Pp OTS HA Om ~ se *, re ara i, rr - ae ml antec Cel a eee A i te Seep co gece te Ee ayk ere e yg tart rere Rosie tact pate i an = $ Paka a eat ng Os . awe 2 — alee = = . = : ope - 7 z ches Ss = = ( - : es bee rte z ote mie 2 Se ae ie a orks Fs eee esis oe poe a wD meee TES5 ede oe : eh Se ab a SO eee nS ha ee Be a i ~4 wns ‘ arts . ae ** « Konig te hah es * ~ Fd Feet Ss get ow ee or S Stas we ig en ee Le * Pia math acne aoe ~ ye Cee tree CASS et aie - earn? oak eng “ nae: Pes ee - beer t Ac gas : ose t= pee Y 0 Tere > Sees ttt, ~ ~ "5 ae x ies PG rap" ppm rege gags 4: e AS "rs ae wal ac , Sky . : AiG nt ~ J - . om Eos ¥ 4 ‘ L 3 “ epee IE = Sen as = z : < Ss é Sn FER ae oe anon an 164 THE LIAS AMMONITES, Table showing the extension of the Upper Lias in the British Islands, Belgium, France, Switzerland, Germany, Austria, and Italy, with indications of the Toarcian Ammonite- Zones found in some typical regions of the Huropean area. C | ’ 2 4 2 4 BritisH 2 FRANCE, SWITZER- Z Shi ISLANDS. 3 DEPARTMENTS OF. NNN es Bu ais t A Pp a Ammonite Zones ea | o —<— | eS of ue | 5 oh % f Upper Lias. : Beall Feral t| (an ee Pi Fale 5S) So |S lesen Neem: t=} || ah Was Pha eaesha arse etge in| Matas Ky a fern ee cesta) mpl oes th 5 + |g ade eal ss © >| I ve) 8 >| a Soll Casi mace) & oO mt ae 2» a = py = 188 THE LIAS AMMONITES. Harpoceras serpentinum, Schlotheim (fig. 54). Harpoceras insigne, Schiidler. — radians, Reinecke. —_ thouarsense, @’ Orbigny. -- bifrons, Brugueere. — opahnum, Leinecke. 11]. Amauruer.—The sickle vanishes, the radii have a very long stem, which bends only near the siphonal area, becoming here very prominent. The margin is sharp, the keel often divided by the folds as if into scales. The siphonal lobe is here also much shorter than the upper lateral, and its wall ascends obliquely up to the siphonal saddle, but not by any means so obliquely as in the Falcifert. ‘The upper lateral is very broad, almost as broad as it is deep, so also is the under lateral. The saddles, as well as the lobes, are extensively foliated, so that in these lobes large and wide outstretched processes are formed in the middle of the saddles, with very deep secondary lobes. The points of the dentations do not hang down, but in general stand perpendicularly upon the axis of the lobes. . By this means the sides of Amaltheus in all the species, even when the shell is wanting, have an especially foliated, incised appearance, in which great intricacy appears to prevail. Notwithstanding, with some attention we easily, even to the least detail, find the ever-repeated symmetry as well in the individual points as in both sides of the whorls. These Ammonites are much inclined to become involute. The family ascends from the Lias up to the Coralline Limestone of the Middle Oolite, and each intermediate formation possesses its own special forms. The following are typical species from the Lias and Coral rag. Fic. 55.—Amaltheus cordatus, Sow. Amaltheus margaritatus, Montfort. ! Amaltheus oxynotus, Quenstedt. = Guibalianus, d@’ Orbigny. — spinatus, Bruguiere. == Greenhoughi, Sowerby. — cordatus, Sowerby (fig. 55). IV. Capricorni.—This group connects itself very closely with the AmaLtTunt. From Amaltheus margaritatus, through Amal. cordatus, Amal. Lamberti, and Amal. omphaloides, we arrive at Aeg. capricornum. ‘The scales upon the keel of these Ammonites have even raised themselves higher, and are first bent forward, then become broad folds with a point before. ‘Lhe siphonal area of the Capricornt is broad, often broader than the sides. The siphuncle is not specially prominent, the ribbing of the folds on the sides is in general unusually strong, always single, even on the back; without much flexion, and rarely with knobs or spines upon the sides. The siphonal lobe in general goes out perpen- dicular with vertical walls. The lateral lobes are, as in the Tre. 56.—Aégoceras capri AMALTHEI, less deep than broad, and often at their bases are cornum, Schloth, broader than at the mouth, they are all very slightly or almost not at all involute. The following species are typical forms. THE CEPHALOPODA. 189 — catenatum, Sow. Aegoceras capricornum, Schloth (fig. 56). Aegoceras Henleyi, Sow. | — planicosta, Sow. — Charmassii, d’ Orbig. — planorbis, Sow. V. Puanunati.—The siphonal area is. always perfectly round, and is joined to the sides without a border. The whorls lie almost on the same plane, whereby al! Fie. 57.—Stephancceras annulatum Sow. ° Fie. 58.—Stephanoceras commune, Sow. the species receive a more or less strikingly discoidal form. ‘The numerous close-set ribs divide near the half or two thirds of their height into two, three, or many small folds, without any tubercle at the point of bifurcation. ‘The lower portion of the rib is thicker and directed backwards, as in the modern genus Stephanoceras, which is the type of this group. ‘The disposition of the lobes is very peculiar and complicated in the Puanatuti. The upper lateral is large and very deeply sunk, and occupies the middle of the side; the lower lateral is smaller, and there proceeds from it two or three auxiliary lobes with branches directed obliquely backwards or sometimes even horizontal, and these form together a compound lobe larger than the lower lateral, under which it retires, the whole constituting a most intricate arrangement which is very difficult to trace out. The Puanunatr are abundant in the Middle Oolites and in the Upper White Jurassic Limestone of Germany. They are also found in some of the beds of the Upper lias. They are entirely absent from the Chalk. The following forms are characteristic of this group. Perisphinctes biplex, Sow. Perisphinctes polyplocus, Rein. _ giganteus, Sow. Stephanoceras commune, Sow. (fig. 58). — plicatilis, Sow. _— annulatum, Sow. (fig. 57). — polygyratus, Schloth. — crassum, Young and Bird. (as) ot 190 THE LIAS AMMONITES. VI. Dorsatt.—The broad siphonal area is united with the sides almost at aright angle. A series of simple tubercles extend round near the margin, through which the simple lateral folds become divided into double ones, before crossing the area. The siphonal area is always smaller than the sides, whereby most of the species preserve a tolerably discoidal form. The auxiliary lobes often extend obliquely against the upper lateral, although not m all the species. The Dorsatt unite the PLanunati with the Coronari. The following are typical species. Fig. 59.—Aegoceras Dave, Sow. Aegoceras Daveei, Sow. (fig. 59). Stephanoceras fibulatum, Sow. — armatum, Sow. — Brocchii, Sow. VII. Coronaru.—A well-marked series of tubercles so widens the siphonal area that it becomes wholly flat, and a good deal broader than the sides. The sharp, wide, forward-directed folds become divided by the tubercles, the whorls are much involuted and Fic. 60. Fie. 61. Fic. 62. Fie. 63. Stephanoceras Blagdeni, Sow. Stephanoceras Braikenridgii, showing labial prolongation. Side view. Front view. Side view. Front view, proportionally short, and form a deep umbilicus. The upper lateral lobe stands always above the tubercles, the under lateral beneath. By this character they are readily, and with greater certainty, distinguished from other forms. The siphonal lobe is longer than the upper lateral; and there are several auxiliary lobes, which in their form and position entirely resemble those of the Puanunatr. This group is very characteristic of the middle division of the Inferior Oolite as the following species demonstrates. Stephanoceras Humphriesianum, Sow. Stephanoceras Gervillii, Sow. — Brongniartii, Sow. — Blagdeni, Sow. (fig. 60). ae Brocchii, Sow. — Braikenridgii, Sow. (fig. 62). VIL. Macrocrrnart.—The increase of the whorls is unusually rapid, especially in the breadth of the mouth. The siphonal area and sides are joined imperceptibly together THE CEPHALOPODA. 19} in a complete half circle; and the sides fall off towards the suture, which have often a sharper border, and sometimes a perpendicular surface. Fic. 64.—Stephanoceras coronatum, Brug. Fic. 65.—Steph. coronatum, Brug. Fic. 66.—Stephanoceras tumidum, Ziet. Side view. Front view. Front view. The lower lateral stands always above the inner border, not under it, as in the Coro- narit. The very large ventral lobe is accompanied by two extended arms, and besides by two auxiliary lobes. The upper lateral stands always directly opposite the arms of the columellar, the under lateral directly opposite the lower auxiliary. Stephanoceras coronatum, Brugiere (fig. 64). Stephanoceras macrocephalum, Schloth. — modiolare, Lhwyd. — tumidum, Zieten (fig. 66). IX. Armartr.—Two or more rows of tubercles form a longitudinal parallel series upon the sides, but rarely on the siphonal area, which is flat, often broader than the sides, and joined to them by an almost right-angled border. The upper row of tubercles stand upon the border; then follows a vacant space between them and the lower series, in which the upper lateral lobe.comes in; then follows either one or more rows of tubercles. The siphonal lobe is somewhat deeper than the upper lateral, which is sometimes almost three times as deep as it is broad. The siphonal saddle is always of a remarkable breadth, Mii AZ NoS nN more than double that of the upper lateral, with a deep fre. 67.—Aspidoceras longi- secondary lobe in the middle and quite even above. The eae lower lateral, on the other hand, is not larger than the secondary lobes of the siphonal saddle. This is a remarkable group, and very rich in species, found chiefly in the uppermost strata of the Oolitic series and the Cretaceous formation. Aegoceras Birchii and deg. Henleyi occur in the Middle Lias, and Aspidoceras longispinum (fig. 67) in the Oxford clay. Hoplites mammillaris (fig. 69,70), H. Rhotomagensis, H. Mantelli, and H. Woolgari represent Cretaceous forms. The following are typical species : Aegoceras Birchu, Sow. Hoplites Deverianus, @’ Orbig. (fig. 79). Aspidoceras perarmatum, Sow. — Rhotomagensis, Sow. — longispinum, Sow. (fig. 67). — Mantelli, Sow. Hoplites mammillaris, Schloth (fig. 69). — Woolgari, Mant. 192 THE LIAS AMMONITES. X. Denratit.—In the Argonauts the tubercles which border the narrow margin of their shell are probably formed by the rising of the mantle in the shape of folds, due to the sucking discs of the dorsal or back-folding arms of the female (fig. 68). So probably in the Fie. 68. Fic. 69. Fie. 70. Fie. 71. Argonauta argo, Linn. Hoplites mammillaris, Schloth. Cosmoceras Jason, Reinecke. same manner might the decoration of the shell of the Denrat1 have been formed. The tubercles grow on both sides of a flat, narrow siphonal area like a double projecting wreath. They do not always stand in the direction of the radu, whereby they are especially distinguished from other prominences and tubercles showing the back folding, which are only strongly elevated folds or arms stretched over the shell. The lateral surfaces are moderately parallel and very large, because the whorls increase, in general, very rapidly in height; at other times they are, in general, without any wider elevation or important processes and points. From the lower part many folds ascend, which, upon half of the sides, are divided, and then, sometimes, a pearl-like series of small tubercles rise up. They are very elegant forms, which are peculiar to the Upper Oolitic formations. The siphonal lobe is much less deep than the upper lateral one. ‘This less depth distinguishes the Denratr from the Armati. The following species are typical forms of the group: Cosmoceras dentatus, Sow. Cosmoceras Duncani, Sow. (fig. 72). — Jason, Reinecke (fig. 71). — Calloviense, Sow. XI. Ornatt.—Spines or tubercles bound the narrow siphonal area, as in the Denvatt. Another series of tubercles are developed upon the middle of the sides. In the flat interspace between these two rows of tubercles the, upper lateral lobe is sunk, as in the Armati. ‘This plain surface is not, as in the latter, the side itself, but only a truncation of the border between the margin of the area and sides. The lower lateral lobe is also separated by a series of tubercles from the suture, and by a surface which converges towards the columellar. The mouth-opening thereby acquires an almost regular hexagonal form. ‘These beautiful Ammonites are in general small, and peculiar to the Oxford Clay and Upper Oolites. Cosmoceras pollux, Reinecke | Cosmoceras castor, Reinecke. THE CEPHALOPODA. 193 XII. Fruxvost.—Tubercles are developed on both sides of the siphonal area, which is not sunk flat between two rows of a depressed surface, but is elevated therefrom and divided by a continuous row of tubercles. The radii on the sides are strongly bent forward towards the margin. ‘They are, in general, divided, and here form long knobs, which are somewhat elevated at the lower part of the lateral surface. The siphonal lobe is much shorter than the upper lateral. They are special to the Upper or White Lime- stone of the Jurassic formation of Germany, and are found, likewise, in the Lower Chalk. The following are typical species : Fie. 72.—Cosmoceras Duncani, Sow. Fig. 73.—Cosmoceras radiatus, Brugiére. Cosmoceras flexuosus, Munst. Cosmoceras radiatus, Brugicre (fig. 73). _— Jason, Rein. Hoplites faleatus, ant. Professor Quenstedt in 1849 published an important work on the Cephalopoda, together with an atlas of beautiful plates," in which he divided the Jurassic Ammonites into fourteen groups, retaining those so well established by von Buch, and adding four more to the list : 1. ARIETEN. 8. DENTICULATEN. 2. CaPRICORNEN. 9. ORNATEN. | 3. AMALTHEEN, 10. DeEnTaTEN. 4. HEvrEROPHYLLEN. 11. PLANULATEN. 5. LIneatt. 12. CoRONATEN. 6. FAaLcIFEREN. 13. MacrocrerHaLEn. 7. Disct. 14. ARMATI. and divided the Ammonites from the Chalk formations as follows : 15. Cristati, d’ Orbigny. 16. RuoromaceEnsss, d’ Orbigny. 17. Lieatt, d’ Orbigny. and classed the Ammonites of the Red Alpine Limestone (Triassic), distinguished by Terebratula diphya as: 18. GuoBosi, Quenstedt. 1 « Petrefactenkunde Deutschlands : der ersten Abtheilung, die Cephalopoden,’ 8vo., nebst einen Atlas von 36 Tafeln, fol. Tubingen, 1849. 194 THE LIAS AMMONITES. But the Ammonites of the St. Cassian (Triassic) beds with Ammonites Aon, Minster, were not comprehended in a distinct group. M. Alcide d’Orbigny divided the Ammonites into twenty-one sections ;' in these he included the groups established by von Buch, and added others to receive the many new forms which he had discovered among the very rich materials he had assembled for his sreat work on the Terrains Crétacée and Terrains Jurassique of France. a. Species with a siphonal keel entire. Ist Section. Artutes, von Buch. See page 186. 2nd Section. Faucrreri, von Buch. See page 187. 3rd Section. Cristati, d’ Orbigny. Shell compressed, sides ornamented with ribs, bifurcated and bent forwards without forming an angle; with or without prominent tuber- cles. Siphonal area prominent in the keel, which contains the siphuncle. Mouth, when Fic. 74.—Schloenbachia Roissyana, W Orb. Fic. 75.—Schloenbachia cristata, Deluc. perfect, prolonged into a prominent rostrum upon the median line of the margin. Septa formed of lobes, in general divided into unequal parts and into equal saddles. Siphonal lobe longer than the superior lateral. The lateral saddle less elevated than the others. The siphonal saddle very high. The best types are Schloenbachia cristata, Deluc (fig. 75), and Schloenbachia Roissyana, VOrb. (fig. 74), both from the Cretaceous Formations. b. Species with the siphonal area canaliculated. Ath Section. Tusrrovnatt, d’Ordigny. The sides of the shell ornamented with ribs and tubercles. Siphonal area provided in the middle with a deep well-defined channel. Mouth, when complete, representing an elongated rostrum corresponding to the siphonal 1 «Paléontologie Francaise ; Terrains crétacés,’ tom. i, p. 405, 1840. THE CEPHALOPODA. 195 canal. Septa formed of lobes and saddles divided into single parts. Siphonal lobe shorter than the superior lateral lobe. Hoplites falcatus, Mantell (fig. 76), from the Chalk Marl, and H. auritus, Sow., from the Gault, are good types of TuBERCULATI. mM | Hil] \ a Uj ; ARN Ng Ai iW Vii th Afi ) y “Ls Le Fic. 76.—Hoplites falcatus, Mantell. Fic. 77.—Schloenbachia Goupiliana, a’Orb. c. Species with the siphonal area trenchant without forming a keel. 5th Section. Cryprirormi, d’Orbigny. Shell compressed, generally smooth or little ornamented with undulating folds or radii. Siphonal area sharply bevelled, without a keel. Spire with large wherls mostly much involuted. Sepéa divided into a great number of lobes formed of single parts, and of saddles partly in pairs and partly single. Siphonal lobe shorter than the superior lateral lobe; the saddles and the lobes large and short. S. Goupiliana, dOrb. (fig. 77), from the Upper Greensand, is a good type of this section. d. Species with the siphonal area prominent and crenulated on the median line. 6th Section. AmMaLruEt, von Buch. See page 188. 7th Section. Puncuzuut, d’ Ordigny. Sheil elegantly divided on the sides by promi- nent ribs, straight and not flexed, which passing from one side to the other leave upon Fic. 78.—Hoplites Brottianus, d’Orb. Fic. 79.—Hoplites Deverianus, d’Orb. 196 THE LIAS AMMONITES. the siphonal area compressed tubercles, which collectively represent a series of crests. ' Septa formed of lobes divided into single parts, and of saddles divided into pairs of parts. Siphonal lobe nearly equal in length to the inferior lateral lobe. Hoplites Brottianus, d’Orb. (fig. 78), from the Lower Cretaceous Rocks, is a good type of this section. Sth Section. Ruotomacenses, @’Orbigny. Shell with inflated whorls, square or oval, ornamented with prominent ribs, more or less tuberculated upon four or five lines, one of which runs along the median line of the area, and renders it more or less angular. Septa formed of lobes and saddles partly divided into pairs. The siphonal lobe longer than the superior lateral. The species characterise the Middle Cretaceous Formation, and Hoplites Deverianus, d’Orb. (fig. 79), from the Upper Greensand, is a good type of this section. e. Species with the siphonal area excavated, and provided with tubercles on the sides. 9th Section. Dunrati, von Buch. See p. 192. 10th Section. Ornati, von Buch. See p. 192. J. Species with the stphonal area more or less square. 11th Section. Fiexvosi, von Buch. See p. 198. 12th Section. Compresst, d@’Ordigny. Shell in general very much compressed, composed of large whorls, highly involute. Sides provided with radii or fine strie, all slightly flexed, and passing on to the margin of the siphonal area, where they develop small tubercles. Siphonal area narrow and squarely truncated. Septa composed of a great number of lobes formed of single parts, and of saddles often formed of pairs of parts. Siphonal lobe very large, much longer than the superior lateral. These Ammonites all appertain to the different divisions of the Cretaceous Formation, Fre. 80. Cos. Beaumontianum, ®Orb. Cos. Beaumontianum, d Orb. (fig. 80), from the Lower Chalk, is a good type. 13th Section. Armati, von Buch. See p. 191. 14th Section. Ancunicosrati, d’ Orbigny. Shell thick, with whorls almost round, each side of the siphonal area ornamented throughout with slight ribs which make this part THE CEPHALOPODA. 197 nearly square. Siphonal area much narrower than the sides. Ribs elevated, passing alternately across the area from the one side to the other. Septa composed of lobes formed of single parts, and of saddles often in pairs. Siphonal lobe shorter than the superior lateral ; the auxiliary lobes oblique towards the umbilicus. Found in the Lower Chalk, Gault, and Neocomian Formations. oplites Martinii, d’Orb. (fig. 81), from the Neocomian, or Lower Greensand of the Isle of Wight, is a fair type of this group. 15th Section. Capricorni, von Buch. See p. 188. < Vi if yy, } Fie. 81.—Hoplites Martinii, d’Orb. Fie. 82. Fie. 83. Phylloceras heterophyllum, Sow. g. Species with the siphonal area convex. 16th Section. Herrropnyiui, @’Orbigny. Shell compressed, formed of whorls almost completely involute, rarely appearing in the umbilicus. The sides are smooth, slightly striated, or furrowed with fine lines. Siphonal area narrow and very convex. Septa symmetrical, divided into a great number of lobes, very much ramified, formed of single parts, and of saddles often in pairs. Siphonal lobe always shorter than the upper lateral. The great number of ramifications of the lobes produces a most complicated, foliated structure on the siphonal area and sides of the casts of this section. Phylloceras heterophyllum (figs. 82, 83), from the Upper Lias, is typical of this group. 17th Section. Lieati, d’Orbigny. Shell in general compressed, smooth, or a little undulated, and usually marked with grooves or ribs at regular distances apart, indicating the former position of labial appendages. ‘The siphonal area convex, sometimes a little compressed. Septa composed of lobes formed of single parts and of saddles, often in pairs. The siphonal lobe shorter than the superior Jateral. The last auxiliary lobes often directed obliquely backwards towards the umbilicus. The saddles very much divided and never 26 198 THE LIAS AMMONITES. foliated. The Licatt are all Cretaceous forms, and Haploceras ligatum, VOrb. (fig. 84), from the Neocomian, is a typical species. 18th Section. Pranunati, von Buch. See p. 189 19th Section. Coronarit, von Buch. See p. 190. 20th Section. Macrocernaut, von Buch. See p. 190. 21st Section. Fnrpriatt, d’Orbigny. Shell discoidal; formed of cylindrical whorls ; often contiguous and without involution ; smooth, or ornamented transversely at regular distances apart, with prominent ribs or grooves, which are the remains of a portion of the mouth appendages of the species. Mouth circular. Sep/a symmetrical, formed of lobes and saddles divided in part into pairs, always enlarged at their extremity and narrow at the base; siphonal lobe often the longest. Aegoceras fimbriatum, Sow. (fig, 85), ‘of the Middle Lias, is a good type of this group. The Fimpriari are found in the Jurassic rocks and Lower Cretaceous strata. Fic. 84.—Haploceras ligatum, d’Orb. Fie. 85.— degoceras timbriatum, Sow. Fre. 86.—Crioceras Emerici, Léveillé. Species with ramified septa; whorls coiled spirally on the same plane, not contiguous. Genus Crioceras, Léveillé. Animal unknown. Shell discoidal, rolled on the same plane, whorls round or oval, and not contiguous. Septa transverse, divided regularly into six lobes, mostly formed of single parts, the siphonal lobe excepted, and the saddles formed of parts nearly always in pairs. The superior lateral lobe is longer than the siphonal lobe. The lobes and the saddles are narrow at the base and much enlarged at their extremity. Siphuncle continuous, always marginal. Two thirds of the last whorl formed the dwelling chamber of the animal. Found in the lower strata of the Cretaceous formation. Crioceras Emerict (fig. 86) is a typical form. Genus Scarurres, Parkinson, Shell spiral, rolled on the same plane; whorls at THE CEPHALOPODA. 199 first contiguous, then separated from the others and projected in nearly a straight line, afterwards bent upwards and forwards, forming a horse-shoe curve. Septa transverse, symmetrical, divided regularly into unequal lobes. The recurved portion always without Fic. 87.—Scaphites gigas, Sowerby. septa, formed the dwelling chamber of the animal. Siphuncle continuous and marginal. Mouth oval, provided with large protuberent bands, more or less prominent. All the species are obtained from the Cretaceous formation, and very large forms are obtained from the Neocomian strata. Scaphites gigas, Sow. (fig. 87), and Scaphites Ivanti, Puzos. (fig. 88), are typical forms of this group. « i Abd) NSS ae IN iia Fie. 88.—Scaphites Ivanii, Puzos. Genus Ancyiocrras, d’Orbigny. Shell spiral, rolled on the same plane, with very few whorls perfect, and not contiguous; the last separated from the others and projected Fie. 89.—Ancyloceras Matheronanum, d’Orb. outwards in a horizontal line, then turned upwards and inwards, forming an arch opposed to the turns of the spine, the recurved portion without septa formed the dwelling chamber. 200 THE LIAS AMMONITES. Septa symmetrical, divided into unequal lobes. Mouth round or oval, and provided with tubercles at the circumference. Siphuncle marginal. This genus ranges from the Inferior Oolite to the upper strata of the Chalk, and Ancyloceras Matheronianum, d Orb. (fig. 89), from the Upper Neocomian, and Ancyloceras Puzosianum, d’Orb. (fig. 90), from the lower Neocomian, are typical of the genus. Fie. 90.—Ancyloceras Puzosianum, d’Orb. 2. Species only arched. Genus Toxocrras, d’ Orbigny. Shell conical, subcylindrical or compressed, symme- trical, much elongated, and more or less arched, but never forming a spire. Septa transverse, deep, sinuous, and presenting six unequal lobes, foliaceous on their border. Siphuncle marginal. Mouth oval, compressed or round, prominent at the inner border. The species belong to the Jurassic and Cretaceous formations. Zozoceras Honnora- tianum, d’Orb. (fig. 91), is typical of the group. Se Fic. 91.—Toxoceras Honnoratianum, d’Orb. Genus, Hamires, Parkinson. Shell conical, symmetrical, bent upon one plane, spire irregular, very elliptical, formed of bends at the two extremities of the ellipse, WIN MIT a, yp iaip iN, VUE Ll. Yi eb jikop bb ssi Fie. 92.—Hamites elegans, @’Ord. CA 7p RAPT if jl U) if le LN Le = THE CEPHALOPODA. 201 and more or less straight in the interval. The bends few and never in contact. Septa transverse, divided regularly into six unequal lobes. Siphuncle marginal. Mouth round or oval, with or without processes or oval bands. All are Cretaceous forms, of which Hamites elegans, d’Orbigny (fig. 92), is a good type from the Gault. k. Species straight. Genus Bacuuites, Lamarck. Shell straight, conical, cylindrical or compressed, with parietes articulated by sinuous sutures. Septa approximate, perforate, and much fringed Fic. 93.—Baculites anceps, Lamarck. near the circumference. The last dwelling chamber is very large, and formed a long sheath. Siphuncle marginal. These straight Ammonites are found from the Neoco- mian formation to the Upper Cretaceous. Baculites anceps, Lamarck (fig. 93), is a type. l. Species with shell spiral and turreted. Genus Turritites, Lamarck. Shell spiral, turreted; whorls contiguous, and exposed, with articulated walls formed by sinuous sutures (fig. 94). Spire dextral or sinistral, umbilicated throughout. Septa transverse, divided into six lobes, foliated at their margin. Mouth round. Siphuncle marginal, continuous. The Turriirrss are true Cretaceous forms. Some species from the Lias were referred by d’Orbigny to this genus. These, however, have been proved to be only distorted species of Ammonites well known in the beds in which they are found. Type, Zurrilites catenatus, d’Orb. (fig. 94). Fic. 94.—Turrilites catenatus, d’Orb. Fic. 95.—Helicoceras Robertianum, d’Orb. Fie. 96.—Hetoroceras Emerici, d’Orb. 202 THE LIAS AMMONITES. Genus Finutcoceras, d’Orbigny. Shell turbinoid, spiral, composed of a few whorls obliquely coiled and rather widely separated. Spire dextral or sinistral, and elevated above the plane of the last large whorl, which was the dwelling chamber of the animal. Septa transverse, oblique, and deeply sinuous. Siphuncle marginal. Helicoceras Robertianus, VOrb. (fig. 95), forms the type. The species are found in the Jurassic and Cretaceous rocks. Genus Huteroceras, d’ Orbigny. Shell spiral, turreted, whorls contiguous in youth ; with age, the last whorl separates from the others and becomes produced and recurved, forming an arch without septa, and which doubtless constituted the dwelling chamber of the animal. He¢eroceras is a Turrilite with the dwelling chamber in the adult shell detached, produced, and recurved. The most’ typical specimen is Heteroceras Emeric, d’Orb. (fig. 96). Genus Anisocrras, Pictet. Turns of the shell at first spiral not in the same plane, next tangentially divergent, and finally recurved, none of the turns in contact. Found in Oolitic and Cretaceous formations. Professor Pictet,' in his excellent ‘Traité Hlémentaire de Paléontologie,’ gave a copious résumé of the Cephalopoda, in which he closely adhered to the system of Von Buch and d’Orbigny. Professor H. B. Geinitz,’ in his ‘Grundriss der Verstemerungen Kunde,’ followed out the same method. Dr. C. G. Giebel,3 in his ‘Fauna der Vorwelt, gave a valuable synopsis of the Fossil Cephalopoda, and brought together a great quantity of material bearing upon this subject, in the arrangement of which he followed the methods of von Buch and d’Orbigny. The late Mr. Daniel Sharpe, F.R.S.,* contributed an unfinished monograph on the British Cretaceous Nautili and Ammonites to the volumes of the Paleeontograpbical Society in 1853, 1857. In this important work its learned author followed the lines laid down by d’Orbigny in the systematic arrangement of the groups, and illustrated his work with well-executed plates. The Jurassic geology of the north-eastern Alps received an important illustration from the researches of Franz Ritter von Hauer,’ whose exhaustive monograph, illustrated with beautiful plates, ‘Die Cephalopoden aus dem Lias der Nordéstlichen Alpen,’ marked an epoch in our knowledge of the Liassic groups of that region. In this important work the learned author followed the grouping of von Buch. ‘Traité elementaire de Paléontologie,’ tom. ii, p. 309, pl. xiv—xx, 1844. ‘Grundriss der Versteinerungens Kunde,’ pp. 256—315, pl. x—xii, 1846. ‘Fauna der Vorwelt Cephalopoden,’ Band iii, 1852. ‘Cretaceous Ammonites,’ Paleontogr. Soc., vols. for years 1853 and 1855. 1 2 3 4 > “Ueber die Cephalopoden aus dem Lias der Norddstlichen Alpen,’ 1856. THE CEPHALOPODA. 203 Dr. Oppel, in his ‘ Juraformation,” and in his later and larger work on the Ammonites of the Malm formation of Germany, and the Jurassic formations of India, delineated im ‘ Palaeontologische Mittheilungen,” adhered to the classification of von Buch. Between 1863 and 1870 the late lamented Prof. Phillips, of Oxford, contributed five parts of his unfortunately unfinished Monograph on another important group of the Fossil Cephalopoda, viz. the Belemnites, in the volumes of the Paleeontographical Society, issued for the years 1863, 1864, 1866, 1868, and 1869. My old esteemed friend, the learned Secretary of the Palseontographical Society, the Rev. Thos. Wiltshire, M.A., F.G.S., in 1867 contributed a valuable memoir on the chief groups of the Cephalopoda to the Geologists’ Association,* and in an Appendix to this work added an Analysis of the Families and Genera of the Fossil Cephalopoda, with their range in time. This résumé of a very difficult subject has been so carefully prepared by its author that I shall, with permission, insert it 2 eatenso (at pages 204 to 218), as it clearly exhibits the actual state of the systematic classification of the Cephalopoda at the date of its publication, and before changes in several of the groups composing the different sections of these remarkable fossils had been rendered inevitable by subsequent discoveries. 1 ‘Die Juraformation Englands, Frankreichs, and S.-W. Deutschlands,’ 1859. 2 *Palacontologische Mittheilungen,’ vols. i, 11, 1862-63. 3 Geologists’ Association, ‘ Chief Groups of the Cephalopoda,’ 1869. 204 THE LIAS AMMONITES. ANALYSIS OF THE FAMILIES AND GENERA OF THE FOSSIL CEPHALOPODA.* First Orper.—DIBRANCHIATA, contarnine Sxcrion I. Octopopa, AND Section II. Drcaropa. Section I.—OctoroDa. I.—Shell involute, the turns in the same plane, thin, one chambered. Family, Argonautidee (Reeve, 1841). One fossil genus, Argonauta. 1. Arconavta, Linné, 1758. Tertiary. Section I7T.—DeEcapoDa. II].—Shell lance-shape, slender, with central ridge, generally terminating in a slight expansion of no great length without air chambers. Family, OnycHoTEvTHIDz (Gray, 1847). Three fossil genera, Enoploteuthis, Plesioteuthis, and Ommas- trephes. 2. Enoptorevtuis, D’Orbigny, 1840. Sides sinuous, with lateral expansions ; central ridge keeled; Oolitic. 3. Piusiorruruis, Wagner, 1860. Sides sinuous, with central and two side ridges ; projection arrow-shaped ; arms with hooks ; Liassic. 4. OmmastrepuEs, D’Orbigny, 1840. Sides generally straight, contracted towards base, point expanded, central and side ridges ; Oolitic. 1 Drawn up by the Rev. T. Wiltshire, M.A., F.G.S., in 1867, see page 203. THE CEPHALOPODA. 205 I1I.—Shell lance-shape, slender, with central keeled ridge, and side expansions of some length. Family, Gonatip#. One fossil genus, Loligo. 5. Lorico, Lamarck, 1799. Liassic. TV.—Shell lance-shape, subovate, with central ridge, and side expansions of some length. Family, Benorrurnip#. Five fossil genera, Teudopsis, Phylloteuthis, Belo- teuthis, Geoteuthis, and Leptoteuthis. 6. Trupopsis, Deslongchamps, 1835. Narrow at top, enlarged below, with a concavity at base, and narrow central rib ; Liassic into Oolite. 7. PuyttorzurHis, Meek and Hayden, 1858. Narrow at top, enlarged below, with slight concavity at base, where the lateral margins are obtusely angular ; Cretaceous. 8. BeLoteutuis, Miinster, 1843. Pointed at top and bottom, lateral expansions forming a sudden angle on the sides towards the lower half of total length; Liassic. 9. Grornutuis, Minster, 1843. == Belemnosepia, Agassiz, 1835. == Loliyosepia, Quenstedt, 1839. == Coccoteuthis (pars), Owen, 1855. Wide at top, pointed at base, side expansions forming a sudden angle on the sides towards the upper half of total length ; Liassic. 10. Leprorgutuis, von Meyer, 1834. Wide and rounded at top, pointed at base, lateral expansions gradually angular, ribs slight and diverging ; Oolitic. V.—Shell ovate, thick, with thin lateral projections, inclined to the sides, terminating in a projecting point imperfectly chambered. Family, Sur1apm (Owen, 1836). One fossil genus, Sepia. 11. Supra, Linné, 1735. = Belosepia, Voltz, 1830. = Sepiolithes, Minster, 27 206 THE LIAS AMMONITES. 1843. = Trachyteuthis, Meyer, 1846. == Coccoteuthis, Owen, 1855. = Paleo- teuthis, Roemer, 1856. Oolitic and Tertiary. VI.—Shell conical, slightly bent, having at its upper part a cavity containing chambers with a siphuncle. Family, Betumnosipm. Four fossil genera, Belemnosis, Beloptera, Helicerus, and Spirulirostra. 12. Butemnosis, Edwards, 1849. Shell conical, and suddenly bent at a short distance from the base, no side expan- sions; Tertiary. 13. Brtoprera, Deshayes, 1830. Shell conical, and slightly bent, side expansions at the angle; Tertiary. 14. Henicervus, Dana, 1849. Shell conical, the chambers at the upper part, slender and terminating in a spiral arrangement ; Liassic ? 15. SprrubrrostrRa, d’Orbigny, 1842. Shell conical, the chambers at the upper part, of some size and terminating in a spiral arrangement, the portion covering the commencement of the spiral projected for- wards, the extremity pointed ; Tertiary. VII.—Shell straight, with a series of conical chambers at its upper portion. Family, BreLeMNitip# (Owen, 1836). Five fossil genera, Belemnites, Belemnitella, Belemnoteuthis, Conoteuthis, and Xiphoteuthis. 16. Betemnites, Lister, 1678. == Belemnitis lapis, Agricola, 1546. = Belem- nitis, Gesner, 1565. == Acamas, Montfort, 1808. == Hibolithes, Montfort, 1808. = Thalamus (—alveolus, &c.), 1808. == Actinocamax, Miller, 1823. == Pseudobelus, Blainville, 1827. == Belemnosepia, Buckland, 1836. = Belopeltis, Voltz, 1840 (a pro- ostracum). == Notosiphites, Duval-Jouve, 1841. = Gasterosiphites, Duval-Jouve, 1841. Shell (guard) straight, generally long, somewhat cylindrical, conical below, with a hollow cone (alveolus) in the upper part, containing a chambered cone (phragmacone), THE CEPHALOPODA. 207 which has a marginal canal (siphuncle); the thin, shelly covering (conotheca) investing the chambers, prolonged on one side into a broad lobe (pro-ostracum, pen) ; animal not clearly known, double rows of hooks on the arms; from Liassic into Cretaceous forma- tions. 17. Bevemnrreya, d’Orbigny, 1840. Shell (guard) in its highest part, marked by a short longitudinal slit ; Cretaceous. 18. BeLeMNoTEuTHIS, Pearce, 1842. == Keleno, Minster, 1836. == Acanthoteuthis, Minster, 1839. = Plesioteuthis, Wagner, 1860. Shell consisting of a chambered cone, having at its upper part a horny pen with thin side bands, and at its lowest part a thin fibrous guard, with two diverging ridges ; animal with arms and horny hooks, fins large; Oolitic. 19. Conorzurnuis, d’Orbigny, 1840. Chambered cone slightly curved, pen elongated and very narrow ; Cretaceous. 20. XipnorEeutTuis, Huxley, 1864. Shell cylindrical ; chambered cone long and narrow; pen very long and slender, sec- tion an ellipse ; Liassic. SzconD Orper.—TETRABRANCHIATA. VIII.—Shell many chambered; the last (exterior) chamber large, siphuncle generally subcentral ; the edges of the partitions (septa) which separate the chambers either without folds, or slightly undulating. Family, Navutitipa. ‘Thirty fossil genera: Nautilus, Discoceras, Ophidioceras, Gyroceras, Cyrtoceras, Cyrtocerina, Oncoceras, Streptoceras, Piloceras, Lituites, Lituunculus, Ortho- ceras, Tretoceras, Huronia, Actinoceras, Ormoceras, Aulacoceras, Endoceras, Cameroceras, 'T'rochoceras, Hercoceras, Gomphoceras, Phragmoceras, Ascoceras, Glossoceras, Aphragmites, Aturia, Nothoceras, Bathmoceras, and Gonioceras. Division A.—Ldges of septa without folds. I. Shell spiral, in the same plane. 21. Navutitus, Belon, 1553. = Nautilus, Breynius, 1732. = Planorbites, 208 THE LIAS AMMONITES. Lamarck, 1799. == Angulithes, Montfort, 1808. == Oceanus, Montfort, 1808. = Ammonites (pars), Montfort, 1808. = Bisiphites (pars), Montfort, 1808. == Con- chyliolithus, Martin, 1809. == Ammonellipsites, Parkinson, 1811. = Ellipsolithes (pars), Sowerby, 1812. == Rhabdites, de Haan, 1825. == Omphalia, de Haan, 1825. = Globites, de Haan, 1825. == Aganides (pars), d’Orbigny, 1826. = Aganites (pars), Quenstedt, 1834. == Aturia (pars), Bronn, 1835. == Hamites (pars), Fischer, 1837. == Trocholites (pars), Conrad, 1838. = Simplegas (pars), Sowerby, 1842. = Discites (pars), M’Coy, 1844. == Discus (pars), King, 1844. = Cryptoceras (pars), d’Orbigny, 1850. = Trematodiscus (pars), Meek, 1861. Turns (whorls) of the shell, in contact, partially overlapping ; siphuncle almost cen- tral; aperture of exterior chamber open without folds; Silurian into Tertiary, still living. RuyncenouitHEs, Faure-Biguet, 1819. == Conchorhynchus, De Blainville, 1827. = Rhynchoteuthis, d’Orbigny, 1847. Comprising the beaks of the Nautilus animal. 22. Discocrras, Barrande, 1867. Turns of the shell touching, siphuncle variable; aperture of exterior chamber open, its edge not contracted ; Silurian. 23. Opnipioceras, Barrande, 1867. Turns of the shell touching; siphuncle variable ; aperture of exterior chamber con- tracted ; Silurian. 24. Gyrocreras, de Koninck, 1844. = Gyroceratites, H. von Meyer, 1829. = Hortolus, Steininger, 1831. = Spirula, Goldfuss, 1832. = Lituites, Quenstedt, 1834, == Cyrtocera (pars), Minster, 1839. = Cyrtoceras (pars), Phillips, 1841. = Cyrthoceratites (pars), D’Archiac, 1842. Turns of the shell not in contact; siphuncle marginal on external (convex) side; last chamber somewhat small, edge without fold; from Silurian into Carboniferous. 2. Shell an arc of a spiral, in the same plane. 25. Cyrrocrras, Goldfuss, 1832. == Orthoceratites, Lamarck, 1799. == Ortho- cera (pars), Sowerby, 1812. == Campulites, Deshayes, 1832. = Lituites (pars), Quenstedt, 1836. == Cyrtoceratites, d’Archiac, 1842. == Trigonoceras, M’Coy, 1844. = Campyloceras, M’Coy, 1844. = Aploceras, d@’Orbigny, 1850. THE CEPHALOPODA. 209 Shell slightly curved, never forming a complete revolution; siphuncle variable in position, generally on convex side; exterior chamber open, its edge not contracted ; from Silurian into Devonian. 26. Cyrtocerina, Billings, 1866. Shell like Cyrtoceras, but shorter and thicker; Silurian. 27. Oncoceras, Hall, 1847. Shell slightly curved, pear-shaped; siphuncle lateral, edge of exterior chamber contracted in the middle ; Silurian. 28. Srreptoceras, Billings, 1866. Shell slightly curved, pear-shaped, edge of exterior chamber contracted to form three lobes ; Silurian. 29. Pinoceras, Salter, 1859. Same as Cyrtoceras, but the septa forming a series of conical partitions, pointing towards the smaller (earliest) part of the shell ; Silurian. 3. Shell a combination of curved and straight lines in the same plane. 30. Lirvirus, Breynius, 1732. == Hortolus, Montfort, 1808. == Spirulites, Parkinson, 1811. = Clymenia (pars), d’Hichwald, 1842. == Ancistroceras (pars), Boll, 1857. Tums of the shell at first generally in contact, afterwards tangentially divergent ; siphuncle variable ; edge of exterior chamber contracted ; Silurian. 30a. Lirutuncuuus, Barrande, 1867. Same as Lituites, but with the edge of the exterior chamber not contracted, the form ideal, not yet discovered in rocks; Silurian P A, Shell straight. 31. Orrnoceras, Breynius, 1732. == Molossus, Montfort, 1808. == Hchidnis, Montfort, 1808. = Achelois, Montfort, 1808. == Hyolithes, d’Hichwald, 1842. = Koleoceras, Portlock, 1843. = Cycloceras, M’Coy, 1844. Siphuncle small, almost central, bead-like ; aperture of exterior chamber open, with- out folds ; from Silurian into Trias. 210 THE LIAS AMMONITES. 32. Treroceras, Salter, 1859. Siphuncle small, almost central, bead-like; the chambers surrounding the siphuncle pierced by a longitudinal tube; Silurian. 33. Huronta, Stokes, 1824. Siphuncle large, central, the upper part of each division expanded and connected with a small central tube by radiating plates ; Silurian. 34. Actinoceras, Stokes, 1840. Siphuncle large, central, the middle part of each division expanded and connected with a small central tube by radiating plates ; Silurian into Carboniferous. 35. Ormoceras, Stokes, 1840. Siphuncle large, almost central, bead-like, the middle of each division contracted ; Silurian into Devonian. 36. AuLAacocErRas, Hauer, 1860. Siphuncle small, lateral, plain; shell externally corrugated, thickening towards the base. ‘Trias. 37. Enpoceras, Hall, 1847. Siphuncle large, lateral, with cone-like partitions inserted in each other, their points being directed towards the small or earliest portion of the shell ; Silurian. 38. Cameroceras, Conrad, 1847. = Melia, Fischer, 1829. == Thoracoceras, Fischer, 1844. Siphuncle sometimes large, lateral, not complex ; Silurian into Trias. 5. Shell spiral, not in the same plane. 39. Trocnoceras, Barrande, 1847. == Semicornu, Klein, 1770. = Inachus, Hisinger, 1837. Turns of the shell at first in contact, not overlapping, afterwards generally spirally divergent, occasionally tangentially divergent ; siphuncle mostly near the margin on the outer (convex) side, edge of exterior chamber without fold; Silurian. THE CEPHALOPODA. 211 40. Hercocrras, Barrande, 1865. Turns of the shell at first in contact, slightly overlapping, afterwards spirally divergent ; siphuncle marginal on outer side, edge of exterior chamber contracted and compressed transversely ; Silurian. 6. Shell neither spiral nor linear. 41. Gompnoczras, Sowerby, 1839. == Orthoceras (pars), Sowerby, 1812. = Conilites, Pusch, 1837. == Nelimenia, Castelnau, 1843. == Bolboceras, Fischer, 1844. = Apioceras, Fischer, 1844. == Poterioceras, M’Coy, 1844. = Lituites ( pars) Quenstedt, 1846. = Syncoceras (pars), Pictet, 1854. Shell straight, pear-shaped; aperture of exterior chamber contracted, small and lobed, the exterior chamber somewhat globular; position of siphuncle variable; from Silurian into Carboniferous. 42. Puragmoceras, Broderip, 1839. == Campulites (pars), Deshayes, 1830. = Orthoceratites, Steminger, 1831. Shell slightly curved, pear-shaped; aperture of exterior chamber contracted, small and lobed; siphuncle generally on the internal (concave) side; from Silurian into Devonian. 43. Ascocsras, Barrande, 1846. = Cryptoceras, Barrande, 1846. Shell slightly curved, flask-shaped, lower portion more globular than the upper ; partitions of the chambers few and running parallel to the long axis of the shell, leaving a space the whole length of the shell for the body of the creature; aperture of exterior chamber not lobed; Silurian. 44. Guossoceras, Barrande, 1867. _ Shell same as in Ascoceras, but with the aperture of the exterior chamber lobed ; Silurian. 45, Apnracmites, Barrande, 1867. Shell same in general form as Ascoceras, but without several internal partitions ; aperture not lobed; Silurian. 212 THE LIAS AMMONITES. Division B.—Ldges of septa with a single marked fold. 1. Shell spiral in the same plane. 46. Arturia, Bronn, 1836. The turns of the shell in contact overlapping ; siphuncle almost marginal, on concave (inner) edge, and formed of a series of inserted cone-shaped partitions; edges of the partitions separating the chamber with a strong lateral lobe. Cretaceous into Tertiary. 47. Nornocrras, Barrande, 1856. Turns of the shell slightly overlapping, sipbuncle marginal, on convex (outer) side, and furnished with internal radiating plates ; septa with a slight lobe on the back of the shell, corresponding in direction to that of the Ammonites; aperture not lobed; Silurian. 2. Shell straight. 48. Batumoceras, Barrande, 1867. Siphuncle marginal, containing a series of inserted cone-like partitions, whose points are directed towards the final chamber, being the reverse of that observed in Endoceras. Septa incomplete towards the final chamber, and with a slight lobe, planned as in Notho- ceras ; aperture not lobed; Silurian. 49. Gonroceras, Hall, 1847. Siphuncle marginal. Septa waved, shell compressed into an elliptic form ; Silurian. 1X.—Shell many chambered ; the last (exterior) chamber large; siphuncle marginal ; the edges of the partitions (septa), which separate the chambers, angulated or waved, but not dentated or foliated. Family, Gontatipa (Barrande, 1867). Three Genera: Goniatites, Clymenia, and Bactrites. 1. Shell spiral in the same plane. 50. Goniatites, de Haan, 1825. = Nautilus, Lamarck, 1799. = Orbulites, Lamarck, 1801. == Aganides, Montfort, 1808. = Nautellipsites, Parkinson, 1811. = Ellipsolithes (pars), Sowerby, 1812. THE CEPHALOPODA. 213 The turns of the shell in contact, overlapping ; siphuncle near the outer (convex) side; edges of the partitions separating the chambers much waved, but not having at their base small, convex, tooth-like projections ; from Silurian into Trias. 51. Crymenia, Minster, 1832. == Endosiphonites, Ansted, 1838. = Subclymenia, d’Orbigny, 1850. The turns of the shell in contact, overlapping; siphuncle near the inner (concave) side; edges. of partitions waved with slight angular depressions. (‘This genus has affinities with A¢uria, but the turns of the shell are more overlapping in the latter, and the siphuncle is larger). Devonian into Carboniferous. 2. Shell straight. 52. Bactritzs, Sandberger, 1842. == Stenoceras, d’Orbigny, 1850. == Trematoceras, d’Hichwald, 1851. Siphuncle marginal ; septa gently waved, a single angular depression (lobe) ; external chamber not known ; from Silurian into Devonian. X.—Shell many chambered ; the last (exterior) chamber large ; siphuncle marginal ; the edges of the partitions (septa), which separate the chambers, many-waved, with single circular or subcircular depressions at their base. Family, Chyponrtipa. Four genera: Clydonites, Choristoceras, Rhabdoceras, and Cochloceras. 1. Shell spiral, the turns touching. in the same plane. 538. Cryponites, Hauer, 1860. Triassic and Cretaceous. 2. Shell spiral, the turns not touching, in the same plane. 54. CHoristocreras, Hauer, 1865. Triassic. 3. Shell straight. 55. Ruaspoceras, Hauer, 1860. Triassic. 4. Shell spiral, the turns touching, not in the same plane. 56. Cocuiocrras, Hauer, 1860. Triassic. 214 THE LIAS AMMONITES. XI.—Shell many chambered; the last (exterior) chamber large; siphuncle marginal (dorsal) ; the edges of the partitions (septa), which separate the chambers, waved, with many small circular elevations (crenulations) at the base of each wave. Crratitip®. ‘Two genera: Ceratites and Baculina. 1. Shell spiral, the turns touching, in the same plane. 57. Crratites, de Haan, 1825. From Triassic into Cretaceous. 2. Shell straight. 58. Bactrina, d’Orbigny, 1850. Cretaceous. XII.—Shell many chambered ; the last (exterior) chamber large; siphuncle marginal (dorsal) ; the edges of the partitions (septa), which separate the chambers, folaceous. Ammonitipa@ (Owen, 1836). ‘Thirteen genera: Ammonites, Crioceras, Toxoceras, Scaphites, Ancyloceras, Ptychoceras, Hamites, Hamulina, Baculites, Turrilites, Helicoceras, Heteroceras, and Anisoceras. 1. Shell spiral, in the same plane. 59. Ammonirtss, Bruguiére, 1789. == Ammonis cornu, Auctorum. = Planorbites, Lamarck, 1799. = Planulites, Lamarck, 1801. == Amaltheus, Montfort, 1808. = Orbulites, Montfort, 1808. == Globites, de Haan, 1825. = Planites, de Haan, 1825. Turns of the shell in contact, overlapping ; siphuncle on the exterior side; Triassic into Cretaceous. Aprycuus, H. von Meyer, 1831. = Trigonellites, Parkinson, 1811. = Tellinites, Schlotheim, 1820. == Minsteria, Deslongchamps, 1835. == Ichthyosiagones, Bourdet, 1822. Opercula, or doors, closing the external opening of the Ammonite shell. Peltarion, Deslongschamps, 1859. Circular, or somewhat oval calcareous plates, with an undulating margin, supposed to be connected with the mandibles of the Ammonite animal; Lias into Oolite. THE CEPHALOPODA. 215 2. Shell spiral, turns of the shell not in contact, in the same plane. 60. Criocuras, d’Orbigny, 1840. = @roceratites: Leveillé, 1837. == Tropzum, Sowerby, 1840. Cretaceous. 2. Shell an are of a spiral, in the same plane. 61. Toxocrras, d’Orbigny, 1840. From Oolitic into Cretaceous. 4, Shell changing from a spiral, in the same plane. 62. Scarnites, Parkinson, 1811. Turns of the shell at first spiral, in contact, and overlapping, afterwards tangentially divergent ; finally recurved and not in contact ; Cretaceous. 63. AncyLoceras, d’Orbigny, 1840. Turns of the shell at first spiral, zof in contact, afterwards tangentially divergent ; finally recurved, and not in contact ; from Oolitic into Cretaceous formations. 5. Shell forming straight and curved lines, in the same plane. 64. Prycnoceras, d’Orbigny, 1840. == Ptychocerus, King, 1844. The shell at first straight, afterwards curved, and next straight, the turns in contact ; Cretaceous. 65. Hamitss, Parkinson, 1811. = Baculita, Fleming, 1828. = Toxerites, Rafinesque, 1819. The shell at first straight, afterwards curved, and next twice repeating the process ; the arrangement forming a species of compressed spiral; the turns zof im contact ; Cretaceous. 66. Hamuutna, d’Orbigny, 1850. The shell at first straight, afterwards curved, next straight; the turns zo¢ in contact ; Cretaceous. 6. Shell forming a straight line. 67. Bacutites, Lamarck, 1801. == Homaloceratites, Htipsch, 1781. = Tiranites, Montfort, 1808. The shell slightly conical; Cretaceous. 216 THE LIAS AMMONITES. 7. Shell spiral, not in the same plane. 68. Turritrres, Lamarck, 1801. == Turrites, de Haan, 1825. == Turrilithes, Bronn, 1832. ‘Turns of the shell spiral, in contact ; Oolitic into Cretaceous. 69. Henicocrras, d’Orbigny, 1840. = Helicocerus, King, 1844. Turns of the shell spiral, zo¢ in contact ; Oolitic into Cretaceous. 8. Shell forming straight and curved lines, not in the same plane. 70. Hernrocrras, d’Orbigny, 1850. Turns of the shell at first spiral and in contact, not in the same plane, afterwards tangentially divergent, finally recurved and zo¢t im contact, and produced at a different angle to that of the spiral ; Cretaceous. 71. Antsoceras, Pictet, 1854. Turns of the shell at first spiral, not in the same plane, next tangentially divergent, and finally recurved, none of the turns in contact ; Oolitic into Cretaceous. THE CEPHALOPODA. 217 RANGE OF THE GENERA OF THE FOSSIL CEPHALOPODA IN GEOLOGICAL TIME.’ Drawn uP BY THE Rev. T. Wittsurre, M.A., F.G.S., rv 1867. See page 203. Cretaceous. Carboniferous. Devonian. Silurian Tertiary. Jurassic Triassic. Permian . Argonauta . le aes . Enoploteuthis . Plesioteuthis . Ommastrephes ° Loligo . Teudopsis . ale at a . Phylloteuthis Aire: : . Beloteuthis . signa te: Rina erg . Geoteuthis . 5 Cun aetau Rau os 10. Leptoteuthis ‘ 11. Sepia . 12. Belemnosis . 13. Beloptera sa ‘o 14. Heliceras . Slee ot ile | 15. Spirulirostra Sawing ee 16. Belemnites . eee S 17. Belemnitella hes ie Pee aa 18. Belemnoteuthis .| ... Gn: * 19. Conoteuthis cles cate 20. Xiphoteuthis Aiaates Meee) ra gh Rae a s 21. Nautilus . ds ns - 4 z m e | 22. Discoceras . 23. Ophidioceras alone ae si ae ae sii t 24. Gyroceras . eas ae a Age ee Feil olen’ 25. Cyrtoceras . 26. Cyrtocerina 27. Oncoceras 28. Streptoceras 29. Piloceras 30. Lituites ee Se OOnNOHoPwwr # oe KF KK ROKK K HK ae * *% 1 The stars opposite a genus in one or more of the columns show that the genus existed in the geological period referred to in the column or columns. * The Jurassic formation includes the Oolite and the Lias. 29 18 31. 38. 34. 35. 36. 37. 38. 39. AO. Al. A2. 43. 44. 45. AG. AT. 48. AQ. 50. ol, 52. 53. 54. 05. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. i. Orthoceras . Tretoceras Huronia Actinoceras . Ormoceras Aulacoceras . Endoceras Cameroceras Trochoceras Hercoceras . Gomphoceras Phragmoceras Ascoceras . Glossoceras . Aphragmites Aturia : Nothoceras . Bathmoceras Gonioceras . Goniatites Clymenia Bactrites. . Clydonites . Choristoceras Rhabdoceras Cochloceras Ceratites . Baculina . Ammonites . Crioceras . Toxoceras . Scaphites . Ancyloceras Ptychoceras Hamites . Hamulina Baculites . Turrilites Helicoceras. Heteroceras Anisoceras . THE LIAS AMMONITES a (=) : oe e ° D g Ss Bs 8 g S Scene S a « a a ‘g = a aS » 3 3S = a2 iS 5 x 5 fo) o ej ® \ WN ~\\j WA \\ \ f Ww \Y \ \\\ Fifi y | Ay ) Fic. 184.—Amaltheus margaritatus, Mont. Fig. 135.—Amaltheus cordatus, Sow. chamber short ; one half to two thirds of a whorl. Mouth-border simple, ventral portion ending in a long projecting process. Lobe-line extremely ramified, the siphonal lobe MODERN CLASSIFICATION. 241 shorter than the principal lateral lobe, which is mostly broad and wedge-shaped. A divided horny Anaptychus has been found in this genus. The genus Amaltheus has an extensive geological range; it is found in the Trias, Amal. megalodiscus, Beyr., Amal. floridus, Wulf.; it is largely developed in the Jurassic strata, commencing with Amal. Guibalianus, VOrb., Amal. margaritatus, Mont. (fig. 134), and Amal. spinatus, Brug., in the Lias, and many forms are found in the higher Oolitic beds, as Amal. cordatus, Sow., Coral Rag (fig. 135) ; numerous species are likewise discovered in the Cretaceous rocks, as Amal. Gevrilianus, d’Orb., Amal. Vibrayeanus, d’ Orb. Genus ScuLonnBacuia, Veuwm.—Shell keeled, with strong forward-bent ribs on the sides, sometimes developing lateral tubercles. Body-chamber two thirds of a whorl long. Mouth-border falciform, ventral side with a forward directed process. Siphon \/ Y WA Fic. 136.—Schloenbachia Roissyana, Fie. 137.—Schloenbachia Fig. 138.—Sechloenbachia Goupilanus, d’Orb. cristata, Deluc. d’Orb. large, mostly lodged in the high keel (fig. 137); this genus is entirely limited to the Cretaceous rocks ; figs. 136, 137, and 138 represent typical forms of the group. Il. Family.—Tropitipa, Wojs. Shell more or less richly ornamented, and provided with radial ribs, which almost always support tubercles or spiny processes on the border of the siphonal area. Wrinkle- layer and impression on the surface of the mantle entirely wanting. Genus Troritus, v. Mojs.—Body-chamber from one and a half to one and three quarters of a whorl in length. The strong-ribbed sculpture is interrupted upon the ventral surface, and rises as a median keel on the same. ‘The ventral side of the mouth- border projects forward in a short broad lappet; the last whorl seldom loses the form and sculpture of the mner whorls. The lobes are characterised by a broad saddle stem with transverse incised branches, a transverse placing of the lobe points, great develop- ment of the chief lobes, and a remarkable diminution of the auxiliaries. All the species are Triassic. Ex. Zropites Pamphagus, Dittm., Trop. Saturnus, Dittm. 32 242 THE LIAS AMMONITES. Genus TracuycERAs, Laube.—Body-chamber short, from one half to two thirds of a whorl in length. The sculpture interrupted on the ventral surface (fig. 140.) In Fre. 139. Fic. 140. Trachyceras Aon, Minst. some species there is a deep median furrow, at which the ribs with their tubercles end. The mouth-border has a short ventral process. All the species are Triassic. Ex. Trachyceras Aon, Mist. (figs. 139, 140). Zrach. binodosum, Hau., Trach. Attila, Mojs. Genus Cuortstoceras, Hauer.—This genus is nearly allied to the preceding. The body-chamber is short; the lobes are very slightly imcised. ‘The inner whorls have their sculpture interrupted on the ventral surface, whilst on the last whorl it extends . -uninterruptedly across the abdomen. ‘The structure of the lobes shows a persistent relation to an older type, whilst in the sculpture on the ribs there is an evident inclination towards the Zrachyceras type. All the species belong to the Trias formation. Ex. Choristoceras decoratum, Hauer, Chor. noricum, Mojs., Chor. nasturtium, Dittm. Genus Ruaspocerras, /Zaver.—Staff-shaped and tubular, with expanded mouth, and with a transverse ring-like sculpture and simple bent lobes; the genus is very little known, and probably connected with Choristoceras, to which it stands very near. A. Suessi, Hauer. Genus Cocutocrras, Hauer.—The whorls are screw-shaped, with continuous ribs and simple bent lohes. This form is also near to Choristoceras ; it is found in the Trias beds at Zamblach and Salzkammergut. Cochl. Mischeri, Hau. TIT. Family.—Lytoczrativn, Neumayr. This family includes several groups which differ much from each other as regards their external form, but which nevertheless appear to have a close relationship in their MODERN CLASSIFICATION. 243 internal structure. They are characterised by having a short body-chamber, about two thirds of a whorl in length, a simple mouth-border slightly produced on the columellar side; but in all the other features there is a wide difference of structure. This family includes the typical groups Lytoceras and Phylloceras, and others which differ much from them in external form, as Hamites, Turrilites, and Baculites. The Aptychus appears to be absent in this family; at least, it has not as yet been found. Genus Lytocrras, Suvess.—Shell discoidal, more or less flat ; umbilicus large and open ; involution slight, whorls round, only slightly embracing each other around the spire. Body-chamber two thirds of a whorl in length; mouth-border simple, with imter- mittent contractions and prominent fimbriz; columellar side with a lappet which rests on the preceding whorl; the ventral and lateral sides without any prolongation. The sculpture and lines of growth parallel with the mouth-border ; near the spiral suture they bend a little forward. Sculpture feeble, consisting mostly of small radial lines, and intermittent contractions of the shell, with corresponding fimbriz or prominent fringed ribs at certain intervals of growth (fig. 141). Suture line very complicated. Lobes few, much branched; lateral lobes and saddles divided into smail uniform symmetrical digitations ; only two lateral lobes; and a large columellar lobe covered by the former whorl. No Aptychus has as yet been found. This genus commences in the Trias. Lyt. Morloti, Hauer ; Lyt. spherophyllum, Hauer; Lyt. patens, Mojs. It is represented in the Lias formation by Lytoceras fimbria- tum, Sow. (fig. 141). By Lyt. Cornucopia, Young ; Lyt. Jurense, Zitt.; Lyt. hircinum, Schloth.; and Lyt. torulosum, Schiibl. ; Fie. 141. Lyt. Budesianum, d’Orb., in the Inferior Oolite. By Lyt. Adela, — Lytoceras fimbriatum, Sow. d’Orb., in the Kelloway. In the Cretaceous rocks by Lyt. Duvalianum, VOrb.; Lyt. Honoratianum, VOrb. ; Lyt. sub-fimbriatum, VOrb. Dr. Waagen! has figured and described Lytoceras rex., Waag., from the middle Oolite of Kutch, Western India, which is nearly allied to Lytoceras Eudestanum, VOrb. ; it is a magnificent specimen 113 inches in diameter, with thirty fimbriz on its last whorl. Genus Hamires, Parkinson.—With reference to the Cretaceous forms having a conical shell bent in one plane or more without the bends being in contact, Professor Neumayr remarks that a spiral curve of a particular curvature does not give sufficient data for the establishment of a distinct genus. With this view the recognised genera Anisoceras, Ancyloceras, Baculina, Hamulina, Helicoceras, Ptychoceras, and Towxoceras, where the ‘Paleeontologia Indica, Jurassic Fauna of Kutch,’ pl. viii, p. 36, 1875. 244 THE LIAS AMMONITES. curvature receives many modifications, and exists in some of the examples in more than one plane, are all suppressed, and the whole series is reduced to the single genus Hamites, which, in the primary significance of the word, implied a conical straight shell, as Hamites elegans, VOrb. (fig. 142), bent in one plane, without the bends being in Fie. 142.— Hamites elegans, v’Orb, contact. The suture-line is divided into six lobes ; the upper lateral lobe always, the under lateral mostly, divided into pairs of branches. Genus Turriuirus, Lamarck.—Under this genus Professor Neumayr classes Helico- ceras (fig. 148), with an open spiral not in one plane, and /eteroceras, with a closed spiral only in the earlier stage of growth. In TZurrilites (fig. 143) the suture-line is Fie. 143.— Turrilites catenatus, d Orb. Fie. 144.—Helicoceras Robertsoni, d’ Orb. divided into six lobes, each formed of a single pair of digitations. The ventral lobe formed of a pair which are a little longer or shorter than the lateral. Genus Bacuuires, Lamarck.—This genus connects, according to Professor Neumayr, Lytoceras with Hamites in the structure of the principal lateral lobe. Baculites (fig. 145) has a straight conical shell. Mouth oval or compressed, provided on the ventral Fre. 145,— Baculites anceps, Lamarck. MODERN CLASSIFICATION. 245 side with a projecting linguiform process and two lateral grooves which extend to the opposite side of the shell. Septa symmetrical, divided into four or six lobes each formed of a pair of digitations. The ventral lobe equals in length the adjoining principal lateral, which is longer than the lower lateral, and the columellar is small or absent. Genus PuyLLocERAS, Suess.—Shell discoidal, highly involute, covered with very fine strize which describe graceful forward bent lines (fig. 147). Body-chamber short, mouth- border simple, with lateral Jappets directed forward. Lobes numerous and very com- plicated, as many as eight or nine on each side. Saddles bladder-shaped and well rounded (fig. 148); body-chamber widely expanded and fan-shaped, with undulating radiations in Phylloceras heterophyllum, Sow. hx NS i \ SQ \ IN \ , H \ == SS N\ = Ly Ny g 4, | Lf Wf] ie th . . Sz Ko ) \ | < = yy x y Ht} , [ 4 Z Wy }})\|\\\ y Boe LMI) = eo Fie. 146.—Disposition of the lobes Fie. 147.—-Phylloceras heterophyllum, Fic. 148.—Disposition of the lobes (D, L, L’, a) in Phylloceras hetero- Sow. Side view showing the lines and saddles (p, £, L’, a) in Phyll. phyllum. of growth. heterophyllum, Sow. Professor Neumayr' distinguishes, from the Dogger and Malm, four groups in this genus, of which the following are types:—I. Phyll. heterophyllum, Sow.; II. Phyl. tatricum, Pusch ; III. Phyll. Capitanei, Catullo ; IV. Phyll. ultramontanum, Zitt. This genus commences in the Trias with Phyll. debile, Hauer; Phyll Neojurense, Quenst.; Phyll. despectum, Mojs.; Phyll. occultum, Mojs. In the Middle Lias Phyil. Loscombi, Sow., Phyll. Zetes, VOrb. In the Upper Lias Phyll. heterophyllum, Sow., Phyll. subcarinatum, Young. In the Oxfordian Phyll. tatricum, Pusch., Phyll. viator, @Orb., Phyll. Hommairei, VOrb., Phyll. Zignoanum, VOrb. In the Cretaceous rocks Phyll. subalpinum, VOrb., Phyll. Vellede, VOrb. Dr. W. Waagen has figured and described’ several interesting species, closely allied to European forms, collected from the Upper Jurassic rocks of Kutch, Western India, by the Geological Survey of India. 1 Neumayr, ‘‘ Phylloceratten des Dogger und Malm,” ‘Jahrbuch der Geol. Reichsanstalt,’ 1871, bd. xxi. 2 ¢Paleeontologia Indica,’ pls. v, vi, vii, p. 25, 1875. fo) Pp ) Pp ? 246 THE LIAS AMMONITES. IV. Family—Axrcocreratipa, Veumayr. Y y This family includes a considerable number of Ammonite groups which have widely different forms and affinities, so that it is almost impossible to give a general description of the family which shall be correct and comprehensive at the same time. The lobes present a great variety of ramified figures; the suture-line is in general complicated ; the siphonal lobe large, and the principal lateral and secondary laterals attain considerable dimensions. The siphonal or ventral area is in general round and well developed ; in some there is a keel with lateral channels more or less deeply grooved ; in others the shell is flattened and discoidal, with a wide open umbilicus ; or it is round and inflated, with highly involute whorls and a small umbilicus, sometimes nearly occluded by the last. In the presence of so much diversity in form and structure this family is subdivided into three sections : I. AncocrratitEs.—Aegoceras and Arietites. If. Harpocuratites.—Harpoceras, Oppelia, Haploceras. III. SreeHanoceratites.—Stephanoceras, Cosmoceras, Ancyloceras, Baculinu, Simo- ceras, Perisphinctes, Olcostephanus, Scaphites, Hoplites, Acanthoceras, Stoliczkava, Crioceras, Heteroceras, Peltoceras, Aspidoceras. Genus Ancocrras, Waag.—The form of the shell in this genus is very variable ; it 1s flat and discoidal, with a wide umbilicus, or round and involute with a small umbili- cus ; in some shells the ventral side is convex and enlarged, and the sides highly orna- mented with ribs, tubercles, or elongated spines; in other species the sides have simple folds or undulations, as Aeg. Jamesoni, Sow. (Pl. XI, figs. 4—6) and some are smooth, nom, ey Fie. 149.— Aegoceras capri- Fie. 150.— Aegoceras Davai, cornum, Schloth. Sow. as deg. planorbis, Sow. (Pl. XIV, figs. 1—4). The ventral side is in general round, as deg, capricornum, Schlot. (fig. 149), and deg. Dave, Sow. (fig. 150); sometimes it is grooved by a median channel, which interrupts the passage of the ribs from the right to the left side of the shell, as is especially the case in deg. angulatum, Schlot. (Pl. XIV, MODERN CLASSIFICATION. 247 fig. 6) and dey. Charmassei, dV’Orb., (Pl. XX, figs. 2, 3). In all the species a keel is absent, and there are no lateral longitudinal channels in the siphonal or ventral area. The body-chamber varies in length from two thirds to an entire whorl. The mouth- border is simple; the edge has sometimes a thickened withdrawn lip and a ventral prolongation, and in 4eg. planorbis there is a contraction near the aperture (Pl. XIV, fig. 3), with no lateral auricles. The Axaptychus is horny, thin, and bivalved (Pl. XIV, fig. 3). The lobe-line is much ramified, and the lobes in general are very complicated. There is a highly branched principal lateral, a smaller lower lateral, and the siphonal lobe, less than the principal lateral, ends in two divergent branches. There are several small auxiliary lobes near the suture, which are concealed by the involution of the spire, as in Aeg. Charmassei, d’Orb. (Pl. XX). This genus may be naturally divided into four sections : Furst Section—Psi.onott. Sides smooth, or with undulated folds or straight ribs; suture-line simple; ventral area round and smooth. dey. planorbis, Sow.; Aeg. Johnstoni, Sow. ; Aeg. torus, q’Orb. ; Aeg. intermedium, Portlock; Aeg. Belcheri, Simp.; Aeg. liassicum, a’ Orb. All these forms are found in the Planorbis zone of the Lower Lias. Second Section—ANGULATI. Sides covered with sharply flexed ribs, interrupted on the ventral area by a channel more or less developed. deg. angulatum, Schl.; Aeg. Charmassei, @Orb.; Aeg. catenatum, Sow.; Aeg. lacunatum, Buck.; Aeg. Boucaultianum, VOrb. All these forms, the two last excepted, are from the Angulatum-zone of the Lower Lias. Third Section—ARMATI. Sides with numerous ribs, many of which develop tubercles or elongated spines ; in some forms they are absent. dey. Davai, Sow.; deg. planicosta, Sow.; deg. Birchii, Sow.; Aeg. armatum, Sow.; Aeg. Taylori, Sow.; Aeg. densinodum, Quenst. ; Aeg. brevispinum, Sow. ; Aeg. Valdani, VOrb.; Aeg. Maugenesti, WOrb. Aeg. planicosta and Aeg. Birchii are from the Upper Bucklandi beds of the Lower, and all the others are from the Jamesoni-zone of the Middle Lias. 248 THE LIAS AMMONITES. Fourth Section—Invouvrt. Shell highly involute ; inner whorls sometimes almost entirely concealed. Shell during middle age often undergoes a great change of form, and the involution become less and the umbilicus widens. dey. Henleyi, Sow.; Aeg. striatum, Reinecke; Aeg. Bechet, Sow.; deg. curvicornum, Schloenb. ; deg. pettos, Quenst. ; deg. heterogenes, Young. All the forms of this section are from the Henleyi zone of the Middle Lias. This genus begins in the Muschelkalk zone of