong*. A peculiarly obtuse-looking shell, whose diameter is nearly double its length ; the whorls are convex, but the sutures between them are not sharply defined ; the um- bilicus is of a moderate size ; the aperture is longitudi- nal as in the last, it approaches much towards circular, with an indentation in its upper half made by the pre- ceding whorl. Some individuals have an obscure band round the outer whorl. Not very unfrequent in the black foetid limestone of Ireland. The oval specimen, fig. 3. is, I believe, from near Cork ; the other from Queen’s County. These two species are referred to the genus Ampulla- ria, until another generic name is proposed under which to arrange them, along with such other fossil shells as we have recommended should be separated from that genus, to which Mons. Lamarck had with some hesita- tion referred them, and which do not belong to the neighbouring genus Natica. See vol. 4, p. 97. 523. 41 MELANOPSIS carinata. TAB. DXXIIL —fig. 1. Spec. Char. Ovate, acuminated, with a sharp carina wound about the spire. Rather more than twice as long as wide, smooth ; the last whorl flattened upon the sides, and sometimes having an obscure carina near its upper edge besides that projection of the edge which higher up the spire forms a sharp, spiral keel ; the aperture is elongated, its upper part rendered even linear by the large callus upon the inner lip. Found abundantly in a light greenish clay in a well near Newport, Isle of Wight, by Mr. Sowerby, in 1818, accompanied by Potamides ventricosus (tab. 341. fig. 1.), a new subulate Melanea, and various other fresh-water shells. It also occurs in a similar clay, and accompanied by the same shells, from Hampstead Cliff* to Cowes, and among the fresh-water series on the opposite Cliff’s of Hampshire, as we learn by specimens collected by the Rev. Professor Sedgwick and Charles Lyell, jun. Esq. It is also sparingly found at Headon Hill. 42 MELANOPSIS brevis. TAB. DXXIII. —Jig. 2. Spec. Char. Ovate., pointed^ short ; whorls ven- tricose., contracted in their upper parts ; aper- ture oval ; inner lip thick ; callus not very pro- minent. Much resembling several species of Buccinum : the con- vexity of its volutions is peculiar for a Melanopsis. Its width is about two-thirds its length ; the inner lip is of nearly an equal thickness throughout^ affording a strong contrast to the species above described. Picked up rather plentifully upon the Hampshire coast by the Rev. Professor Sedgwick. It has probably fallen from the fresh-water series near Hordwell. 624-. Z 1 43 SOLARIUM canaliculatum, TAB. DXXIV.— ^g. 1. Spec. Char. Convex, ornamented on both sides with granulated unequal lines ; edge promi- nent, crenated ; umbilicus furrowed and ere- nated within ; aperture round. Syn. Turbo. Brunder , Jigs . 7 8$ 8. Solarium canaliculatum. Lamarck , Env. de Paris , 104. Lam. Hist. Nat. 7. p. 5. Trochus canaliculatus. Brocchi , vol. 2. 359. There are three very distinct varieties of this Solarium. The English one, with only a few granulated ridges on the upper side, and the margin slightly prominent but relieved by a furrow on each side of it. The French va- riety, which has one prominent row of granules and many very minute rows on the upper side, the margin much produced and very finely crenated. And the Italian va- riety, of which the upper surface is beautifully orna- mented with many rows of conspicuous granules ; the margin very much produced, deflected, solid ; and so sharply crenated as to be almost dentated. In this va- riety the crenulations within the umbilicus are also very sharp and pointed. — The actual aperture is round in all the varieties, and the characters above mentioned are liable to some variation. Very abundant in the Clay at Barton Cliff. 44 SOLARIUM plicatum. TAB. DXXIV.— 2. Spec. Char. Convex, wrinkled, concentrically sul- cated ; umbilicus bounded by a more or less projecting crenated ridge ; aperture round. Syn. Solarium plicatum. Lamarck , Env. de Paris , 104. Hist. Nat. v. 7 ,p. 5. The sulci that cross the wrinkled surface of this shell are very narrow and deep upon the upper surface, but broader and unequal beneath ; they vary in number, but are generally 3 or 4 above, and 5 or 6 beneath : the crenulated keel that projects into the umbilicus, some- times half closes it, at others it leaves it more open, es- pecially in the French variety, whose umbilicus is very wide and open. Equally abundant as the last at Barton. 626 45 FUSUS alveolatus. TAB. DXXV.—fig. 1. Spec. Char. Turreted; volutions ornamented with two spiral obtuse carinae, crossed by thick ribs; beak half cylindrical, ribbed. Three rows of nearly square pits or cells are formed upon each whorl by the crossing of the carinae and ribs ; the last whorl exhibits several more carinae, which gra- dually diminish in size as they proceed upon the beak : aperture round, with an elongation into the beak. Found in the Suffolk Crag by Mrs. Cobbold and the Rev. G. R. Leathes : it is very scarce. FUSUS cancellatus. TAB. DXXV.— /g. 2. Spec. Char. Lanceolate, acute, covered with acute decussating ridges, with short spines at the points of their intersection ; volutions ventri- cose ; aperture oblong, produced into a short beak. Four or five spiral rows of cells appear upon each whorl, bounded by sharp divisions and short spines at their angles ; the spire is nearly twice as long as the aperture, which is rather contracted at its upper part. From the very rich cabinet of Suffolk and Norfolk Crag fossils, from which the Rev. G. R. Leathes has long and liberally supplied us. ' ■ - ... ' ■:* ' ■ ' 1 / . . . • ' ' - ' . 47 GASTROCHiENA Spengler. Gen. Char. An inequilateral equivalved bivalve, with the anterior margin obliquely truncated and gaping; the hinge-line straight, without a tooth, inclosed in a shelly sheath. The animal to which the shell above described belongs, perforates calcareous stones, corals or shells, by some solvent power, most probably not by wearing or scraping a hole, as Pholas and Teredo do ; and lines the hollows more or less completely with shelly matter ; or it forms it- self a sheath of the same substance in sand or other loose or soft materials, some of which it unites to its fabric for its protection, as it is only in part covered by the two valves, which moreover are very slender. This sheath or case is commonly ovate, and of such a size and form as to hold the Valves easily, with the posterior part so produced into a tube as to contain the two united tubes of the animal, its extremity being flattened and partially 48 divided by two opposite ridges, so as to fit very close when the animal is distended, and prevent the introduction of foreign substances. A tube very similar is formed by the Teredo, and some Lithodomi deposit calcareous earth about the openings of their cells, apparently for the same purpose. The two valves of the shell are thin, obliquely elongated, with the beaks near the anterior extremity ; the oblique truncation of the anterior mar- gin leaves a large space between the edges of the valves for the passage of the foot : the posterior portion is large, oval, and its edges towards the back more or less gaping. We are indebted to the accurate observer Spengler, for the establishment of this very natural genus ; and if Bruguiere had never proposed the genus Fistulana, Conchologists would not have had to encounter the mass of confusion created by Lamarck, but have found good places for all the shells he has crowded into it, by the adoption only of Gastrochaena, in addition to the genera before formed. The genus Fistulana, as given by La- marck, has gradually been deprived of nearly all its species ; only one is retained by my brother, who has given an able account of this dismemberment. M. Des- hayes on the other hand, only deprives it of all the spe- cies that do not belong to Gastrochaena, which genus 1 49 lie would lay aside, substituting Fistulana for it, not- withstanding Spengler’s priority and acknowledged ac- curate definition. To this plan we cannot subscribe. GASTROCHiENA tortuosa. TAB. DXXV L—fig. 1. Spec. Char. Obliquely lanceolate, twisted. The longest diameter is four times the united depths of the two valves, or above three times the length ; the hinge line is straight, the remainder of the shell twisted almost one turn : the sinus in the edge for the passage of the foot is elongated, acute towards the front ; the whole surface nearly smooth. Occurs in a dark brown clayey sandstone much stained with iron, in the Cliffs of Robin-Hood’s Bay, near Scarborough. The specimen is in the collection of Mr. Bean of that place : it consists of one valve placed upon the surface of the stone, without any indication of the tube that once inclosed it. 50 GASTROCHiENA contorta. TAB. DXXVI. —Jig. 2. Spec. Char. Sheath clavate, bent nearly at a right angle : valves ovate-elongated, marked with very slender stride ; the sinus between them wide, oval, pointed. Syn. Fistulana contorta. Deshayes Cocquilles Fossiles , v. 1. p. 16. pi. 1. Jig . 24, 25, & 27. Mem. de la Societe d’Hist. Nat. v. 1. pt. 2. p. 251. n. 3. pi. 15. f. 4. This species exhibits all the characters of the genus, forming a sheath that is more or less imbedded in other shells ; and the aperture of which, produced and often bent, is partially divided by two opposite ridges : the general form of the valves, especially the width of their anterior extremities, and the fine striae upon their sur- face, distinguish it from other species. The form of the sheath depends so much upon its situation, that it is not safe to lay any stress upon it as a specific character : we admit it, however, as it has been employed by Mons. Deshayes. By no means unfrequent in other fossil shells of co- temporary formation with those of the London Clay. The specimens figured are from Barton. From the larger size of some empty sheaths which are upon the same specimens, we suppose the shells are sometimes much larger than those figured. The five large figures are magnified representations. At letter a is seen the external portion of a sheath. . . J2 7. 51 CYCLAS pulcher. TAB. DXXYll.—fg. 1. Spec. Char. Suborbicular, convex, smooth, slen- der ; posteriorly truncated ; one sharp-edged and two bifid teeth near the beaks in each valve ; lateral teeth plain, obtuse. A thin shell in proportion to its size, which much ex- ceeds that of any other British species ; the angular form of its posterior portion is a conspicuous character. This species belongs to Lamarck’s Genus Cyrena ; but as we have much doubt of that being a natural di- vision, we do not at present adopt it. A discovery, for which we are indebted to the un- wearied research of Professor Sedgwick, who found it in abundance on the shore opposite Hampstead Cliff, Isle of Wight, at low water, in a stiff clay, accompanied by a small Cyclas, a striated Mytilus, Potamides ventri- cosus, (t. 341. f. 1.) Melanopsis carinatus, several small univalves, and a Serpula, — all together forming a curious mixture of apparently marine and fresh- water shells. CYCLAS medius. TAB. DXXYII. —Jig. 2. Spec. Char. Transversely obovate, depressed, thick, smooth ; anterior side small ; posterior rather pointed ; one tooth near the beaks in each valve. Syn. Cyrena media. Annals of Phil. New Series , vol. 8 .p. 376, 378, 379. Intermediate between Cyclas obovatus and C. cunei- formis, (tab. 162.) being flatter and thinner than the first, 52 but thicker and less pointed than the last : the hinge also appears to differ, as I have only been able to detect one central tooth in each valve ; but the clayey stone is so hard, that it is difficult to clear the hinge. This fossil occurs in various parts of the Weald Clay and Hastings Sands, both in Sussex and on the Isle of Wight. See Dr. Fitton’s paper in the Annals of Phi- losophy above quoted. The specimen figured consists of indurated clay, and was collected at Chart. CYCLAS membranaceus. TAB DXXYII. —jig, 3. Spec. Char. Transversely obovate, depressed, smooth, very thin ; anterior side small, pos- terior rather pointed. Syn. Cyrenamembranacea. Annals of Philosophy, Second Series , vol. 8. p. 376. Very much resembling the last, but it is extremely thin. Occurs in slaty clay, accompanied by two other bi- valves and two univalves, which for the present are named Melania attenuata and M. tricarinata, but which are so much compressed and broken that they cannot be well defined. Found at Funfield by Dr. Fitton, in the Weald Clay. 328. 53 L1MNEA maxima. TAB. DXXVIIL —Jig. 1. Spec. Char. Ovate-elongated, rather obtuse ; whorls about 6, slightly convex ; aperture narrow, occupying less than half the length of the shell. Readily distinguished by the bluntness of its outline and the large proportion which the spire bears to the whole shell. The columella appears to be thin. The Rev. Professor Sedgwick was so fortunate as to discover this large species of Limnea in the Stone Quarries at Binstead near Ride, in the Isle of Wight, this spring ( 1826). The specimens have lost almost all the exterior crust of the shell, the interior only adhering to the cast. LIMNEA columellaris. TAB. DXXVIIL— /g. 2. Spec. Char. Ovate-p6inted ; spire short ; whorls about 5, convex ; aperture wide, above half the length of the shell; columella much twist- ed and very thick. No other Limnea has so remarkable a columella : it is further distinguishable from most other species by the roundness of the whorls and shortness of the spire. Collected in the Hordwell Cliff by Charles Lyell, Esq. during a careful examination of the Freshwater Strata there, — the valuable results of which we expect shortly to see published ; it is accompanied by Planorbis rotundatus of Brongniart. 54 LIMNEA pyramidalis. TAB. DXXVIII. —fig. 3. Spec. Char. Ovate-acute ; whorls convex ; aper- ture half as long as the shelly dilated ; columella plait (or callus) obscurely divided. Syn. Lymnsea pyramidalis. Brard, Ann. du Mus. tom. 15. pi. 24./. 1 8$ 2. Desliayes, tom. 2, 95. pi. 10./. 14$ 15. A degree of symmetrical elegance in the form of this species is perceived at first sight : it arises from the slight convexity of the whorls, the pyramidal form of the spire, and the proportions of its parts. The plait, or rather callus, upon the columella has a shallow furrow in the middle, but it is not very conspicuous. Occurs at Headon Hill in the Isle of Wight. Our specimens agree well with Mons. Deshayes’s figures, but are shorter than Brard’s. We trust Deshayes was acquainted with Brard’s shell, as we follow his autho- rity. SZ9. 55 NAUTILUS excavatus. TAB. DXXI X.—fig. 1. Spec. Char. Nearly globose, smooth ; sides ex- cavated by a very large conical umbilicus. The whorls of this Nautilus increase very rapidly : they are so wide that they would produce a spherical form, were it not for the large umbilicus which occu- pies nearly half the diameter of the shell. The front of the aperture is arched ; the sides straight, converging towards the preceding whorl ; the siphuncle nearly central. From the collection of the late Mr. G. Humphries ; most probably from Dorsetshire. It seems to have been taken from the Inferior Oolite. NAUTILUS hexagonus. TAB. DXXIX.— fig. 2. Spec. Char. Short cylindrical ; sides depressed, conical; front broad, straight; umbilicus small; aperture sagittate, truncated ; siphuncle nearest the inner edge of the septum. In this species the septa are rather numerous and not much curved : its most remarkable character is the straightness of the lines that bound a section of it in the plane of the aperture, which section being an elongated hexagon has suggested the name. Far from rare in the Calciferous Grit at Shotover, Abingdon, &c. — the specimen figured was from the former place. It is in the cabinet of H. H. Goodhall, Esq. Sometimes the shell is decayed, when the casts ot the cells become loose, and may be separated like those of Ammonites Catena, tab. 420, along with which they are found. 56 NAUTILUS polygon alis. TAB. DXXX. Spec. Char. Sphaeroidal, compressed, smooth ; columella prominent ; umbilicus very small ; aperture arcuate, above half the diameter of the shell, long ; septa distant ; siphuncle near the outer edge of the septum, composed of a number of straight tubes. The thickness of this is about two-thirds of its diameter : it has a large aperture, the reflected extremities of which nearly close the umbilicus ; the septa are distant, very concave, and but slightly curved at their edges ; the siphuncle consists of a number of straight tubes, each projecting a little behind the septum it pierces to join the preceding tube. The whole series appears to be disjointed ; the polygon formed by it in the section has suggested the specific name. Probably from Dorsetshire. The only specimens we have met with were in the immense and various collec- tion of the late Mr. G. Humphries, along with specimens of N. lineatus tab. 41, marked from that county. The stone attached to the specimens resembles the Inferior Oolite. In N. lineatus, (which this nearly resembles,) the septa are numerous, the siphuncle central and curved, and the columella solid. 57 MYA? angustata. TAB. DXXXl.—fg. 1. Spec. Char. Valves unequal ; transversely elon- gated,, thin, antiquated, irregularly compressed; extremities obtuse, gaping; lower edge of the lesser (right) valve concave. Two or even sometimes three times as wide as long, uneven, and sometimes curved ; the umbones are much nearest to the anterior extremity ; they are small, and not eroded : the hinge resembles those of Myae plana and subangulata, tab. 76; but that it belongs to the same genus as the Mya labiosa is doubtful. Newly discovered by Professor Sedgwick in Colville Bay, Isle of Wight, along with Mytili, Ostreae, and some shells sometimes referred to fresh water, in a bed of Sand and Clay evidently belonging to that mixture ge- nerally called the Upper Marine Formation. 58 MYA Pullus. TAB. DXXXI. —fig. 2. Spec. Char. Transversely ovate and striated^ compressed ; anterior side largest ; posterior side rather pointed. A small slender shell about half as wide as long ; it is strongly marked by lines of growth, and therefore ap- pears to be a full-grown shell. Drawn from a specimen found in Crag at Butley, in Suffolk, and which is in the late Mrs. Cobbold’s collec- tion. It is said to be the only one met with. It is pos- sible it may be the young of M. arenaria tab. 364; but the difference of form and the roughness of its surface militate against that idea. 59 MYTILUS affinis. TAB. DXXXII. —Jig. 1 Spec. Char. Obliquely oblong, carinated, smooth ; sides parallel, straight; the posterior arched in the young shell ; hinge without teeth, its an- terior margin reflected. Very similar in shape and proportion to the common Mussel, or rather M. pellucidus, but more decidedly carinated ; the extremity of the hinge within the beaks is reflected, and has no appearance of teeth ; the poste- rior surface is not quite flat, but is convex near the beaks, a little approaching the genus Modiola. It dif- fers in the same way from M. Antiquorum (tab. 275.), as it does from M. pellucidus ; — it is remarkably pearly. Found in Colville Bay, Isle of Wight, by Professor Sedgwick, along with Mya angustata, Potamides ventri- cosus, &c. in Sand and Sandy Clay. V 60 MYTILUS Brardii. TAB. DXXXII.— /g. 2. Spec. Char. Convex, straight, pear-shaped, elon- gated ; beaks acute, terminal (within each beak a plate is extended to the opposite edge for the support of a tendon, and within that is a flat angular process). Syn. Mytilus Brardii. Faujas , Ann. du Mus . 8, t. 58./. 11 $ 12? Brongn. Ter. du Vicentin. 78. t . 6. /. 14?* Basterot , Mem . de la Soc . d’Hist. Nat. 2. Part 1, 78. A rather variable shell, its surface being generally convex with an approach to keel-shaped near the pointed beaks. Specimens from Dax are often sharply keeled for nearly half their length, and the rest is antiquated. The plate which extends across the cavity within each beak, bears a small muscular impression, analogous to that upon the surface near the beak in most other Mussels. The only other species that has a similar sup- port for the attachment of the smaller muscle or tendon, whichever it may be, is the Freshwater one, M. poly- morphus, found in the Danube and most of the rivers in the north of Europe, and lately in the Commercial Docks and Surry Canal, near London ; and a small one often brought from the coasts of Africa (M. murinus ? of Gmel.). The former is well distinguished by its curved very deep keel-shaped valves, and by having in general an irregular thin septum within and parallel to the * The figures given by Faujas and Brongniart are both un- satisfactory. 61 plate above mentioned, but quite detached from it. The second species so nearly resembles the fossil, that we can point out no difference ; they are both liable to the same variations of form, are of the same size, and both possess within the hinge the same kind of flat angular process ; a process that is attached in part to the line that supports the hinge cartilage, and in part to the be- fore-mentioned plate, from which it descends obliquely into the cavity of the valve. This appendage is regular and constant, and therefore should appear to be con- nected with the form of the animal ; whereas the second septum in M. polymorphus, does not always occur ; and when it does, it is irregular and seems to be the effect of disease or over-luxuriant growth. This very interesting shell is abundant at Dax and Merignac, and probably in several other parts of the Continent : but it was reserved for Charles Lyell, Esq. jun. to discover it in England. He found it in the ex- tensive bed of White Sand connected with the Lower Freshwater (or rather perhaps the so called Upper Ma- rine) Formation, in the Hordwell Cliff. It is accompa- nied by Mya plana (tab. 76.) in profusion, a Potamides like margaritaceus (tab. 339. f. 4.) a little Melanea ? (Bulimus conicus ? Brard), and, what is most curious, a small Serpula. We have therefore either a mixture of Marine and Freshwater shells in a bed hitherto thought by us to contain only Freshwater ones, or we are mis- taken in drawing conclusions from analogy without suf- ficient examination. The Mya plana certainly resem- bles the Mya labiosa (a recent Freshwater species) more than it does any known Marine one : but it is slenderer, and the beaks are not eroded as in most Freshwater shells. The Potamides is an ambiguous genus. What we call a Melanea, and which Brard has referred to Bulimus, greatly resembles some species of Phasianella. The marks of distinction are small ; as we are ignorant of the operculum, or if it ever had one. The Mytilus re- sembles more closely the African species, than that from the Danube ; but the African species may be washed from the rivers down to the coast, or, like that from the Danube and the Wolga, it may be capable of living in 62 both fresh and salt water. All these shells still leave us, therefore, in doubt. But what does the Serpula prove ? No Serpula is known to live in fresh water, and the one we have along with these Mussels is too tender to have been removed far ; so if the other shells belong to fresh water, they must have been brought down by a river into the sea ; but they are extremely well preserved, and many as tender as the Serpula, which makes us rather incline to the opinion that they are all Marine, at least those which occur in the same stratum. That river shells should be washed down to the coast and mix with marine ones is probable : even large masses or islands, consisting of decayed vegetable matter with the shelly remains of animals that lived in lakes, may by floods be carried into rivers, and by them down to the sea, and be deposited upon the ordinary sediment in the bed of the ocean. The analogy of the various shells in the formations we allude to, rather favours this hypothesis. We leave it to geologists to compare a number of facts, respecting situation and many other circumstances, to determine the question. \ 63 ANCYLUS M idler. Gen. Char. Shell slender., patelliform, obliquely conical ; apex rather acute, turned back ; aper- ture oval, with an entire edge. A genus of small almost minute shells resembling Pa- tella, but differing in the form and direction of the apex, which takes a position indicating an incipient spire, and is not turned forward as in Patella. The recent species have a membranous epidermis. The animal resembles that of Limnea, living in fresh water, and breathing air, and is consequently very different from that of Patella ; it is attached to the shell along an involute line open on one side. Two recent species and two fossil ones are all that have hitherto been published. We now add a third fossil, which, although small, illustrates the genus well, and is consequently a valuable acquisition. 64 •* ANCYLUS elegans. TAB. DXXXIII. Spec. Char. Convex,, subconical ; aperture longi- tudinally obovate ; apex oblique, eccentric, near the narrowest part of the aperture. The aperture is exactly intermediate in form between that of the two recent species. Considering the aper- ture as the base, it is narrowest towards the back : the apex is far from central, and is bent down towards one side. With a high power, minute striae are seen de- scending from the apex ; the height is nearly equal to half the greatest diameter of the aperture. Found along with Mya subangulata (probably only a young state of M. plana), Melanopsis brevis, tab. 523 , and Paludina lenta, tab. 31, in a dark gray Sand imme- diately under the white Sand at Hordwell, in which My- tilus Brardii occurs. We are indebted to the generosity of Charles Lyell, Esq., jun. for the specimens ; no one else appears to have found it. <533 . € 99 CARDIUM decussatum. TAB. DLII.— /g*. 1. Spec, Char. Cordiform, antiquated, longitudinally ribbed ; anterior margin rounded ; posterior side a broad area raised in the middle ; length and breadth nearly equal. Syn. Cardium? decussatum. Mantell 3 Geol.Suss. p. 126. t. 2b. f. 3, The form of the posterior side of this Cardium is pre- cisely like that of C. cardissa ; the keel, however, by which it is bounded is obtuse ; the anterior side is much more prominent ; it is conical with a rounded margin. The beaks are elegantly incurved. For this rare production of the Chalk Marl we are indebted to the intelligent author of the Geology of Sus- sex: the specimen is from a pit at Hamsey ; the one fi- gured by our friend was found at Brighton. When the anterior side is viewed, a general resemblance is obser- vable to the genus Pholadomya ; but the posterior side is so exactly similar in form to the heart-shaped cockles, that, in the absence of all knowledge of the hinge, we follow Mr. Mantell in referring this species to Cardium, along with the hibernicum. 100 CARDIUM alaeforme. TAB. DLIL— fig. 2. Spec. Char. Triangular, ventricose, longitudinally ribbed ; anterior side truncated, produced near the hinge, concentrically ribbed ; posterior side much produced, compressed, ribbed. This approaches much to Cardium hibernicum in ge- neral aspect ; but it has no sharp keel, and the anterior side is strongly ribbed. The posterior side is so pro- duced as to form a kind of lobe, which improves the re- semblance the outline has to a wing. The ribs upon the central part of the anterior side diverge from one of the longitudinal ribs on each margin of it ; the ribs upon the other parts are very close, and alternately large and small ; the cast has only the larger ribs. The specimens figured are from Queen’s County, Ire- land : the same species has also been found at Scarlet on the Isle of Man, by Mr. Henslow ; in both places in dark coloured foetid Limestone. CARDIUM hibernicum. TAB. DLII.— 3. and TAB. LXXXIL— fig- 1, & 2. We here give a representation of a part of this fossil which had formerly escaped notice, — the remarkable ex- tension of the keel around the anterior portion of the shell, to which, if perfect, it would give the form of a cup with a broad bottom ; this keel is of a cellular struc- ture, the cells long and placed transversely. . 101 CARDIUM striatulum. TAB. DLIII.— /g. 1. Spec. Char. Orbicular,, convex., concentrically striated ; posterior side longitudinally striated with a toothed edge. Strongly resembling Cardium Hillanum, tab. 14, but it is more perfectly orbicular ; the transverse striae are less regular, and the longitudinal ones twice as nume- rous as the angular sulci which occupy a similar situ- ation in the Hillanum. This Cardium accompanies the Sanguinolaria undu- lata (tab. 548), &c. in the argillaceous and at the same time areniferous Limestone next above the coal at Brora, where it wras collected by R. I. Murchison, Esq. in the reef opposite the Old Salt Pans (seq the larger figure) ; the smaller figure is from a specimen preserved by Mr. Farey, — it is accompanied by another species. CARDIUM dissimile. TAB. DLIIL— ^g. 2. Spec. Char. Transversely obovate, gibbose, smooth ; posterior side bounded by a small rib, longi- tudinally striated ; front rather straight. A smooth shell, so much resembling several species of Venus, that it has been referred to that genus : it is very thick every where except near the beaks : the length is a little less than the width. Very frequent in the Portland Limestone. We have specimens from Portland, Purbeck, and Tisbury. % 102 CARDIUM truncatum. TAB. DLIII.— -fig. 3. Spec. Char. Transversely ovate^ gibbose/ smooth ; posterior side obliquely truncated, longitudi- nally sulcated ; beaks small. Syn. Cardium pectinatum, Young and Bird, 226. pi. 8./. 5. Nearly as long as wide, most gibbose towards the beaks, the ridges between the sulci upon the posterior flattened side are scabrous. Specimens of this remarkable shell have been supplied to us by S. Hailstone, Esq., who found them in a gray sandy Limestone, along with Terebratulae, Pectens, and Aviculae, at Roseberry Topping, Yorkshire : also by Mrs. Murchison, who collected them on the Cleveland Hills ; and by Mr. Williamson, from Robin Hood’s Bay. At both these latter places they are composed of ferru- ginous sandstone, which from its friable texture appears to be produced by the decomposition of a limestone. It was also found on Brambury Hill, Sutherland, by R. I. Murchison, Esq. _ 554-. 103 NUCULA deltoidea. TAB. DLIV.— /g. 1. Spec. Char. Triangular,, inflated ; posterior side obliquely truncated, flat, pointed ; anterior side short, rounded. Syn. Nucula deltoidea, Lamarck, Env. de Paris, 194. Hist. Nat. vi. 60. A pretty little shell, unlike any other species of Nu- cula : it is generally smooth, but is sometimes longitu- dinally striated, especially near the anterior margin. Very abundant in some parts of the Clay of the so called upper marine formation on the Isle of Wight. Specimens are sometimes found at Grignon half as wide as the larger figures** which are magnified. NUCULA inflata. TAB. DLIV.— fig. 2. Spec. Char. Nearly globular, smooth ; the pos- terior side produced, compressed, pointed. Large individuals of this shell are transversely oblong; the small ones heart-shaped or nearly globose ; the pro- duced side is small. Found in Septaria in the London Clay at Highgate, in 1810. I have been favoured with casts in pyrites from Southend, by the Rev. F. W. Hope, who has made a very extensive collection at that place. 104 NUCULA undulata. TAB. DLIV.— ^g. 3. Spec. Char. Globular, concentrically undulated ; posterior side produced,, contracted, pointed. Much resembling the last : its width is rather greater than its length, and it is a little oblique. A cast in pyrites from the Clay at Folkstone. Its valves are equal, or it might be referred to Corbula. NUCULA amygdaloides. TAB. DLIV.— fig. 4. Spec. Char. Transversely elliptical, elongated and sulcated, compressed ; sides equal. The width of this neat shell is double the length : the sulci are small, numerous, and regular. Found at various periods in Hyde Park, and also St. James’s Park : and casts in pyrites have been collected in abundance at Southend, by the Rev. Mr. Hope. 105 AMMONITES Jamesoni, TAB. DLV.— /g. I. Spec. Char. Discoid,, radiated ; sides flattened ; volutions 5 or 6 ; the inner ones exposed ; radii large,, simple, obtuse, equal to the spaces between them, bent towards the aperture as they pass over the front. The numerous large radii, considerably bent as they pass over the front, strongly characterize this shell ; the aperture is nearly twice as long as wide. Collected on the Isle of Mull, by R. I. Murchison, Esq., during a tour which has been the foundation of a valuable paper lately read before the Geological Society. At the request of this gentleman I am happy to com- memorate the celebrated Geologist whose name it bears, and who needs no panegyric from me. It has also been found in Robin Hood’s Bay, AMMONITES navicularis. TAB. DLV.— /g. 2. Spec. Char. Umbilicated, costated ; costas large, numerous, annular, simple ; whorls ventricose, very few ; the inner ones half exposed ; aper- ture transversely oblong. Svn. Ammonites navicularis. Mantell , Geol. of Sussex , 198. t. 22. /. 5. About three whorls, rapidly increasing, compose this Ammonite : all the costae reach the edge of the umbilicus, half or more of them turn into it, and at the same time are rather enlarged ; the costae and the spaces between them are nearly equal. From the lower Chalk at Guildford : presented to Mrs. Murchison by Mr. Mantell. It is only half the size of the one figured in the Geology of Sussex, where it is spoken of as a very rare shell. 106 AMMONITES lataecosta. TAB. DLVI. —fig. I. Spec. Char. Discoid, compressed, radiated ; whorls 5, exposed ; radii large, sharp, slightly waved, much flattened and widened as they pass over the rounded front ; aperture oblong. The flattened sides of this Ammonite distinguish it from the young state of A. planicosta (tabs. 73 and 406), independently of its much larger size. When young, nei- ther of them has any appearance of spines ; when old, the last whorl of the lataecosta has only slight indications of tubercles, which consist of two small knots upon each ray on each side ; the planicosta has one large spine in place of two, and that only upon some of the rays. A Eyas fossil : all the specimens I have seen except one are from Alluvium ; that one is from Lyme : it is about 3^ inches in diameter, and was liberally presented by Mrs. Murchison. One specimen nearly four inches in diameter shows the little knots upon the rays; it is in the collection of W. Peete, Esq. of Dartford. Several small ones have been found by Miss Baker at Braunston, in what is called a gravel-pit. AMMONITES brevispina. TAB. DLVI.— fig. 2. Spec. Char. Discoid, compressed, radiated; whorls 5 or 6 ; inner ones exposed ; rays numerous, passing over the round front, furnished with 2 small spines on each side ; aperture obovate. The rays are rather blunt, and not much elevated, but most prominent where they pass over the front. The spines are short, and placed near the inner and outer edges of the whorls. Fragments of this Ammonite were brought from Pabba last year, by R. I. Murchison, Esq. / 107 LUCINA mitis. TAB. DLVII. —Jig. 1. Spec. Char. Orbicular, convex, ornamented with minute, longitudinal striae,, and numerous small, regular, concentric laminae ; lunette oval, very concave ; cardinal teeth obscure ; no lateral tooth. Lucina mitis, Deshayes MSS. The concentric laminae are beautifully regular, the spaces between them are crossed by minute irregular striae : within, the surface is rough, but not marked with sunken puntums, as many of the genus are ; it is in these two characters we conceive this species to differ from B. ele- gans (Deshayes, i. p. 101, t. 14, f. 10, 11.), of which we have no authentic specimen. Specimens of L. mitis, sent us >y Mons. Deshayes, agree precisely with the shell before us. Found abundantly in Barton Cliff by Miss Bemister. 108 LUCINA antiquata. TAB. DLVII. — Jig. 2. Spec. Char, orbicular, convex, ornamented with concentric laminae ; surface irregular ; ante- rior side angular ; lunette flat, lanceolate. Generally the laminae are worn off the surface, and leave it irregularly furrowed ; there are two teeth under the beaks, one of which is bifid, and one lateral tooth under the lunette ; the shell is moderately thick. I have not been able to refer this to any published species, although we possess many specimens from near Yalognes, that accord precisely with the small unworn English ones. It approaches near to L. circinaria of La- marck. Occurs in Crag at Woodbridge, and other parts of Suffolk. — — — BPa— - LUCINA crassa. TAB. DLVII.— 3. Spec. Char. Nearly orbicular, convex; covered with thick, slightly elevated, concentric lami- nae ; superior margin obtuse ; lunette linear, concealed ; valves thick. A little wider than long, rather flat in the middle, and irregular ; the beaks are very small. Found by Mr. Weir in Sandstone at Horncastle, and by R. I. Murchison, Esq. at Brambury Hill, Suther- land. Our figure is from a specimen from the former place. 558. 109 ROSTELLARIA Pes-Pelicani. TAB. DLY1IL — -fig. 1. Spec. Char. Turreted^ striated; whorls angular in the middle and nodulose; last whorl three- keeled ; the two upper keels divided into tu- bercles ; lip expanded into three, pointed, di- verging lobes ; the canal at the base oblique, subfoliaceous. Syn. Strombus Pes-Pelicani. Linn. etAuct. Br oc- elli, 2. 385. Rostellaria Pes-Pelicani. Parkinson's Organic Remains , 3. 63. Lamarck, Sj/st. 7. 193. Yar. meridionalis. Raster ot, Mem. de la Soc . d’Histoire Nat. de Paris, 2. 69. The fossil shell now before us so precisely resembles the species well known as an inhabitant of the sea at the present day, that we can but consider them the same. Similar shells are found in the vicinity of Bax and in Placentia ; but although they are referred to the same species, some differences may be observed which appear to be constant those found near Bax are smaller, and have more elongated but less prominent tubercles ; those of Placentia have the angles upon the upper whorls, and 110 the keels upon the last whorl, as Mons. Brongniart has justly observed, either smooth without any tubercle, or only furnished with projecting points. It may be doubted whether these and the ft. Pes-Carbonis of Brongniart (Terrains du Vicentin, p. 75.), which has no angles upon the upper whorls, but only elongated tubercles or costae, are not varieties of the same species, depending upon locality. We find much difference among specimens of the recent type from different places. In a clay-pit at Tottenhill near Lynn in Norfolk, are great numbers of this fossil, as we learnt several years ago from Mr. Wales of Downham. We have also been supplied with specimens by Mr. Rose of Swaffham, who finds Turbo Terebra (Linn.) with them. Specimens have been found in Suffolk, in Crag, by the Rev. G. R. Leathes, of which we have represented one, but not perfect enough to show the three lobes of the lip. May it not have been such a one that Parkinson found in the Essex Cliff, since he describes it as having but one spur-like process ? or did he find the London Clay species ? Ill ROSTELLARIA composita. TAB. DLVIIL— -fig. 2. Spec. Char. Turreted, striated ; spire costated ; last whorl bicarinated ; lip with but one, cuspi- dated lobe, besides the canal at its upper part. A small species, distinguished by the costated spire and the broadly expanded lip with a spine where the upper keel terminates upon its edge. We have seen but very imperfect individuals of this interesting shell. One (the upper figure), more strongly costated than the others, was picked up at Weymouth, in the Oxford Clay ; others have been sent us from Scar- borough : but the only ones that have the lip preserved (see the lower figure) were collected at Brora, in the stone immediately above the Coal, by our assiduous friend R. I. Murchison, Esq. It is an interesting species, be- cause it proves that the genus occurs in a stratum older than the Greensand, at the same time that it helps to support the parallelism that may be traced between the fossil contents of the Greensand and Oxford Clay. ROSTELLARIA Parkinsoni. TAB. DLVIII.— -fig. 3. Spec. Char. Turreted, striated, costated ; last whorl costated and obscurely carinated ; lip expanded and furnished with one styloid process ; costae numerous. Syn. Rostellaria, having only one spur-like process. Parkinson , Org. Rem. 3. 63. lab . b.f 1 1. Rostellaria Parkinsoni. Mantell , Geology of Sussex , p. 72j 82, & 108. The length of the costae upon the last whorl, and the single spur-like process, are the essential characters of this shell. The former seems to distinguish it from the London Clay species given under the same name at tab. 349 ; but so great is their resemblance, that, with only imperfect specimens before us, we still remain in doubt. The late sale of Mr. Parkinson’s collection has enabled us to give figures of the type of this species. The upper specimen is from Blackdown, the other from near Faver- sliam. We have seen two other species from the Greensand : one with four smooth carinae and a very long beak (R. carinata, Mantell ?), another with the lip resembling that of the Pes-Pelicani ; but the specimens are much too indistinct for figuring. The Syn. 66 S. Pes-Pelicani Brocchi,” must be erased from p. 66 of vol. iv. ; as indeed ail the synonyms per- haps ought to be, and even a new name given. <559. 113 PLAG10ST0MA concentrica. TAB. DLIX.— /g. 1. Spec. Char. Elliptical, oblique, convex, ornamented with many longitudinal striae and a few regular concentric lines ; hinge-line short ; shell thin. A neatly marked slender shell, whose greatest diame- ter is about double the least : it is most convex towards the beaks, which are but a little produced. One of the many discoveries made by R. I. Murchison, Esq. in his late tour to the North of Scotland. It was found in a block of gray argillaceous Limestone, accom- panied by Ammonites, upon the beach at Ethie, near Cromarty. PLAGIOSTOMA elongata. TAB. DLIX.— /g. 2. Spec. Char. Obliquely elliptical, convex, costated; costae few, distinct, rounded; hinge-line short. Syn. Plagiostoma. Mantell , Geology of Sussex, p. 129. t. 19./. 1. The longest diameter of this Plagiostoma is equal to twice the shortest. The costse are about fifteen or six- teen, prominent, rounded and smooth : they produce undulated margins to the valves. An inhabitant of the Gray Chalk Marl and Upper Greensand. The upper figure is from a specimen found at Folkstone; the other from one presented in 1814 by Mr. Mantell, who obtained it at Hamsey. 114 FLAGIOSTGMA duplicate. TAB. DUX.— fig. 3. Spec. Char. Obliquely obovate, convex, costated ; costas numerous, sharp; between each of the costae is a sharp elevated line ; beaks rather prominent. The costae, which are sharp-edged, are about 25 in number : alternating with them is a set of much smaller but equally sharp elevations, which appear characferistic of the species. The larger specimen is from the Oolite at Malton, the other apparently from Cornbrash ; but the label has un- fortunately been lost. We have a group with one an inch and a half long ; but we do not know from what country it came. 560, 115 PRODUCTA costata, TAR. DL X.—fig. 1. Spec. Char. Transversely oblong, with an angu- lar depression in the middle, costated ; costae few, broad, decussated at their upper parts, compressed upon the deflected front ; each side furnished with two or three spines and a small lobe. Strong, sulci divide the surface of this shell into 18 broad ribs, which are crossed by concentric furrows upon the upper part of the convex valve : at each side is formed a small lobe, upon which are two or three spines : the front is much produced and deflected. For the use of this strongly marked Producta wre are indebted to Mrs. Murchison. It was found near Glas- gow; and seems to have been imbedded in a shaley Limestone. PRODUCTA calva . TAB. DLX—figs. 2 to 6. Spec. Char. Nearly square, smooth, flat or con- cave in the middle; beak much incurved; one row of spines on each side the hinge-line. Var. 05. Small, flat or slightly concave in the middle, fig. 2. Var. (3. Twice the size of var. a, with a canal along the middle, figs . 3—6. iifXTE Anally this species is remarkably smooth ; but, like many others, it is scabrous within, or beset with 116 short spines. The surface of var. a is generally very flat in the middle ; but some specimens are concave, and lead to the larger variety, from which they differ only in size. The spines upon each side the beak are in a single row, and few. Jt is difficult to detect them except in casts. Var. /3 much resembles P. horrida (t. 319. f. 1.). Var. a (fig. 2.) was found some years back, and for- warded to us by Samuel Hailstone, Esq., at Nosterfield near Tanfield, north of Ripon, Yorkshire, in Magnesian Limestone, where Prof. Sedgwick has since observed it. Var. (3 (figs. 3 and 4) are from a bed of compact gray Magnesian Limestone, immediately above a yellow Marl-slate, containing at least six species of fish, at East Thickley, near West Aukland, Durham while the casts represented at figs. 5 and 6, are from the higher bed of yellow Magnesian Limestone of Humbleton Hill and other quarries near Sunderland, towards Durham. In the series of figures given upon this plate, we have a complete illustration of the genus Producta. Figs. 1, 2, 3, and 4, exhibit various views of the outer surfaces of the two valves, as they appear when separated from the stone; in which case the spines are commonly lost. Fig. 6. shows the cast of the same surfaces with the im- pressions of the spines near the hinge line. Fig. 5. ex- hibits a cast of the inside ; it discovers the impressions of the muscles and tendons that gave the valves motion, a short septum in the lesser valve, and the impressions of the short spines of its scabrous surface. 117 PRODUCTA hemisphaerica. TAB. DLXI. This plate represents some large specimens that were formerly referred to P. scotica : but upon an exact com- parison, we find they do not agree with the figure in Mineral Conchology, tab. 69. f. 3 ; but that in fact half of the small specimen drawn at fig. 2. of the present plate was given upon tab. 32 8. to show a section of P. he- misphaerica ; to which species we see no reason why the large specimens should not be referred : and we consider the figures of them essential to illustrate it. The very narrow space between the valves is a useful character ; the total want of spines distinguishes it from P. scotica. It is more difficult to distinguish from P. personata (tab. 321.), which is perhaps the internal cast of the same species, but seems rather more globose. We have recently discovered, by purchasing the spe- cimen it is taken from, that fig. 11. of tab. 12. of Par- kinson’s Organic Remains, which is called Trigonia rugosa (vol. iii. p. 177.), is taken from a large crushed individual of Producta scabricula (tab. 69. f. 1.). 662. 119 SPIRIFER undulatus. TAB, DLXIL- fig. 1. Spec. Char. Transversely elongated, very convex, with pointed extremities, radiated, transversely and deeply striated ; front elevated, with a rounded sinus ; radii obtuse, about 16 on each side the central elevation ; beaks a little re- moved ; area flat, narrow. Full twice as wide as long, nearly semicircular, with the sides produced as they approach the extremities of the hinge ; the area between the beaks is narrow, with nearly parallel edges ; the striae upon the surface are regular, and waved by the obtuse radii, which scarcely rise enough to be called ribs ; the central elevation is obtuse, and occupies the space of about four radii. Presented by Professor Sedgwick, who collected it at East Thickley, along with Producta calva /3 (tab. 560.). 120 SPIRIFER octoplicatus. TAB. DLXII. —Jigs. 2 , 3, & 4. Spec. Char. Transverselyeiongated, gibbose, semi- circular, plaited ; plaits 8 or 10, deep and an- gular ; central elevation plain ; beaks remote, incurved ; area triangular, curved. A neat shell, strongly marked by the depth and small number of its plaits. Collected in Derbyshire by the author of a Petrificata Derbyensia but it does not appear to be figured in that work. Fig, 4. represents a larger specimen from the same place, with a striated or rather imbricated surface ; but in other respects strongly resembling the small ones. May additional specimens prove it to be a distinct spe- cies ? SPIRIFER triangularis. TAB. DLXII.-; figs. 5 & 6. Spec. Char. Triangular, transversely elongated, convex, radiated ; extremities acute; front angular, with an acute elevation ; radii about 16, obtuse ; area narrow, flat, Syn. Conch. Anomites triangularis. Martin , Pet. Derb.t.36.f. 2. Readily known by the straight lines that form its out- line. From the collection of the late Mr. Martin. Fig. 6. is from a remarkable specimen with dissimilar sides. 1 m AMMONITES Sutherlandiae. TAB. DLXIII. Spec. Char. Discoid, gibbose, smooth ; whorls two or three,, partly exposed ; umbilicus large and deep ; aperture obovate, nearly circular. Syn. A. Sutherlandiae. Murchison in Geol. Trans . 2d Series, vol. ii. pt. ii. p. 323. A plain thick Ammonite with very few whorls, small portions only of the inner turns are seen within the wide umbilicus. The front is regularly rounded ; the length of the aperture is nearly equal to half the diameter of the shell. Discovered by R. I. Murchison, Esq. in the white Sandstone that composes the hills of Braambury in the district of Brora *, Sutherlandshire. It is named, at the request of Mr. Murchison, in compliment to the Mar- chioness of Stafford as Countess of Sutherland. Fig. 1. represents a specimen that was found by the quarrymen after Mr. Murchison’s visit to the district, and was reported to be a fossil human skull, whereon the Marquis of Stafford ordered it to be sent to London and presented to the Geological Society, in whose cabi- net it now is. It is so compressed as to resemble a Sea- phites ; its diameter is double that of the figure. Fig. 2. is from the first discovered specimen, and is two-thirds its diameter. * For an account of this district see Mr. Murchison’s very valuable and elaborate paper in the Geol. Trans. 2nd Series, vol. ii. part ii. p„ 293. 122 AMMONITES cinctus. TAB. DLXIV.— fig. 1. Spec. Char. Discoidal, subumbilicate ; volutions depressed, half inserted,, transversely radiated; radii annular, distant, bifurcated, undulated ; umbilicus expanded, sides smooth, with a mar- ginal row of oblique tubercles ; ambit convex, embraced by the radii ; aperture o veto -sagit- tate. The volutions, although compressed, have a slight de- gree of convexity, and are ornamented by transverse ra- diations that arise from a row of small tubercles on the inner margin. Each radius divides into two branches, which pass with a gentle sweep across the ambit, and unite with the corresponding undulations of the oppo- site side ; small oblique tubercles are placed on each ra- dius at the point of bifurcation. It is scarcely necessary to remark, that although this species approaches to A. varians in having bifurcating radiations and a row of tubercles on the inner margin, yet it is widely separated from it by the rounded form of the back (front) and other obvious differences. Longest diameter 3'S inches ; width of the outer volu- tion two-fifths of the diameter ; transverse diameter of the aperture 1*1 inch. Locality, Middleham.” The above description is copied from the Geology of Sussex, pp. 116 and 117. It appears that only one indi- vidual has been found ; and the permission granted by Mr. Mantell to figure that, is the more valuable, because it had not been figured before. It is a cast in Chalk Marl ; the edge of the aperture seems to have been per- fected, as it was evidently somewhat thickened. <564. m AMMONITES Catillus. TAB. DLXIV. — -Jig. 2. Spec. Char. Discoid, thin, with obscure, tubercu- lar elevations near the narrow, obtuse edge ; inner whorls one-third exposed ; aperture lan~ ceolato-sagittate with obtuse angles. A very flat species with only three or four whorls; the surface of it is even, except a row of short tubercles on each side the margin, which degenerate into obscure waves upon the outer whorl. It might possibly be taken for a compressed specimen of A. varians, but it wants both the carina and radii, vestiges of which are distin* guishable in the most flattened specimens of the A. va- rians. Found in the Malm-rock of Sussex (Upper Greensand) in a quarry at Nursted near Petersfield. We are indebt- ed to Mrs. Murchison for the discovery. The figure is two-thirds of the diameter of the specimen, which is above six inches wide and only nine-tenths of an inch thick. , SGS. TURRITELLA granulata TAB, DL XV.— jig. 1. Spec, Char. Subulate, transversely striated and granulated ; whorls about fifteen, their upper edges bordered with an antiquated band. The rows of granules between the striae are very cha- racteristic of this species; they are numerous, but three or four of them are generally larger than the rest. Very abundant, replaced by Silex, in the whetstone pits at Blackdown, where it appears to be gregarious. It is mentioned as a Turritella by Smith in his Strati- graphical System, p. 25, and figured in his Strata Iden- tified. Parkinson calls it Cerithium turritellatum, which is however a different shell (Org. Rem. vol. iii. p. 71.), so that it does not appear to have been hitherto cor- rectly named. The group figured is part of a larger one in the cabi- net of II. H. Goodhall, Esq. TURRITELLA abbreviata. TAB. DL XW.—Jig. 2. Spec. Char. Conical, pointed ; two small close ridges run round the middle, and one large obscurely granulated ridge forms each edge of every whorl, the produced base has one ridge upon it. A very short turreted shell with about seven whorls. I have not seen the aperture, but judge by the lines of growth and the absence of plaits upon the columella that it is a Turritella. Found in the decomposing carboniferous Limestone (Mountain Limestone) of Bradley, near Newton Bushel, Devonshire : the specimen is in the cabinet of H. T. De la Beche, Esq. 126 TURRITELLA Terebra. TAB. DL XV.— jig. S. Spec. Char. Turreted, elongated transversely sulcated ; whorls convex, sulci many, nearly equal ; spire pointed. Syn. Turritella Terebra. Lamarck Hist . Nat. 7. p. 56. Turbo Terebra Auct. If this differ at all from the recent species, it is in the thickness of the shell and greater distinctness of the whorls ; but these differences are very slight. Found with Rostellaria Pes Pellicani (t. 558.) by Mr. Rose of Swaffham. I suspect both to be shells of a more modern growth than any genuine Crag shells. TURRITELLA costata. TAB. BLXV.— fig. 4. Spec. Char. Subulate, striated, rough, costated; the costae terminate above the lower carinated edge of each whorl ; base flat, its edge carinated. The carinated edge of this elegant shell forms a thread that winds round the spire separating the costae of one whorl from those of the next ; the whorls are very nu- merous. An individual of this species is now and then met with along with T. granulata. TURRITELLA concava, TAB. DL XV. -Jig. 5. Spec. Char. Short subulate, smooth ; whorls many, concave ; base convex. From eight to twelve whorls with elevated edges and concave surfaces form this shell : when full grown the last whorls have a ridge in the middle, as shown in the lower figure. Occurs not rarely in the Limestone at Chilmark near Tisbury, Wiltshire. Presented by Miss Benett, SS'd' 127 BUCCINUM acutum. TAB. DLXVI. —Jig. 1. Spec. Char. Ovate,, elongated., pointed, smooth ; volutions convex ; aperture elongated, pointed above, nearly half as long as the shell. Somewhat resembling the following, but longer and more acute, besides being well distinguished by the sim- ple union of the whorls. This figure is taken from a large individual obtained in Queen’s County, Ireland, where the species occurs of various sizes in the Mountain Limestone. BUCCINUM imbricatum. TAB. DLXVI.— /g. 2. Spec. Char. Ovate pointed, obscurely striated ; whorls about six, their upper edges blunt, pro- duced and pressed against the spire ; aperture ovate, elongated, half the length of the shell. A nearly smooth shell, that has nothing remarkable in its general appearance; but the upper edge of each whorl is upon close examination found to embrace the preceding whorl in a peculiar manner. 128 BUCCINUM breve. TAB. DLXVI. —Jig. 3. Spec. Char. Nearly globose, tuberculated ; upper edges of the whorls wavy. Each whorl upon the spire, which has only three, is furnished with one row of obtuse knobs ; upon the last whorl are exposed three similar rows ; the upper edges of the whorls are undulated as they pass over a row of knobs which they conceal ; the aperture is nearly round with a short canal at its upper angle ; the lower edge is not notched, but only a little bent back, conse- quently it approaches that of the genus Turbo. BUCCINUM spinosum. TAB. DLXVI — -fig. 4. Spec. ChAr. Conical, elongated with a produced base ; a sharp furrow winds round each whorl, a row of large blunt spines is above it ; a row of smaller spines surrounds the base. When perfect, this must have been a handsome shell : the specimens we have now before us are however so mutilated, that it is with doubt we place it among the Buccina. The three species last described are from the Carbo- niferous Limestone (Mountain Limestone) of Bradley, near Newton Bushel, Devonshire, and are figured from specimens in the cabinet of H. T. De la Beche, Esq., who is at present engaged in preparing an account of the Torquay Limestones for the Geological Society. J&7 129 VENUS ovalis. TAB. DLXVII .— figs. 1. & 2. Spec. Char. Transversely oval, and finely striated^ convex^ thin ; beaks not very prominent ; lu- nette obscure,, convex, smooth, elongated. Length little more than two-thirds the width ; the re- gular oval form and fine concentric striae distinguish this from every other Venus. From Blackdown, collected by H. H. Goodhall, Esq. Fig. 2. is probably a variety : it is so worn that it may- have lost the striae ; it differs slightly in the position of the beak, which is further removed from the centre ; it was found near Faversham in Kent. Both specimens are siliceous. VENUS Faba. TAB. DLXVII — /g. 3. Spec. Char. Transversely obovate, elongated,, finely striated, convex,, flattened in the middle ; sides unequal ; beaks very short. Much resembling the last, but it is less convex towards the beaks and less pointed at the sides ; the length is three-fourths of the width. A siliceous fossil from Blackdown. Casts also occur at Parham Park and Shanklin Chine. 131 MEGALODON. Gen. Char. An equal-valved, longitudinal bivalve, acuminated towards the beaks ; hinge a long external ligament, a large bifid tooth placed upon a septum across the beak of the right valve,, and one irregular and one pointed tooth similarly placed in .the left valve; a small pit near the teeth for the reception of the anterior ligament. A genus nearly related to Mytilus, but distinguished by the large teeth of the hinge and weight of the shell. It also resembles Myoconcha ; but the situation of the only muscular impression the specimens expose to view indicates its place in a natural arrangement nearer to Mytilus. 132 MEGALODON cucullatus. TAB. DLXVIII. Spec. Char . A smooth, ovato-lanceolate, thick shell with pointed in- curved beaks, the surface is uniformly convex. We have not seen a perfect specimen, so cannot describe the po- sition of the posterior muscle or tendon ; for the recep- tion of the anterior one, there is a sharply excavated pit close to the thick plate that supports the hinge teeth. For the knowledge of this remarkable shell we are indebted to our friend H. T. De la Beche, Esq., who obtained the specimens from the limestone of Bradley, near Newton Bushel, Devonshire. The decomposed state of the stone has much facilitated the development of the hinge. The shells accompanying this are Car- dium alas forme, Terebratulae, Spiriferae, Buccina, Tur- ritellae, &c., — a list of which will be laid before the Geo- logical Society by Mr. De la Beche. <568. ■% S6\9. 133 AMMONITES complanatus. TAB. DLXIX.- -fig. 1. Spec. Char. “ Fiat, volutions wholly inserted, the inner half marked with numerous indistinct transverse undulating striae, the outer portion plicated ; umbilicus very small, almost con- cealed ; carene slightly convex, its margins crenated by the angular terminations of the plicae ; aperture sagittate/' u The longest diameter is about 8 inches, greatest thick- ness 1*8 inch, width of the outer volution 5 inches. u The volutions are thickest near the middle, and gra- dually contract into a narrow keel, which at the aperture does not exceed 4-tenths of an inch in width, and has an elevation or ridge down the centre. . . .The septa are nu- merous, and very foliaceous. “ Locality, Hamsey.” With Mr. Mantell’s kind permission we have figured the specimen from which the above description, copied from his Geology of Sussex, pages 1 18 and 1 19, was taken. We know of no other example of the species : it is twice the diameter of the figure. The plicae do not occur upon the outer volution. 134 AMMONITES undatus. TAB. DLXI X.—Jig. 2. Spec. Char. Discoid,, smooth,, with a rounded edge; whorls flat on their sides, their inner edges square ; inner whorls partly visible ; aperture much elongated, sagittate., with obtuse angles ; edge crossed by undulations which proceed a short way over the sides. A very flat Ammonite, distinguished from all others by the undulations over the edge and square inner margins of the whorls. This rare specimen was presented to my father in 1820, by G. A. Mantell, Esq., who obtained it from the Upper Chalk of Sussex. AMMONITES Bakerim. TAB. DLXX.—^g’s. 1. & 2. Spec. Char. Depressed, radiated ; inner whorls exposed ; radii curved, furcate, continued over the front ; whorls crossed by about ten sinuous lines ; aperture oblong. The peculiarity of this Ammonite consists in the sinuous lines that mark its surface, and probably indicate suc- cessive periods when the edge of the aperture was com- pleted and the growth for a while suspended, although 570. 135 they are mere lines ; thus leading to those Ammonites which have deep furrows in several parts of their whorls, and which have been elevated into another genus. The radii form rings that are split just before they pass over the front. Upon the inner laminae of the shell these rings are interrupted where they pass over the siphuncle, but on the outer surface they are continuous. The specimen represented at fig. 1. is a portion of an indurated Marl Nodule found amongst Alluvium in the parish of Braunston in N orthamptonshire, by Miss Baker, whose zeal in collecting the natural productions of the district, to assist her brother in a general history, has in- duced me to commemorate her name. Fig. 2. represents a cast in Pyrites. AMMONITES laevigatus. TAB. DL XX.— Jig. 3. Spec. Char. Depressed, smooth ; inner whorls ex- posed ; aperture transversely oblong ; the edge of the aperture thickened, produced in the front. The convex smooth whorls of this shell are so like the innermost ones of some large Ammonites, that I suspect it to be very young, probably the first period of its growth only has been completed. It therefore serves to introduce us to the two following species, as well as to Ellipsolites funatus (tab. 32.), andMontfort’s genus Pla- nulites. Drawn from a specimen in the collection of H. T. De laBeche, Esq., who found it in the Lyas near Lyme-Regis. 136 AMMONITES Rotula. TAB. DLXX.— jig. 4. Spec. Char. Gibbose, smooth, umbilicated ; each whorl contracted by six or seven varices ; inner whorls partly exposed ; front rounded, crossed by many small furrows ; aperture orbicular. Whorls very few. In this species of Montfort’s genus Planulites the con- tractions of the whorls are very conspicuous. Their num- ber is various ; some specimens having seven or even eight in each whorl : they are perfectly independent of the septa. Casts in Pyrites collected at Speeton on the coast of Yorkshire. AMMONITES planulatus. TAB. DL XX.— jig. 5. Spec. Char. Depressed ; whorls flat on their sides, contracted by four or five varices ; inner whorls two-thirds exposed ; front crossed by many broad furrows ; aperture oblong oval. Half of each whorl is plain, the remaining part mark- ed with numerous broad furrows that pass over the rounded front ; the inner edges of the whorls are ob- tuse, the exposed portion of the inner whorls is flat. A single specimen found in the Marl at Hamsey, near Lewes, is in the collection of Mr. Mantell, who has kindly permitted it to be engraved. 13? NAUTILUS sulcatus. TAB. DLXXI. —Jigs. 1. & 2. Spec. Char. Discoid, minutely striated ; whorls almost wholly exposed, ventricose, with two large furrows on each side and several small ones ; front concave. One of the remarkable furrows that modify the form of the whorls of this shell is concealed in the inner turns ; the concave front is bounded by sharp edges ; there is also a sharp elevation between the two furrows : the rest of the side is gibbose, with two or three very shal- low broad furrows upon its most elevated part. The aperture is half as long again as it is wide, its sides of course indented : the siphuncle is placed just opposite to the inner indentation ; the septa are numerous, with even edges. Occurs in the Mountain Limestone. We have met with two or three specimens in the late Mr. G. Hum- phreys’s collection, labelled by him as having been found at Castleton. Fig. 1. shows a cast of the inside. Fig. 2. the exter- nal surface of the shell. 138 NAUTILUS Woodwardii. TAB. DLXXI.— fig. 3. Spec. Char. Discoid, granulated ; inner whorls exposed ; sides of the whorls angular ; front rounded with a linear sulcus along its middle : aperture obovate with angular sides. Syn. Conch. Naut. Ammonites Woodwardii, Martin Pet . Derb . t. 35. f. 4. & 5. The granulations upon this fossil are arranged in con- centric lines ; they cover the whole surface : the sub- stance of the shell is very thin where the furrow occurs upon the front, for that on the outer whorls is met by a sharp carina in the cast, which is otherwise smooth. Although from its similarity in form to the preceding species this is placed as a Nautilus, it is highly probable that it belongs to the genus Rellerophon ; for although I have removed a considerable portion of the shell, no traces of septa can be discovered : the furrow on the front is also in favour of this opinion. Drawn from Mr. Martin’s specimen, which was found at Winster, Derbyshire. 57% . 139 CORBULA elegans. TAB. DLXXII- fig. I. Spec. Char. Subglobose, concentrically sulcated ; posterior side produced,, smooth, truncated; left valve subtriangular, smooth. Of this neat little Corbula one valve is gibbose, sharply sulcated, and has a smooth rather curved beak ; the other is flatter, angular, and smooth without a beak. It much resembles Corbula gigantea (tab. 209.) in miniature. Very abundant in the Whetstone Pits at Blackdown. CORBULA striatula. TAB. DLXXII .—Jigs. 2. & 3. Spec. Char. Ventricose, obovate, beaked, minutely striated ; valves nearly equal ; beak long, straight, channeled within. A larger species than the last, with more equal valves and distinct two-channeled beak. Very abundant in the ferruginous beds belonging to the Lower Greensand at Pulborough in Sussex. W. P. Martin, Esq. communicated the specimens. The shell has entirely disappeared, but the casts of both surfaces remain very neat -see fig. 3. 140 CORBULA rotundata. TAB. DLXXII.— j£g. 4. Spec. Char. Obovate with produced beaks,, gib- bose, concentrically sulcated ; sides nearly equal, the posterior slightly truncated. The lesser valve of this is probably smooth, but the specimen is too much worn to be depended upon. Found in the Crag of Suffolk. The specimens figured are from Holy wells, presented by the late Mrs. Cobbould. CORBULA obscura. TAB. DLXXIL— ^g. 5. Spec. Char. Obovate, gibbose, smooth ; posterior side flattened, so as to form an angle upon the surface. Syn. Corbula ( new species). Trans. Geol. Soc. 2d series, vol. ii. p. 32 0. A small shell much resembling Corbula Pisum, but smaller and flatter. An abundance of this species of shell, which appears to be a Corbula, is firmly imbedded in the sandy stone above the coal in the district of Brora, and has been preserved by R. J. Murchison, Esq., Sec. G.S. 141 PETRICOLA. Lamarck. Gen. Char. An unequal-sided,, equal-valved, trans- verse bivalve ; the anterior side smallest, round- ed, the posterior produced, rather gaping; teeth of the hinge three or four, small, curved ; no lateral teeth ; a large sinus in the mark of the attachment of the mantle ; ligament ex- ternal, short. Under the generic name Petricola are arranged some of the shells belonging to animals that have the power of forming hollows in calcareous rocks, not by a rotatory motion as the Pholas does, but by some solvent power that enables them to make holes that nearly fit the shells. Dirt and foreign substances that are not calcareous often make way into these holes ; and as they cannot easily be removed, they interfere with the growth of the shells, which are consequently often distorted*. The species are almost as variable in their external forms as in the number and form of their teeth ; some are nearly smooth, others striated and even rough like Pholades, some depressed, others gibbose ; they are mostly white, but one or two are coloured. They are all tender shells. * Lithodomi and some other boring shells belong to animals pos- sessed of the same power, and which at the same time line a por- tion of the hole with a calcareous deposit. The animals of many spiral shells operate in a similar way upon their own shells, re- moving parts of their surface or spines to lighten them or make room for their further growth. In these cases, does the animal secrete two kinds of fluid, or, which seems more probable, is it endowed with the faculty of changing the electric state of the same fluid, so as to make it dissolve or deposit the lime at differ- ent seasons or as occasion may require ? 143 PETRICOLA laminosa, TAB. DLXXIII. Spec. Char. Ovate,, gibbose, ornamented with erect concentric laminae ; posterior side subcunei- form ; one broad bifid tooth in the left valve^ two small teeth in the other. This is the largest species of Petricola known ; the la- minae upon its surface are entire, rather thick, and tole- rably close set ; they distinguish it from every other. Found by the Rev. G. R. Leathes in the Suffolk Crag; who has kindly allowed us the use of the only specimens he has. Fig. 1. represents two views of the left valve of a re- gularly grown shell : Fig. 2. the same valve from a dis- torted individual : Fig. 3 . the inside of the right valve, also a distorted shell. S73. i <574. 14 3 PECTEN dentatus. TAB. DLXXIV.— ^g*. 1. Spec. Char. Nearly orbicular, convex, minutely seriated concentrically, ribbed ; ribs about twenty close, large, angular, obtuse ; ears defined, small ; margin deeply toothed ; valves similar. The peculiar characters of this Pecten are, the sharp projection of the edge between each rib and the flat in- clined sides of each rib Several specimens of this fossil are in the collection of Miss Baker, who found them in transported fragments of limestone, in what are there called gravel-pits, at Bugbrook and Staverton, in Northamptonshire. It also occurs in the valley of Catmus in Rutlandshire. The figure is taken from a specimen which has both valves, but wants the ears; they are supplied from another, in other respects inferior, individual. 144 PECTEN granosus TAB. DLXX1Y .—fig. 2. Spec. Char. Nearly orbicular, oblique, convex ; surface marked with about thirty granulated rays, and as many nearly smooth ones, alter- nating with them ; ears undefined, unequal, extending nearly the width of the valve. Rather wider than long ; the ears, although they form a long hinge line, are narrow and small; the alternately large and small rays are very regular. Found in the Black Limestone in Queen’s County, Ireland. PECTEN plicatus. TAB. DLXXI V.—Jig. 3. Spec. Char. Nearly orbicular, oblique, convex, with numerous irregular, elevated, smooth striae ; ears undefined, unequal, extending the whole width of the sheik Nearly like Pecten papyraceus (tab. 354); but it has smaller ears, a less number of striae, and is more convex. From Black Limestone with the last. In this limestone several Pectens occur nearly resem- bling this : but it is difficult from such specimens as are to be obtained, to determine whether they be different or not ; we shall not at present attempt it. 575, 145 PECTEN duplicates. TAB. BLXXV.— figs. 1. 2. &3. Spec. Char. Orbicular, depressed, radiated ; one valve nearly smooth, the other very rough and ornamented with many distant, thin, round ribs, which become more numerous towards the margin ; ears defined, small. One of the valves has the surface covered with minute sharp scales; the other is smooth and almost free from ribs, being only undulated in their places : this is the most convex, the inside of both valves is nearly plain. Near the beak the ribs are about ten ; but at the margin there are forty, in consequence of the interposition of new ones as the shell increases in size. First found 200 feet from the surface in a well dug in London Clay on the top of the hill in Richmond Park. See fig. 3. In Hyde Park it has been found whenever the Clay has been exposed. The specimen delineated at figs. 1. and 2. was kindly given me by Mr. Marshal, who collected several last year. PECTEN carinatus. TAB. BLXXV.— -fig. 4. Spec. Char. Orbicular, rather elongated, convex, smooth, ribbed ; ribs about seventeen, distant, rounded, with a sharp keel along the middle of each ; ears defined, rather large ; internally sulcated. Between each of the broad carinated ribs is an equally broad flat smooth space, along whose middle there ge- nerally runs a sharp line : the ears are square and am- ple ; the valves are equally convex. / Found in Barton Cliff, and also in other parts of Hampshire. 146 PECTEN reconditus. TAB. DL XXV.— figs. 5. & 6. Spec. Char. Orbicular, oblique, with above twenty rounded rays, the intermediate spaces not lon- gitudinally striated ; the whole surface cover- ed by concentric lines of sharp scales ; valves unequally convex, sulcated within ; ears de- fined, nearly equal. Syn. Ostrea recondita ? Brander^jig . 107. Very nearly resembling Pecten sulcatus (tab. 393. fig. 1.), but there is something, not easily described, in its general aspect, that has caused it to be separated by several acute observers. The most obvious mark of dis- tinction is the want of longitudinal striae between the rays ; each ray at a little distance from the beaks is fur- nished with three rows of scales, while the spaces be- tween the rays have only one large scale : the valves only differ in convexity, together they are more convex than those of P. sulcatus, and more unequal. Common in Crag on various parts of Norfolk and Suf- folk ; it is also sometimes found at Stubbington and Bar- ton, where P. sulcatus also occurs, but generally small. Brander’s fig. 107. is evidently taken from a damaged specimen. We quote it with doubt, because it is of a longer form. We have reason to suspect that P. sulcatus of M. C. is P. plebeius of Lamarck ; it is certainly P. plebeius of Brocchi, who quotes Lamarck, but it does not agree with Lamarck’s description, neither have we met with speci- mens from the neighbourhood of Paris that are nearly equal to it in size. 147 TEREBRATULA porrecfca. TAB. DLXXVL— J?g. 1. Spec. Char. Nearly square, with rounded angles,, convex, smooth ; beak of the larger valve very much produced, pointed* slightly curved, the area within it large ; margin sharp. Most specimens have the beak of the larger valve al- most straight : it is perforated, but the perforation is elongated and placed within the sharp apex, and point- ing towards the sinus in the area, which it nearly meets : the largest specimen is wider than long ; the others vary, but in general are longer than wide, with an obtuse an- gular front. From the Carboniferous Limestone of Bradley, de- scribed in a paper now in course of reading before the Geological Society, from H. T. De la Beche, Esq. It was accompanied by several uncommon shells. See tab. 566. p. 128. 148 TEREBRATULA variabilis. TAB. DLXXVI. —figs. 2—5. Spec. Char. Orbicular or oblong, very convex, smooth ; the beak of the larger valve pro- duced, truncated, with a round perforation. Always very convex, but varying in shape from oblong oval to orbicular : the beak is large, straight, and trun- cated deeply ; the area within it is convex, with a large sinus. A very abundant fossil in the Crag ; but the valves are never found joined, and are always much worn. Figs. 2. and 4. are from specimens collected by our zealous geological friend Mrs. Murchison. '577. 5 * 149 SCALARIA frondosa. TAB. DLXXVII.— -^g. 1. Spec. Char. Conical, elongated, costated, smooth; costae membranous, recurved, their upper parts produced into concave spines; volutions dis- tinct, but close, about seven. A very distinct and extremely beautiful shell. The very thin costae are very uniform ; there are about twelve upon each whorl : it is rather a shorter shell than the S. acuta. The unique specimen figured is from Crag. It graces the splendid collection of the Rev. G. R. Leathes. SCALARIA acuta. TAB. DLXXVIL— /g. 2. and TAB. XVI. Yar. mutica : costas thick, sharp-edged, reflected, unequal, not produced above into a spine. About an inch long and four-tenths wide. The volutions are ventricose, with about sixteen costae upon each. Collected in the London Clay in Alum Bay, Isle of Wight, by G. E. Smith, Esq.— It was not until the plate was finished that I discovered this to be only a variety. SCALARIA interrupta. TAB. DLXXVII.-/g. 3. Spec. Char. Subulate ? transversely striated, cos- tated, with one large varix upon each whorl ; costas numerous, obtuse, slightly elevated, united at both ends by transverse ridges ; whorls united, convex. The most remarkable character in this Scalaria is the union of all the ribs together by two transverse ridges, forming the exact resemblance to a spirally curved rope ladder. The only specimen we have seen of this consists of about two whorls: it is preserved by H. J. Goodhall, Esq., who brought it from Barton Cliff. 150 SCALARIA undosa. TAB. DLXXVII. —fig. 4. Spec. Char. Subulate, transversely striated,, costated; costae numerous, slightly elevated, crossed by the striae, terminating in a band that covers the base ; volutions united, convex. Costa; about twenty-four upon each whorl, waved, broad, and very slightly raised; the base is nearly smooth, being only marked lightly by lines continuing from the costae. An imperfect specimen from Barton is in Mr. Good- hall’s collection. SCALARIA reticulata. TAB. DLXXVII.— /g. 5. Spec. Char. Subulate, short; surface reticulated; whorls united ; columella hollow ; base smooth. Syn. Turbo reticulatus. Brander,jig. 27. Eight whorls compose this shell, which is only about half an inch long ; nine or ten prominent transverse striae cross numerous not more prominent ribs, forming a net- work that covers the convex whorls, and is bounded by a nearly smooth band extended over the base. Presented many years ago by Miss Bemister : found at Barton. Miss Teed has in her cabinet a broken indivi- dual above an inch long. SCALARIA semicostata. TAB. DLXXVIL— fig. 6. This figure is from a nearly full-grown individual, such as are not uncommon at Barton. A small one only has been represented in the middle of tab. 16. In the vici- nity of Paris a Scalaria is found still longer, with more numerous costae and less distinct striae, but apparently the same species ; I have received it as S. plicata from Mons. Deshayes* 578 151 MUREX Smithii. TAB. DLXXVJIL- fig, 1. 2. & 3. Spec. Char. Pyriform,, transversely striated, fur- nished with three rows of short tubercles, those of the upper row largest, pointed ; beak elongated, straight ; upper parts of the whorls flattened. Far. (3. spire produced : fig. 3. The spire being very short, the last whorl very large, and the beak much produced, give the pear-like form to this shell : two rows of the tubercles are wholly conceal- ed within the last whorl. When the shell is removed from the stone, the cast of the spire appears longer, and in var. (3. it is so much produced as to show the middle row of tubercles. The beautiful specimen represented at figs. 1. and 2. is nearly covered by a Flustra : it was collected in Alum Bay, Isle of Wight, by Gerrard E. Smith, Esq., whose zeal we wish to commemorate by naming it after him. The variety fig. 3 . is a cast found at Maida Hill, Pad- dington : it is in the collection of G. A. Mantell, Esq., who also possesses a cast of the first variety imbedded in part of a Septarium from Bognor. It seems to be a rare London Clay shell, as we know of no other speci- mens. 152 MUREX tuberosus. TAB. DLXXVIII.— fig. 4. Spec. Char. Ovate, pointed, transversely striated; one row of blunt tubercles upon the upper part of each whorl ; whorls squarish ; spire as long as the last whorl ; beak produced. A general bluntness in the outline of this shell gives it some resemblance to a tuberose root. The length of the aperture is about equal to the diameter of the last whorl, which is something greater than the length of the spire. Casts in compact oolitic limestone, with small portions of the shell replaced by calcareous spar, are not unfre- quent in the Pisolite at Malton. We have never met with a specimen sufficiently perfect to determine the form of the beak by, or even to ascertain for certain the true genus to which to refer the species. MUREX Harpula. TAB. DLXXVI1I.— /g. 5. Spec. Char. Obovate, squarish, pointed at both ends, decorated with numerous longitudinal ribs ; spire very short, aperture nearly orbicu- lar ; beak straight. Close, thin, oblique ribs, squarish whorls, broadest towards the base, and a small spire, are the prominent features of this pretty Murex. The ribs are extended quite over the base, where their number is increased by the irregular insertion of shorter ones. The speci- men is very imperfect, the aperture particularly being incomplete. Taken out of the Carboniferous Limestone of Bradley, and now in the cabinet of H. T. De la Beche, Esq. 57.9. 153 AMMONITES falcatus. TAB. DLXXIX.— fig. 1. Spec. Char. Discoid,, subumbilicate, radiated ; whorls crenated and flat at both edges, the in- ner ones almost concealed ; radii falciform, bent in the middle ; aperture sagittate with truncated angles. Syn. A. falcatus. Mantell Geol. Suss.p. 17. tab . 21. /. 6. & 12. a This rare and elegant species is almost flat, the long- est diameter exceeding its greatest thickness nearly four- fifths. The volutions are slightly enlarged in the centre, but are contracted at the ambit .... with delicate pli- cated edges. The radii are very slender at their origin in the umbilicus, but gradually increase in breadth; and passing obliquely to the centre of the volutions, make a sudden curve towards the margin, where they terminate in obtuse folds.” The front is very narrow and flat ; the cast of it shows a furrow along the middle in which the siphuncle was placed. I am indebted to Mr. Mantell for permission to figure his best specimen, which was found at Middleham in Gray Chalk Marl. 154 AMMONITES curvatus. TAB. DLXXIX— ^g. 2. Spec. Char. Discoid, subumbilicate, radiated ; in- ner whorls almost concealed ; radii falcate, near equal over half the whorl, then bent, and alternately broad and narrow ; the broad ones furnished with two tubercles each near the front, the narrow ones gradually lost towards the front; front flat, narrow ; umbilicus large, with a row of flattened tubercles around it ; aperture obtusely sagittate. Syn. A. curvatus. Mantell Geol. Suss . p. 118. tab. 21. /. 18. C6 rp 1 his Ammonite is nearly allied to the preceding, but is evidently a distinct species. In A. falcatus the cur- vatures are more numerous than the oblique radii ; but in the present species the proportions are reversed, two or three radii uniting to form one curved rib. The ter- minations of the ribs in the latter are tubercular, and separated from each other by a sulcus ; in the former they are gently curved, and appear as if folded or plaited over each other. The umbilicus is rather deeper than in A. falcatus, and has a marginal row of oblique tuber- cular projections, from each of which two or three radii proceed. “ Locality, Hamsey.” We are favoured with this along with the last: it ap- pears to be unique. In both descriptions parts of Mr. Mantell’s are copied, as they appeared so appropriate. The furrow in the front mentioned by him is the situa- tion of the siphuncle, and of course would be covered by the shell. 155 CORBIS. Cuvier. Gen. Char. A free,, transverse, equal-valved, bi- valve, with incurved umbones; two lateral and two hinge teeth in each valve, one of the late- ral teeth near the hinge, the other remote ; attachment of the mantle upon a curved, not sinuated line. All the species of this genus that have hitherto come under observation are transverse shells (that is, they are longer in a direction transverse to the position of their hinge-teeth) : in common with many other bivalves, the umbones are curved inwards, in opposite directions in the two valves ; there are two cardinal and two lateral teeth in each valve ; that which is on the opposite side of the hinge to the ligament, is much nearer to the cardinal teeth than the other, which is rather remote, but placed near the termination of the ligament. This is external ; but the parts to which it is attached form a deep groove when the two valves are closed ; when also, a rather ob- long cordiform impression immediately behind the um- bones may be observed. u This Genus was established by Cuvier, and is adopted by Lamarck. It is related to Lucina, but may be distin- guished from that genus by its muscular impressions, which are simple and rather oblong, but neither of them produced into an elongated tongue shape ; it approaches also to Tellina, but, wanting the fold of the anterior (posterior) margin of that genus, it will not be confound- ed with it. Not many species of this genus are yet known ; the only recent one with which we are acquainted is a very beautiful, transversely oval, rather gibbous shell, with longitudinal striae and undulated transverse fur- rows, and its interior margin is crenulated; it is the Ve- nus fimbriata of Linne, the Corbis fimbriata of Cuvier, and according to Lamarck an inhabitant of the Indian 156 Ocean. Two fossil species are described by Lamarck, both of which are found in the more recent formation above the Chalk; one at Grignon, and the other at Granville. Neither of them are so gibbous as the re- cent one. Several others are now known. “Whether the shells of this genus be covered with an epidermis in their natural state or not, we have no means of ascertaining ; there is, however, some reason for be- lieving this to be the case.” The above description is taken from my brother’s “ Genera of Recent and Fossil Shells,” No. 2. I have only to add, that the hinge teeth are unequal, that the anterior side is largest, and that the recent species is nearly colourless. CORBIS laevis. TAB. DLXXX. Spec. Char. Transversely oval, elongated, rather gibbose, smooth except a small portion of the posterior extremity which is transversely undu- lated or rather imbricated ; margin entire. In the general form of the valves and the disposition of the muscular impressions, this agrees well with the ge- nus Corbis : the hinge is somewhat different, but as one of the remote teeth is worn away, and the whole cannot be relieved from the stone, we will not venture to say that it is sufficiently different to characterize a new genus. Collected many years ago by G. E. Smith, Esq., from the Sandy Limestone at Marsham Field, near Oxford. A second specimen has not been found. <580. 381. 157 PHOLAS prisons. TAB. DLXXXI. Spec. Char. Oblong oval, finely striated; striae smooth, transverse ; anterior extremity round- ed very short, with a deep angular sinus in its edge, becoming closed by shell when old; posterior extremity truncated ; beaks covered by an accessory valve ; a series of scales form a longitudinal band nearly in the middle of each valve. A small species, very similar to P. clavata of Lamarck and others, that dwell in holes they form in wood. The anterior side is very small ; its edges near the beaks are reflected and covered by a heart-shaped valve. In the young state of the animal the sinuses in the valves form a rhomboidal opening, which in the adult is closed by a smooth continuation of the shell. For the discovery of this highly interesting Fossil we are indebted to H. H. Goodhall, Esq. Wood penetrated 158 by Teredines had long been known in a fossil state ; but the genus Pholas was unknown, except in Crag, until Mr, Goodhall was so fortunate as to pick up the specimen here figured, behind Lord Darnley’s park. It is a siliceous mass, from the uppermost stratum of Lime- stone near Sandgate. Exposure to the weather has laid open the shells to view in their natural situations in the fossil wood, part of which, being impregnated with silex, is preserved around the stony matter that has filled their cells. The mass also contains numerous single valves of a small Avicula. SS2 . 159 INOCERAMUS latus. TAB. DLXXXII.— fig. 1. Spec. Char. Ovato-rhomboidal, depressed, con- centrically undulated ; valves equal ; anterior side * concave ; posterior side broad, expand- ed towards the very oblique hinge line ; beaks small, short. Syn. Inoceramus latus. Mantell , Geol. Suss. 216. t. 21. f. 10. A large flat species, almost uniformly covered with large, slightly elevated, angularly bent undulations or ridges, and sharp striae. The part upon which the hinge line is placed does not form a lobe, but is an almost smooth projection, that completes the rhomboidal form of the margin. The regularity and obliquity of the un- dulations distinguish this from I. Cuvieri, which is either plain, or has a few large irregular waves upon its sur- face. At the time Inoceramus Cuvieri was published in u Mineral Conchology,” I did not possess characteristic specimens of the I. latus. Such have been supplied by C. B. Rose, Esq. from the Upper Chalk near Swaffham, Norfolk. In size it equals I. Cuvieri, acquiring eighteen inchcc or more in length. The front is often suddenly deflected. * In the descriptions of the species of Inoceramus formerly given, this is called the ‘posterior side ; whereas the side upon which the ligament of the hinge is placed is the posterior. 160 INOCERAMUS striatus. TAB. DLXXXII. —fig. 2. Spec. Char. Subglobose, even, concentrically striated, the striae accompanied by shallow furrows ; anterior side concave, smooth. Syn. Inoceramus striatus. Mantell, Geol.Suss. 217. t.W.f.5. This rare species has not been found sufficiently perfect to exhibit all its characters. Its valves, however, appear to be equal, and the beaks very short and blunt. Its form readily distinguishes it from I. mytilloides, which it accompanies in Sussex and Wiltshire. The specimen figured is from Heytesbury. I am indebted to the intel- ligent author of the u Geology of Sussex” for it. INOCERAMUS involutus. TAB. DLXXXIII. Spec. Char. Subglobose ; valves very unequal ; one gibbose, even, with a large incurved beak and very hollow sides, the other nearly flat, with deep concentric waves ; its margin very thick, deflected ; hinge line upon an elevated narrow lobe. When once this species has been observed, even frag- ments are readily recognized, — especially of the larger valve, by the smoothness of its surface and convex form ; or of the smaller valve, by the strength of the undula« tions, their circular disposition, and the long narrow lobe of the hinge, that looks as if the margin were rolled over. The flatter valve offers the greatest variation of 583. 564 161 thickness I have observed in any shell within the same extent of surface ; some parts near the edge being almost half an inch thick, while others near the beaks (only three or four inches distant) are as thin as card-paper. For several fine illustrative specimens of this species, mostly too large to figure even in a quarto plate, I am indebted to C. B. Rose, Esq. : they are from the Upper Chalk of SwafFham and West Lex ham, Norfolk. Fig. 1. is taken from a pair of shells, filled with flint, that was bought at Mr. Parkinson’s sale. Fig. 2. is from a por- tion of the flatter valve picked out of a Chalk-pit at Bury St. Edmonds by the Rev. J. Holme, M.A. F.L.S. The inequality of the valves of this shell, which can- not be separated from Inoceramus, proves the impro- priety of forming two genera. While the above was in the press, I received the spe- cimen represented at fig. 3. from the Rev. G. R. Leathes. It came from the Bury Chalk. INOCERAMUS gryphssoides. TAB. DLXXXIV.— fig. 1. Spec. Char. Ovate, ventricose, concentrically un- dulated ; valves unequal, the smallest gibbose; beaks incurved, pointed, approximated. So nearly does this resemble I. concentricus, that, ex- cept size and the close beaks, we can see no marked dif- ference ; yet few persons would be induced to consider them the same species. From the Green Sandstone west of Lyme Regis, in Dorsetshire. Large pearly fragments also occur in Blue Marie at Ringmer in Sussex, which are probably the same species. It is too gibbose for either I. tenuis or I. Cripsii, — our specimens of which are not perfect enough to describe. 162 INOCERAMUS vetustus. TAB. DLXXXI 2. Spec, Char. Ovate,, convex, smooth, regularly un- dulated ; valves nearly equal ; beaks short, pointed, curved ; a concave space in the ante- rior side resembling a line short. Very regularly arched and gradually rising undula- tions of a smooth surface distinguish this from I. Bron- gniarti, independently of the difference in the anterior side. I have not seen the hinge, but the line to which it is attached is short ; the front is very round. Occurs in the Mountain Limestone at Castleton in Derbyshire, and near Settle in Yorkshire. INOCERAMUS dubius. TAB. DLXXXIV.— /g. S. Spec. Char. Ovate pointed, concentrically striated and indistinctly waved ; valves unequal, both convex ; beaks short, pointed. Strongly resembling I. concentricus. The convexity of the valves is variable ; one valve is sometimes flat : it is then more strongly marked by the striae formed of the edges of the laminae, so characteristic of shells of the genus Inoceramus. I have not seen the hinge. A mass of indurated Alum Shale, containing brilliant casts in Pyrites of this shell and a portion of Ammo- nites elegans ? was collected by that indefatigable geo- logist, R. I. Murchison, Esq. on the Whitby coast in 1826. A portion of it is the subject of this figure. large lunette ; hinge 163 PECTEN grandis. TAB. DLXXXV. Spec. Char. Suborbicular, wider than long,, con- centrically striated, furnished with thirteen much elevated, rounded, more or less com- pound rays, each of which has generally a sulcus along its middle, and between each is a single secondary ray ; one valve rather con- vex, towards the beak concave, the other very convex ; ears nearly equal, square. A large Pecten, in general shape resembling P. maxi- mus, but differing in the form and structure of the rays. The concentric striae, as in P. maximus, are very irre- gular, and but little elevated upon the convex valve, while upon the other they are very regular, close, and raised into sharp laminae : the rays upon the convex valve especially are more elevated and deeply divided or sulcated, approaching to the form of those of P. Jaco- baeus, but differing from them in being much smoother and rounder. The Rev. G. R. Leathes, to whose liberality I am indebted for a series of specimens of this species, has a selected the trivial name grandis for it ; — not but that there are several fossil species found much larger, but as approximating to maximus , given to our common Escallop.’’ Occurs at Ramsholt in a native bed, and Newbourn, and in various other parts of the Suffolk Crag, 164 PECTEN complanatus. TAB. DLXXXYI. Spec. Char. Suborbicular, wider than long, orna- mented with thirteen broad flat elevated rays, concentrically striated ; one valve nearly flat, concave near the beak ; ears equal, square. Similar in size and shape to P. maximus, but distinct, the rays being flat, with nearly perpendicular sides ; the two lateral rays are blended with many striae upon the sides of the valve. The two valves have not, that I know of, been discovered in contact : we are therefore unac- quainted with its particular characters ; the flatter one is less convex than that of either P. grandis or P. maximus. Our intelligent friend Mrs. Murchison has obtained several valves of this species from the Crag at Aid- borough, and near Ipswich. It is also in the cabinet of the Rev. Mr. Leathes ; but it is by no means so common as the grandis. Besides the two species just described, there are found in the Crag, P. maximus and P. Jacobaeus : but I have only seen fragments ; and these are so identical with the recent species, that there is hardly any necessity for figuring them. JS0-. 587. 165 AMMONITES Woollgari. TAB. DLXXXVII. —jig. 1. Spec. Char. Compressed, carinated, radiated ; whorls three or four,, the inner ones partly concealed; radii distant, upon the inner whorls curved and prominent, each furnished with three tubercles, the outer of which is flat and small, as the whorls increase the middle row of tubercles expands so as nearly to occupy the whole ribs and form large blunt spines ; keel deeply serrated. Syn. A. Woollgari. Mantell , Geol. of Suss. p. 197. tab. 21. /. 16. & tab. 22. f. 7. The central whorls of this fossil, separated and com- pared with the external one, would never be thought the same species ; they are compressed, and crossed by pro- minent curved rays, while the outer one is ventricose and furnished with about ten large conical spines on each side, placed opposite to each other, with one tooth of the carina in the middle of each pair : in the smaller whorls each ray has a flattened tubercle placed near and parallel to the keel ; within this is another smaller tu- bercle, which as the whorls proceed is greatly enlarged and blended with a third tubercle, that seems gradually to recede from the inner edge of the whorl until it is lost ; the flat tubercle still remains more or less distinct. A handsome and scarce shell, peculiar to the Lower Chalk near Lewes in Sussex. The figure is from the same adult specimen of which Mr. Mantell has given a diminished representation in his very complete work. I beg to acknowledge his kind- ness in allowing me free use of it, as well as of many other rare specimens. 166 AMMONITES tetrammata. TAB. DLXXXVIL— ^g\ 2. Spec. Char. Discoid, carinated, tuberculated ; vo- lutions about four, convex,, crossed by many obscure rays, upon each of which are four tu- bercles, each alternate ray has a branch with two tubercles ; outer tubercles compressed ; keel entire, sharp. This Ammonite, as far as we at present know, varies but little in its different stages of growth. It bears a great resemblance to some of the forms of A. varians (t. 176.), but is a larger shell; and the four rows, instead of three, of tubercles distinguish it. We received a specimen of this many years ago from our kind friend G. A. Mantell, Esq. It is rather less than the one figured, which is in the cabinet of H. H. Goodhall, Esq., who found it at Hamsey *, and pointed it out as a new species. The specimen sent by Mr. Man- tell was obtained in the same parish. * From a pit in the road from Lewes towards Ditchling. 668. 167 ORTHOCERA fusiformis. TAR. DLXXXVIII.- figs. 1.&2. Spec. Char. Fusiform. A middling-sized Orthocera : it is smooth, round, and rather rapidly tapering towards both ends, the open end truncated ; the siphon nearly central ; the last chamber is large, commencing at the widest part. Occurs in the Black Limestone of Ireland, particularly in Queen’s County, where it is, in common with other fossils, often variously curved (See a portion at fig. 2.) by some change the rock has undergone subsequently to its being deposited. The last chamber is rarely found. The specimen figured (fig. 1.) enriches the collection of W. Gilbertson, Esq., who obtained it near Preston in Lancashire, from a Limestone corresponding in its con- tents very closely with that of Ireland. A great portion of the last chamber has been filled with loose earthy matter that settled to one side, and being easily removed, has left the last septum with the opening into the siphon very distinct : a few minute crystals of quartz are scat- tered over the surface. 168 ORTHOCERA cincta. TAB. DLXXXVIII.-; fig. 3. Spec. Char. Nearly cylindrical, surface ornament- ed with numerous sharp annular striae ; siphon central. In this species the septa are rather more concave than is usual, and also distant. The transversely striated surface is what it is best distinguished by, and seems to indicate a shell formed outside the animal. I have seen but one specimen ; it was lent me by Dr. A. Moore, who obtained it near Preston. 169 BELEMNITES. Auct. Gen. Char. An elongated, straight, ponderous, uni- valved, shell; cavity much shorter than the shell, conical, divided by septa which have entire even edges, and are penetrated by a lateral siphuncle. The shells of this long-known genus are all much elon- gated, never spiral nor even curved, except very slightly in one or two species near the apex. The chambered cavity is composed of thin laminae, exactly similar to the corresponding part in Nautilus, except that it is a straight, not an involute, tube or cone : this is sur- rounded by a coat formed of layers of fibres of a lami- nated or sparry structure, placed nearly perpendicularly to the surface, and corresponding to the outer coloured coat of Nautilus* or shells generally, but with the cry- stalline tissue much more largely developed than even in Pinna, with which Mr. Miller has very justly com- * In speaking of the various parts of a Belemnite, we shall keep in view this analogy : the pointed extremity will thus be considered as the apex , the opposite end the base , and the side on which the siphuncle is placed the (as in Ammonites) front : we say the front, because that part of the base or aperture seems similarly situated to the anterior margin in the genus Helix. We cannot agree, when we are describing a Nautilus or Am- monite, to call this the back, which has often been done by other writers. This part in the Belemnite is by Blainville termed u ventrale in Spirula the position of the siphuncle is reversed. 170 pared it. This fibrous coat is so much produced beyond the apex of the chambered cavity upon an axis, (or elon- gated nucleus which probably existed in the ovum,) that it often forms the largest portion of the shell : in this circumstance principally it differs from Orthocera, the genus next akin to it. The genuine fossil Orthocerae (no fossil Orthocera is given by Lamarck) have, more- over, a central siphuncle ; and were, at least some spe- cies, external shells. A few fossils hitherto referred to that genus, would deservedly arrange under an interme- diate one. Much has been written about the nature of the animal of which the Belemnite formed a part. The opinions of Platt and Miller agree, as far as they suppose it to have inclosed the shell by two lobes curved round it so as to meet in a line along the front : the smooth surface, showing the impression of ramose veins in many species, and fibrous structure of the external coat, in which it resembles Cypraea, greatly favour this opinion. Lamarck, justly considering the chambered cone very similar to the genus Nautilus and Spirula, the animals of which were known to resemble Sepia, has placed Belem- nites, Orthocera, Nautilus, and all the chambered shells, with Sepia in the fourth order of Mollusca, the Cephalo- poda, and appears to consider the Belemnite an internal shell. This opinion is supported by all later authors, and by Mr. Miller, as far as regards the form of the animal. M. de Blainville, the last writer upon the subject, thinks with Cuvier and Lamarck, that the shell was internal like the hard substance called bone in the Sepia offici- nalis, and brings forward two fossils of intermediate 171 forms in the series including Belemnites, between this bone and Nautilus. The first, Beloptera sepioidea*, ge- nerally known as a fossil Sepia, has septa half closing an expanded cavity. The second, B. belemnitoidea f, has septa quite across a conical cavity : but it is not proved that either of these was wholly internal, while it is known that the shell of Spirula is partly external, and the shell of Nautilus almost wholly so. Now it appears very probable that the Belemnite was inclosed, not en- tirely within its animal, but within two folds or lobes of its mantle or skin, partly, as supposed by Mr. Miller ; these lobes, however, might be similar to what would be produced by making an incision along the back of a Se- pia so as to let the apex of its bone protrude, and so bear an analogy to the two lobes that inclose the spi- rula, and not be produced by curving the edges or wings (fins) of the animal around it, as described by Mr. Miller. The idea of the shell having undergone any such an alteration by mineralization as to produce the fibrous structure, is not consistent either with Mr. Miller’s expe- riments or the general characters of changed fossil shells, wherein the internal tissue is generally wholly destroy- ed, as in Echinus’ spines or siliceous casts, and even in parts of some Belemnites. Lamarck and all modern authors, except M. de Blain- ville, yielding to old prejudices, have continued to de- scribe the Belemnite as composed of two parts ; the etui, * Sepia Cuvieri. D'Orbigny , Cephalopodes , p. 66. f Sepia parisiensis, ib . — A third species of this genus without lateral projections has been found at Highgate, and forms an additional link. (See tab. 591.) 172 sheath or guard, and the alveolus. Now the alveolus is composed of foreign matter that has insinuated itself intoJ;he?chambers of the conical cavity, and becoming stony is easily separated from that cavity, tearing the fragile septa away with it, (when this consists of sparry matter it may be observed, that it is of a different charac- ter from the sheath, which confirms the opinion of the latter not being mineralized,) but leaving the edges of the septa attached to the inner almost pearly coat of the shell. Lamarck states the siphuncle to be central, which it never is in Belemnites : he has probably intended to include fossil Orthoceratites in the same genus. The strata that contain Belemnites are all above the New Red Sandstone ; they are, the Lyas, the inferior or iron-shot Oolite, the Stonesfield Slate, the Oxford Clay and sandy Limestone above it ; the Gault and mixtures of it with the Green-sand, and the lower and upper Chalk. It is to be remarked, that above the red marl there has not been seen a single straight-chambered shell with a central siphuncle ; nor below the red marie a single one the apex of which is known to extend far beyond the apex of the chambered cavity. In the older formations the substance of the chambered shells is entirely changed into calcareous spar, the distinction between the tissues of their several coats being destroyed. The elaborate Memoire sur les Belemnites , 4to, 1827, by M. deBlainville, will furnish every particular relating to their history, &c. which may be desired; with descrip- tions and figures of about fifty species ; and to that work we beg to refer our readers. We differ in some points from the opinions of the author of this excellent work ; 173 but it is because we have viewed the same facts in a light which seems to warrant us in drawing conclusions from them which may tend to combine the opinions of the two best authors upon the subject. The situation of the genus in a natural series is neatly pointed out by M. de Blainville; but the sections of the genus, at least the three first by him, and the separation of Actinoca- max by Mr. Miller, are ill-founded, as will be shown hereafter. M. de Blainville places the genus Beloptera immediately after Sepia, next Belemnites, then Ortho- cera, — so commencing the long series of chambered shells, all of which are supposed to belong to cephalo- podous Molluscae. The genus Argonauta has long been included in the same series ; but it by no means appears in its natural situation, and spoils the harmony, in whatever part it be introduced : it is in fact much nearer related toCarinaria. The question respecting the Ocythoe that is found in it, being a parasite or not, is still undecided ; and we must be cautious when contemplating it, to avoid being led by the supposed analogy the shell bears to Nautilus, — an analogy which holds little further than in the name. The fact that there is no surface of attachment between the animal found in it and the shell, that the animal is sometimes placed with the rectum over the beak of the shell and sometimes in the opposite direction, joined with the facility of quitting the shell the animal shows when captured, strongly favour the idea of its being a parasite ; and when we contemplate the irregular form and size of the apex of the spire, we are led to conclude that the egg of the animal proper to the shell, must have been 174 much larger than any of the eggs that have been found to accompany the Ocythoe, in the proportion of at least a pea to a pin’s head ; Mr. Poli must therefore have been somehow deceived when he thought he saw the Argonauta developed in the eggs of Ocythoe. The pro- bability is, that the Ocythoe chooses the shell of an Ar- gonauta as a convenient protection for its spawn, be- cause it is light and portable ; and that the sac or mantle of Ocythoe in the egg has been taken for the shell. We think therefore there is good reason for removing Argo- nauta from the Cephalopoda to the Heteropoda, of which Order we take the present opportunity of mentioning, that we know of no fossil belonging to it. <589. 175 BELEMNITES minimus. TAB. DLXXXIX— /g. 1. Spec. Char. Fusiform, squarish, expanded towards the apex, cylindrical towards the base ; apex indistinctly papillose, each side marked with an obscure double furrow ; base not expand- ed; a sulcus in the front extending a short way from the base. Syn. Belemnites minimus. Lister. B. Listeri. Mantell , Geol. Suss.p. 88. tab. 19. fig. 17. 18. & 23. B. minimus. Miller , Geol. Trans. 2d series. v. II. p . 62. pi. IX./. 6. De Blainville , Mem. sur les Belemn. 75. pi. IV./. 1 . and p. Il9.pl. V./ 5. This small Belemnite is generally of a rather bright yellow brown colour, and possesses much transparency ; its outer laminae often show a tendency to flake off* about the apex, and the axis is always opaque or tubular from decomposition, which shows that the imperfect state of the base, which has not only lost the septa that we sup- pose from analogy must once have existed within it, but also much of its fibrous portion, has arisen from its having remained in an exposed situation a long time before it was buried in its grave of clay or marl, which has preserved its remains for our inspection and admi- ration. So much indeed of the fibrous substance has de- cayed away from the surface of the conical cavity in many cases, that a considerable portion of the axis is 176 left projecting into it in the form of a tube. The length rarely exceeds two inches and a half. It is peculiar to the Marl (blue marl, blue chalk marl or gault) between the upper and lower green-sands. The small specimens figured are from Folkstone. Mr. Goodhall has similar fromMaulden and Clophill, and that vicinity, in Bedfordshire. We have others from Sussex and Cambridge. The large ones are from Speeton Cliff, Yorkshire, by favour of Mr. Williamson. In Mr. Miller’s figure two furrows are represented near the base : we have never seen such a specimen. BELEMNITES attenuatus. TAB. DLXXXIX.— ^g*. 2. Spec. Char. Subfusiform, squarish, not much di- minished towards the base; suddenly con- tracted a little above the middle, whence to the rather blunt apex it is elongated and al- most cylindrical ; an obscure double furrow on each side, and a sulcus in the front ex- tending a little way from the base. This has a curious appearance, one third of it from the apex being more cylindrical and much narrower than the remainder, and often striated. In colour, state of preservation, and every thing ex- cept the general form and greater length, this exactly resembles the B. minimus : it was found along with that species at Folkstone. BELEMNITES pistilliformis. TAB. DLXXXI X.—Jig.3. Spec. Char. Fusiform, pointed, round, very much attenuated and elongated towards the base. Syn. B. pistilliformis. De Rlainville , Mem. sur les Belemn. p. 98. pi. V./. 14. 15. 16. & 17. An elegant but variable species ; sometimes it is equally attenuated at both ends, at other times it is much thick- est near the apex ; the older individuals generally ap- proach most towards cylindrical, and have an obtuse ex- tremity. We are not quite certain that this is exactly the species described by De Blainville, because we find some traces of longitudinal furrows or impressions of veins. It is very possibly the young of B. elongatus. The figures are all from specimens collected by our indefatigable friend H. H. Goodhall, Esq., out of the Lyas Clay at Shorne Cliff, east of Charmouth. De Blain- ville says it is from the J ura Limestone, 178 BELEMNITES elongatus. TAB. DXC .—Jig. 1. Spec. Char. Slender,, cylindrical in the middle,, gradually expanding to a broad base one way,, and tapering to a point the other ; round, and free from furrows ; the chambered cavity two- thirds the length of the shell. Syn. B. elongatus. Miller, Geol. Trans. 2d series. vol. II. p. 60. pi. VII. / 6. 7. & 8. BeBlain- ville, Mem. sur les Belemn. p. 95. A Belemnite. Joshua Platt, Phil. Trans . vol. liv. p. SS ( with a figure). A great portion of the shell of this Belemnite is so thin as to give rise to the opinion that only part of the cham- bered cavity (the alveolus) is covered by the fibrous coat (guard or sheath) ; and that the last formed chamber, whose sides would principally consist of this coat, is not proportionally larger than the preceding one, — an opi- nion that has been formed from the examination of im- perfect specimens, and influenced by the idea that the alveolus may be independent of the guard. The cylin- drical portion of the shell extends for about one fourth of its length, and is over the extremity of the cavity. The diameter of the base when perfect nearly equals a quarter of the length. Found in the Lyas Clay at Lyme, Charmouth, and near Bath. The specimen figured was lent in 1814 to Mr. Sowerby by the much-to-be-lamented friend to science Sir Joseph Banks, to whom it had been sent the year before by Mr. Bevan, who obtained it from the Crick Tunnel near Daventry, in Northamptonshire. 59C. 179 BELEMNITES abbreviate. TAB. DXC — figs. 2. 3. & 9. Spec. Char. Short, subcylindrical, with an ex- panded base ; extremity suddenly tapering and slightly recurved to a blunt excentric apex; sides flattened; cavity about half the length of the shell, its apex far from central. Syn. B. abbreviatus. Miller , Geol. Trans. 2d se- ries. p. 59. pi. VII. f. 9. & 10. De Blain- ville , Mem. sur les Belemn. p. 91. There appear to be no furrows upon any part of this shell ; its thickness in proportion to its length, the con- traction and curvature of its superior extremity, and the cavity inclining towards the front, are so many marks by which the species may be known. Occurs in the Inferior or Ironshot Oolite (probably only in the lower beds), and the upper beds of Lyas. Fig. 1. is from a Weymouth specimen : fig. 2. is from Banbury in Oxfordshire, by favour of the Rev. W. D. Conybeare ; it is part of an alveolus, and shows how closely the inflated tubes of the siphuncle between the septa approach the surface of the cavity, which in fact cuts off a segment from each. Fig. 9. represents a young individual of precisely the same form, from near Bath : it is in Mr. Goodhall’s cabinet. The figure referred to by Miller in Parkinson’s Org « Remains , does not decidedly represent this species. 180 BELEMNITES acutus. TAB. DXC .—Jigs. 7. 8. & 10. Spec. Char. Conical, terminating in an acute point, round ; cavity very deep, central. Syn. B. acutus. Miller , Geol.Trans . Sdseries. vol. II. p. 60. pi. VIII./. 9. A regularly conical smooth shell ; very slightly com- pressed on the sides, and without any furrow. From the great diameter of the cavity at the base, we judge it to be very deep. B. acutus of De Blainville is certainly not the same species ; that has a distinct longitudinal furrow, and is more cylindrical. M. De Blainville has probably been misled by Mr. Miller’s having quoted, with a query, a figure in Luid that does not agree with his own. Both our figures are taken from specimens in Mr. Goodhall’s cabinet : fig. 7. was found at Weston, near Bath ; and fig. 10. in Shorne Cliff, Charmouth. The latter shows some curious marks produced by decomposition and partial exfoliation of the outermost crust : the shell is also split in two or three parts by the expansion of some substance within its cavity. 181 BELEMNITES penicillatus. TAB. DXC .—Jigs. 5. & 6. Spec. Char. Short, compressed, very gradually ta- pering towards the superior extremity , near which it is suddenly contracted to an obtuse nearly central striated or sulcated obtuse point ; cavity deep. Syn. B. penicillatus. De Blainville , Mem. sur les Belemn . p. 89. pi. III. f. 7. Knorr, part 2. pi. I* /. 1, 2. 3. & 4. The short compressed form and suddenly contracted extremity serve to distinguish this species by, although the furrowed or striated apex may be concealed, which it often is. Found in Shorne Cliff by Mr. Goodhall, but by no means plentiful. We strongly suspect B. brevis and B. penicillatus, and also B. digitalis, to be but varieties of one species. 182 BELEMNITES compressus. TAB. DXC .—fig. 4. Jr Spec. Char. Thick, straight, compressed, regularly tapering to a furrowed extremity ; furrows deep, two of them extending down the flattened sides further than the others ; cavity deep, its apex excentral ; base oval, not expanded. Syn. B. compressus. De Blainvitle , Mem. sur les Belemn. p. 84. pi. II./. 9. Distinguished from B. ellipticus of Miller by being much shorter, and from B. Gigas of De Blainville by the sulcated extremity. It has no furrow at the base, nor any indication of veins upon its surface. The septa are very numerous. An inhabitant of the Inferior Oolite. Our specimens are from near Scarborough, out of the gray Oolite below the coal grit, where they were accompanied by Saurian remains. 183 BELOPTERA. Deshayes. Gen. Char. Shell (bone?) internal, oblong, expand- ed, concave, thin : to its inner surface is at- tached a chambered cone, placed longitudi- nally; from the apex of the cone the shell is considerably thickened. This genus has been formed to receive those organic remains found in the Calcaire grossier of France, which resemble the bones of cuttle-fish (Sepia officinalis) ; but one of the species is (perhaps two may be) so nearly like the recent Sepia, that it does not seem necessary to remove it from that genus. We have modified the Gen. Char, of Beloptera so that it may only include such species as have a chambered cone resembling Belem- nite, that is, De Blainville’s 2nd section of the genus. We have given outlines of two of the species De Blainville refers to the genus; the third we have never seen. Fig. 1. is B. sepioidea (Sepia Cuvieri), which we would refer to Sepia; its septa being placed like the la- minae of that bone, and not crossing a conical cavity. Fig. 3. is B. belemnitoidea, the only species in De Blain- ville’s 2nd section; the cone in it is completely divided by the septa into many narrow cells ; we know not whe- ther it had a siphuncle. The first appears to be a small portion only of the shell or bone, while this has rather the appearance of being nearly entire, the chambered cone filling half its length. We consider it as the type of the genus. Only one species is found in England, which is in the London Clay. 184 BELOPTERA anomala. TAB. DXCI-— fig. 2. Spec. Char. Oblong; section trigonal ; sides very little expanded ; apex very obtuse, with a cir- cular pore on the front. Chambered cone very thin, filling the whole of the con- cave side or front of the shell, a little curved ; as the cone diminishes, the shell increases in thickness at the back and sides until it terminates in a convex apex as broad as the base of the cone ; on the front of the ter- mination is placed a circular hole, towards which the apex of the cone is curved ; the shell about the base of the cone is very thin ; the whole is smooth. A very curious little fossil found at the time the exca- vations were in progress in Highgate Hill. Only one individual has been discovered ; it is in a good state of preservation, although its chambers are filled with Py- rites. The central figure is an enlarged representation. ■ ■ 185 BACULITES. Lamarck . Gen. Char. A straight lanceolate shell, a part of it internally divided by septa whose edges are sinuated : a siphuncle penetrates the septa near their anterior margins. A genus very closely related to Hamites, differing only in being quite straight. Most of the species are very long and laterally compressed, so that the transverse section is elliptical ; the apex has never been discovered, and we only know of one instance of the opposite extremity : it is furnished with two elongated lobes, which, bending a little, seem to point out the anterior part ; they turn from the siphuncle : the edge near these lobes is thicken- ed, and is only completed periodically, as appears from the successive impressions left upon the casts of many in- dividuals. The six principal lobes of the septa have a peculiar roundness of form, which helps to distinguish small specimens from Hamites. The first generic name was Homaloceratites, given by the Baron Hupsch. We are not aware of Lamarck’s reason for changing it ; but his name is now come into general use, therefore we retain it. Lamarck describes three species ; — one from Maestricht, and two British : we regret that the latter have not fallen under our observation. One (B. anceps) is described with one sharp edge; in which it resembles a species very abun- dant in Normandy, which we have received as B. verte- bral is : the other may possibly prove to be a Hamites from Folkstone. All the species occur in the lower beds of Chalk or Chalk Marl and the Upper Greensand. 186 BACUL1TES Faujasii. TAB. DXCII. —Jig. 1. Spec. Char. Smooth ; section oval ; sides com- pressed. Syn. Ammonite droite. Faujas, Hist . Nat. de la Mont, de St. Pierre , 140. pi. 21. f. 2. & 3. Baculites vertebralis. Lam. Syst. 103. — Faujasii. Lam. Hist. 7. 647. Both edges of this species are equally rounded, and the sides a little compressed : there is no appearance of any kind of undulation upon the surface. A cast in Chalk, figured from the collection of C. B. Rose, Esq. : it was found at Norwich. We have seen a larger specimen from Hamsey, in Mr. Goodhall’s cabinet. It is very near B. ovata of Dr. Morton, in the Journ. of the Academy of Nat. Sciences of Philadelphia, vol. vi. ; but we cannot trace any undulations upon the sides. BACULITES obliquatus. TAB. DXCII .—jigs. 2. & 3. Spec. Char. Surface undulated; section oval; undu- lations oblique, annular, deepest at the margins. Syn. Hamites baculoides. Mantell , Geol. Suss, p. 123. t. 23. /. 6. & 7. The very oblique undulations or furrows which pass all round the surface readily distinguish this species : they are generally deepest over the part where the siphuncle is placed, which is marked by S in the figures. The shorter (fig. 2.) represents an unique specimen, that shows the form of the aperture, which is placed obliquely ; on each side is a large oval lobe, placed anteriorly and bent backward : upon the specimen of which two portions are represented (fig. 3.), may be seen the contractions upon the cast produced by the thickened shell near the edge of the aperture at each succeeding period of growth. An abundant fossil in the Gray Chalk Marl about Lewes. The specimens were placed in Mr. Sowerby’s Museum many years ago by his liberal friend G. Mantell, Esq. : they are from Hamsey. S93 . 187 HAMITES grandis. TAB. DXCIII. —Jig. 1. Spec. Char. Section circular; surface anteriorly undulated; undulations numerous, not deep, oblique ; on each side are a few short, oblique ribs, enlarged at their extremities. Between each rib, which only occupies a small portion of each side, are about six rounded furrows, that extend to the line beneath which the siphuncle lies : the posterior surface is smooth. The edges of the septa are formed into very acute and numerous intricate sinuses, arranged in six very unequal lobes. Found in a quarry of Kentish Rag-stone (a calcareous bed in the Lower Green-sand), on the estate of E. Hughes, Esq. in the parish of Smeeth, near Hythe. We are in- debted to Dr. Buckland for the use of the specimen. 188 HAMITES Gigas. TAB. DXCIIL— ^g. 2. Spec. Char. Largely ribbed ; inner side plain, flattish; ribs composed of six laterally ex- panded tubercles. A rather suddenly curved species : six blunt spines are united, three on a side, to form each oblique rib, which is nearly lost as it passes over the front ; the spines near the front are largest ; the section is rather square. We have to acknowledge our obligations to the Right Honourable Lord Greenock, whose anxiety to render a service to Geology has induced him to lend us this and several other rare subjects from the Greensand formation near Sandgate. u It occurred in the second or lower bed of Limestone, in its uppermost course of Rag and Clay above Seabrooke, between Sandgate and Hythe. Other specimens have been collected in the same stratum and bed, upon the Roughs west of Hythe, one of which is in Mr. Hill’s collection.” For these particulars I am obliged to my respected friend G. E. Smith, Esq. who is residing at Sandgate. We are informed that there are much more gigantic Hamites to be found in the rocks at the south-eastern part of the Isle of Wight : possibly they are of the same spe- cies ? ■ h ■ .! , :;r \/ ^ . . k}'p ' ■ % . . .. . ' if . .- ■ ■ ; .ta; fin nd . : ;V ■ ; . ■ Lfe . ■ . . . £24. 189 LJNIO porrectus. TAB. DXCIV. —~j£g\ 1 Spec. Char. Subcylindrical, rather compressed, above twice as wide as long ; anterior side very small,, the other pointed. This is the largest species of Unio found in the Sand- stone of Tilgate Forest : it is distinguished by its regu- larly convex surface and pointed posterior extremity. UNIO compressus, TAB. DXCIY. —Jig. % Spec. Char. Ovate, compressed; hinge-line bent; beaks rather prominent ; lateral ridge square. Length and breadth in the proportion of 2 to 3 : the hinge slope is flattened, so as to make the ridges that bound it square. The anterior side is as large as in the preceding species, although the other is much less. A rare species, from Tilgate Forest. 190 UNIO antiquus. TAB. DXCIV.—^g’s. 3. 4. & 5. Spec. Char. Transversely ovate, elongated, com- pressed ; back and front nearly parallel and straight; anterior side small. Length half the width. The anterior side is larger in this than in U. porrectus, and the general form is more square. Fig. 3. exhibits the usual character of casts. Fig. 4. has the substance of the shell remaining, but con- verted into spar. Fig. 5. is from a cast that is more pointed than usual, and approaches to U. porrectus, of which it is even possible that it may be the young shell. The commonest species in the Sandstone of Tilgate Forest in the Weald Clay. UNIO aduncus. TAB. DXCV.— /g. 2. Spec. Char. Wedge-shaped, gibbose, antiquated ; anterior side straight, small ; the opposite ex- tremity more or less produced, truncated, and bent downwards ; shell very thick. The straight anterior extremity and concave margin of the front are striking characters. Length generally ex- ceeding half the width, but variable. Not very uncommon in the same formation as the last : it seems to be the species figured by Mr. Mantell in his Fossils of Tilgate Forest, p. 57. pi. 10. f. 11. ■ ■ ■ ■ , , V 191 UNIO cordiformis. TAB. DXCV.—^g*. 1. Spec. Char. Heart-shaped, posteriorly pointed ; umbones inflated. A thick shell, whose length, width, and the united depth of the valves, are nearly equal. The anterior side is very small. This is the rarest shell that occurs in the beds of Sand- stone at Tilgate Forest, subordinate to the Weald Clay of Sussex. We are under obligations to G. Mantell, Esq. for the loan or possession of the specimens figured in this and the preceding plates. Much diversity of opinion exists regarding the pro- priety of arranging the shells given in these two tables in the genus Unio. They appear to be confined to certain Sandstone beds included in the Weald Clay ; a formation that contains very few species of shells excepting oysters, and these referable to only three genera, Paludina, Cy- clas, and Unio. In most cases the shells are firmly united to the stone, and only casts can in general be extracted, which renders it difficult to observe those parts by which the genera are clearly indicated, and lay a foundation for doubt. The genera above assumed are composed of fresh= water shells ; and from this it has been concluded that the formation they are found in is of freshwater origin, pro= 192 bably deposited in an extensive lake. This opinion is strengthened by the discovery of Cypris (see t. 485.) in some of the beds connected with the formation, while the presence of oysters excites much speculation. It has been justly observed, that the shells referred to Paludina (Vivi- para, Min. Conch, t. 31.) are thicker than the recent species of that genus, and approach very near to Turbo littoreus ; but the general form is nearer to Paludina flu- viorum, and we have never been able to extract an indi- vidual with a perfect lip. The Cyclades have been better determined, the hinge having been freed from the stone (see t. 527.). The shells immediately under our consi- deration, although very abundant, are never very perfect : casts of their interior are most frequent ; and they present strong indications of the deep muscular impressions, the laminated lateral tooth, and the large teeth in the hinge, characteristic of the genus Unio ; so that we cannot choose but arrange them under that genus of freshwater shells ; and although it must appear extraordinary to find oysters mixed with freshwater shells, or a freshwater formation between marine deposits, we must not, however praise- worthy it is to admire, lose ourselves in wonder, but steadily persevere in searching after the whole truth ; for by so doing we shall best display the harmony that exists in all the works of Nature, and prove that we possess a mind open to conviction, the possession of which is an enjoyment we must ever feel grateful for to Him who gave it. 193 VERMETUS. Lamarck , Hist . Nat. ( Vermicularia , supra vol. i. p. 125.) Gen. Char.* Shell tubular,, in part spiral, fixed by its apex ; operculum corneous, flat, attached to the foot of the cephalous animal. It is by the animal principally that the Vermetus (for- merly called Vermicularia by Lamarck) is distinguished from Serpula and similar genera : it is formed by an ani- mal not composed of joints, that has a distinct head, two tentaculae, with an eye at the base of each, and a cylindri- cal foot (or analogous part) supporting a horny operculum, and consequently nearly related to the animals of true spiral shells, and belonging to Trachelepodous mollusca. There does not appear to be any certain external cha- racter to distinguish the shell by ; but the animal seems much less disposed to attach any large portion of its shell to foreign substances, and generally forms a tolerably re- gular and more or less open spire of the commencement of its tube, which is either discoid or conical. There can of course be no certainty respecting the fossil species; but as it is convenient to separate those shelly tubes which have hitherto been called Vermiculariae, from among the Serpulae, we shall still consider such as have been attach- ed only by the apex (which, by the bye, form a very na- tural group) as belonging to the genus Vermetus. Most of the individuals turn one way, which, if the cone be placed in the same position, is found to be the reverse of most univalves. * The generic character formerly given being inaccurate, and the observations upon it being founded partly in error, we wish to cancel them. 194 VERMETUS Bognoriensis. TAB. DXCVI. —figs. 1. 2. & 3. Spec. Char. Spiral portion conical, subdiscoid, concave beneath ; tube obscurely five-sided, with a furrow above and below ; the produced part cylindrical, slightly curved. Syn. Vermicularia Bognoriensis. Mantell , Geol. Suss. p. 272. Serpula ? Parkinson , 3. 97. pi. 7. f. 8. The tube of this is more angular, and the whorls more numerous, than in V. concava, t. 57. to which it nearly approaches ; but when the surface is worn away, it ap- pears cylindrical. Very abundant in some parts of the Sandstone of the Bognor Rocks, figs. 1. & 2. It also occurs filled with Pyrites on the Sheppy coast (fig. 3.), and also at High- gate. Mr. Parkinson seems to be the first person who has noticed it. 195 VERMETUS tumidus0 TAB. DXCVI.— /g. 4. Spec. Char. Discoid ; whorls few ; tube thicks externally marked with a broad furrow on two sides; the produced part small, short, cylindri- cal ; edge of the aperture thickened. The shell of this is so thick that it appears tumid just before the small cylindrical part of the tube that precedes the aperture : the whorls are seldom more than two, with a concentric furrow on each side, and a callus at the apex. From the Coral Rag near Scarborough. VERMETUS concinnus. TAB. DXCVI. — /g\ 5. Spec. Char. Discoid or slightly convex, a large portion of tube produced ; tube five-angled, four angles acute, the fifth obscure. A neat little shell : at first sight it seems to be a square tube, but upon close examination an obtuse angle is per- ceived round the margin of the disk. Very abundant in a thin stratum of brown sandy Lime- stone in Robin Hood’s Bay, said to be equivalent to the Inferior Oolite. We have received it from several cor- respondents. 196 VERMETUS polygonalis. TAB. DXCYI. —Jig. 6. Spec. Char. Spiral portion a short cone,, with one involute ridge running up to the apex, and two ridges round the margin ; produced part trumpet- formed, with seven acute angles. The ridge around the spire is erect and very prominent; the other ridges are less elevated, except near the ex- panded mouth, where they are equally prominent, and produced into short spines. One of the specimens figured is from the Limestone, and the other from the Sand beneath it, both belonging to the Lower Greensand : they were found above Seabrooke, between Sandgate and Hythe, and are in the collection of Lord Greenock, who has liberally allowed them to travel to London. 197 SERPULA. Linn . Gen. Char.* Shell tubular, variously curved, fixed by a considerable portion of one side ; opercu- lum corneous or shelly, pedunculated, attached to the anterior extremity of an articulated, acephalous animal, whose feathered branchiae surround its mouth. The difficulty there always must be in distinguishing the four genera of Annelides that have shelly tubes, when we only have the means of examining the tubes deprived of their animals, has induced me to relinquish the attempt ; neither does it appear to be of much importance, since the animals are very similar, and their habits the same. The following are the four genera alluded to, which are distinguished by the characters attached. They may form subgenera. Spirorbis. Shell curved into a discoid volute, attached by its lower flattened surface. Animal furnished with six-pinnated branchiae and a peltate operculum. Obs. The shells are mostly minute, often produced beyond the convoluted part, and then irregularly curved. Scrpula . Shell irregularly contorted, fixed by a part of its side ; aperture simple. * The generic character given with tab. 30. not being suffi- cient, we add the present. 198 Animal furnished with two fan-shaped branchiae* and a funnel or club-shaped corneous operculum. Obs . The tubes often assume the same form as the preceding genus; they are generally larger, often very large in comparison. Vermilia . Shell variously curved, attached by its side : one or more teeth occur upon the edge of the aper- ture. Animal furnished with two fan-shaped branehiae, and a shelly, simple, operculum. Obs . One or more carinae upon the tube being produced, form the teeth upon the margin of the aperture : these carinae do not always extend to the aperture, and are sometimes wanting in a few indi- viduals of the same species as those which have them (see S. ampullacea, tab. 597.). The operculum is sometimes conical, sometimes has a tricuspidate apex, and sometimes flat. Serpula crassa (tab. SO.) belongs to this genus, unless the concave radiated operculum would be sufficient to form a new one from. Galeolaria. Shell variously curved, attached by its side ; a spatulate process upon the edge of the aperture terminates a double keel along the back. Opercu- lum shelly, concave ; in its disk are inserted a num- ber of lanceolate moveable pieces. Obs. This is the most distinct genus ; but should it occur among fossils, it would be difficult to disco- ver, unless the operculum should happen to be pre- served. Serpula crassa is between it and Vermilia. Many Serpulae form septa in their tubes, as the animals proceed from the smaller extremities towards the larger, in consequence of their increased thickness. 597. 199 SERJPULA ampullacea. TAB. DXCVII. —Jigs. 1. 2. 3. 4. & 5. Spec. Char. Thick, irregular, antiquated, with a globose enlargement near the entire aperture ; more or less carinated upon the back ; surface of attachment expanded, thickened. Kentish Chalk Fossil, a Serpulite. Parkinson , 3. 94. pL 7 ./. 11. A large thick species, varying in form according to the surface to which it fixed, often choosing a thin cylindrical substance, when it becomes discoid, with a perforation in the centre (figs. 2. 3. 4. & 5.). It has sometimes a carina extending its whole length (as in figs. 2. & 5.), sometimes only for a part of it (as in fig. 4.), and at other times scarcely to be discovered (figs. 1. & 3.). The surface is often marked with small undulating lines, that give it in parts a granulated appearance (figs. 1.4. & 5.); other specimens are smooth (figs. 2. & 3.). All these varieties, when full grown, are considerably thickened before the aperture is finished ; so that the extremity appears to be inflated, but the inside remains cylindrical. Not unfrequent in Chalk, although hitherto almost un- noticed. All our figures are from the Norwich Chalk. No. 2. was presented to us by Mr. Barnes of Norwich ; the others belong to the Rev. G. R. Leathes, whose favours we have so frequently had to acknowledge. We have a specimen from Northfleet resembling in form Mr. Parkin- son’s : it is to be distinguished from Vermetus by the sur- face of attachment which occupies one side of the disk and a great part of the tube beyond it. 200 SERPULA (VERMILIA ?) macropus. TAB. DXCVII. —fig. 6. Spec. Char. Tube thicks slightly curved, rapidly increasing, triquetrous ; aperture small, round, elevated by the thick mass that fixes the tube; front sulcated. The two free sides of this worm-shell are nearly flat ; they have, however, sometimes a slight angle along the middle of each : the thick mass that elevates the aperture from the substance it is placed upon is so divided in front as to resemble two clumsy feet. From the Norwich Chalk in the cabinet of the Rev. G. R. Leathes. SERPULA (SPIRORB1S?) granulate. TAB. DXCVII.— figs. 7. & 8. Spec. Char. Discoid, thick; surface granulated. A pretty Serpula, composed of little more than one whorl, ornamented by rows of very prominent granules : it is about two lines in diameter. Attached to a Terebratula in Chalk. Presented by the Rev. R. T. Lowe. Fig. 8. is a magnified representation. 598, 201 SERPULA Plexus. TAB. DXCV1II .—Jig. 1. Spec. Char. Cylindrical,, smooth, very much curved, entangled into dense masses ; dia- meter about half a line, diminishing very slowly from the aperture. A common species that occurs in compact masses in Chalk. We have it from Norfolk and Sussex. The masses are sometimes as large as one’s fist, and com- posed wholly of numerous individuals of the same spe- cies. SERPULA Carinella. TAB. DXCVIII.— /g. 2. Spec. Char. Cylindrical, gradually tapering to- wards the apex, repent ; with a minute carina upon the back gradually lost towards the aper- ture. Nearly a line in diameter, moderately tortuose and partially raised from the substance upon which it creeps. Occurs in the Greensand. Our figure is taken from a Blackdown specimen, in which the shells are replaced by silex ; they are fixed inside a Venus. SERPULA compressa. TAB. DXCVIIL— /g. 3. Spec. Char. Lanceolate, rather compressed, smooth ; slightly tortuose ; aperture elliptical. Largest diameter four lines, rapidly diminishing ; a large part of the tube is free. From the great Limestone Strata which traverse in a northerly direction the county of Linlithgow, and consti- tute the independent Coal formation of the Lothians. Presented by the Rev. John Fleming, D.D. in 1814. 202 SERPULA antiquata. TAB. DXCVIII .—jig. 4. Spec. Char. Cylindrical,, partly attached by an expanded surface; surface uneven, with trans- verse irregular rings. The diameter is three or four lines, very slowly decreas- ing ; the edge of the aperture is obtuse. Casts in silex marked with the small rings peculiar to that substance, are common in the Greensand of Wilt- shire. A small portion imbedded in clay, found in East Weare Bay near Folkstone by H. H. Goodhall, Esq., is added to the figures, as it appears to be the same species. SERPULA tenuis. TAB. DXCVIII .—fig. 5. Spec. Char. Cylindrical, with a minute carina upon the back, and a few distant sharp rings ; shell thin. A very small species occurring in little groups, and single individuals fixed by an expanded part of the sur- face to each other or to other substances. This is the Serpula found in the freshwater deposit of the Hampshire Coast described by Charles Lyell, Esq., in the Second Series of the Geol. Trans, vol. ii. part II. p. 289. It occurs in the White Sand in Hordwell Cliff along with Mya plana, Mytilus Brardii, & c. See Min. Con. tab. 532. It also was observed along with Cyclas pulcher opposite Hampstead Cliff in the Isle of Wight, and is noticed on page 51 of the present volume. We have not ascertained that it is attached to the shells it accompanies. The lower figures are magnified. £&9. 203 SERPULA tetragona. TAB. DXCI X.—Jigs. 1. & 2. Spec. Char. Tube very long and narrow; free for a great part of its length ; externally four- sided, with prominent angles; aperture round. About one line in diameter and several inches long, va- riously curved ; the sides are equal, nearly flat. This square Serpula is very abundant in blocks of marl that have been removed from the oolite, and scat- tered over various parts of the country. Our specimens are from Suffolk, and contain also Avicula inequivalvis, a Cardium, and Astarte elegans. Fig. 2. represents a variety probably of the same species in Cornbrash Limestone, from Bedfordshire. Serpula quadrangularis of Lamarck is probably a dis- tinct species, perhaps even a Vermetus. SERPULA rustica. TAB. DXCI X.—fig. 3. Spec. Char. Tube externally four-angled, angles obtuse ; as the tube increases, the angles are variously bent and interrupted, at length be- coming irregular convexities arranged about a cylindrical tube. Nearly two lines in diameter and almost straight. The aperture is circular with a sharp edge. Found in a light-coloured marl belonging to the Upper Greensand, at East Weare Bay, by H.H.Goodhall, Esq., in whose cabinet the specimen remains. 204 SERPULA articulata. TAB. DXCI X.—jig. 4. Spec. Char. Externally square, furnished with rings, composed of four oval tubercles each,, placed at remote irregular distances ; angles rounded ; aperture round. Diameter about two lines; there is no flat space be- tween the ribs of which the angles are formed; these ribs are thickened into four oval tubercles each time the orbicular sharp-edged aperture is completed. Found in coarse sandstone of the Upper Greensand near Folkstone. SERPULA vertebralis. TAB. DXCI X.—jig. 5. Spec. Char. Tube externally square., its angles set with longitudinal, blunt tubercles disposed in rings placed at short regular distances. Somewhat smaller than the last, its tubercles are more regularly arranged and more numerous, four in each ring. Found in the clay of the Castle Hill, Bedford. 205 BELEMNITES mucronatus. TAB. DC.— Jigs. 1. 2. 4. 6. & 7. Spec. Char. Subcylindrical, base expanded ; the other end obtuse, with a central macro ; aperture nearly orbicular. Syn. Belemnites nmcronat\is(Schlottheim.),Brongn. $ Cuvier Geol. des Env. de Paris , 382. PL 3. f. 1 . De Blainville, Mem. sur les Belemnites , 64. PI. 1./. 12. B. electrinus, Miller , Trans. Geol. Soc. 2nd series, vol. 2. part i. 61. PL 8. /. 18. 19. 20. 21. PL 9./. l.$3. B. coniformis ? Parkinson, Org. Remains , vol. 3. p. 127. $ 132. PZ.8./. 12. PL 9.f. 1. Belemnite, Faujas, Maestricht. 178. PL 32. f. 3. Actinocamax verus. Miller , Trans . Geo/. 8oc. 2nd series, vol. 2. p&rZ 1. 64. PL 9.f. 17. 18. B. Scanias, B. (Esterfieldi, & B. quadratus ? Blainville, 61. # 62. P/. 1./. 7. 8. § 9. The otherwise cylindrical form of this Belemnite is de- stroyed by a slight contraction towards the expanded base, and by a rather sudden decrease to the mucronated apex ; along the front of the expanded portion is a fur- row communicating with the conical internal cavity ; on each side of the back is a flat space extending nearly the whole length of the shell ; numerous ramified chan- nels diverge from these spaces round the sides and meet upon the front, or enter the furrow above mentioned. We have never seen any septa in the conical cavity, which is very deep, but only circles indicating their edges, and a furrow along the back, besides the fissure in the front. Length about four inches, greatest diameter 206 nearly three quarters of an inch, cavity one inch and three quarters deep. We have ventured to arrange under one specific ap- pellation, Mr. Miller’s Belemnites electrinus and Acti- nocamax verus, and almost all the species of the second and third of M. de Blainville’s sections of the genus. The B. plenus, which forms the first section, and which M. de Blainville confounds with Actinocamax verus, is a distinct species, rather fusiform, gradually tapering to a point, and not mucronated nor marked with what ap- pear like the impressions of veins upon its surface : we have not seen a specimen of which we know the locality, but possess two very good ones that appear to have been imbedded in clay. The form of the base, which has led Mr. Miller to separate the Actinocamax, and M. de Blainville the two first sections of the genus from one species, is to be explained as follows. When the shell, upon the death of the animal, sunk from its native ele- ment into the mud, the thin sides of its conical cavity were soon worn away ; the two surfaces being both ex- posed and worn, the cavity was gradually shortened, as we find it in Blainville’s second section, where in some cases a portion of the fissure still remains, the same ac- tion continuing until the cavity had entirely disappeared, one surface alone remained to be acted upon, which was rendered first flat and thin, in consequence of the edges being most worn, then convex or conical as in the Acti- nocamax. Small individuals are most subject to this com- plete metamorphosis, because in them it would much sooner take place under the same circumstances. The base is either oval or triangular, or perhaps even squarish, according to the part of the tube of which it is the section, and the depth of the vein-like impressions that flatten the sides. No two specimens are found precisely similar in the depth of the worn cavity nor the convexity of the base, and all are more or less irregularly striated and furrowed from the centre. We have no proof of the existence of septa in the ca- vity. M. Blainville has asserted that they do not exist ; and they are not described by Mr. Miller, although he 207 speaks of the alveolus : circles in the direction of then- edges are figured by M. Brongniart ; and we have speci- mens that prove the accuracy of his figure, but they show no projections. The ramose impressions upon the sur- face and entering the fissure indicate an internal shell ; this circumstance and the absence of septa would be suf- ficient grounds for placing this and one or two other spe- cies together as a distinct genus from the Belemnites with chambered alveoli, provided we could ascertain the latter character ; but in all probability the want of septa is accidental. This mucronated Belemnite is a constant inmate of the upper beds of chalk in all countries. The specimens represented figs. 1. 2. & 4. are from Norwich. Fig. 1. shows a peculiar asperity about the pointed extremity. Fig. 2. a small specimen, with part of a Gryphaea globosa attached to it. Fig. 4. a section, such as is easily ob- tained by fracture. Fig. 6. the variety called Actinoca- max verus. Fig. 7. a young individual from Margate. We have a specimen considerably larger than fig. 1. Some specimens are coated with sitex, and even pene- trated in parts by it. We have specimens from the hardened chalk of the North of Ireland. BELEMNITES granulatus. TAB. DC.-— jigs. 3. & 5. Spec. Char. Subcylindrical ; apex obtuse,, mucro- nated ; surface granulated. Syn. Belemnites granulatus. ( De France) Blain - mile, 63. pi 1./. 10. The form of this shell (we have not seen the expanded base) is precisely the same as that of B. mucronatus ; it 208 has also similar impressions of veins, the granulated sur- faces of the lamina it is composed of alone distinguish it. Of this species we have seen three individuals ; one from Bridgwiek Pit near Lewes, and another from Ando- ver, both collected by H. H. Goodhall, Esq. ; one of them shows the reticulated structure exposed by decomposi- tion, the other the worn base in its progress towards Ac- tinocamax : the third is in Mr.Mantelf s collection. We have shown a view of its base at tig. 5. This species occurs also in St. Peter’s Mountain, near Maestricht. BELEMNITES lanceolatus. TAB. DC.— Jigs. 8. & 9. Spec. Char. Subfusiform, much elongated, gra- dually tapering to a point, an obscure double furrow on each side, base obscurely trian- gular. A much more elongated shell than B. plenus, which it much resembles ; its base is but slightly expanded, the surface smooth ; length three inches and a half, diameter four lines. G. Mantell, Esq. has kindly lent us one, and H. H. Goodhall, Esq. another specimen of this elegantly shaped Belemnite : they are both from Hamsey ; the first has a convex, the other a conical base, with a small portion of the original cavity remaining, which is fre- quently the case with individuals of other species that would be referred to Actinocamax by Mr. Miller. We have fragments from Chute Farm that seem to belong to this species. / 209 HINNITES. De France. Gen. Char. An un equal- valved, nearly equal-sided, radiated, bivalve ; valves eared; the area of the hinge quadrangular, tripartite, its cartilage im- mersed in a deep longitudinal pit in the cen- tre, the lateral portions striated, supporting the ligament ; sinus for the byssus small ; muscu- lar impression large, connected with impres- sions remaining from the attachment of the mantle parallel to the margin of the valves. A genus established by M. de France, who has de- scribed two fossil species. Mr. Gray has added one re- cent one from the British Museum ; and three others have been added by my brother and M. des Hayes, the last of which is the Pecten Pusio of authors. All the species are more or less muricated upon the surface, and when advanced in age, employ the squamae of the most convex valves to attach them to foreign substances. This habit and the peculiar form of the hinge pit, distinguish them from Pecten and Lima ; the form of the hinge, es- pecially of the fossil species, approaches near that of Os- trea, but the shell does not appear to be attached in the young state, nor constantly when old ; and when it is at- tached, it is by the right valve, which is the most convex, not the left as in Ostrea. It has been supposed that the attachment is caused by the pressure against the sides of holes in which the shells have been confined ; but it rather appears to us to be the effect of choice on the part of the animal, for it is con- stantly the right valve that is attached ; and the surface of the other, although they are both distorted, is not rendered smooth nor indeed changed, as it would neces- sarily be if confined. We possess a specimen of H. Cor- tesyi that seems to set the question at rest ; it consists of two convex valves, one attached by almost its whole outer surface (even the ears) to the inside of the other, which does not show any marks of having ever been fixed. The animal is distinguished from that of the Oyster by having its mantle attached to the shell, as is 210 proved by the impressions within the valves ; and by a byssus, for which there is a sinus under the anterior ear. It is probable that when the byssus is by any accident lost, or when the shell becomes too heavy to be conveni- ently retained by it, resort is had to the expedient of fixing the shell by spreading the squamae, as they are formed at the edges, upon any neighbouring substance. The fossil species belong apparently to the Crag, or a deposit immediately succeeding to the London Clay. HINNITES Dubuissoni. TAB. DCI. Spec. Char. Shell rather thick, oblong; right valve covered with concentric circles, the other charged with elevated rays, which are imbricated near the margin. Syn. Hinnites Dubuissoni. De France , Diction - aire des Sciences Naturelles , 21. 170. Des Hayes , Diet. Classique d' Hist. Nat. 201. Gray , Annals of Phil, new series, 12. 104. G . B. Sowerby , Zool. Journal , 3. 70. The left valve is flat, ovate, the hinge and ears pro- duced, the surface marked with many irregular elevated thin rays, which towards the margin are elevated into numerous semicylindrical scales. We have not seen the other valve. It is described as convex, with only con- centric lines that mark the successive additions to the shell, and not fimbriated as in the H. Cortesyi, the other fossil species. We have not seen an authentic specimen of H. Du- buissoni, but are induced to refer the shell before us to that species, although we have not seen the right valve ; because the squamae upon this are most numerous near the edge, and are not flat as in our specimen of H. Cortesyi, which we received direct from M. De France. Found in the Crag of Ramsholt by Searles V. Wood, Esq., of Woodbridge, who liberally entrusted us with such a rarity for publication. 601 211 PANOPiEA. Menard. Gen. Char. An equal-valved transverse bivalve ; sides unequally gaping ; one hinge tooth in each ; hinge ligament external supported by a thick prominent fulcrum in each valve. A well defined genus, formed of the Mya glycimeris of Linneus. Only one recent species is known ; it is a large heavy shell that inhabits the Mediterranean Sea. The thick rudely formed hinge with only one tooth in each valve, and that even disappearing by age, the external short ligament and gaping sides, are strong characters of the genus. There are several fossil species, but hitherto only one has been recorded by authors ; it is found in Italy along with fossils of the same, or nearly the same, aera as those of the London Clay. The other fossil species have been published in Min. Conchology under Mya and Lutraria, but recent examinations have shown that they are Panopaeae ; they are the following : Lutraria gibbosa, tab. 42. Mya intermedia, tab. 76. & 419. f. 2. Mya plicata, tab. 419. f. 3 . We are indebted to Mr. Gray of the British Museum for pointing out the propriety of placing the first of these under this genus. 212 PANOPAEA Faujas. TAB. DCII. Spec. Char. Transversely oblong, elongated, sub- cylindrical ; posteriorly truncate ; anteriorly cuneiform, slightly gaping; shell thin. Syn. Panopaea Faujas. Menard de la Groye , An- nates du Museum , vol. 9. p. 131. t. 12. Broc - chi , 2. 532. Lam. Hist. Nat. 5. 457. This differs from the recent species (P. Aldrovandi) in being less obliquely truncated at the anterior side, in being more regularly cylindrical, and in being thinner. A sandy mass of indurated marl replete with fragments of shells apparently from the London Clay formation found lying upon the coast near Lowestoft in Suffolk, by Dawson Turner, Esq., contained several fragments of this celebrated shell. Figs. 1. & 2. represent two of these fragments. The Crag near Ipswich also contains fragments of the Panopaea Faujas, as well as of P. (Mya) intermedia. Figs. 3. & 5. are of the first species ; in one of them a large pearl has been formed. Fig. 4. is probably a portion of the intermedia. Panopaea Faujas is one of the Italian shells that has by several authors been considered as identical with the recent species in the surrounding sea ; but although they are nearly alike, there are distinctions that cannot be mistaken when once pointed out. Since the above went to press we have seen one entire valve and a considerable portion of another valve of a small Panopaea that appears to be different from P. Fau- jas : they were found in Crag, by S. V. Wood, Esq. C TO 2. 603 21 3 PHOLAS ? compressa. TAB. DCIII. Spec. Char. Transversely obovate, compressed; sides deeper than the middle ; extremities gaping ; along the middle of one valve is a rounded ridge,, and a corresponding furrow in the other ; surface marked with many sharp concentric ridges crossed by eight or ten others,, equally sharp, upon the anterior side. The base is rather angular, the ridges thin, distant, bent in the middle of the valve ; the whole surface is longi- tudinally striated. An intermediate shell between Pholas Candida and P, crispata, since the valves gape at the sides but have no sinus in the margin : in its flattened form and prominent beaks it differs from all the species of Pholas we are ac- quainted with ; it is not without some hesitation there- fore that we place it under that genus . The specimen is a cast of the inside of the shell ; it was broken out of an indurated Marl nodule found in the Kimmeridge Clay upon Shotover Hill by our valued friend G. E. Smith, Esq. We take this opportunity to acknowledge an error in the description of Pholas priscus, p. 158. where we ob- serve u the genus Pholas was unknown;” forgetting that M. des Hayes had described several species from the Paris Basin. , . 2 215 INOCERAMUS pictus. TAB. DCIV — fig. 1. Spec. Char. Oblong’, convex, wavy, nearly co- vered by small concentric furrows ; anterior side flattish, smooth ; valves equal. Intermediate between I. Brongniarti, t. 441. and I. striatus, t. 582. It resembles the first in length and the smoothness of the anterior side, its surface is furrowed like the latter, (which by the by the I. Brongniarti is ob- scurely,) but it is flatter than either. The most remark- able circumstance attending it is, that it is marked with broad stripes of a brown colour. Of this extraordinary shell we have seen but one spe- cimen, for the use of which we are indebted to our very scientific and liberal friend Mrs. Murchison. It was found in the Chalk Marl at Guildford. INOCERAMUS digitatus. TAB. DCIV.—/. 2. Spec. Char. Longitudinally furrowed ; furrows large, round, equal to the ribs between them. Many large round ribs and intermediate equal furrows crossed by the lines of growth distinguish this gigantic shell. Only small fragments of this species, which appears to exceed in size even the I. Cuvieri, have come under 216 our observation. They are mostly upon the surface of large gravel Flints among diluvium derived from the Chalk. The figured specimen still retains the shell and a portion of chalk adhering to it. 217 EXOGYRA. Say. Gen. Char. An unequal valved, unequal sided, attached bivalve ; umbones spirally curved to one side ; hinge pit curved, nearly linear ; an obtuse tooth in the flat, free valve, fits into a cavity parallel with the hinge pit in the con- vex, attached valve ; one muscular impression in each valve. A genus established by Mr. Say of Philadelphia* upon good grounds ; — we say established by Mr. Say, for the imperfect indications given by Faujas j~ and Lamarck (who, seeing but one valve of one species, considered it an univalve shell, and named it Planospirites ostracina,) had been abandoned. It is well distinguished from Ostrea by its impressed lateral spire and the consequent linear form of the hinge pit, and by the parallel furrow in the attached valve which receives the obtuse, compress- ed, sometimes striated tooth of the other valve. This tooth is an enlargement of that part of one of the edges which is often crenated in Oysters. It is distinguished from Gryphasa by the same characters of the hinge, by the spire being impressed, laterally curved, and very apparent in the flat valve, and further by the absence of the lobe that forms the distinction between Gryphaea and Ostrea. In its general structure it resembles Ostrea, * Described by him in the Amer. Journ. of Sci. and Arts, vol. ii. p. 43. t Faujas, Maestricht, p. 145. Rastellum is a name that has been applied to some species; and Faujas has proposed to se- parate them and Gryphaea from Ostreae, but this name is not applicable. X Lam. Syst. 400. This species is very large and smooth, nearly related to Ex. haliotoidea ; but we have only one valve, which however shows both sides, thus displaying the hinge and muscu- lar impression. 218 being composed of laminae whose edges rise succes- sively in more or less elevated scales upon the surface. I^ike Gryphaea it is sometimes attached only by the apex of the convex valve, and is free when full grown ; and sometimes by a large part of its surface. Some species are ribbed, but irregularly, like oysters. The mistake under which several shells that might better have been called Gryphaeae w7ere published in the first volume of Mineral Conchology as Chamae, seems to have arisen from considering the tooth in the hinge without taking into account the muscular impressions, which in Chama are two. This important tooth seems to have been overlooked by Say, although he mentions the cavity or furrow that receives it. In the sixth vo- lume of the Journal of the Acad, of Nat. Sciences of Philadelphia, Dr. Morton, when describing the Exogyra costata of America, has rightly referred the Chama ha- liotoidea, (Min. Conch, t. 25.) to the same genus, and dis- covers the mistake above alluded to ; but is rather hard upon English Conchologists, in supposing that they join in the blunder. The shells formerly published in Min. Conch, that should be arranged under this genus, are Chama haliotoidea, tab. 25.* recurvata tab. 26. f. 2. conica tab. 26. f. 3. plicata digitata tab. 26. tab. 174. f. 4. Chama canaliculata tab. 26. is a Gryphaea. Thus far it appears that the genus Exogyra is bound- ed by distinct lines of demarcation ; but in fact it is no more insulated than any other artificial genus ; for Gry- phasa nana and G. sinuata have often the beaks laterally curved, and at the same time possess the characteristic lobe of Gryphaea, and we have seen several recent Oysters whose beaks strongly resemble those of Exogyra. * Miss Benett has kindly lent us a noble specimen of Ex. ha- liotoidea nearly four inches long, which we propose to figure in a Supplement. ■ 219 Exogyrae appear confined principally to the Green- sand formation: but as we do not know that the American species Ex. costata has ever been found in Europe, it is going too far to consider that as a proof of the identity of the beds in which it occurs with our Green-sand. The smooth varieties of it which are said to resemble the G. haliotoidea of Min. Conch, we have not seen; but it probably is that species: if so, the consideration of it with Gryphaea convexa of Mr. Vanuxem and Dr. Morton, (which is G. globosa of Min. Conch, and Podopsis Gry- phaeoides of the French, and occurs in Green-sand as well as Chalk,) Baculites and other shells, will go far to prove what those gentlemen have suggested, that the beds in which these shells occur are the equivalents of the Green- sand and Chalk formations of Europe ; and we see no reason why different remote districts of the same forma- tion and period should not, like the present surface of the globe, be furnished with different shells, as well as vary in the proportions, arrangement and mineral characters, of its several members. EXOGYRA conica. TAB. DCV .—Jigs. 1. 2. & 3. Spec. Char. Smooth ; deep valve more or less gibbose, curved,, obtusely keeled along the middle; flat valve suborbicular, its beak im- pressed,, very much incurved. Syn. Chamae conica, recurvata, et plicata. Min. Conch, vol. 1. p. 69, 70. t . 26. f. 2. 3. & 4. The short, almost orbicular flat valve and small size, rarely exceeding an inch and a half, are the principal marks by which to distinguish this from the following species. The nearly central keel will also assist. The small wings mentioned in the descriptions in vol. I. 220 are accidental, being produced by the form of the sub- stance or shell that the individuals were attached to when young. We have found it proper to refer all three to one species, and retained the name conica as being the best of the three. We have specimens from Folkstone, Parham Park, Chute Farm, Warminster, and Blackdown ; those from the latter place are selected for the present figures. The necessity of removing this fossil from the genus Chama has induced us to take it again under considera- tion. EXOGYRA laevigata. TAB. DCV.— /g.4. Spec. Char. Elongated, curved, smooth ; deep valve rather gibbose, obtusely keeled ; keel near the hollow side ; flat valve semicircular, pointed, its beak small. Nearly double the size of the last, also more elon- gated and curved with proportionally smaller beaks. The figures are from Irish specimens in a compact sandy limestone, from the Green-sand formation. We have seen English ones very similar. EXOGYRA undata. TAB. DC V.—figs. 5. 6. & 7. Spec. Char. Convex ; deep valve keeled along the middle, and marked with branching ridges that diverge from the keel; flat valve plain. A small and rare shell, found at Blackdown. Fig. 5. and 6. represent specimens lent us by H. H. Goodhall, Esq. 221 P0LLIC1PES. Leach. m Gen. Char. Shell multivalved, laterally compress- ed, supported by a squamiferous peduncle; the five upper valves largest, the lower diminishing in size as they increase in number; apices of the valves free, pointed. This genus is distinguished from other cirripodous Mol- lusca by the squamiferous peduncle, the slightly curved lanceolate dorsal valve, the continued succession of small valves diminishing in size towards the peduncle, and the free points of all the valves. The most common recent species, P. Cornucopias, occurs in the Mediterranean in clusters attached to shells, &c. We have given a small figure of it. POLLICIPE8 sulcatus. TAB. DCVI.—^gs. 1. 2. & 7. Spec. Char. Valves marked with longitudinal, ele- vated striae. The central or terminal valve (fig. 1.) is elongated, rhomboidal; the posterior valve (fig. 2. & 7.) is arched, broad, lanceolate and subcarinated ; both are marked with irregular, sharply elevated, longitudinal strise : we have not recognized the other valves. An inhabitant of the Upper Chalk at Norwich, Maid- stone, and Northfleet. 222 P0LLIC1PES maximus. TAB. DCVI. —jigs. 3—6. Spec. Char. Terminal valves rhomboidal plane, except sometimes a central ridge, and lines of growth ; posterior valve arched, lanceolate, much elongated. This differs from the last in the narrowness of the pos- terior valve (fig. 4.), and smoothness of the terminal valve which in old valves (fig. 3.) has a furrow along its middle in place of a ridge (fig. 5.); the anterior valve (fig. 6.) is hooked and has an obtuse keel. We are not acquainted with any other valves ; and in this limited state of our knowledge, we must confess that it is with some degree of hesitation we declare these two species as distinct from each other. From the Upper Chalk, collected by Mr. Barnes at Norwich. The posterior valve (fig. 4.) is from North- fleet. POLLICIPES reflexus. TAB. DCVI.— fig. 8. Spec. Char. Lateral valves nearly flat, smooth ; posterior valve lanceolate, straight or recurved. A small smooth species, found by G. E. Smith, Esq. in Colville Bay in the Isle of Wight, among sand accom- panied by many minute shells and valves of Chitones, and probably connected with the so called upper marine formation. > 223 PILEOPSIS .—Lamarck. Gen. Char. Shell a recurved cone covering* the animal ; the apex turned backward and to the right, minute, involute ; muscular impression posterior, arched, its extremities dilated. A genus formerly included under Patella, now evidently well separated from it, even if only its own characters independent of those of its animal be considered : but when the situation of the branchiae in a distinct cavity near the head, and the connection of the mantle with the shell are observed, no doubt can be entertained. It is more difficult to distinguish Hipponix from it when the secondary valve (or support as M. De France calls it) of that genus is absent : indeed Lamarck has made Hipponix only a section of the genus Pileopsis ; the form and posi- tion of the apex seem to indicate a difference. Patella Unguis (t. 139. f. 7. & 8.) belongs to this genus. There are also two or three recent species known ; one, P. ungarica, is British, it is covered with a fringed epi- dermis. The Fossil species are only in the oldest and newest conchiferous formations. PILEOPSIS vetusta. TAB. DCVIL— figs. 1. 2. & 3. Spec. Char. Smooth, contracted posteriorly ; two or three irregular undulations rise up the front; margin sinuose. The sides of this shell being rather flattened, the ovate 224 aperture is longitudinal, it is broadest at the front ; the shell is moderately thick. Not very unfrequent in the black limestone of Queen’s County Ireland (fig. 1.), and Preston in Lancashire (fig. 2. & 3.) From the latter place we have been presented with several specimens by William Gilbertson, Esq. PILEOPSIS tubifer. TAB. DCVII— /g. 4. Spec. Char. Front surmounted by three rows of long tubes. Much like the last but rather taller, the three rows of tubes are placed upon obscure ridges that run up the front, they equal the diameter of the aperture in length. The specimen figured is in the rich cabinet of W. Gil- bertson, Esq. We have seen only one other, which is smaller, but exhibits the bases of the three rows of spines very neatly : it is in the possession of Dr. Alexander Moore of Preston, from which place both individuals come. 1 6V8. 225 SERPULA (Vermilia?) sulcata. TAB. DCVIII — figs. 1. & 2. Spec. Char. Repent, much elevated; back and sides flattened ; along the centre of the back an irregular thick keel, and along each side a narrow sulcus ; lines of growth conspicuous. This Serpula seems composed of reflected scales placed in close succession, they are blunt and irregular ; the aperture is round with a single tooth proceeding from the dorsal keel. It acquires the size of a swan’s quill. The lateral grooves form a prominent mark of distinc- tion. Abundant in the Calcareous Grit at Shotover Hill near Oxford. Part of a specimen presented by G. E. Smith, Esq. is represented at fig. 1. It is chiefly composed of Silex. Fig. 2. has more of the Shell remaining. Some specimens have small pores between the laminae. 226 SERPULA tricarinata. TAB, DCVHI .—Jigs. 3. & 4. Spec. Char. Repent, rather smooth, but some- times when old squamose, round, with three thick keels, the central one largest ; keels en- tire, sometimes disappearing. Aperture round with two thick lobes at the base, the edge thin. Seldom so thick as a goose quill, tapering rather quickly, the surface of attachment is expanded until the shell is old, when the last portions are nearly cylindrical and often free from keels, its surface is then squamose. Among the squamae in such individuals, or between the lines of growth in others, there are frequently minute pores or short tubes, but whether formed by the animal of the Serpula or some minute one is not easily discovered. The specimens figured are from the Calcareous Grit of Shotover Hill. We have others, that appear precisely the same, from the Coral Rag at Steeple Ashton, and from the Cornbrash of Felmersham, the latter collected by the Rev. T. O. Marsh : it is also found in the Diluvium of Norfolk. We have sometimes suspected it to be the Ser- pula intestinalis of Phillips’s Geology of Yorkshire, but in the absence of description we cannot tell whether that be a decurrent species or not. 227 SERPULA triangulata. TAB. DCVIII. —Jig. 7. Spec. Char. Repent, roundish,, elevated., smooth, three angles upon the back, the central one elevated into a keel ; lines of growth circular. A much smaller and more cylindrical shell than the last, which it very nearly approaches ; indeed there are upon the same mass of Stone several individuals so near S. tri- carinata that, except in size, we cannot detect a differ- ence. Brought from Bradford, Wiltshire. Upon the same surface are two other species of Serpula, an Exogyra ? and portions of the Pear Encrinite. SERPULA runcinata. TAB. DCVIII.— -fig. 6. Spec. Char. Repent, subtriangular, with three distinct serrated or lacerated keels upon its back ; aperture round. Less than a crow’s quill, tortuose, with an expanded base ; the back is round, with a central and two lateral keels, the latter are particularly sharp and lacerated. Upon an unnamed Plicatula, attached to a mass of Coral from the Coral Rag of Shotover Hill : the upper fi- gure is magnified. 228 SERPULA obtusa, TAB. DCVIII. —Jig. 8. Spec. Char. Repent, smooth, obtusely quadran- gular, with an obtuse thick keel along the flat back ; edge of the aperture produced as a short cylinder beyond a bilobed thick margin ; base expanded. Almost as thick as a goose quill ; when young the aper- ture has a tooth at top, and when nearly full grown the edge is much thickened by two reflected variciform lobes, that meet upon this tooth ; when quite perfect, a short cy- linder projects beyond these lobes. The surface is re- markably smooth, the lines of growth very indistinct ; the keel is sometimes wavy and sometimes even. A beautiful group of this Serpula upon a portion of an Inoceramus, from part of which the figure is copied, is in the rich collection of C. B. Rose, Esq., it is from the Upper Chalk of Sayham in Norfolk. SERPULA fluctuata. TAB. DCVIII.— fig. 5. Spec. Char. Repent, smooth, circular, with five regularly waved low keels. This very neat little Serpula is at once known by its regularly waved wire-like keels ; the surface of attach- ment is small. Found upon various shells in the Upper Chalk at Norwich : we have it from the Rev. G. R. Leathes and Mr. Barnes. * 609. 3 4- 229 RISSOA. Freminville & Desmarest* . Gen. Char. Shell univalved, spiral, oblong or tur- reted, not umbilicated, often costated ; aper- ture entire,, oval, oblique, dilated, rather an- gular above and with a slight sinus at the base ; lips nearly united, the outer thickened, its edge not reflected. Operculum shelly. Under this genus are included a number of small ele- gant marine Shells, many of which are ribbed, especially in the young state, while some are nearly plain ; the outer lip being thickened more than the cost®, but not producing varicose sutures, and the obscure sinus or truncation at its base define it neatly. This genus is only known in the great Oolite, the newer parts of the tertiary formation and recent. RISSOA iaevis. TAB. DCI X.—Jig. 1. Spec. Char. Oblong-oval, smooth. .The sides of the whorls are rather flat, and the aper- ture less expanded than in some species : the two last whorls are almost cylindrical. * Bull, de la Soc. Phil, de Paris, 1814. 230 RISSOA acuta. TAB. DCIX.- fig. 2. Spec. Char. Turreted, acute, costated ; costae many, longitudinal ; aperture large, outer lip much expanded ; whorls convex,, 7. A rather large aperture, a pointed, almost subulate spire, and ten or twelve rows of costae mark this species. RISSOA obliquata. TAB. DCI X.—fig. 3. Spec. Char. Elongated, pointed, costated; costae many, oblique, curved; aperture rather small; whorls 5 or 6, convex. Shorter in proportion to its width than the last, with fewer and oblique ribs and a smaller aperture ; other- wise much resembling it. RISSOA duplicata. TAB. DCI X.—fig. 4. Spec. Char. Elongated, pointed, costated ; costae very numerous, divided in their middle by a low carina ; aperture rather large. This beautiful little shell cannot fail to be easily recog- nized in all stages of its growth by the double set of ribs that extends from the central keel. These four species of almost minute shells are all from the Ancliffe Oolite. < . ♦