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PART III. CONTAINING THE ACTINOPTERYGIAN TELEOSTOMI or THE OrpErs CHONDROSTEI (concrupEp), PROTOSPONDYLI, AETHEO- SPONDYLI, anp ISOSPONDYLI (iy Part). J32 TA — IS 6 6S OF8™ BY \ & Ger ARTHUR SMITH WOODWARD): | F.G.S., F.ZS. a LONDON: PRINTED BY ORDER OF THE TRUSTEES. SOLD BY LONGMANS & Co., 39 PATERNOSTER ROW ; B. QUARITCH, 15 PICCADILLY; DULAU & Co., 37 SOHO SQUARE, W.; KEGAN PAUL & Co., PATERNOSTER HOUSE, CHARING CROSS ROAD; AND AT THE BRITISH MUSEUM (NATURAL HISTORY), CROMWELL ROAD, S.W. 1895. PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET, PREFACE. Tue first volume of the present Catalogue of Fossil Fishes—the result of several years’ most patient and assiduous study—appeared in March 1889; the second followed in January 1891; now, after an interval of four years, the third instalment of Mr. Arthur Smith Woodward’s carefully-executed work is satisfactorily completed. The whole of the first volume, and a part of the second, are occupied with .the description of the great series of remains of the _Elasmobranch Fishes (Sharks, Rays, and Chimeras); followed in Volume II. by the Ostracodermi (that remarkable group of most - ancient bony-plated fishes, represented by Cephalaspis, Asterolepis, Pierichthys, &c.), the Dipnoi, Crossopterygu, and, lastly, by the Paleeoniscide and Platysomide. The present volume carries us through the great series of Actinopterygian fishes of the Chondrostean type, and completes the Catalogue to the end of the Jurassic series, including also some of the later survivors of these older forms. Many of these Jurassic fishes. seem to foreshadow, in various points of their structure, an approach to the more modern forms of Teleostean fishes by which they were presen tly to be succeeded. This third volume will be found to contain much new and important information regarding the osteology and systematic position of the Pycnodonts. From specimens obtained from the a Iv PREFACE. Leeds Collection, most interesting points have also been worked out in reference to the osteology of Lepidotus and Caturus. The plates and illustrations throughout this work have been entirely prepared by Miss G. M. Woodward, and attention is specially called to the admirable restorations of Lepidotus, Dapedius, Cleithrolepis, Hugnathus, Caturus, Aspidorhynchus, and Leptolepis in the present volume, executed by that Artist under the Author’s direction. It is hoped that the next volume will complete the Catalogue of the Fossil Fishes in the Museum. It will be devoted entirely to that great series of later forms, commonly termed the “ Teleostean Fishes.” HENRY WOODWARD. British Museum (Natural History), Geological Department, November 15th, 1895, INTRODUCTION. Durine the Mesozoic Period the Actinoptierygian fishes of the Chondrostean type were gradually replaced by others which advanced towards the modern Teleostean type. The latter finally became dominant in the seas of the epoch of the Chalk. In the course of this change in the character of the fish-fauna, the successive stages were represented by numerous minor modifications, which have little relation to the direct line of progress but present many features of great morphological interest. It is the object of the present volume to trace these phases of development in detail, and to record in as nearly a natural order as possible the variations of each at the time of its dominance. CHONDROSTEI. Firstly, however, there is the question of the fate of the Chondrostei themselves, which are represented even at the present day by a few survivors. The origin of these fishes, as defined in the present Catalogue, is still entirely obscure. Among known fossils they range downwards as far as the Crossopterygians, while there is as yet no evidence of a link between these two groups. On the other hand, it is clear that the Chondrostean is later than the Crossopterygian type; for the former is represented in the Devonian solely by the rare genus Cheirolepis, while the latter is dominant throughout, and the members of the Chondrostei do not flourish vigorously until those of the Crossopterygii begin to decline in the Carboniferous and Permian. The modifications by which a Crossopterygian could be changed into a Chondrostean are also readily comprehensible. In the latter the paired fins are always polybasal, with excessively shortened lobe; and among Crossopterygii the genera with most al INTRODUCTION. elongated lobate fins flourish the earliest, all survivors above the Devonian having the lobe comparatively abbreviate. The large pair of gular plates so characteristic of the Crossopterygii is always wanting in the Chondrostei; but the lateral gulars are merely further subdivided to become the ordinary paired series of branchio- stegal rays, and in this connection it is noteworthy that both in Cheirolepis and many later Palseoniscide the subdivision is not complete anteriorly where a pair of very large plates persists. The ridge-scales on the upper caudal lobe of Chondrostei represent the superior rays of the caudal fin in Crossopterygii, as is indicated by the presence of the endoskeletal supports in Chondrosteus and the existing genera; whileit is not unlikely that the fulcra are modified enamelled anterior fin-rays such as occur, for example, in Osteo- lepis. When the Chondrostei suddenly become dominant, as they do in the Lower Carboniferous, they already exhibit a remarkable series of modifications, which are enumerated in Part II. of this Catalogue. The family of Palseoniscide is represented chiefly by fishes with regular rhombic scales and distally-bifurcating fin-rays ; but there is one case in which the scales are cycloidal and deeply imbricating (Cryphiolepis), another in which the scales are absent except upon the caudal lobe (Phanerosteon), and a third in which the fin-rays never branch (Holurus). Some, moreover, have a large mouth with powerful conical teeth ; others, a small mouth with comparatively insignificant teeth. There is also a good deal of variety among the Platysomide, which are deep-bodied fishes closely related to the Paleoniscide. As these fishes are traced upwards, they exhibit very little essential change. The upper caudal lobe never appears to atrophy in the least; the supports of the dorsal and anal fins never equal in number the appended dermal rays; the infraclavicular plates always remain ; theribs, if present, never ossify. The Platysomida, indeed, become extinct in the Upper Permian, where, in addition to the normal genus Platysomus, there is ascaleless fish (Dorypterus) which seems to represent them. The large-mouthed and small- mouthed, rhombic-scaled and round-scaled, perhaps also the scaleless, Paloniscidee range as far upwards as the Permian; and then the family presents less variety in its representatives. All the Mesozoic genera are predaceous fishes with a large mouth and deeply over- lapping scales which are usually very thin; and the genus Cocco- lepis, which is the only known Palwoniscid ranging above the Lias, INTRODUCTION. Vil has practically cycloidal scales without peg-and-socket articulation. Moreover, while the endoskeletal supports of the dorsal and anal fins are in two series in such Paleozoic genera as Hlonichthys and Pygopterus, they are distinctly shown to be confined to one series in the Mesozoic Coccolepis. The last term of the Palwoniscid series (Coccolepis) thus approaches a higher grade than that of the Chondrostei in the character of its dorsal and anal fins. In every other respect, however, it is typically and essentially Chondrostean ; the baseosts of its pelvic fins are relatively as large and numerous as those of a modern sturgeon. It is noteworthy that the only known approxi" mation to a higher grade occurs among much more generalized fishes, those of the Triassic family of Catopteride. The little that is known of Catopterus and Dictyopyge, the two genera of Catopteride, forms the subject of the opening pages of the present volume. Much of this information is unsatisfactory and needs verification; but it may be asserted, with considerable probability of correctness, that these fishes possess a Paleoniscid head and shoulder-girdle, while the tail is only hemi-heterocercal, and the single series of supports in the dorsal and anal fins almost equals in number the apposed dermal rays. Such being the case, here is an interesting illustration of the common law, that the links between a lower and a higher group are not to be sought among the specialized types of the former but among those with the most generalized secondary characters. Paleontology seems to demonstrate that the various modifications in the minor characters of the Palzoniscid fishes eventually led to the development of a series of types which can only be described as extremely degenerate, namely the modern sturgeons (Acipenseridz) and paddle-fishes (Polyodontide), There is much probability, indeed, that other degenerate series originated from Chondrosteans related to them ; and it is interesting in this connection to notice the case of the Belonorhynchide (catalogued on pp. 9-23). These are eel-shaped fishes with a long pointed head, an abbreviate-diphycercal tail, short dorsal and anal fins, and small paired fins. The trunk is nearly always, if not always, destitute of ordinary scales ; but it is armoured with four distinct longitudinal series of imbricating scutes—one median dorsal, one median ventral, and a pair supporting the “ lateral line.” The dorsal and anal fin-supports are much fewer than their apposed rays, though apparently only in a single series ; and the Vill INTRODUCTION. whole of the branchiostegal apparatus is wanting, while the opercular series is reduced to a single small operculum. If these are not degenerate Chondrosteans they must be abnormally modified Crossopterygians, as suggested by O. M. Reis’. Degeneracy of the Paleoniscid type in the direction of the modern sturgeons is distinctly observed in the Chondrosteide of the English Lower Lias. Chondrosteus resembles the Paleconiscidee in the arrangement of its cranial roof and the opercular apparatus, except that the gular plate and possibly a few of the branchiostegal rays have disappeared; its trunk is like that of the abnormal Palzoniscid Phanerosteon, and equally similar to that of the modern Polyodon ; its reduced toothless jaws are much simpler than those of the Paleoniscide, and the premaxille have disappeared as in all the modern sturgeons and paddle-fishes. A more clearly inter- mediate type can scarcely be conceived ; and the fact that the Polyodontide at least once possessed a regular squamation is demonstrated by the Eocene genus Crossopholis. PRotTosPoNDYLI. It has already been remarked that the Catopteride of the Trias incline towards a higher type of fish than the Chondrostei, to which they technically belong; but the two known genera cannot be the ancestors of this more advanced race, for at least one of its repre- sentatives (Acentrophorus) has already been found in the Upper Permian, while numerous and varied forms are commonly met with in the Trias and Rhetic. It can only be affirmed that as soon as six important modifications had simultaneously affected the Chondrostean skeleton, another vigorous race arose and a new impetus seems to have been given to variation. These changes comprised (i.) the almost complete atrophy of the upper.caudal lobe, (ii.) the reduction of the dorsal and anal fin-rays to exactly the same number as their supports, (i11.) the disappearance of the infraclavicular plates, (iv.) the loss of the pelvic baseosts, (v.) the subdivision of the hinder expansion of the maxilla, and (vi.) the withdrawal of the preoperculum from its extension over the cheek. Numerous types, in some respects parallel to those already noticed among the Chondrostei, are to be recognized in this later race; and the only difficulty is that, owing to the imperfection of the geolo- gical record, very few of these types are revealed until approaching 10. M. Reis, “ Zur Osteologie und Systematik der Belonorhynchiden und Tetragonolepiden,” Geogn. Jahresh. 1891 (1892), p. 157. INTRODUCTION. 1x full development. It is true that there are links between most of the families, rendering precise definitions almost impossible; and evidences of evolution can be detected in a slight degree as the different groups are traced upwards in their range. All the families, however, except the modern Lepidosteide and Amitide, had already become differentiated before the period of the Lower Oolites. Semionotidee. Robust Protospondyli with a small mouth and grinding teeth, and predaceous forms with a large mouth and conical teeth, appear abundantly in the Trias; but as the former do not seem to pass into modern bony fishes, while the latter can be distinctly traced towards the characteristic types of Upper Cretaceous and Tertiary times, those with a small mouth and more or less tritoral dentition are treated first. This arrangement seems all the more natural since the family of Semionotidee—the most generalized of the series—is first re- presented by Acentrophorus in the Upper Permian. No other representative of the Protospondyli has hitherto been discovered in Paleozoic formations, and it is interesting to notice that this unique fish is the most generalized genus of the family to which it belongs. Before the end of the Triassic period, however, all the principal types of Semionotide had appeared ; and the most specialized genus Tetragonolepis occurs in the Upper Lias. The Triassic genera most closely related to Acentrophorus, namely, Semionotus and Pristisomus, scarcely differ from it except in possessing well-developed ridge-scales. The former is confined to the Trias in North America, and is not known to range above the Rheetic in Europe. There is, however, an interesting allied genus, Aphnelepis, in the supposed Jurassic of New South Wales; and this exhibits comparatively thin scales, which suddenly become extremely delicate on the caudal region behind a line connecting the points of origin of the dorsal and anal fins. The Triassic genus Colobodus scarcely differs from Semionotus except in its powerful grinding dentition and the reduction of its fin-fulcra to a fine and close series. In many respects it resembles Lepidotus : but the tooth-pavement does not appear to exhibit any regular arrangement, and the scale-articulation is not strengthened by the development of spurs from the overlapped margin such as characterize even the earliest species of Lepidotus, x INTRODUCTION Lepidotus itself, exhibiting all its typical characters, has also been lately discovered in the Upper Trias or Rhetic (Prolepidotus gallineki of Michael). Moreover, it is clear that this genus cannot be a specialized form of Colobodus; for all the early species to the summit of the Lias exhibit the inner teeth of moderate size on comparatively long pedicles, and the powerful tritoral arrangement is not observed before the Upper Jurassic. Some of the Wealden species are distinguished by the possession of ring-vertebree; but all still retain the thick scales, large biserial fin-fulcra, and com- plete opercular apparatus. The comparatively regular arrangement of this slowly-acquired tritoral dentition is striking, when compared with the early approach to a similar type in the Triassic Colobodus. The deep-bodied fishes which begin with Dapedius in the Upper Trias are noteworthy for the rapid changes exhibited in their form and squamation. Oleithrolepis from South Africa and Australia, and Tetragonolepis from the European Upper Lias and the Indian Kota Formation, have an excessively deepened trunk, with scales strengthened by an unusually thickened anterior margin; and the latter genus is characterized by very thin scales cn the hinder part of the caudal region. Still more interesting is the newly-established genus Aetheolepis, from the Upper Hawkesbury-Wianamatta Series of New South Wales, which has the ordinary deepened rhombic scales, united by peg-and-socket, on the abdominal region, while these gradually lose their articulation, become cycloidal and deeply over- lapping as they pass backwards towards the pedicle of the tail. Among Semionotide, therefore, a precocious though irregular development of grinding-teeth is observed in a genus of the Trias (Colobodus); deep-bodied fishes with styliform rather than tritoral teeth, lose their caudal scales in the Upper Lias (Tetragonolepis) ; and a more normal series (Lepidotus), abundantly represented throughout the Jurassic period, retains most of its primitive out- ward features, while the dentition forms a nearly regular tritoral pavement, ring-vertebre are acquired, and the cheek-plates and supratemporals are irregularly subdivided in the latest Wealden forms. Macrosemude. Another series of Protospondyli, with small mouth and styliform rather than conical teeth, also appears first in the Trias, and is represented throughout the Jurassic period by numerous long- bodied fishes with extended dorsal fin, while at least one genus survives even in the Upper Cretaceous. INTRODUCTION. xi Here, again, the earliest term in the series (Ophiopsis) is the most generalized; and it has the most extensive range (Upper Trias—Purbeckian). It is, indeed, a distinct link between the family of Macrosemiide (to which this Catalogue assigns it) and that of the Eugnathide to be considered below. The Lower Kim- meridgian and Purbeckian species are also interesting as exhibiting ring-vertebre, the separate, alternating pleurocentral and hypo- central rings being sometimes observable in part of the caudal region. The diminutive Rhetic Legnonotus, with greatly extended dorsal fin, is a more pronounced member of the Macrosemiide. This has an apparently regular squamation ; but the closely-related genus Macrosemius (Lower Kimmeridgian, Portlandian, and Purbeckian) is remarkable for the degeneration of its scales, which are very thin and subdivide towards the dorsal and ventral margins, being usually wanting near the former. The dwarfed species of Portlandian and Purbeckian age may perhaps have been entirely scaleless. There are no fulcra except on the caudal fin; but the rays of the dorsal fin in some species are curiously denticulated on the hinder border. Traces of vertebral centra are never observable. Histionotus is a thick-scaled contemporary of Macrosemius, with fulera on all the fins and with delicate ring-vertebre. Propterus and WNotagoqgus, of the same age, are characterized by the subdivision of the dorsal fin into two parts; and the former has thinner scales and more delicate vertebree than the latter. The late Cretaceous genus Petalopteryx is an excessively elon- gated fish with irregularly arranged rhombic scales, and the robust cheek-plates subdivided into small tessere. The two most characteristic features of the Macrosemiide—the elongated trunk and excessively extended dorsal fin—are thus developed early in a Rhetic fish with normal squamation (Legno- notus); ring-vertebre are only well-formed in the genera which retain comparatively thick scales; the scales and fulcra begin to degenerate in the Upper Jurassic (Macrosemius); the scales, though still rhombic, are irregularly subdivided in the Cretaceous Petalo- pteryx, and in this unique genus the cheek-plates are represented by an investment of small tesseree. Pycnodontide. A curious parallelism will be noticed in the development of the Semionotide and Macrosemiide as thus briefly sketched, Vertebral Xil INTRODUCTION. centra are never fully formed, and they only reach even the annular stage when, notwithstanding specialization, the fish retains its original thick and continuous squamation. The cheek-plates are apparently never lost, but become irregularly subdivided in the later forms; and there is always a tendency to reduction of the branchiostegal apparatus. The scales often degenerate or disappear in certain parts—on the back in Macrosemzus, on the tail in Aphne- lenis, Aetheolepis, and Tetragonolepis. Fulecra are least conspicuous in the genera which exhibit most tendency to such degeneration of the scales. . These considerations are important because, if truly expressions of fact, they seem to determine the systematic position and affinities of the anomalous family of Pycnodontide. As amply demonstrated in the Catalogue, these fishes exhibit an appendicular skeleton quite distinct from that of the Chondrostei, but identical with that of the Protospondyli and Aetheospondyli, and only distinguished from that of the Isospondyli by the large number of basals in the pectoral fin. The additional characters of the axial skeleton of the trunk and the mandible place them unhesitatingly among the Proto- spondyli. In five respects they are merely extreme members of the modified series of deep-bodied Protospondyli, which begins with Dapedius. There is never any approach to the development of vertebral centra ; and even when the axis acquires special rigidity (e.g. Paleoba- listum and Pycnodus) this is attained by the interlocking of laminar expansions of the neural and hemal arches. The cheek-plates, so far as known, are reduced to tesseree. The branchiostegal rays are not more than two in number. ‘The fin-fulcra are still more insignificant than in Tetragonolepis. The caudal region is very commonly destitute, or nearly destitute, of scales behind a line con- necting the origin of the dorsal with that of the anal fin. When examined more closely, it is not difficult to perceive that even the apparently unique characters of the Pycnodonts are also the ultimate result of tendencies to specialization already exhibited by the Semionotidee. Firstly, there is the forwardly-displaced mouth with crushing- teeth, which is much like that of the latest species of Lepidotus, only a little more advanced and powerful, and thus more firmly fixed to the skull. The mode of fixation, however, resembles that observed in fishes so remotely related to each other as Gymmnarchus, Tetrodon, and Mormyrus; proving that it is merely a physiological INTRODUCTION. Xij1 necessity, and not a character of taxonomic importance. The absence of a maxillary dentition is not remarkable, considering its feebleness in the species of Lepidotus with most specialized grinding- teeth. Secondly, there is the question of the mode of growth of the dentition. There may sometimes be vertical successional teeth, but the present writer has never observed satisfactory evidence of them ; even if occurring, they must thus be extremely unusual. The contrast with Lepidotus is indeed very marked; but the loss of successional teeth in the higher Vertebrata (e.g. in elephants and kangaroos) is a sign of great specialization, and it is not improbably the sanie among these fishes. So far as the dentition is concerned, Lepidotus need not be more widely separated from Mesodon than is the extinct Dinotherium from the modern elephant. Thirdly, the enormous development of the preoperculum and the concomitant reduction of the operculum are again paralleled in distantly-related fishes, which possess similarly powerful, short jaws in a very forward position. The existing genera Tetrodon and Lampris may be cited as illustrations. Once more it is thus evi- dent that we are concerned with a physiological correlation of no fundamental significance, and one which is the mere outcome of specializations towards which there is already a tendency in the Semionotide. Finally, the anomalous character of the cranial roof is at first more difficult to understand. It will, however, be observed that there is a most striking resemblance between this roof as known in Mestwrus (p. 192, fig. 30) and that of the modern sturgeon (Acipenser). Moreover, the disposition of the sutures is evidently as capricious as that in Acipenser; for not only do the parietal plates lack bilateral symmetry in the specimen figured, but there is also considerable difference in the arrangement of the median plates in a second specimen in the Leeds Collection, which is otherwise very similar. Now, it has already been shown (p. viii) that Acipenser is merely the surviving terminal form of a long series of Chondrostean fishes, which in the Liassic period still re- tained a normal cranial roof. Such having been demonstrated among Chondrostei, it would not be surprising to find a similar case of development or degeneracy among Protospondyli. In the present state of knowledge it appears likely that this parallel case is to be recognized among the Pyenodonts. The result of these considerations is, therefore, that the Pyeno- X1V INTRODUCTION. dontide bear much the same relation to the Permian Acentrophorus _as the modern sturgeons to the Paleozoic Palzoniscide ; the latter having only advanced a stage further in the matter of teeth, which ~ are in them not only destitute of successors, but are also lost before the fish becomes adult. Among Pycnodontide as a race, tooth- specialization consists in the reduction of the tritors into a few regular longitudinal series, and there is only one known genus (the Cretaceous Anomeodus) in which there is much tendency towards the loss of this armature. The facts detailed in the Catalogue, as just briefly analysed, seem to render it unnecessary to discuss the still widely prevalent belief that the Pycnodonts are the direct successors of the Platysomide. The elaborate researches and careful reasoning of Traquair sixteen years ago,’ ought to have sufficed ere this to banish the theory even from popular handbooks; nevertheless, it survives in a shape scarcely different from that current at the time when comparatively nothing was known of the Platysomid skeleton. It must suffice to repeat, that the Platysomide never make the faintest approach to the Pycnodontide in a single essential character. The trunk and fins are as thoroughly Chondrostean in the most specialized as in the most generalized type; the cranial osteology and arrangement of the jaws are fundamentally different even when the dentition is most powerful. If speculation were permitted in seeking for the direct ancestors of the Pycnodonts, it might be most profitable to turn towards the earliest Mesozoic fishes of the Colobodus-type. The appearance of the family, however, still remains as mysterious as that of the Ccelacanthide among the Crossopterygians ; and the long-continued | permanence of so remarkably specializeda type (Lower Lias—Kocene) is curiously paralleled in the range of the more primitive family just mentioned (Lower Carboniferous—Chalk), Persistent types of this character are rarely met with. Hugnathide. It has already been mentioned that the small-mouthed Proto- spondyli considered above appear to have left no descendants. At least, no definite links can be recognized between these and modern fishes. The large-mouthed Protospondyli with conical teeth, on the other hand, can be traced from the Trias upwards 1 R. H. Traquair, “On the Structure and Affinities of the Platysomidz,” Trans. Roy. Soc. Edinb. vol. xxix. pp. 343-391, pls. iii.—vi. (1879). INTRODUCTION. XV until they pass almost imperceptibly into the typical physostomous bony fishes; and these forms may be arranged in at least three families. This classification, adopted in the Catalogue, is a little different from any hitherto proposed, because no great systematic value is ascribed to the characters of the scales. When one genus of Meso- zoic ganoid (Aetheolepis) is proved to exhibit every variety, from the thick, rhombic, firmly articulated scales of the abdominal region to the delicate, cycloidal, deeply-overlapping scales of the caudal pedicle—when, moreover, thick and thin scales cover respectively the abdominal and caudal regions of Tetragonolepis, it is no longer possible to depend entirely upon scale-characters for the definition of families and orders. Since, therefore, Hugnathus and Caturus are identical in their osteology, the latter merely differing from the former in the subdivision of its supraorbital plates and the tenuity of its overlapping scales, these two genera are now placed in one and the same family. They and their allies constitute the Hugnathide, which range from the Upper Trias to the Upper Cretaceous; and it is difficult to distinguish the more specialized forms from the Amiide. Both Hugnathus and Caturus range from the Upper Trias to the Kimmeridgian, and the latter probably even to the Wealden. The deeper-bodied Heterolepidotus, which is scarcely distinguishable from Eugnathus, also seems to exhibit as wide a range as the latter. More specialized genera, however, like the highly ornate Ptycho- lepis (Upper Trias—Upper Lias), the delicate, overgrown Osteo- rachis (Lower Lias), and the cycloidal-scaled Hurycormus (Oxfordian and Kimmeridgian), are very restricted in their range; so also are the Cretaceous genera Neorhombolepis, Otomitla, and Lophiostomus. Neorhombolepis and Otomitla are particularly interesting because, so far as known, they retain the external characters of Hugnathus, and at the same time possess vertebral centra as completely developed as those of Ama. If correctly placed in the Eugnathide, they form another illustration of the principle noted among the Semionotide and Macrosemiide, that the most advanced stage of the endo- skeleton is attained in the latest members of the race with the least modified exoskeleton. JLophiostomus, which is characterized by the fusion of most of its cranial roof-bones, and is proyided with a pair of bosses on the hinder portion of this roof, seems to exhibit only ring-vertebre. Xv1 ° INTRODUCTION. Amide. | The separation of the Amiide from the Hugnathide is perhaps arbitrary, but it is at least convenient. The genus Hurycormus, with cycloidal scales and ring-vertebre, may be as appropriately placed in one family as in the other; so also may the small noto- chordal fishes named Liodesmus. The former, however, is assigned to the Eugnathide because it exhibits fulcra on the fins; the latter to the Amiidee, because all its fins seem to be destitute of fulera. Amia itself does not date back beyond the Upper Eocene, but the extinct species and possibly allied genera are very unsatisfactorily known, owing to the fragmentary nature of the fossils. Never- theless, the vertebral centra are so characteristic that it is possible to obtain considerable information as to its former range; and the interesting result is arrived at, that Amvza (or fishes represented by fragments indistinguishable from it) was distributed throughout Western Europe in the Eocene period, and survived in some areas so late as the Lower Miocene. The supposed Amioid from the Miocene of Oeningen, Switzerland, proves to have been wrongly determined, and is a truly ‘‘ Teleostean ” fish. Pachycormide. A remarkable modification of the thin-scaled type of Hugnathide suddenly appears in the Upper Lias. The segments of the axial skeleton of the trunk multiply considerably ; the rostrum begins to project and prevents the premaxille from meeting in the middle line; while the fins, especially the pectorals and caudal, are adapted for rapid progression. This modification, in fact, eventually results in genera having the outward form of the modern “ sword-fishes ” ; and they are particularly interesting as showing how the Proto- spondylic type of axial skeleton may be modified to produce the same mechanical effect as a robust chain of vertebrae terminated behind by its complex hypural bone. All these fishes are proved to have had a persistent notochord, and it is not improbably to com- pensate for this weakness that the segments of the axial skeleton are so remakably shortened and multiplied. In most genera also a single, much-expanded hemal arch has been observed at the base of the lower lobe of the powerful, deeply-forked tail; this admir- ably serving the purpose of a hypural, and yet not fundamentally altering the normal “ stegurous” tail such as characterizes all Protospondyli. INTRODUCTION. xvii Sauropsis, apparently ranging from the Upper Lias to the Lower Kimmeridgian, and Huthynotus, confined to the Upper Lias, are the least specialized genera of Pachycormide. Pachycormus itself is known only from the Upper Lias, and is a little more modified, having lost the pelvic fins. Hypsocormus, from the Oxfordian and Kimmeridgian, exhibits more powerful teeth than any of the earlier genera, these fixed to the base of sockets which are incomplete on the inner side; and there is one species, H. leedsi, possessing a slightly more prominent rostrum than any earlier fish. The latest genus Protosphyrena, known only by comparatively fragmentary specimens from the Cretaceous both of Europe and America, nearly always exhibits a much more produced rostrum, while its large teeth are fixed in complete sockets; and the pectoral fins of this fish are still narrower and more elongated than those of its forerunners in the Jurassic period. If the interpretation of the Pachycormide suggested in this Catalogue prove correct, there is thus most distinct evidence of gradual progression as they are traced upwards in their range. AETHEOSPONDYLI. The recognition of this group is a confession of ignorance. As to the origin and immediate relationships of the Aspidorhynchide and Lepidosteide, there is still not the faintest clue. That these two families are close allies is generally admitted; that they are connected in some way with the Protospondyli as above defined, is also a common belief. They are peculiar, however, in exhibiting annular or solid centra throughout the length of the vertebral column, no alternating pleurocentra and hypocentra even in the caudal region; and they cannot be referred to the Isospondyli on account of the complexity of the mandible. They may thus be pro- visionally assigned to an intermediate, though scarcely annectant group, which is named Aetheospondyli in allusion to the unique variations of the vertebral centra from the biconcave or amphi- coelous to an opisthoccelous type. Aspidorhynchidee. The Aspidorhynchide are long-bodied fishes with deep ganoid flank-scales, small fins, and elongated snout, ranging from the Bathonian to the Upper Cretaceous inclusive. They are remarkable for the possession of a median presymphysial bone in the mandible. PART III. 6 Xvlil INTRODUCTION. Aspidorhynchus, with prominent rostrum, exhibits only one series of small teeth on the splenial bone, and has ring-vertebre. It seems to be confined to the Jurassic; but a second genus, Belono- stomus, ranges from the Upper Jurassic to the Upper Cretaceous inclusive, and in the course of this range the delicate ring-vertebra gradually pass into centra which are pierced only by a very delicate thread of notochord. It is also noteworthy that the enlarged splenial, covered with tubercular teeth, excludes the dentary from the margin of the mandible in the English Chalk species, Belono- stomus cinctus. Otherwise there is no special evidence of evolution jn the family. It is just possible that the small Triassic fish Pholidopleurus, doubtfully assigned to the Pholidophoride in the Catalogue (p. 479), may be a forerunner of the Aspidorhynchide; but its cranial osteology is as yet too imperfectly known for comparison. Lepidosteide. Nearly all the known fossil remains of Lepidosteide are mere fragments, none dating back further than the Lower Kocene. ‘The only interesting fact to be deduced from these remains is, that fishes with scales and vertebre identical with those of the existing American Lepidosteus inhabited Western Europe during the period of deposition of the Eocene and Lower Miocene deposits. Their range in the Old World thus corresponds with that of the fossil Amia already described. It is, of course, likely that their Mesozoic ancestors would not be recognized at first sight on account of the normal character of their vertebral centra; but the markedly forward inclination of the mandibular suspensorium seems to exclude comparison with all large-mouthed, conical-toothed Mesozoic ganoids except the Aspidorhynchide, and these cannot be their direct progenitors for many obvious reasons. The irregular subdivision of the facial bones has been shown to occur commonly among highly-specialized ganoids, though Lepidosteus still remains unique in having this segmentation extended to the maxilla. As to the well-known remarkable features in the soft parts of the existing fish, it is unfortunate that Paleontology cannot afford any definite information. Only one point may be mentioned, namely, that so far as can be judged from the cranium, the course of the olfactory nerves in Dapedius differs from the course of these nerves in the elosely-allied genus Lepidotus, exactly in the same way that ® INTRODUCTION. x1x the corresponding feature in Lepidosteus differs from that in all other surviving ganoids (cf. Proc. Zool. Soc. 1893, p. 565). IsosPonDYLI. It is interesting to note that all the higher fishes, like the highest of the terrestrial Vertebrata, are characterized by a comparatively simple mandible. Only doubtful or extremely rare exceptions are recorded* to the rule, that each mandibular ramus in these types consists of two or three elements, an articulo-angular (or articular and angular) behind, a dentary in front. The circumstance is all the more remarkable because, on acquiring this simplification of the jaw, the Teleostomes seem to be infused with new vigour: vertebral centra invariably occur, at first as simple rings, then as robust amphiccelous bodies ; and astill more varied series of families arises, including analogues of all the principal modifications observed among the lower races, these being superinduced upon the new and advanced type of skeletal frame. The first and least specialized suborder of these higher fishes is that of the Isospondyli, thus named by Prof. E. D. Cope in allusion to the fact that the vertebre are simple, not fused into a group behind the head or related in any way to arrangements for an osseous connection between the air-bladder and the organs of hearing. It comprises a large number of families, mostly Tertiary and Recent, and only the few Jurassic representatives of the sub- order with some of those of Cretaceous age are treated in the present Part of the Catalogue. Pholidophoride. The earliest clearly-proved instance of the simple mandible just _ referred to, is that afforded by the small fishes of the genus Lepto- lepis occurring in the European Upper Lias. As already observed by Agassiz, however, the genus Phoicdophorus exhibits a very close resemblance to Leptolepis in general aspect, the osteology of the head being remarkably similar, vertebral rings being tolerably well ossified, the fin-fulcra very small and usually lost, while the scales are often extremely thin and deeply overlapping though for the most part united by a peg-and-socket articulation; and it is note- worthy that no indications of splenial and coronoid elements have 1 BH. g., Arapaima, according to Owen, ‘ Anatomy of Vertebrates,’ vol. i. p- 123, fig. 88 (1866). b2 | xx INTRODUCTION. hitherto been discovered in the jaw. It is thus very probable that the Pholidophoride are the earliest known family of Isospondyli; and if more conclusive specimens eventually confirm this inference, the suborder is proved to date back at least to the Upper Trias. In any case it is remarkable that Leptolepis and its immediate allies were a comparatively insignificant race until the Cretaceous period, when the Isospondyli and higher suborders became domi- nant; and they form an interesting example of the long persistence of a newly-acquired character before its possession becomes a factor of real importance in favouring the supremacy of the type. | The Pholidophoride, as defined in the Catalogue, are the only fishes with articulated rhombic scales which can be reasonably claimed as Isospondyli; and even the peg-and-socket articulation is inconstant if the genus Archwomane (p. 488) is correctly associated with them. ‘The most generalized member of the family, Pholido- phorus itself, ranges practically unchanged from the Upper Trias, throughout the Jurassic, as far as the Purbeckian. An apparently allied genus (Thoracopterus), with excessively enlarged pectoral fins, is restricted to the Upper Trias. The Triassic Pholdopleurus, as already mentioned, is very doubtfully placed here; but two other genera with much-deepened flank-scales, namely, Peltopleurus of the Upper Trias, and Plewropholis of the Upper Jurassic and Pur- beckian, may be ascribed to the Pholidophoridz with less hesitation ; and there is possibly an almost scaleless representative of the family (Ceramurus) in the Purbeckian. One unique feature is also worthy of special note in Pleuropholis, namely, that the canal of the “lateral line” is deflected immediately behind the pectoral arch and extends not along the deepest flank-scales but along the adjoining series below. Oligopleuride. The few Upper Jurassic and Cretaceous fishes included in this family bear much superficial resemblance to the Amiide. All of them, however, exhibit completely ossified vertebral centra, never any alternating pleurocentral and hypocentral discs even in the caudal region; while the mandible appears to be destitute of splenial and coronoid elements, and thus confirms the suspicion suggested by the first character, that these fishes must be referred to a higher suborder than that of the Protospondyli. The fins, like those of the Pholidophoride, are fringed with fulera; and it seems most reasonable in the present state of knowledge to place the INTRODUCTION, Xxi Oligopleuride with the latter family at the base of the Isospondylic series. Leptolepide. The Leptolepide differ from the two preceding families in the absence of fulcra on the fins, and are remarkable as being the earliest family in which intermuscular bones occur. These elements, forming so conspicuous a feature among modern fishes, appear to be arranged here only in a single series above the vertebral column in the abdominal region; though there may perhaps be traces of them sometimes also in the lower half of the caudal region. The vertebral centra in Leptolevis itself exhibit interesting gradations in the degree of development according to the geological age of the species; these centra never being more than delicate constricted rings or cylinders in the Upper lias, and always strengthened by secondary peripheral calcifications in the Oxfordian and upwards. In Thrissops, which ranges as far at least as the Lower Cretaceous, the vertebral centra are still more robust. These fishes, it will be noticed, approach very closely the Clupeide, among which they are sometimes included; but they are distinguished by the meeting of the parietal bones in the median line, by the non-fusion of the hemal spines at the base of the tail, and by the presence of a thin film of ganoine on the scales. The interpretation of the relationships of the Mesozoic Actino- pterygian fishes thus briefly summarized, differs so much from any hitherto proposed that it has not been found possible to arrange a synonymy under the subordinal and family-headings in the Catalogue. Family-names not derived from generic names have also been ignored. The existing Acwpenser, Polyodon, Spatularia, Lepidosieus, and Ama are now shown to afford a very inadequate and misleading idea of the actinopterygian ganoids, on account of their remarkably specialized nature. The characters of the appen- dicular skeleton are observed to be much more important than those even of the axial skeleton of the trunk, while the form and absence or presence of the scales, as also the degree of development of the branchiostegal apparatus, are features comparatively insignificant. It is thus no longer scientific to regard the “ Acipenseroidei” as typical members of the group to which they belong ; they are mere XXxil INTRODUCTION. degenerate survivors. It is equally impossible to justify the conception of the groups ‘‘ Lepidosteoidei” and “‘ Amioidei,” most of the extinct fishes which are still commonly ascribed to the former being proved in the Catalogue to be much more closely related to the latter. This result is merely the logical outcome of the new departure in Ichthyology made by Traquair in 1876, when he published his classic memoir on the systematic position of the Paloniscide. The characters which Traquair’s researches have proved to be secondary in the group to which these typically Paleozoic fishes belong, are similarly shown to be of comparatively small taxonomic value in the higher groups of Mesozoic age to which the present volume specially refers. It therefore seems unnecessary to recapi- tulate and discuss the various classifications which have been proposed ; for nearly all of them, even those published during the last fifteen years, fail to distinguish between the fundamental and the secondary features, which the memoirs cited have made quite clear. : It only remains to add that, in a work of this kind, a more or less definite judgment must sometimes be pronounced in cases where the known facts scarcely suffice for more than premature speculation; and it is always difficult to express a tentative result in terms which cannot be exaggerated in quotation. The present volume, like its predecessors, is therefore to be accepted merely as a convenient basis for further research, full of imperfections which each specialist will readily discover for himself. A few partly novel conceptions have been introduced, to direct attention to certain problems which seem hitherto to have been inadequately considered. A careful examination of nearly all the available specimens has enabled the writer to attempt a more detailed account of the osteology of the principal genera than has previously been published. For continued generous co-operation, thanks are not only due to the many scientific colleagues at home and abroad, to whom indebtedness has already been expressed in the previous volumes ; they are likewise gratefully tendered to the Government 1 R. H. Traquair, ‘The Ganoid Fishes of the British Carboniferous Forma- tions,’ Part I. (Mon. Palzont. Soc., 1876). See also Memoir on Platysomidz already quoted, and “Report on Fossil Fishes collected by the Geological Survey of Scotland in Eskdale and Liddesdale,” Trans. Roy. Soc. Edinb. vol. xxx. pp. 15-71, pls. ivi. (1881), and “Notes on Chondrosteus acipen- seroides, Agassiz,” Geol. Mag. [3] vol. iy. pp. 248-257, figs. 1-5 (1887). INTRODUCTION. XXill Geologist of New South Wales (the late Mr. C. 8. Wilkinson, and now Mr. E. F. Pittman), the Rev. H. H. Winwood (Bath), the Rev. P. B. Brodie (Warwick), Edward Crane, Esq. (Brighton), and the Curators of the Museums of York, Whitby, Scarborough, Malton, Leicester, and Worcester, for facilities in studying the important collections under their charge. The unique collections of Mesozoic fishes in the Universities of Munich and Naples must be particularly mentioned as having afforded very special aid, thanks to the kindness of Professor K. A. von Zittel and of Professor F. Bassani. ARTHUR SMITH WOODWARD. Department of Geology, November 15th, 1895. List oF COLLECTIONS. In addition to the Collections enumerated in Part I. (p. xxix) and in Part II. (p. xxiii), the following are also referred to in the present volume :— 3 Beckles Collection. A large collection comprising fossil fishes especially from the Wealden of Sussex, purchased from the executors of the late Mr. 8. H. Beckles, F.R.S., of St. Leonard’s, 1891. John Brown Collection.—Numerous Pleistocene Vertebrata and other fossils chiefly from Essex and Suffolk, collected by the late . Mr. John Brown, of Stanway, and bequeathed by him to the late Sir Richard Owen, K.C.B., who presented them to the Museum in 59, Croizet COollectionSpecimens from the Tertiaries, chiefly Miocene, of Auvergne, France, purchased from the Abbé Croizet in 1848 and 1849. Damon Collection—The private cabinet of the late Mr. Robert. Damon, of Weymouth, comprising fossils from the neighbourhood of Weymouth, purchased from his executors, 1890. Jesson Collection.—A series of fossils from the Cambridge Green- sand, Cambridge, collected by Mr. Thomas Jesson, of Northampton, and obtained by purchase, 1894. | Leeds CollectionA large collection of Vertebrata from the Oxford Clay in the neighbourhood of Peterborough, made by Messrs. Charles EK. Leeds and Alfred N. Leeds, of Eyebury, and obtained by: purchase, 1890-95, XXiv INTRODUCTION. Rufford Collection. — Fossil vertebrata and plants from the Wealden of the neighbourhood of Hastings, purchased from Mr, P. Rufford, of Hastings, at various dates since 1890. Tristram Collection.—Fossil fishes from the Cretaceous of Mount Lebanon, collected by the Rev. Canon H. B. Tristram, F.R.S., and obtained by purchase from Mr. B. M. Wright, 1865. Ward Collection.—A large collection of fossil fishes and amphi- bians, chiefly from the Coal Measures of Staffordshire, purchased from Mr. John Ward, of Longton, 1894. The following Collections have also been acquired by purchase since the Catalogue was printed (October, 1895) :— Brodie Collection.—A large collection of Triassic, Jurassic, and other fossils, comprising many type and figured specimens of fishes, made by the Rev. P. B. Brodie, M.A., of Rowington -Vicarage, Warwick. Davis Collection.—Fossil fishes chiefly from the Yorkshire Coal Measures and the Lower Lias of Lyme Regis, comprising many type and figured specimens, collected by the late Mr. James W. Davis, of Chevinedge, Halifax. SYSTEMATIC INDEX OF GENERA AND SPECIES DESCRIBED IN PART III. Page Subclass TELEOSTOMI (continued) iL Order ACTINOPTERYGII (continued) . . . . 1 Suborder CHONDROSTET (continued) . . . . . 1 Family CATOPTERIDE . Catopterus gracilis . redfieldi. Dictyopyge —— macrura — socialis . — catoptera . —— superstes —— rhenana INN OPP FR WON) KF FE symmetrica —— illustrans . robusta. Re ie eee w——— (2) GTApGM siti. ses 88 CoO © © XXV1 SYSTEMATIC INDEX. Page Family BELONORHYNCHIDA Belonorhynchus-. 595 ).5 eee ‘) striolatus .+ 7... |...) nn gracilis. . ...° 2°... , 2 gigas 2°.) . 2 4. 2 ——— macrocephalus.’ .7 2 |...) eee tenuirostris . . 2 . . |. aaeeeeeee acutus . . ow. 3 se Ce brevirostris' . . |. .’ . .)]. Saurichthys . . . .°. ... =n apicalis’. .) 1/4.) '.” ) mougeoti . . .. . . « on acuminatus . 9... « 4.) Family CHONDROSTEIDA. . . . . 3 ee Chondrosteus. . . .°. . = =) =e acipenseroides. ... . « nie pachyurus .. . . . . ee Gyrosteus .9'. 05.03.) rr mirabilis . ree Family ACIPENSERIDAL . 5°... «eee Acipenser.. . . . . . . }) nn toliapicus .-. +. . . « s\n Family POLYODONTIDAD .°. . . | eee Crossopholis . 9. °°. 2. sr magnicaudatus . . .. . + =. Pholidurus ..%.' .°%. 2. «| disjectus. . 9°. ). Go. 9. 3 =a Suborder PROTOSPONDYLI ...... 2 . =r Family SEMIONOTIDA 2 5.0: . eee Acentrophorus, . 5 0.0. "2. |.) rr variaDs 54)! $6. = )@ o aera abbsi Ma RC ee imc en aT ACHR | ACI 52 SYSTEMATIC INDEX, XXVll Family SEMIONOTIDAN (continued). Page Acentrophorus’altms. 0.4. 2.°. =. . 53 slapliyEnaeeel pon. Se 3) Oe Semionoiisweyes wpe eee eee OS DerecEmener ey ee oan OO Kap ieeee eee ee oe SRL Sb OO Bender Peetu eh a as fhe Oe SLEGISDES Poe se oe el A Caplensiste Mii eet os oe OS pea PUNGUSeE 6 NOM) Oo eee RD oie OR FORUICOPCH ee) So eto hs, es Oe dlqaalcut iets Se oe eS OO PONT EMMETT ONL sake els, OL PPL pHSMetmnaniec UD rere Pret) soo OF SRN ERa SO Manne 8 Roe. ce GD Serrolepiees noe white oe) ly Sy, 5) 6S SHeMemsey Te PAF es ys OS Merbictroommic anes US) ee er OG Seed cure Bt H al ere Tn Sg + OG nena: Marmara ter ive 60s 9. GG ELE SS USI 7 eet ces een ie OY | SEILER TEE 2 ee a A em | fombetign se enue) foc egy 2, GS Colotomissa See soe eS |S ieee Che gmeo Ts om oo PRCOMCHEM eM pos S00 ot ee, at. OU Gemabmensis Ong RL eo TO Pa MAES OS eo gd ge Ne ORL = Waxman SEE —— chorzowensis’. . . ... ... a GRMABUS cM ee Ph ee Pe See EU | CEI Xs ie fe sm a Wopidontern. ROUIS9 oe ea us) Shonsis. i oaibe heh ee |. oS eee SGmisGEPabuS an eens fe Ma Oe eee Sallinelenpeung gets). Se PUDereHaGMSIION soe- ks) eG SE XXVilll "SYSTEMATIC INDEX, Family SEMIONOTID AS (continued). Page Lepidotus latifrons 4.77). ; .. eee macrocheirus .9i.\.« 5 . < nee notopterus «) eli. «+ 2. subovatusiwired,. . < «i. oe ——— minor... 50 ee leedgi 2. 0 Gti ts 5 allinis wf. lly. <. 4) unguiculatus .). -. . <5 eee ——levis-. «rit. ss . 2. palliattis 0 /,0).-4) . . 3) 3 —— maximus . o.v. ss. 1. ss ea mantelli, 2uci/.-.-.< 2 Je depenhardtii./ie 3) . . = =e hauchecornei:.. . . .... «| = ees ————- MAWSONI 4 4h Were). . wee (?) pustulatuss: . . .° . . lee Dapedius ..,. do nok 2°. 2. politus|. joist. . |. ¥ 2 ee radiatus: 5) f)).0-. 0. « \ sn Orbis. . aise. dorsalis. . cj) 46. re colel. dik ead ks | ——milloi . 2. 24 ..). . . ee —— punctatus. . . ..... . 142 angulifer;4/). 5s... 2. ne ——pholidotus. . . ..... . 145 celatus: “a... 2 4... —.e granulatus a's. so. 6 eo re magneyillels;..!)...0. 4. <5 Cleithrolepis . 4i:)) s\. 22>. 2 ee granulatus: -. < . «eee extoni....-Te10R4ja4". .. |. ee Aetheolepis: .¢ 2.4004. .’ .. SOs mirabilig- Wikinews. «do Qe Tetragonolepisiii) lis...» «oh ee —— semicinctus «ys. « + 2 « woe SYSTEMATIC INDEX. | Xx1x Family SEMIONOTIDA (continued). Page Tetragonolepis discuss 2: . we. «160 oldiqmmarerets = s ..) Se TBE dErOSerusey ee en ce sl ee oe FGI Pamitly MACKOSHNEEED ar ete... te ew as LOS Opltiopsis seems rales re 52s. GS DEQCEE TA se) ota WE wk ae VEO ancOMmeaban Ata er ese Log abn cc HATA AES va 8's a bank Od PEMMISCELALAN ir ee se tees a AOS SHIP ALOR MICH ih sas cm se! ote! cS Pemiemletagapats wos oe we) oS EOS DEGMICC SME hah ie 6 x es oe EO Borsa istmy en oes 3 ors ae a Ne ER HESHEED iPad cues no) es epbtietin i cise < a street RRS BMG Han ODS enon iehan te os ee TS BGM ACIS Shey foot tee (6 fe eo eke EA OMEEMOORCEB ire cus «) x hak APD ee REEES MUON Fait ereninal, inf cso es EEO WeGHONnGEh Son Tobi ats eo ets ede oy LEG Cobbemensitneste : Palos in eases TG INEZ eKONEIMTHS SO Ae 2 tye ae i eh EEG EOS DEMIS rs Wiesivia po la sic els LER == GUBIOTHERE = sete ccs tk CTE ROMENERM Parsee theo ay o.oo oes EFS Pechoetiom serene wh. <2) eo ce Lo eG AMOUR Hticwhiscwe ne ants. « 4 > £86 Rermlopreaye aay syraieclie ws Sj. ASE SVEICIMRGeaiys.- cue. 2 Og 66 | ESE rsa arate te ee ee, gs BED cleornee i ohtte sta vos 2 EGS PrOpeceun a Uap iuss) ats 1 a) heehee =—— _MicrostomuUsyiA..—..... « »« « « 188 SPECIESHSiraiiacy ss .2, ee Sie EOE SYSTEMATIC INDEX. Family MACROSEMITIDAK (continued). Propterus elongatus scacchil Notagogus pentlandi . inimontis . Family PYCNODONTID: . Mesodon . daviesi . simus comosus liassicus rugulosus . — bucklandi . tenuidens . —levior . —— granulatus —— nicoleti. damoni ——— gas affinis . Athrodon . douvillei intermedius crassus . jessoni . Mesturus . Verrucosus . leedsi Microdon . elegans radiatus bernardi denticulatus . macropterus . macropterus . SYSTEMATIC INDEX. Family PYCNODONTID A (continued). Microdon wagneri egertoni sauvanausl itieri — hugii ——minutus .... quincuncialis . pagoda . biserialis (?) discoides Gyrodus macrophthalmus . hexagonus frontatus . circularis . cuyieri . ———— TOR re coccoderma planidens . —— murchisoni (?) cretaceus . Stemmatodus rhombus Ceelodus saturnus suillus . rosthorni erandis . costee mantelli —— gyrodoides ellipticus —— inequidens cantabrigiensis —— fimbriatus . parallelus . XxXXI Page 225 226 226 227 227 229 229 230 230 231 233 233 234 235 238 240 242 243 244 244 245 248 248 249 250 250 251 251 252 252 254 254 255 256 256 256 XXXil SYSTEMATIC INDEX. Family PYCNODONTIDAE (continued). Page Anomeodus 2°). 2 295. . subclavatus 50! *. . 2 re distans *.)"'.) "P00 3 angustus. . 0. ". 5 | a — willetti «2 2°. 2. . . 2a fraiponti *) 0), 5), 3 —— muensterl. . . . « . « a eeee superbus. Go... sr Coccodus . « 1). 0%. «+. 2 ee armatus S °.) 1... | nn lindstroeml. ...\. |)... 2 Xenopholis §f0.0.5. a’. @ 3a es carinatus ...0).-.+.. i 2 Paleobalistum'*:)..-.. . ee orbiculatum ).\. .. . ee ponsorti. 2.1. -.4. . 2 goedeli 2. 20. 0. 4. rr flabellatum 9. °.-.. . . | ee Pyenodus .j 2.2... 4 re ——platessus . .. . . . » =e gibbus 3... . toliapicus’. .. 1.0.7. . 3 koenigi 2vciteelico.: . 2 bowerbanki. 2.1.05). . | =e Acrotemnus faba... 5 . 2) ee Pycnodus scrobiculatus- . . . . J jemeem Phacodus punctatus .°.-. . . | ues Family KUGNATHIDAD .° 2. ws, Eugnathus ... .)... 4% A = orthostomus ........ . 4 ee ——philpotte . . ... s+ . ee MINOP 6%. wie se se : SOXITAtUS (6. wy ss ot eee a—alttiS §. ue we te OO =—-—hastingsie ...... . . 299 SYSTEMATIC INDEX. XXXili Family EUGNATHID A: (continued). Page Kugnathus microlepidotus . . . . . 300 longiserratus eS a's a RO latimanistegeade tot es can ate) COOL Meterolepidotusmte2- 5. as 5 S04 Tobusin see wae eee ee OE 2 sermilatsias a2 Gee. 807 = LY PICUS Sig pee oo ia an ee O08 = SiRiavls wer were ae GA ee SOLE ==, Cephalic Mae oe soe ie! ire cs ORE Ee PeChORAlIsp en THOS Soa) ah ge OLS SerbauUset aways eso. fines Sees! Oke (?) radiato-punctatus . . . . . 312 Allolepidotus.e! Sets soe!) fw we 1 UBIS BUCpPe ll ee eat rz) Se oS a ole nothosomoides =. 2’ 2) 2 2% 22 BN5 MOEsahis Sheree Gt 8 Ny seas LoS PEvGHOle DISH esata itt high: bec es at OLS noltencis: “arses se ee ES SN SLAC a aU nA es he ae SO GUE USare: Pris bae— «teen. eo a ee LOE ae ENOMTRCT A ty Ar 5% cual ase oe Bem Orninor pts. et Le & eli. 88 DVULGUUE EN LT Ny oh ai gm thy ead RRS IFS ies ee TTP) er 5s Re Sg TR a peloton eae Seite tes 7: Osteorachig ii meer aiid Al) eel aene: OOF macroceplalis oo. 4.0) we et ZO SEANUMALUSe he tit ce! het) we gh el (OO Gen Ca ae Ducane bao. s s airless OO BULECA GUS ams i AUN Balak hg Sees Gnd Ss eS Waehyurus 2 ee 386 GErTION ST Poe ent Kats we N say ae ee Oe! ERMC ani ge a May atc cwigh an 3 © OOO PUSHER oo 6) ep ating el ah a | ae Rehenmniss vise wee eco a. ak OBS labipenmig... Ge sl es ss let OES FOS SRT Tey Nl ON lek ANS ire le ER en A 2 PART III, Cc XXXIV SYSTEMATIC INDEX. Family ELUGNATHIDAL (continued). 7 Page Caturus insignis), 9.07.05.) . 2 ene (Conodus) chirotes . . . . . . 3o44 —— (Strobilodus) giganteus . . . . 3846 —— (Thlattodus) suchoides. . . . . 346 cliftoni 2.0.4. >. —— (Ditaxiodus)impar... . . . . od47 (Strobilodus) purbeckensis . . . 348 Callopterus. .. .. .°. 2 >. 1 agassizi' 9... .) Eurycormus,. 20 .'.0 . 3) 5 speciosus: |. ....> 2°... 2) ee egertont . 0..." . 2) ei - grandis . {09° 2. ed Neorhombolepis.. 9. =... =. 2 eer excelsus (020 0.00. -. crs —--— valdensis: 2.0... |... ee (?) punctatus °. 4. |. 2 Reema Lophiostomus =... |... .-)) ees dixoni. .. 0.0. .0+. 2 tel affinis: 620.) 80... 1 en Family AMTIDAG. ww oa Liodesmus . >... |.. + . ..) eee gracilis. . 0, . . a 5 ) eee sprattiformis . . . . . « .ueammewon Megalurus . . . . » «+ «. «einen lepidotus . . ..,.. |. ..—entes ——elongatus . . . . 5 . 2) eee ——elegantissimus ... .. .) sees ——damonit. .... ... .”) oes ——austend. . . . . . . . Ss AMI 40. a. rn ——valenciennesi. . .. . . . . BOF ——macrocephala .. . ... | eng ——ignota ... 1 « + « « s) 9 eneRtD SYSTEMATIC INDEX. XXXV Page Family PACH YCORMIDMGB yy 6 Bre SauULopecisy. ee eeeneNE To Gove 8k OTS lonzimanismeean. yas) ne OS S/O atu! “OP veeermietemte os ie UG Brosauropsis: mamante wer ee eke is.) OLO cloneatustrer an lew. ne Oy dO Hathynotistssmeg ee ai ele os Ck ae he ONE IMCONMICUSH Troy ats ho a Nhe COLL IMLOKMECCIUS gta Leas sor aAL et aya el OLS SPEClOSUSM Ries tes ake ae ts EO ee MOU ee hth a a ee Ke Oe ASEMEMOCOMMUSGH Sth. sw ve ts ek | OOO ChAT MMe. ae Ny Sot ay Vo th OU ACH CONMNUG Wye ie es eh eo ke OU = MaerOpventis 7. 8 as 888 ACMEIEOSEEISMY Vane ke Gy Sree ee OOS CUMS te Pe ne! othe ticn sl) OOO (Saurostomus) esocinus . . . . 388 Ey PSOCOrMUss | Ba tayeer lo 5 2a 9. Od0 UL SU SSTING preg eee teh ore yay atl oe DOL IMA CROC OMS catery oh!) ai Seo ao eg de ae OO Werle veal LIS ed 8 PE ME te iy ere es 225) LEMUIFOSHHISL GE yok) eid eee ee O9G6 ISLOLOS MMH MAG let i a ee OOO LCLOXG ME BD AN sy aiptsig ats. 400) = COMMMFESSINOSELIS) 4 ns 400 SS MIMOT Oe ye ea aoe OG VEMUMEOSEDISM Hise ay lta eee oy AO =o RCEPINSly pig Asean 6 AO ON Wa Gelemeeaemre so eM OI kM or mse ys Phe ALO, Gh DKOVIFOSURISM Oe le) st cicertiee se 408 WeMessaaet es rec cl tars een. 208 MILIO Ae a Nite Sere same Ti oh OO = WCNOUAMGn a) ok 8) ae ne ss , 209 XXXV1 SYSTEMATIC INDEX. Page Suborder AETHHOSPONDYLI 5... ’. eee Family ASPIDORHYNCHIDA |... ee Aspidorhynchus .° 2 2°...) . eee acutirostiis ~~. 5... ):- . ) eee ——euodus . . . . 2 » » es —— sphekodes. . . . . .°. 3 eo ——fisheri . . . . . . . SES ———CYassus . . 0. ww we se ee Belonostomus: . . . .... « 2) Neen sphyrenoidés . . . . . yee ——muensteri. . . ... . ae kochi .00 2.) ). ee Oligopledrus ) a esocinus =... os 4. vectensis: 0p). St Oconoscopus 2°. > petrarote °°. 5... eyprinoides’ °°... ©. | 0 ees ——— muenstert . . 2 5°. >. es desorl =... Se Spathiuris «. . .. . .) eso dorsalis . 0 2... 2) ee Family LEPTOLEPIDAG 2... . Leptolepis . ..\.. . . i. ie ——bronm. .. .. . . ) 2 saltviclensis . . . . , 2). jacgeri.. 2 wc... ——— autissiodorensis . . ... . . 506 talbragarensis =. . . . | 2) eamonuGn Jowei . 0... . a disjectls . . . . .) . ood ——— macrophthalmus. . .. . 2 sy eeeee dubius . js, ws ri vomthi . . ee en er spratiiformis,. . . . =. «© aenmmegles brodiel. . 9... >: ee neumayri . . . . el Aethalion. ..0.... . . . es : Rmorti . 2. 2. 4 err : angustus . 4. sa) er Thrissops 0." 5 re formosus. 7... ss | 6 ee Salmonetis. .° . . 4 5 a) ener clupeoides.. 22°. °°. 3. a, re TOCHEL “Li 6 ek ke he portlandicus . : .. . «|. aeons oily LEPLOLEPIDA (Gaitinscd) a ms OV 19 20 leedsi. Operculum and suboperculum 20a leedsi. Mandibular ramus 21. —— leedsi. Dentary and tooth . 22. —— minor. Restoration . aoe mantel. Head) a = 2) - +. 24. mantelli, Arrangement of teeth 25. Dapedius politus. Restoration . . . . . 26 politus. Endoskeleton of trunk restored . 27 colei. Facial bones . PART III. OO ID MH Ow bw xli LIST OF WOODCUTS. . Dictyopyge macrura. ish in shale . Chondrosteus acipenseroides. ftestoration . —— acipenseroides. Profile of head restored acipenseroides. Cranial roof . — acipenseroides. Head . Gyrosteus mirabilis. Parasphenoid . Acipenser (recent). Parasphenoid . . Gyrosteus mirabilis. Hyomandibular . mirabilis. Mazilla . . Acipenser (recent). Mazilla. 12, 18. Gyrosteus mirabilis. Ceratohyals mirabilis. Clavicle . Acipenser (recent). Clavicle . . Gyrosteus mirabilis. Supraclavicle . Me. . Acipenser (recent). S/releton . mirabilis. Caudal jfin-rays . Lepidotus macrocheirus. Mandibular ramus. . Cleithrolepis granulatus. Restoration . acipenseroides. Head and pectoral arch 100 100 100 100 95 113 116 129 131 141 156 xhi Fig. 29. 30. 31. . Coccodus armatus. Left clavicle . LIST OF WOODCUTS. Macrosemius latiusculus. Head and opercular apparatus PE eG). 84 Mesturus leedsi. Bones of cranial roof Coeelodus gyrodoides. Vomerine dentition . . Kugnathus orthostomus. Restoration orthostomus. Left mandibular ramus . . Heterolepidotus typicus. Head-bones . . Caturus furcatus. Restoration . Amia calva. Skeleton . calva. Head and opercular apparatus . calva. Left pterygo-palatime arcade . . Hypsocormus insignis. Restoration . . Protosphyrena. Lostra me . Aspidorhynchus acutirostris. Restoration . . Lepidosteus viridis. Head and opercular apparatus . Pholidophorus macrocephalus. Head . .— . Leptolepis dubius. Restoration . Page 163 192 255 267 288 — 293 309 ool 368 369 369 393 403 418: — 44] 448 510 CATALOGUE OF FOSSIL FISHES. PARE LEE. Order Il. ACTINOPTERYGII (continued). Suborder I. CHONDROSTEI (continued). Family CATOPTERID AL. Trunk elongate or elongate-fusiform ; tail abbreviate-heterocercal. Head-bones well developed, ganoid; no median series of cranial roof-bones ; teeth slender, conical; eye far forwards and snout prominent ; mandibular suspensorium more or less obliquely directed backwards and downwards. A series of branchiostegal rays present. Dorsal fin single and not much extended. Scales rhombic, ganoid. Synopsis of Genera. Origin of dorsal fin behind that of the anal.......... Catopterus (p. 1). Origin of dorsal fin not behind that of the anal...... Dictyopyge (p. 4). Genus CATOPTERUS, J. H. Redfield. [Ann. Lyceum Nat. Hist. New York, vol. iv. 1837, p. 39.] Trunk elegantly fusiform, and head relatively small. External bones more or less ornamented with ridges and tubercles of ganoine. Fins of moderate size, consisting of robust rays, more or less enamelled, and distaily bifurcating; fulcra well developed. Dorsal PART IIL. B A ACTINOPTERYGII. and anal fins triangular, the origin of the former behind that of the latter ; caudal fin forked. Scales large or of moderate size, nearly or quite smooth ; dorsal ridge-scales somewhat enlarged. A description of the known species of Catopterus is given by J. S. Newberry in his “Fossil Fishes and Fossil Plants of the Triassic Rocks of New Jersey and the Connecticut Valley ” (Monogr. U.S. Geol. Surv. no. xiv. 1888). Catopterus gracilis, J. H. Redfield. 1837. Catopterus gracilis, J. H. Redfield, Ann. Lyceum Nat. Hist. New York, vol. iv. pp. 87-39 (? non pl. i.). 1841. Catopterus gracilis, W.C. Redfield, Amer. Journ. Sci. vol. xli. ue 1988, Catopterus gracilis, J. 8. Newberry, Foss. Fishes Trias. N. Jersey and Connecticut (Mon. U.S. Geol. Surv. no. xiv.), p. 55, pl. xvi. figs. 1-3. Type. Nearly complete fishes; Yale College Museum, New Haven, Connecticut, U.S.A. | | The type species, attaining a length of about 0°25. Length of head with opercular apparatus about equal to the maximum depth of the trunk, and contained five times in the total leneth of the fish ; depth of caudal pedicle somewhat less than half that of the abdominal region. Cranial bones finely granulated. Pelvic fins arising about midway between the pectorals and the anal; dorsal and anal fins nearly equal in size and almost completely opposed. Scales smooth, none deeper than broad, those of the flank in the abdominal region very finely serrated. Some small fishes from Boonton, Middlefield, and Sunderland, named Catopterus parvulus (W. C. Redfield, Amer. Journ. Sci. vol. xli. 1841, p. 28, and J. 8. Newberry, op. cit. 1888, p. 60, pl. xvi. figs. 4, 5) are probably to be regarded as the young of this species. Form. & Loc. Triassic: Connecticut, Massachusetts, and New Jersey. P. 7495. Greater portion of abdominal and caudal region, showing paired fins ; Boonton, New Jersey. Ward Coll. P. 1038. Imperfect hinder portion of the abdominal region, with the caudal region ; Middletown, Westfield, Connecticut. Lgerton Coll. P. 1039. More imperfect specimen of the same; Durham, Con- necticut. Ligerton Coll. P. 3515a. Imperfect caudal region; Durham. Enniskillen Coll. CATOPTERID®. 3 P. 3515. Fragment showing fine serrations on flank-scales; Dur- ham. Enniskillen Coll. . Catopterus redfieldi, Egerton. 1847. Catopterus redfieldi, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. i. p. 278. 1888. Catopterus redfieldi, J. 8. Newberry, Foss. Fishes Trias. N. Jersey and Connecticut (Mon. U.S. Geol. Surv. no. xiv.), p. 53, pl. xv. figs. 1-3. Type. Nearly complete fish. A comparatively robust species as large as the type. Length of head with opercular apparatus not more than two-thirds as great as the maximum depth of the trunk and contained nearly six times in the total length of the fish; depth of caudal pedicle equalling about one-third that of the abdominal region. Cranial bones finely granulated. Pelvic fins arising midway between the pec- torals and the anal; dorsal and anal fins nearly equal in size, and the former arising opposite to the middle of the latter. Scales mostly smooth, but sometimes in part longitudinally striated, the strie terminating in the coarse serrations of the posterior border which characterize the principal flank-scales; many of the flank- scales deeper than broad. The so-called Catopterus minor (Newberry, op. cit. 1888, p. 57, pl. xvii.), from Durham, Connecticut, is probably founded on young individuals of this species variously distorted. It is also uncertain whether or not Catopterus ornatus (Newberry, ibid. p. 58, pl. xviii. fig. 3) must be placed here. The type is a unique, much distorted, small specimen from Durham, which seems to have been chemically eroded in such a way as to display the concentric lines of growth in the scales. Form. § Loc. Triassic: Connecticut and New Jersey, U.S.A. P. 3513. Imperfectly preserved specimen ; Durham, Connecticut. Enniskillen Coll. Vertically crushed specimens of Catopterus, very imperfectly pre- served, seem to have been erroneously described as representing a distinct species, Catopterus anguilliformis (W. C. Redfield, Amer. Journ. Sci. vol. xh. 1841, p. 27, and J. 8. Newberry, Mon. U.S. Geol. Sury. no. xiv. 1888, p. 59, pl. xvii. fig. 5), the type being in the Redfield Collection, Yale College Museum. The following isa specimen of this character :— P.1019. Imperfect, vertically-crushed remains of a large fish. Tri- assic; Middletown, Westfield, Connecticut. yerton Coll. BZ 4 ACTINOPTERYGII. Genus, DICTYOPYGE, Egerton. (Quart. Journ. Geol. Soc. vol. ii. 1847, p. 276.] A group of species differing only from Catopterus in the more forward position of the dorsal fin, which never arises behind the origin of the anal fin. Dictyopyge macrura (Redfield). 1841. Catopterus macrurus, W. C. Redfield, Amer. Journ. Sci. vol. xli. Degade 1847. Dictyopyge macrura, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. iii. p. 276, pl. vili., pl. ix. fig. 1. . 1857. Catopterus macrurus, W. C. Redfield, Proc. Amer. Assoc. Adv. Sci. 1856, pt. ii. p. 186. 1888. Dictyopyye macrura, J. S. Newberry, Foss. Fishes Trias. N. Jersey and Connecticut (Mon. U.S. Geol. Surv. no. xiv.), p. 64, _. pl. xviii. figs. 1, 2. Type. Nearly complete fish. The type species, attaining a length of about 0°15. Length of head with opercular apparatus somewhat less than the maximum depth of the trunk, and equalling less than one-fifth of the total length of the fish ; depth of caudal pedicle less than half that of the abdominal region. Cranial bones externally ornamented with fine granulations. Pelvic fins arisimg midway, between the pectoral arch and the anal fin; dorsal fin at least as deep as long, arising slightly in advance of the anal and scarcely smaller than the latter, which comprises about 30 rays and extends almost to the base of the caudal fin. Scales smooth, not serrated. Form. & Loc. Triassic: Richmond Coalfield, Virginia, U.S.A. Not represented in the Collection. Dictyopyge socialis (Berger). 1843. Semionotus socials, H. A. C. Berger, Neues Jahrb. p. 86. 1864. Dictyopyge socials, J. Striiver, Zeitschr. deutsch. geol. Ges. vol, xvi. p. 822, pl. xii. fig. 2. Type. Nearly complete fish; University Geological Museum, Gottingen. A large species, attaining a length of about 0-2. Length of head with opercular apparatus about equal to the maximum depth of the trunk and contained five times in the total length of the fish; depth of caudal pedicle slightly less than half that of the abdominal region. Cranial bones with an external rugose ornament. Pelvic fins arising about midway between the pectoral arch and the anal CATOPTERID A, (After Hgerton.) irginia, Blackheath, Vi jassic : Dictyopyge macrura, lateral aspect, natural size.—Tr 6 ACTINOPTERYGII. tin; dorsal and anal fins arising almost directly opposite to each other, nearly equal in size, and the latter well separated from the caudal. [Scales not satisfactorily known, but apparently serrated. | Form. & Loc. Upper Keuper : Coburg. | P. 7395. Large slab of sandstone, with remains of several indi- viduals; Coburg. Purchased. P.3488. Smaller slab with three specimens in an imperfect state of preservation ; Coburg. Enniskillen Coil. Dictyopyge catoptera (Agassiz). 1835. Paleoniscus catopterus, L. Agassiz, Edinb. Phil. Journ, vol. xix. p- 338. 1836. Paleoniscus catopterus, R. I. Murchison, Proc. Geol. Soe. vol. ii. p. 206. 1844. Paleoniscus catopterus, L. Agassiz, Poiss. Foss. vol. 1. pt. 1. p. 303 (name only). 1850. Paleoniscus catopterus, W. King, Permian Foss. (Mon. Pal. Soc.) p- 226. 1850. Paleoniscus catopterus, Sir P, Keerton, Quart. Journ, Geol. Soc. vol. vi. p. 4. | | 1858. Paleoniscus catopterus, Sir P. Egerton, 2bed. vol. xiv. p, 165, pl. xi. fig. 4. 1877. Dictyopyge catoptera, R. H. Traquair, zbed. vol. xxxiii. p. 567. Type. Imperfect fishes; British Museum and Museum of Prac- | tical Geology. : ) A small species, attaining a length of about 0°07. Length of head with opercular apparatus at least equalling the maximum . depth of the trunk and contained about five times in the total length of the fish ; depth of caudal pedicle at least half that of the abdominal region. Pelvic fins arising midway between the pectoral arch and the anal fin; dorsal fin arising considerably in advance of the anal, and apparently nearly as large as the latter. Scales not satisfactorily known, but probably smooth and without serrations ; many of those of the flank somewhat deeper than broad. [Narrow ventral scales not hitherto observed. | Form. & Loc. Keuper: Tyrone, Ireland. P, 1033. Two small slabs of red sandstone, each with two imperfect fishes; Roan Hill, Tyrone. Lgerton Coll. P, 3489-91. A large slab and four smaller pieces of similar sand- stone with numerous specimens, one labelled by Agassiz ; Roan Hill, Tyrone. Enniskillen Coll CATOPTERID&. vi Dictyopyge superstes (Egerton). 1858. Paleoniscus superstes, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. xiv. p. 164, pl. xi. figs. 1-3. 1887. Dictyopyge superstes, K. A. von Zittel, Handb. Paleont. vol. iii. p. 203. ; Type. Imperfect trunk ; collection of Rev. P. B. Brodie. A ‘small species, attaining a length of about 0:065. Proportions uncertain, but probably very similar to those of the type species, the caudal pedicle only being relatively longer. ‘The dorsal and anal fins arising directly opposite to each other, and apparently nearly equal in size. Scales smooth, not serrated. Form. § Loc. Upper Keuper: Warwickshire. Not represented in the Collection. Dictyopyge rhenana, Deecke. 1889. Dictyopyge rhenana, W. Deecke, Palzontogyr. vol. xxxv. p. 107, plevi. fie. U1. Type. Imperfect fish; Basle Museum. A species attaining a length of about 0°13. Proportions uncer- tain, but probably very similar to those of the type species, the fin-— rays differing in being more delicate. Dorsal fin arising slightly in advance of the anal fin. Scales smooth or marked mesially with a low longitudinal rib. (Deecke.) Form. & Loc. Bunter Sandstone: Degerfelden, near Basle, Switzer- land. Not represented in the Collection. Dictyopyge symmetrica, A. 8. Woodward. 1890. Dictyopyge symmetrica, A. S. Woodward, Mem. Geol. Surv. N.S. Wales, Paleont. no. 4, p. 17, pl. iv. figs. 5, 6. Type. Nearly complete fish; Geological Survey of New South Wales, Sydney. A small species, attaining a length of about 0°08. Length of head with opercular apparatus about equal to the maximum depth of the trunk and comprised more than four times in the total length .of the fish; depth of caudal pedicle scarcely more than one-third that of the abdominal region. Cranial bones externally rugose. Pelvic fins arising nearer to the anal fin than to the pectoral arch; dorsal fin as deep as long and directly opposed to the anal, which is equally elevated and only slightly more extended. Scales orna- mented with faint oblique ridges or grooves. 8 ACTINOPTERYGII. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6270. Two specimens, one wanting the head. By exchange, 1890. Dictyopyge illustrans, A. 8, Woodward. 1890. Dictyopyge tllustrans, A. S. Woodward, Mem. Geol. Surv. N.S. Wales, Paleont. no. 4, p. 18, pl. iv. figs. 7-9. Type. Nearly complete fish; Geological Survey of New South Wales, Sydney. A small species, attaining a length of about 0:09. Proportions of head and trunk as in D. symmetrica. Pelvic fins arising some- what nearer to the anal fin than to the pectoral arch; dorsal fin as deep as long, almost entirely in advance of the anal, which is larger and more extended. Scales ornamented with oblique ridges or grooves. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6269. Trunk of fish, and slab with other imperfect specimens. By exchange, 1890. Dictyopyge robusta, A. 8. Woodward. 1890. Dictyopyge robusta, A. S. Woodward, Mem. Geol. Surv. N.S. Wales, Palzont. no. 4, p. 20, pl. iii. figs. 4, 5. Type. Imperfect fish ; Geological Survey of New South Wales, Sydney. | A species attaining a length of about 0-09, differing only from D. illustrans in its more robust proportions and in the relatively greater extent of the dorsal and anal fins. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6271. Small specimen and a slab with two imperfect larger fishes. By exchange, 1890. Dictyopyge (?) draperi, A. 8. Woodward. 1893. Dictyopyge (?) drapert, A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol. xii. p. 393, pl. xvii. fig. 1. Type. Fish, wanting caudal extremity ; National Museum, Bloemfontein, Orange Free State. A small species, attaining a length of about 0°09. Length of head with opercular apparatus about equal to the maximum depth BELONORHYNCHID #. 9 of the trunk and contained five times in the total length of the fish. External head-bones ornamented with ruge and striz, the mandible being longitudinally striated. Pelvic fins arising midway between the pectoral arch and the anal fin; dorsal fin at least as deep as long, arising considerably in advance of the anal fin, and smaller than the latter, which is elongated and comprises not less than 40 rays. Scales smooth, their hinder border conspicuously pectinated, except on the caudal region. _ Form. & Loc. Upper Karoo Formation (Stormberg Beds): Roux- ville, Orange Free State, South Africa. Not represented in the Collection. Family BELONORHYNCHIDAS. Trunk elongated and slender ; tail abbreviate-diphycercal. Head- bones well-developed, delicately ornamented with ganoine, and these of the cranial roof forming a continuous shield, without a median longitudinal series of azygous elements ; snout much elongated and slender ; dentition consisting of well-spaced large conical teeth, with numerous intervening minute teeth; opercular apparatus reduced, without branchiostegal rays. Dorsal and anal fins single, remote ; fulcra minute or absent. Trunk wanting a continuous squamation, but exhibiting isolated longitudinal series of scutes. “Only one definable genus of this family, Belonorhynchus, has hitherto been discovered ; the fragments ascribed to Sawrichthys and Brownewhthys being too imperfect for satisfactory discussion. Genus BELONORHYNCHUS, Bronn. [Neues Jahrb. 1858, p. 12. ] Syn. Saurorhynchus, G. von Minster (teste Bronn, Nomencl.), in F. Braun, Verzeichn. Bayreuth befindl. Petrefact. 1840, p. 73 (name only). Ichthyorhynchus, C. Bellotti, in A. Stoppani, Studii Geol. e Paleont. Lombardia, 1857, p. 436. Giffonus, O. G. Costa, Atti R. Accad. Sci. Napoli, vol. vi., Append. 1862, p. 26. Stylorhynchus, K. Martin, Zeitschr. deutsch. geol. Ges. vol. xxv. 1873, p. 725. Saurorhynchus, O. M. Reis, Geogn. Jahresh. 1891 (1892), p. 145. Upper and lower jaws approximately equal in length, provided with few large conical teeth, and a close series of similar but smaller 10 ACTINOPTERYGII. teeth ; mandible very deep posteriorly; a single opercular bone on each side. Head and opercular bones ornamented chiefly with striations, sometimes reticulated and in part tuberculated. Long, slender ribs present. Fin-rays distantly articulated; fulcra absent. Paired fins small; dorsal and anal fins large, directly opposed ; caudal fin truncated behind, symmetrical. Trunk with four longi- tudinal series of dermal scutes, one dorsal and another ventral, and a pair supporting the “lateral line”; no intermediate scales. The cranium in this genus is completely enveloped in membrane- bones, which are more or less fused together in the adult and firmly connected at the side in advance of the orbit with the similarly fused cheek-plates. The constitution of the cranial shield is not satisfactorily known, but it extends backwards beyond the skull to the hinder border of the operculum. The parasphenoid, as seen in side view, appears curved, the convexity being downwards; a short and broad plate extends from it on each side over the otic region ; and the bone is also prolonged backwards beyond the skull to the same degree as the cranial roof already noted. The orbit is large, and there is distinct evidence of an ossified sclerotic, or at least of a hardened sclerotic rmg. The nasal opening is single on each side, and obliquely elongated; and whatever appearance there may be of a second smaller opening between the latter and the orbit in certain specimens, must be regarded as deceptive. One long posterior suborbital bone is distinct, deepest behind, and pro- duced as a narrow bar beneath the orbit; but nothing further is definitely known concerning the limits of the premaxille, maxille, and the other elements of the cheek. The hyomandibular is not much expanded at either extremity, and its long axis is nearly vertical; the quadrate is relatively large and triangular in shape. The mandible is deepest at its hinder extremity, and its posterior border descends almost vertically from the articulation with the skull. The angular and articular bones are fused together, and the expanded outer surface of the former is marked by radiating branches from the sensory canal which traverses its length. As to the limits of the dentary and splenial, there is no precise in- formation; but the fact that a double series of large teeth extends quite to the termination of the mandible, suggests that there is no presymphysial bone. The dentition on the margin of both jaws consists of a series of large, enamel-tipped, conical teeth, well spaced, with minute intermediate teeth; and some of the inner bones of the mouth are also provided with minute teeth. A small oval operculum is attached by an articulation near the upper end of its anterior border to the hyomandibular; but there is no evidence BELONORHYNCHIDA. 1h of any other ossification either in the opercular or branchiostegal membrane. The notochord is persistent, and there are no undoubted ossifi- cations in the notochordal sheath. The neural and hemal arches, however, are much expanded, the former united by zygapophyses and bearing short delicate spines, the latter in the caudal region symmetrical with the neurals. Long slender ribs are also observed in the Australian specimens. The paired fins are small, apparently exhibiting a very feeble lobation, and consisting of delicate rays. The clavicle is also relatively small and sickle-shaped, with a triangular plate affixed to its postero-inferior border; the pelvic fin-supports are unknown. The dorsal and anal fins exhibit a series of robust supports much less numerous than the dermal rays; and neither on these nor on any other fins are there indications of fulera. The longitudinal series of dermal scutes, forming dorsal and ventral ridges and a support for the lateral line, are more or less A-shaped and deeply imbricating, sometimes broad and tuberculated, sometimes narrow and smooth. The ventral series divides to form a ring round the anus. The present writer has not observed any distinct evidence of intermediate scales or calcifications. The species of Belonorhynchus are distinguished chiefly by differ- ences in the relative proportions of the head and trunk, in the form, proportions, and ornamentation of the head and scutes. i Belonorhynchus striolatus, Bronn. 1858. Belonorhynchus striolatus, H. G. Bronn, Neues Jahrb. p. 12, pl. i. figs. 1-10, pl. i1. fig. 1. 1866. Belonorhynchus strivlatus, R. Kner, Sitzungsbh. k. Akad. Wiss. Wien, math.-naturw. Cl. vol. li. pt. 1. p. 189, pl. vi. 1892. Saurichthys striolatus, O. M. Reis, Geogn. Jahresh. 1891, p. 148, fig. 5. Type. Nearly complete fishes. The type species, of small size, attaining a maximum length of about 0:15. Snout extremely attenuated, the head and opercular apparatus occupying about two-fifths of the total length; facial bones marked with prominent vertical striations; operculum about as deep as broad. Space between the pectoral and pelvic fins more than twice as great as that between the latter and the anal. Scutes of dorsal and ventral series narrow and slender, much elongated on the caudal pedicle; scutes of lateral line relatively small. Form. & Loc. Upper Keuper: Raibl, Carinthia. rt ACTINOPTERYGII. 33061. Imperfect specimen, coiled up and wanting the paired fins. Purchased, 1858. P. 966. Typical specimen, displaying the sclerotic plates and remains of all the fins. A pair of plates, not readily determinable, in front of the pectoral fins, are doubtfully regarded as infraclaviculars in Mem. Geol. Surv. N.S. Wales, Palzont. MO. 4, Deeaae Egerton Coll. P. 966 a, P. 3789 a. Imperfect specimen in counterpart, exhibiting the paired fins and the oval ring of scutes between the pelvic pair. Ligerton & Enniskillen Colls. P. 3789. Specimen showing the great elongation of the snout and several characters of the trunk, notably the elongation of the dorsal and ventral scutes on the caudal pedicle. Enniskillen Coll. Belonorhynchus gracilis, A. 8. Woodward. 1890. Belonerhynchus gracilis, A. 8. Woodward, Mem. Geol. Surv. N. 8. Wales, Paleont. no. 4, p. 27, pl. viii. fig. 5, pl. ix. figs. 3, 4, pl. x. figs. 3, 4. 1892. Saurichthys gracilis, O. M. Reis, Geogn. Jahresh. 1891, p. 155. Type. Imperfect fish: Geological Survey of New South Wales, Sydney. A species of moderate size. Head with opercular apparatus occupying about one quarter of the total length; facial bones marked with prominent vertical striations, and mandible longitudi- nally striated. Scutes of dorsal and ventral series narrowly ovate, much longer than broad, acuminate behind, and apparently tuber- culated; scutes of lateral line relatively small. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6273. Portion of trunk, with dorsal fin. By exchange, 1890. Belonorhynchus gigas, A. 8S. Woodward. 1890. Belonorhynchus gigas, A. S. Woodward, Mem. Geol. Surv. N.S. Wales, Paleont. no. 4, p. 23, pl. ix. figs. 1, 2, pl. x. figs. 1, 2. 1892. Saurichthys gigas, O. M. Reis, Geogn. Jahresh. 1891, p. 155. Type. Imperfect fish; Geological Survey of New South Wales, Sydney. A species of large size, attaining a length of not less than 0-5. Head with opercular apparatus occupying about one-third of the total length ; facial bones marked with prominent vertical striations. BELONORHYNCHID&. 13 Scutes of dorsal and ventral series about twice as broad as long, obtusely pointed behind, and ornamented with prominent tubercu- lations ; scutes of lateral line comparatively small; all the scutes much enlarged on the short and narrow caudal pedicle. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6272. Two fragments of trunk. By exchange, 1890. Belonorhynchus macrocephalus, Deecke. (?) 1857. Ichthyorhynchus curion, C. Bellotti, in A. Stoppani, Studii Geol. e Paleont. Lombardia, p. 436. (?) 1886. Belonorhynchus cfr. robustus, F. Bassani (er Bellotti, MS.), Atti Soc. Ital. Sci. Nat. vol. xxix. p. 33. [Portions of head and trunk ; Milan Museum. | 1889. Belonorhynchus macrocephalus, W. Deecke, Paleeontogr. vol. xxxv. p. 127, pl. vil. figs. 1, 2. 1892. Belonorhynchus macrocephalus, F. Bassani, Mem. Soe. Ital. Sci. [3] vol. ix. no. 3, p. 6. 1892. Saurichthys macrocephalus, O. M. Reis, Geogn. Jahresh. 1891, p. 154, fig. 9. Type. Imperfect fish. A species of large size, attaining a length of not less than 0:45. Head with opercular apparatus occupying about one-third of the total length; cranial roof tuberculated, and facial bones marked with prominent vertical striations; operculum deeper than broad. Scutes of dorsal and ventral, series elongated, triangular, not much enlarged on the caudal pedicle; scutes of lateral line smaller, rhombic in form. Form. & Loc. Keuper: Lombardy. Not represented in the Collection. Belonorhynchus tenuirostris (Miinster). 1710. Figures by Buttner, Rudera diluvii testes, pl. xvi. fig. 9, pl. xxii. fig. 3, pl. xxiv. B. fig. 1. 1839. Saurichthys tenuirostris, G. von Miinster, Beitr. Petrefakt. pt. i. p- 118, pl. xiv. fig. 3. 1840. Sawrorhynchus tenuirostris, F. Braun, Verzeichn. Bayreuth befindl. Petrefact. p. 73. 1846. Saurorhynchus tenuirostris, EK. E. Schmid, in Schmid & Schleiden, Geogn. Verhalt. Saalthals, p. 37, pl. ii. figs. 4, 5. 1849. Saurichthys tenwrostris, H. von Meyer, Palzontogy. vol. i. p. 201, pl. xxxi. figs. 29-32. 1861. Saurichthys tenuirostris, KE. E. Schmid, Nova Acta Acad. Ces. Leop.-Car. vol. xxix. no. 9, p. 24. 14 _ ACTINOPTERYGII, 1865. Saurichthys tenuirostris, H. Eck, Form. bunt.Sandst. u. Muschelk. | Oberschlesien, p. 121. 7 1873. Stylorhynchus tenuirostris, K. Martin, Zeitschr. deutsch. geol. Ges. vol. xxv. p. 725, pl. xxii. fig. 14. 1838. Saurichthys tenuirostris, K. A. von Zittel, Handb. Palzeont. vol. i. p. 266. 1892. Saurichthys tenuirostris, O. M. Reis, Geogn. Jahresh. 1891, p. 151, (2) fig. 4. Type. Cranium; Paleontological Museum, Munich. The type species of the so-called Sawrorhynzhus (Minster MS.) and Stylorhynchus, of small size and with very slender snout, the head attaining a length of about 0:06 and its maximum breadth 0-01. The external ornament of the cranial roof consists chiefly of tubercles. Form. & Loc. Muschelkalk : Germany. Not represented in the Collection. Belonorhynchus acutus (Agassiz). Pigieytes TOR aes 0 1844. Belonostomus acutus, L. Agassiz, Poiss. Foss. vol. 11. pt. ii. p. 142, pl. xlvu a. figs. 3, 4. 1844. Belonostomus anningie, L. Agassiz, ibid. p. 143 (name only), [Head; British Museum. ] 1844. Belunostomus tenellus, L. Agassiz, ibid. p. 143 (name only). | [Mandibular symphysis; British Museum. ] | 1858. Belonorhynchus (?) acutus and B.(?) anningie, H. G, Bronn, | Neues Jahrb. p. 12. | 1876. Belonostomus acutus, J. F. Blake, in Tate and Blake, Yorkshire Lias, p. 259.- 1887. Belonorhynchus acutus, K. A. von Zittel, Handb. Palezont. vol. ii. p. 222. | 1888. Belonorhynchus anningi@a, A. S. Woodward, Ann. Mag. Nat. | Hist. [6] vol. i. p. 355, and Quart. Journ. Geol. Soc. vol. xliy. p. 147, pl. vii. fig. 14. 1890. Belonorhynchus acutus, Woodward and Sherborn, Catal. Brit. Foss. Vertebrata, p. 16. 1892. Saurorhynchus acutus, O. M. Reis, Geogn. Jahresh. 1891, p. 145 (in part). : Type. Imperfect cranium; British Museum. The type species of the so-called Sawrorhynchus, of moderate size, the head attaining a length of about 0°15. Head from four and a half to five times as long as its maximum depth; distance between the orbit and the occiput considerably exceeding the maxi- mum depth of the mandible, and the angular bone of the latter much truncated though gently rounded postero-inferiorly ; dentition BELONORHYNCHIDZ. 15 powerful; superficial ornament consisting of short ruge, the majority directed longitudinally. Operculum two-thirds as broad as deep. Scutes of dorsal and ventral series long, narrow, and slender, apparently smooth. Form. & Loc. Upper Lias: Yorkshire. Lower Lias: Dorsetshire. Except the first, all the following specimens were obtained from Lower Lias of the neighbourhood of Lyme Regis. P. 4268. Type specimen, being the fragmentary cranium figured by Agassiz, loc. cit. fig. 4; Upper Lias, Whitby. Enniskillen Coll. P.428. Crushed and somewhat fractured head, lateral aspect, measuring 0:145 in length, but wanting the extremity of the snout. The laniary teeth gradually become more and more robust backwards, and those of the two jaws alternate, fitting into broad notches; the clusters of minute inter- vening denticles are conspicuous. The imperfectly pre- served angular bone of the mandible is shown to be continuous with the articular element. Purchased, 1882. 43054. Smaller head, 0°1 in length, the cranium much crushed but showing the extension of the roof-bones beyond the occiput posteriorly. The jaws are almost of equal length, the mandible being not more than 0-002 shorter than the upper jaw. The angular bone displays its truncated but gently rounded postero-inferior border, and also exhibits the series of vertically-extended markings due to the per- forations of a sensory canal. Purchased, 1871. P. 3791. A fine example of the head, with left operculum and clavicle, shown of the natural size in Pl. II. fig. 1. Be- sides displaying the general proportions, this specimen also exhibits a few details, notably the post-occipital extension of the cranial roof (r.), the presence of cheek- plates, the position of the narial opening (n.), and the form of the articulo-angular bone. The operculum (op.) is nearly one and a half times as deep as broad, tapering downwards, and evidently not succeeded either by a sub- operculum or branchiostegal rays. The clavicle (c/.) is deep, narrow and gently arched, with a relatively large but narrow triangular plate extending far backwards from the hinder border. Enniskillen Coll. P. 965. Somewhat smaller head, lateral aspect, with operculum and clavicle. Egerton Coll. 16 ACTINOPTERYGII. P. 955 a. Much crushed and fractured small head, lateral aspect. Egerton Coll. P. 4271. Similar specimen. Enniskillen Coll. 47462. Imperfect remains of head, displaying the parasphenoid bone in side view, and one of the suborbital plates. In its posterior portion the parasphenoid exhibits a large ascending lateral plate. Purchased, 1876. 48007. Imperfect cranium in side view, showing the orbit, narial opening, and the dentition with the notches for the reception of the lower laniaries. Purchased, 1887. 40499. Small cranium, upper aspect. Purchased, 1867. P. 964. Portion of similar cranial roof, labelled Belonostomus tenellus by Agassiz. Egerton Coll. P. 965 b. Mandible, lateral aspect, showing part of the dentition and the superficial rugose ornament, and the continuity of the articular with the angular bone. Egerton Coll. P. 965 c. Imperfect small mandible, oral aspect, exhibiting a sharp median longitudinal ridge on the long symphysis. Egerton Coll. P. 513. Symphysial portion of mandible, labelled Belonostomus tenellus by Agassiz, and intended to be the type specimen of that undefined species. On account of the form of the fractured extremity, this fossil was described and figured as a presymphysial bone by the present writer in the Quart. Journ. Geol. Soc. vol. xliv. p. 147, pl. vii. fig. 14 ; but such a determination is very doubtful and not con- firmed by any other specimen. Egerton Coll. P. 3790. Head and remains of trunk, without fins, noticed by the present writer in Ann. Mag. Nat. Hist. [6] vol. i. p. 355, and three of the dorsal scutes figured in Mem. Geol. Surv. N. 8S. Wales, Paleont. no. 4, pl. vii. fig. 7. The head exhibits the typical characters of the species, and the mandible is scarcely shorter than the upper jaw. Portions of the operculum and clavicle are preserved, and remains of the axial skeleton of the trunk occur beyond. The neural arches are very broad and bear short slender neural spines, which may have become elongated in the caudal region to be symmetrical with the hemals, of which a few BELONORHYNCHID&#. EVE are shown. ‘There are no satisfactory indications either of ribs or fins; and only fragments of the dorsal series of ridge-scutes are preserved. Enniskillen Coll. P.965d. Imperfect mandible, much ornamented, with part of theseries of arches of the axial skeleton of the trunk. Hgerton Coll. Belonorhynchus brevirostris, sp. nov. [Plate II. fig. 2.] 1858. Belonostomus acutus, F. A. Quenstedt (errore), Der Jura, p. 234,. pl. xxix. fig. 8. 1892. Saurorhynchus acutus, O. M. Reis, Geogn. Jahresh. 1891, p. 145 (in part), figs. 1-5. Type. Head; British Museum. A species of moderate size, the head attaining a length of about 0-11. Head from three and a half to four times as long as its maxi- mum depth ; distance between the orbit and occiput scarcely if at all exceeding the maximum depth of the mandible, and the angular bone of the latter with long, nearly vertical hinder border, sharply rounded off inferiorly ; dentition powerful, the posterior laniaries widely spaced and especially robust; superficial ornament con- sisting of short ruge, the majority directed longitudinally. [Trunk unknown. | . Form. & Loc. Lower Lias: Dorsetshire. Upper Lias:’ Wiirtem- berg and Yorkshire. Gi.) Lower LInas, Lyme Regis. 40726. Type specimen, being a cranium and mandible wanting the extremity of the snout and marked by an oblique line of fracture across the hinder portion. The fossil is shown of the natural size in Pl. II. fig. 2, and exhibits the principal characters of the headfrom theright lateral aspect. Remains of the posterior extension of the cranial roof (7.) occur above the operculum (op.), which is very small and similar in shape to that of B. acutus. The orbit (0.), narial opening (7), and dentition are also indicated; and the form of the hinder portion of the mandible is especially wellshown. The very large articulo-angular bone exhibits the form of the posterior and postero-inferior margin so characteristic of the species; and there are abraded remains of the series of short vertical sensory canals which mark its upper border. Purchased, 1867. 39866. Small head 0-055 in length, the maximum depth contained about three times in the total length, and the mandible PART III. c 18 ACTINOPTERYGII. slightly shorter than the upper jaw. The superficial ruge on the articulo-angular bone appear to be directed vertically. Purchased, 1866. P. 4878. Well-preserved head 0-075 in length. Purchased, 1885. P. 3791 b. Crushed head 0-088 in length, displaying the dentition and the articulo-angular bone of the mandible. Enniskillen Coll. P. 3791 a. Hinder portion of skull and mandible with well-preserved laniary teeth. Portions of the right operculum, clavicle, and some of the neural arches of the trunk are preserved behind. Enmskillen Coll. 43008. Mandible, left outer aspect, with teeth. Purchased, 1871. (ii.) Upper Lias, Whitby. 39153. Abraded skull and mandible 0-095 in length, right lateral aspect; probably obtained from Whitby. Bowerbank Coll. (iii.) Upper Inas, Wurtemberg. P. 3792. Head about 0-11 in length, somewhat fractured and displaying part of the parasphenoid ; Ohmden. Enmiskillen Coll. P. 960. Nearly similar specimen ; Ohmden. Egerton Coll, P. 960a. Remains of skull and mandible showing the hinder half of the parasphenoid and part of the right quadrate; Ohmden. Minute conical teeth appear in side view either on the parasphenoid or on the vomer. Egerton Coll. P. 960 b. Four imperfect heads ; Ohmden. Egerton Coll. 20660-61. Two imperfect heads ; Boll. Purchased, 1846. The following species have also been partially defined, the two last without figures :— Belonorhynchus gypsophilus: Sawrichthys gypsophilus, O. M. Reis, Geogn. Jahresh. 1891 (1892), p. 153, fig. 6.—Keuper ; Altenmiinster, N. Franconia. [Portion of upper jaw. | Belonorhynchus intermedius, F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxix. (1886), p. 34.—Keuper; Besano, Lombardy, [Hinder portion of trunk; Milan Museum. | Belonorhynchus stoppanii, ¥. Bassani, ibid. p. 34.—Ibid. [Nearly complete fish ; Milan Museum. | - BELONORHYNCHIDZ. 19 As pointed out by K. A. von Zittel, Handb. Palewont. vol. iii. (1888), p. 266, the imperfect head of an undetermined large species of Belonorhynchus from the Rheetic of Seefeld, Tyrol, is also described as Teleosaurus tenuistriatus, R. Kner, Sitzungsb. k. Akad. Wiss. Wien, math.-naturw. Cl. vol. lvi. (1867), pt. i. p. 905, pl. i. Fragments of another undetermined species from the Trias of Monte Pettine, near Giffoni, Province of Salerno, Italy, now in the Museum of the University of Naples, are described by O. G. Costa, Atti R. Accad. Sci. Napoli, vol. vi. Append. (1862), under the names of Giffonus deperditus (loc. cit. p. 26, pl. vi. fig. 2) and Acipenser ? (ibid. p. 44, pl. vii. figs. 6 4, 8). Others are described as Paleo- niscus ? (Atti Accad. Pontan. vol. vii. 1856, pp. 36, 358, pl. iv. fig. 5). These are referred to Belonorhynchus sp. by F. Bassani, Fossili Schisti Bitumin. Monte Pettine (Mem. Soc. Ital. Sci. ser. 3, vol. ix. no. 3, 1892), pp. 5-7. ° | Genus SAURICHTHYS, Agassiz. [Neues Jahrb. 1834, p. 386.] Syn. Thelodus, E. E. Schmid, Nova Acta Acad. Css. Leop.-Car. vol, xxix. no. 9, 1861, p. 27 (in part). An indefinable genus known only by detached teeth and frag- ments of jaws. The teeth are enamelled only in their distal portion, and their base is sometimes feebly plicated. The bones are ornamented chiefly with fine tuberculations, though in part striated. The fish to which these remains belong may be generically identical with Belonorhynchus, as suggested by Reis (Geogn. Jahresh. 1891, p. 149); but until proof be forthcoming, it seems inadvisable to change the nomenclature. Saurichthys apicalis, Agassiz. 1834. Saurichthys apicalis, L. Agassiz, Neues Jahrb. p. 387. 1839. Saurichthys apicalis, G. von Minster, Beitr. Petrefakt. pt. i. p. 117, pl. xiv. figs. 1, 2. 1844, Saurichthys apicalis, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 85, pl. lv. a. fies. 6-11. 1849. Saurichthys apicalis, H. von Meyer, Palzontogr. vol. i. p. 234, pl. xxviii. fig. 31. 1855. Saurichthys apicalis, C. G. Giebel, Odontogr. p. 118, pl. xlyv. ined 1856. Saurichthys mougeoti, C. G. Giebel (errore), Zeitschr. f. gesammt. Naturw. vol. viii. p. 425, pl. i. fig. 4. 1861. Saurichthys acuminatus, E. E. Schmid (errore), Nova Acta Acad. Ces. Leop.-Car. vol. xxix. no. 9, p. 21, pl. iii. figs. 20-26 (non figs. 18, 19). c2 20 ' ACTINOPTERYGII. 1865. Saurichthys apicalis, H. Eck, Form. bunt. Sandst. u. Muschelk. Oberschlesien, p. 69. 1888. Saurichthys apicalis, K. A. von Zittel, Handb. Palzeont. vol. iii. p. 266, fig. 271. 1892. Sais apicalis, O. M. Reis, Geogn. Jahresh, 1891, p. 153, fio. 8. Type. Portion of upper jaw ; Palzeontological Museum, Munich. The type species, with much elongated jaws and slender teeth, the head attaining a length of about 0°012. Apical gano-dentine smooth, not usually extending below the distal third of the tooth ; base finely striated. Form. & Loc. Muschelkalk and Lower Riper: Germany. Not represented in the Collection. Saurichthys mougeoti, Agassiz. 1834. “ Zahne von Gottingen,” H. von Meyer, Mus. Senkenberg. vol. i. p- 16, pl. 11. figs. 4-6. 1837. Figure by H. B. Geinitz, Beitr. Kennt. Thuring. Muschelk. pl. iil. fig. 2. 1837. Saurichthys mougeoti, H. Hogard, Descript. Systéme des vee _ p. 405, pl. xii. figs. 14 (also 16, 20). 1837. Saurichthys conidens, H. Hoan) ibid. p. 406, pl. xii. fig. 15. 1839. Saurichthys senucostatus, G. von Minster, Beitr. Petrefakt. pt. i. p. 118. [Teeth ; Paleontological Museum, Munich, | 1844, Saurichthys mougeoti, L. Agassiz, Poiss. Foss. vol. 11. pt. il. p. 85, pl. lv. a. figs. 12-15. 1849. Saurichthys mougeoti, H. von Meyer, Palzontogyr. vol. 1. pp. 203, 235, pl. xxviii. figs. 21-30. 1852. Saurichthys mougeoti, F. A. Quenstedt, Handb. Petrefakt. p. 261, pl. xiii. fig. 56. 1861. Saurichthys acuminatus, EK. E. Schmid (error ¢), Nova Acta Acad. Cees. Leop.-Car. vol. xxix. no. 9, p. 21, pl. iii. figs. 18, 19. 1861. Saurichthys apicahs, K. E. Schmid (errore), gue: p. 22, a lil. figs. 13-17. 1865. Saurichthys mougeott, H. Eck, Form. bunt. Sandst. u. Muschelk. Oberschlesien, p. 120. 1878. Saurichthys mougeoti, K. Martin, Zeitschr. deutsch. geol. Ges. VO), XXxv.p) (20, pla xxi, tio wlonn © 1892. Saurichthys mougeoti, O. M. Reis, Geogn. Jahresh. 1891, p. 154. Type. Portion of jaw. A more: robust and larger species than the type. Apical gano- dentine occupying more than one-third of the length of the tooth, except in the shorter and stouter examples; both the base and at least part of the apex marked with coarse longitudinal ribs and fine striations. Form. § Loc. Muschelkalk and Lettenkohl: France and Germany. BELONORHYNCHIDA. ot 1536-39. Five teeth ; Laineck, near Bayreuth, Bavaria. Braun Coll. P. 853. Robust tooth ; Laineck. Egerton Coll. P. 854. Robust and coarsely ribbed tooth; Mattstedt, near Jena. Egerton Coll. Saurichthys acuminatus, Agassiz. 1845. Saurichthys apicalis, J. E. Portlock (errore), Rep. Geol. London- derry, p. 470, pl. xiv. fig. 19. 1844. Saurichthys acuminatus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p- 86, pl. lv. a. figs. 1-5. 1844. Saurichthys longidens, Li. Agassiz, ibid. p. 87, pl. lv. a. figs. 17, 18. [Tooth from Aust Cliff. ] 1844. Saurichthys acuminatus, Meyer & Plieninger, Pal. Wiirttembergs, p- 118, pl. xii. fig. 30. 1844. Saurichthys mougeott, Meyer & Plieninger, zdid. p. 118, pl. xii. figs. 31, 32. 1844. Saurichthys breviconus, T. Plieninger, in Meyer & Plieninger, op. cit. p. 120, pl. xii. fig. 83. [Tooth; Stuttgart Museum. | 1844. Saurichthys longiconus, T. Plieninger, zded. p. 119, pl. xii. figs. 90,91. [Teeth ; Stuttgart Museum. | 1844. Saurichthys listroconus, T. Plieninger, ib¢d. p. 120, pl. xii. fig. 81. [Tooth ; Stuttgart Museum. | 1858. Saurichthys acuminatus, F. A. Quenstedt, Der Jura, p. 35, pl. 11. figs. 42-51. 1872. Saurichthys acuminatus and 8S. apicalis, R. Etheridge, Proc. Cardiff Naturalists’ Soe. vol. iii. pl. ii. figs. 5-10. 1878. Saurichthys acuminatus, B. Lundgren, Minneskr. Kongl. Fysiogr. Sallsk. Lund, no. v. p. 31, pl. i. figs. 60, 61. 1888. Saurichthys acuminatus, K. A. von Zittel, Handb. Paleont. vol. ili. p. 266, fig. 272. 1889. Saurichthys acuminatus, A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol. ii. p. 301, pl. xiv. figs. 7,8; and Trans. Leicester Lit. & Phil. Soc., n.s., vol. i. pt. xi. p. 20. This name may be provisionally retained for the teeth of Saurichthys from the Rhetic horizons of N.W. Europe. They indicate a species with a robust dentition, the more typical teeth only differing from those named S. mougeoti in the relatively shorter basal portion and the prominence of the inferior rim of the apical gano-dentine. The extreme variations in the form of the teeth are pointed out by Quenstedt; and S. longidens is proved to be a synonym of S. acuminatus by an imperfect maxilla from Aust Cliff described in Ann. Mag. Nat. Hist. [6] vol. ii. p. 301, pl. xiv. nes. 7, 8. ~ Form. § Loc. Rhetic: N.W. Europe. 22 ACTINOPTERYGII. 11205, 11209. Two teeth in matrix; Aust Cliff, near Bristol. Mantell Coll. 23353, 23812. Portions of bone-bed with teeth, and detached teeth ; Aust Cliff. Purchased, 1849. 44835 a. Bone-bed with two teeth; Aust Cliff. Presented by Benjamin Bright, Esq., 1873. P, 855-6. Six teeth, three being in matrix ; Axmouth, Devonshire. Egerton. Coll. P, 3479. Two teeth in matrix; Axmouth. Enniskillen Coll. P. 857 a. Tooth in bone-bed; Newtown Limavady, Londonderry, Ireland. Egerton Coll. 28473-74, 28477. Several detached teeth ; Crailsheim, Wtrtemberg. Purchased, 1853. P, 857. Tooth in bone-bed ; Hohenheim, Wiirtemberg. Egerton Coll. The following names have also been applied to detached teeth, of which there are no examples in the Collection :— Saurichthys annulatus, T. C. Winkler, Archiv. Mus. Teyler, vol. v. (1880), p. 182, pl. viii. figs. 31-34.—Muschelkalk ; Wurz- burg. [Wurzburg University Museum. | Saurichthys breviceps, F. A. Quenstedt, Handb. Petrefakt. (1852), p. 231, pl. xiii. fig. 57.—Lettenkohl; Crailsheim, Wirtem- berg. [Tiibingen University Museum. | Saurichthys costatus,G. von Munster, Beitr. Petrefakt. pt. 1. (1839), p. 118; H. Eck, Form. bunt. Sandst. u. Muschelk. Ober- schlesien (1865), p. 121: Thelodus rectus, E. EK. Schmid, Nova Acta Acad. Cs. Leop.-Car. vol. xxix. no. 9 (1861), p- 28, pl. iv. figs. 20-22.—Upper Muschelkalk ; Bayreuth, Bavaria, also Jena. A dentigerous bone, also probably of Sawrichthys, from the Muschelkallk of Poland, is assigned to an undetermined species of this genus by H. Eck, Form. bunt. Sandst. u. Muschelk. Oberschle- sien (1865), p. 69, pl. il. fig. 5. The specimen is preserved in the Breslau University Museum, and exhibits a pavement of blunt conical teeth. Other portions of jaws from the Muschelkalk of Jena, described as Saurichthys procerus and Saurichthys? gracilis by KE. KE. Schmid (Nova Acta Acad. Ces. Leop.-Car. vol. xxix. no. 9, 1861, p. 28, pl. iii. figs. 27, 28), do not appear to pertain to this genus. Thesame remark applies to some detached teeth from the Carboniferous of the Punjab, India, described under the name of Saurichthys ? indicus, CHONDROSTEID &. 23 L. G. de Koninck, Quart. Journ. Geol. Soc. vol. xix. (1863), p. 17, pl. viii. figs. 6, 7. The teeth from the Muschelkalk of Jena named Thelodus infleaus by E. E. Schmid (Joc. cié. 1861, p. 27, pl. iv. figs. 17-19) are also very doubtfully placed here. Nothing is known of those from Laineck recorded as Saurichthys semistriatus, Minster, in F. Braun, Verzeichn. Beyreuth befindl. Petrefact. (1840), p. 73. A fragmentary fossil from the Lower Lias of Barrow-on-Soar, Leicestershire, now in the Leicester Museum, has been provisionally associated with Belonorhynchus and Saurichthys, under the name of Browneichthys ornatus (A. 8. Woodward, Geol. Mag. [3] vol. vi. 1889, p. 455). The bones of the head are invested with ganoine and ornamented with large tuberculations. The notochord seems to have been persistent. At least the front portion of the trunk is covered with thin, deeply overlapping scales, oval or round in shape, with prominent concentric lines of growth, and externally orna- mented with large ganoine tubercles. There was also a partial or continuous armature of the dorsal and ventral margins, consisting of large, narrow, pointed ridge-scales. Family CHONDROSTEID A. Trunk elongate-fusiform ; tail heterocercal. Head-bones well- developed, those of the cranial roof forming a continuous shield, without a median longitudinal series of azygous elements ; snout prominent and eye far forwards; no premaxilla; dentition rudi- mentary or absent; operculum and suboperculum present, with a few well-developed branchiostegal rays. Squamation rudimentary or absent on the trunk, robust on the upper caudal lobe. Only one definable genus of this family, Chondrosteus, has hitherto been discovered; but it seems probable that the fragmentarily- known genus G'yrosteus will prove to be correctly placed here. Genus CHONDROSTEUS, Egerton. (Phil. Trans. 1858, p. 871 (ea Agassiz, MS.).] External bones feebly ornamented with granulations, partly coated with ganoine; mandibular suspensorium very oblique; jaws toothless; maxilla arched, much expanded behind and tapering in front, without process for palatine articulation; suboperculum large and quadrate, operculum relatively small and triangular. Ribs absent. Fin-rays covered with a very thin film of ganoine, the pectorals also sparsely granulated ; all closely articulated except a few anterior pectorals, which are not enlarged; fulcra absent, ACTINOPTERYGII. 24 i) WL, a AN SNARE NN OT Kay Te Gh Sores EEA A. AJ. CHONDROSTEID A. 25 the anterior rays of each fin gradually increasing in length to an acumination. Pelvic fins remote, the dorsal opposed to this pair ; caudal fin forked, nearly equilobate. Scales absent, except on the upper caudal lobe where they are thick and rhombic, invested with ganoine; caudal fulcral scales large, with ganoine. Nothing is known of the ossifications in the chondrocranium of Chondrosteus, but many specimens exhibit the chief membrane- bones. ‘The parietals (figs. 3, 4, p.) are longer than broad and comparatively small ; both these and the large frontals ( f.) meeting at the middle line in a slightly wavy suture, without any inter- posed elements or vacuities. The squamosals (sq.) are larger than the parietals, extending as far forwards as the latter; the post- frontals (p.f.) are relatively very small. No cranial bones have been recognized in advance of the frontals, and the extent of the rostrum is thus undetermined. Cheek-plates are also almost wanting, only one suborbital (figs. 3, 5, so.) being observed, bearing an upward process ascending towards the postfrontal. A series of five supratemporal plates (fig. 4, s.t.), of which the three inner- most are relatively small, occurs along the occipital border. The hyomandibular (figs. 3, 6, hm.) is shaped as in modern Sturgeons, but apparently ossified as far as its lower extremity; and a sym- plectic must have been present, although it is doubtful whether this was ossified in any part. The pterygo-quadrate arcade exhibits only two ossifications on each side, one being a large expanded Fig. 3. Profile of head of Chondrosteus actpenseroides, restored (after Traquair). j- jugal. Other letters as in figs. 4, 5. element (Pl. I. fig. 3, pt.) of pterygoid nature, and the other a small Y-shaped bone (pl.) articulated with the maxilla, which may be either palatine or ectopterygoid. Sheathing the arcade is 26 ACTINOPTERYGII. a long curved maxilla (Pl. I. figs. 2,3, ma.), deep behind and much contracted anteriorly, meeting its fellow of the opposite side in front in a distinct symphysis. Another small membrane-bone, abutting upon the postero-superior margin of the maxilla, may be regarded as the jugal (Pl. I. fig. 3, ju.). The mandible exhibits three bones, the dentary being much the largest, the articular and angular insignificant. The dentary is somewhat arched, the inferior margin being concave; but there is scarcely any tapering at the symphysis, and the coronoid region is not elevated. The ossified, hour-glass-shaped ceratohyal is frequently shown (Pl. I. fig. 2, ch.), but nothing further is known of the hyoid apparatus. The operculum is relatively small and shaped almost like an inverted comma with the tail pointing forwards and upwards Cranial roof of Chondrosteus acipenseroides (after Traquair). From specimen in Museum of Practical Geology. f., frontal; op., operculum; p., parietal; pf, post-frontal; p.t., post- temporal ; s.7., supra-temporal ; sg., squamosal, (figs. 3, 4, 6, op.). The suboperculum (s.op.) is much broader and almost quadrate, with produced antero-superior angle. About ten branchiostegal rays (6r.) can be counted, the uppermost broad and the lowermost narrower; but there are no indications of a gular plate. The notochord must have been persistent, with no calcifications CHONDROSTEID ®. O7 in its sheath ; and the peripheral arches are only imperfectly calci- fied. The neural arches are stout and each pedicle (PI. I. fig. 4, n.@.) is separate both from its fellow of the opposite side and from the long neural spine (n.s.)._ No traces of ribs have been observed, and robust hemal arches have only been seen at the base of the lower caudal lobe. The pectoral arch closely resembles that of Acipenser. The post- temporal (figs. 3, 4, p.t.) is a small, narrow triangular bone, overlapped at its attenuated anterior end by the supratemporals. The long narrow supraclavicle (figs. 3, 6, s.cl.) is obliquely crossed near its upper extremity by the lateral line. The clavicle (Pl. I. fig. 5, cl.) is sharply bent, with a lower limb and an inner laminar expansion as in Actpenser. The infraclavicle (7.cl.) is relatively small and trapezoidal. The pectoral fin-supports are unsatis- factorily known. The pelvic fin-supports, so far as preserved, are a single regular series of stout, elongated cartilages, much fewer than the dermal rays; but a double series occurs both in the dorsal and anal, the baseosts being short, and the axonosts much elongated, extending almost or quite to the neural and hemal spines of the axial skeleton. The large fuleral scales at the base of the upper caudal lobe are supported by a distinct series of vertically elongated cartilages above the neural arches. Chondrosteus acipenseroides, Egerton. [Plate I. figs. 1-5.] 1844. Chondrosteus accipenseroides, L. Agassiz, Poiss. Foss. vol. ii. pt. il. p- 280 (name only). 1858. Chondrosteus acipenseroides, Sir P. Egerton, Phil. Trans. p. 871, pls. Ixvii., lxix., pl. Ixviil. fig. 2. 1858. Chondrosteus crassior, Sir P. Egerton, ibid. p. 883, pl. Ixviii. fig. 1, pl. xx. [Head; British Museum. | 1887. Chondrosteus acipenserordes, R. H. Traquair, Geol. Mag. [3] vol.iv. p. 248, woode. figs. 1-5 (reprinted in Proc. Roy. Phys. Soc. Edinb. vol. ix. p. 349, with woodcuts). 1887. Chondrosteus acipenseroides, J. W. Davis, Quart. Journ. Geol. Soe. vol. xliii. p. 605, pl. xxii. 1889. Chondrosteus acipenseroides, A.S. Woodward, Proc. Geol. Assoc. vol. xi. p. 36, woode. figs. 8-12. 1889. Chondrosteus acipenseroides, M. Browne, Trans. Leicester Lit. & Phil-Soey aus,, val. iipt. i. ip. 17,, pls..1., 4. Type. Imperfect fish ; British Museum. The type species, usually attaining a length not exceeding one metre. Maximum depth of trunk contained about five and a half 28 ACTINOPTERYGII. times in the total length from the pectoral arch to the extremity of the caudal fin. Superficial granulations of external bones sparse, rounded, and those of the pectoral fin similar. Suboperculum about as deep as broad, with produced antero-superior angle ; operculum much narrower and smaller, with somewhat excavated anterior border; at least nine or ten branchiostegal rays on each side. Pelvic fins more than two-thirds as large as the pectorals, the distance between these two pairs more than twice as great as that between the former and the anal. Anal fin about equal to the pelvic fins in size; dorsal relatively large, as long as deep ; caudal fin large. Caudal fulcral scales narrow and sharply pointed. Form. & Loc. Lower Lias: Dorsetshire and Leicestershire. All the following specimens were obtained from the neighbour- hood of Lyme Regis, Dorsetshire :— P. 3361. Imperfect trunk, wanting the hinder half of the caudal region, but with remains of the head and opercular apparatus, described and figured by Egerton, loc. cit. p. 872, pl. lxvii. This being the first specimen described, must be regarded as the type of the species. Enmskillen Coll. P. 3366. Well-preserved fish about one metre in total length, shown of one-quarter the natural size in Pl. I. fig. 1, and forming the basis of the restoration in fig. 2, p. 24. The head is obliquely crushed and very imperfect, but several elements are distinct. The exposed surface of the bones of the cranial roof is finely rugose, exhibiting a few tuberculations. Below it is the partially-covered robust hyomandibular (hm.); and in the region of the jaws there only remain the imperfect pterygoid (pt.) and jugal (ju.) of the right side. The small narrow operculum (op.) and the relatively large suboperculum (s.op.) are well preserved. Both post-temporals are shown, that of the left side from the inner, that of the right side from the outer aspect ; and the long, narrow supraclavicle (s.cl.) is seen above the comparatively large clavicle (cl.). The axial skeleton of the trunk is only very imperfectly exhibited; but a few of the slender neural spines with their stouter arches occur scattered in the abdominal region. The specially robust hemal arches at the base of the lower caudal lobe are also seen. All the fins are preserved, only the upper extremity of the caudal being wanting. The anterior rays in each fin gradually increase in length to its apex, P. 2047. CHONDROSTEID&. 29 the short foremost of these being apparently unjointed ; all the rays beyond the apex are articulated and finely branched distally. The anterior pectoral rays are not much enlarged, and there are indications of the super- ficial tubercles on this fin. The pelvic fins appear to be slightly deeper than long, and each is supported by a regular series of short and stout hour-glass-shaped basals. The dorsal fin is opposed to the latter and is shown to have been supported by short, stout baseosts and slender, elongated axonosts, which taper towards the neural arches of the axial skeleton. ‘The anal fin is smaller than the dorsal, and its endoskeletal supports are only feebly indicated. A series of supports, slender anteriorly, becoming shorter and robust behind, is displayed beneath the fulcral scales of the upper caudal lobe; seven scales resting upon ten or eleven supports. The caudal fin is nearly equilobate. The oat-shaped scales are well- preserved on the sides of the upper caudal lobe, smooth and flattened externally, tumid on their attached face. There is no evidence of other dermal armature; but fragments apparently of the skin are preserved in the upper half of the abdominal region, and these exhibit a series of short double ridges evidently indicating the course of the lateral line. Some coprolitic matter occurs above the pelvic fins. Enmiskillen Coll. Imperfect small individual, originally about 0°42 in length. Lgerton Coll. 38545. Imperfect small individual, about 0°56 in length, showing portions of all the fins. Purchased, 1864. P. 3367. Slightly larger specimen, with imperfectly preserved tail, P. 2050. wanting the anal fin. The maxillary and pterygoid bones are described and figured by Traquair, loc. cit. p. 254, fig. 4, and re-drawn of the natural size in PI. I. fig. 3 of the present volume. The left operculum and suboperculum are also shown, and the pectoral fins are especially well- preserved; most of the rays of these fins exhibit a longitudinal series of tubercles fused with their basal half. Enniskillen Coll. Remains of head and abdominal region, exhibiting the form of the clavicle, and displaying a long series of neural arches with their loosely apposed neural spines. A 30 ACTINOPTERYGII. few of these arches are shown of the natural size in Pl. I. fig. 4. Egerton Coll. P. 3362. Imperfect head, pectoral arch with fins, and some of the anterior vertebral arches, described and figured by Eger- ton, loc. cit. p. 873, pl. lxix. The portion of axial skeleton behind the head is not accurately drawn, there being only a single series of long slender spines loosely apposed to their more robust neural arches. As remarked by Traquair, the maxilla is interpreted by Egerton as mandible (numbered 32), the palatine (or ectopterygoid) as maxilla (21), the suborbital as premaxilla (22), and the jugal as coalesced mesotympanic and hypotympanic (28d), Enniskillen Coll. Head of Chondrosteus acipenseroides, seen obliquely from below (after Traquair). [No. P. 2048.] Lettering of figs. 5 and 6:— ag., angular ; 7., branchiostegal rays ; cb., cerato-branchial ; ¢.h., cerato-hyal ; cl., clavicle ; d., dentary ; f., frontal; hm., hyomandibular ; m.pt., mesopterygoid ; mz., maxilla; op., operculum; pa.sph., parasphenoid; pt., palatine; ptf, post-frontal ; s.c/., supraclavicle; s.o., suborbital; s.op., suboperculum; sq., squamosal. CHONDROSTEIDZ. ay P. 616. Type specimen of Chondrosteus crassior, Egerton, figured loc. cit. pl. lxviii., displaying vertically crushed remains of the head, pectoral arch, and pectoral fins. The cranial roof-bones and the outer face of the clavicle (‘‘ scapulo- coracoid”) exhibit few coarse tuberculations, apparently not coated with ganoine; the pectoral fin-rays show few traces of nodose granulations. The clavicle has a distinct inferior limb, and, so far as preserved, resembles in shape that of Acepenser. Egerton Coll. P. 2048. Head and pectoral arch, with fins, inferior aspect, de- scribed and figured by R. H. Traquair, loc. cit. p. 252, fig. 3. The outline-illustration is copied, of one-half the natural size, in the accompanying fig. 5, and an actual drawing of the fossilis given in Pl. I. fig. 2. The only modification in Dr. Traquair’s interpretation occurs in the pectoral arch, where an accidental fracture (w) on each side led to the erroneous determination of the inferior limb of the clavicle as infraclavicle in the original description. The true infraclavicle (7.c/.) 1s well shown in the lithographed figure. gerton Coll. P. 2049. Head with opercular apparatus, pectoral arch and portions of the pectoral fins, lateral and partly inferior aspect, SS W\\t . Head and pectoral arch of Chondrosteus acipenserotdes, lateral and partly inferior aspect (after Traquair). [No. P. 2049.] For explanation of lettering see opposite page. 32 ACTINOPTERYGII. described and figured by R. H. Traquair, loc. cit. p. 251, fig. 2. The outline-illustration is copied, of slightly more than one-half the natural size, in the accompanying fig. 6, and explained by the lettering. The transverse cleft in the pectoral arch, though appearing as if a suture and inter- preted as such by Traquair, is proved by other specimens to be accidental ; the clavicle thus exhibits a large in- ferior limb. Egerton Coll. P. 7396. Head and opercular apparatus, exposed from the left side, the aspect being partly lateral and partly ventral. Many of the bones are well exhibited, and an elongated element between the inferior extremity of the hyomandibular and the quadrate region is especially noteworthy ; this may be an ossified symplectic, as remarked by Traquair, loc. cit. p. 250. Purchased. P. 3363-4, P. 3370. Three examples of the head and pectoral arch, with remains of the pectoral fins, the first shown from the dorsal aspect, the others from the lateral aspect. The clavicle in each exhibits a large inferior limb and an extensive inner laminar expansion; and the second fossil also seems to show, from its external ornamented aspect, the small infraclavicle. Enniskillen Coit. P. 3369, P. 3869 a, P. 4341. Three small slabs of Lias with frag- mentary remains of the head and pectoral arch. The first and third specimens exhibit, among other bones, the maxilla, palatine (or ectopterygoid), suborbital, and hyomandibular ; the second specimen displays the clavicle and supraclavicle. Enniskillen Coll, P. 2261 a-c. Three fragmentary small examples of the head and pectoral arch, the first displaying the operculum, among other bones. Egerton Coll. P. 2261 d. Small head and right pectoral fin. The maxilla, jugal, palatine (ectopterygoid), and inner pterygoid are well dis- played. Egerton Coll. 39494. Remains of small head and pectoral fins. Purchased, 1865. P. 4341 a. Remains of pectoral arch and fins. Enmskillen Coll. P, 4341 b. Remains of opercular apparatus and pectoral arch of a small fish, displaying both clavicles from the visceral aspect, and the infraclavicle from the same aspect on the CHONDROSTEID&. ; 33 right side. The right clavicle and infraclavicle are shown, of the natural size, in Pl. I. fig. 5. The clavicle (cl.) is precisely similar to that of Acipenser (fig. 15, p. 40) in shape, but the infraclavicle (2.cl.) 1s relatively smaller than the corresponding element of the recent genus. Enniskillen Coll. 35056. Trunk about 0°51 in length, wanting the pelvic fins. The anal fin is displaced, but exhibits both the series of basal cartilages. Purchased, 1860. P. 3371 a. Caudal region of a medium-sized fish, with the median fins somewhat crushed and broken and remains of the pelvic pair. Some of the neural spines of the axial skeleton are exhibited beneath the supports of the dorsal fin: and each seen in front view shows a bifurcation of its lower extremity. There are no distinct traces of heemal arches except at the base of the caudal fin. Enniskillen Coll. P. 3365. Very small imperfect caudal region, showing the pelvic, anal, and caudal fins. Enniskillen Coll. P. 3365 a. Dorsal and pelvic fins of a small fish. Hnniskillen Coll. P. 7397. Caudal fin of moderate size. Purchased. P. 3365 b. Another specimen, wanting the extremity of the upper caudal lobe. Ennskillen Coll. 39495. Caudal fin 0-28 in depth, displaying the caudal fulcral scales, one figured in Proc. Geol. Assoc. vol. xi. pl. i. fig. 7. Purchased, 1865. P. 3368. Two examples of the caudal fin, slightly smaller. Enmskillen Coll. Chondrosteus pachyurus, Egerton. 1858. Chondrosteus pachyurus, Sir P. Egerton, Phil. Trans. p. 883. Type. Tail; Museum of Practical Geology, London. The undermentioned specimens indicate a fish about twice as large as the ordinary C. acipenseroides, which is regarded by Egerton as specifically distinct from the latter. So far as known, the cranial roof-bones are ornamented with closely-arranged fine tuberculations ; and the caudal fulcral scales appear to be rela- tively broader than those of the type species, though also acuminate. Form. & Loc. Lower Lias: Dorsetshire. PART III. D o4 ACTINOPTERYGII. P. 7398. Plaster cast of tail, the original being the type specimen described by Egerton, loc. cit.; Lyme Regis. This is supposed to belong to the same individual as one of the following specimens. 28714. Crushed remains of head and pectoral arch, with a few fragmentary neural arches of the trunk and some well- preserved pectoral fin-rays, noticed by Egerton, loc. cit., and by the present writer in Proc. Geol. Assoc. vol. xi. (1889), p. 36; Lyme Regis. The tuberculations on the pectoral fin-rays are shown. Purchased, 1853. 28714a. Slab exhibiting the external tuberculated surface of three of the cranial roof-bones and other fragments, with an imperfect clavicle, described by Egerton, loc. cit.; Lyme Regis. The two principal cranial bones are described as mastoids (2. €., Squamosals), and the clavicle appears to be referred to as ‘‘ suprascapula.”’ Purchased, 1853. Genus GYROSTEUS, A. 8. Woodward. | [ Proc. Geol. Assoc. vol. xi. 1889, p. 36 (ew Agassiz, MS.).] An imperfectly definable genus comprising fishes of large size, hitherto known only by fragmentary specimens. External bones with or without a feeble ornamentation, destitute of ganoine; jaws toothless ; maxilla arched, not much expanded behind, but with a ereat upward and inward extension in its anterior half for palatine- pterygoid articulation; hyomandibular completely ossified; sub- operculum (?) large and quadrate. Small ossified ribs present (?). Scales absent, except on the upper caudal lobe, where they are thick; caudal fulcral scales large, without ganoine. Gyrosteus mirabilis, Agassiz, MS. 1844, Gyrosteus mirabilis, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 179 (name only). 1855. Sepia incomposita, M. Simpson, Foss. Yorkshire Lias, p. 21. [Fragment of bone; Whitby Museum. | 1858. Gyrosteus mirabilis, Sir P. Egerton, Phil. Trans. p. 888. 1876. Gyrosteus mirabilis, J. F. Blake, in Tate & Blake, Yorkshire Lias, p. 256, pl. ii. figs. 2, 3. 1889-90. Gyrosteus mirabilis, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p. 82, figs. 2-7; and The Naturalist, 1890, p. 101, figs. 1-6, - . CHONDROSTEID#. 35 Type. Various bones ; British Museum. The type species, of large size, probably attaining a length of not less than six or seven metres. Most of the external head-bones apparently ornamented with large, well-spaced tubercles, those on the suboperculum (?) tending to an arrangement in radiating lines. Maxilla smooth, its length somewhat more than twice as great as its maximum depth at the anterior expansion; the supposed sub- operculum as broad as deep, with excavated anterior border. Caudal fulcral scales smooth, or only in part faintly rugose. Form. § Loc. Upper Lias: Yorkshire. The following specimens were all obtained from the cliffs in the neighbourhood of Whitby. 36185. A large slab displaying numerous bones, among which may be recognized the hyomandibular, ceratohyal, supposed suboperculum, clavicle, supraclavicle, fragments of squa- mous tuberculated bone, and portions of fin-rays. The bone interpreted as suboperculum closely resembles that element in Chondrosteus, but is not coated with ganoine, being covered with coarse tuberculations, of which a few are arranged along the radiating lines of growth. Purchased, 1861. P. 3356 d-f. Three small slabs exhibiting various bones in a more or less fragmentary state. The left clavicle, probably belonging to the first slab, is shown from the outer aspect, of one-sixth the natural size, in fig. 14 (p. 40), and is described and figured by the present writer in Proc. Geol. Assoc. vol. xi. pp. 34, 35, fig. 4. The second slab in- cludes part of a spatulate bone, with remains of an external tubercular ornament. The third slab exhibits the bones in a remarkably friable and crushed condition, partly pyritised, and comprises both supraclavicles, some fin-rays, and part of a hyomandibular. Enniskillen Coll, P. 2262 a, b. Two examples of the parasphenoid bone, the first most nearly complete and shown of one-quarter the natural size, from the inferior aspect, in fig. 7. The general form of the element is much like that of the modern Aczpenser (fig. 8), but the expansion at the origin of the basiptery- goid processes is wider. Egerton Coll. p2 36 ACTINOPTERYGII, Fie. 7. Parasphenoid of Gyrosteus mirabilis, inferior aspect, one-fourth nat. size. [No. P. 2262 a.] Fig. 8. Parasphenoid of the recent Acipenser, inferior aspect. P. 33856 g. More imperfect parasphenoid associated with other fragments. Enniskillen Coll. P. 3356 a, h. Two examples of the hyomandibular, ossified appa- rently as far as the distal border, the first shown of one- third the natural size, from the lateral and posterior aspects, in fig. 9; described and figured loc. cit. pp. 32, 33, fig. 2. Enniskillen Coll. P. 3356 k. Hyomandibular probably of young, wanting the ossifi- cation of the expanded extremities. Enniskillen Coll. CHONDROSTEID&. Sa a. Fig. 9. b. Right hyomandibular of Gyrosteus mirabilis, lateral aspect (a), and posterior aspect (0), one-third nat. size. [No. P. 3356 a.] P. 33561. Left maxilla, shown of one-quarter the natural size from the outer, anterior, and inferior aspects in fig. 10. It differs from the corresponding bone of the recent Aci- penser (fig. 11) in the relatively greater steepness of the anterior border, and in the straightness, shortness, and posterior expansion of the hinder half of the element. 38 ACTINOPTERYGII. Fig. 10, a. Fig. 10, c. Fig. 11.—Left maxilla (mz.) and palatine (pl.) of the recent Acipenser, outer aspect. Fig. 10.—Left maxilla of Gyrosteus mirabilis, outer (a), anterior (0), and inferior (c) aspects, one-quarter nat. size. [No. P. 3356/.] s., symphysial extremity ; x., palatine process. CHONDROSTEID. 39 Viewed from the front and below, it appears as if the palatine bone were fused with the maxilla, as sometimes occurs in Acipenser. Enniskillen Coll. 43304. Ceratohyal, shown of one-third the natural size in fig. 13, described and figured loc. cit. pp. 33, 35, fig. 3. Purchased, 1871. P. 2262 c. Finer example of the same bone, labelled ‘‘ Gyrosteus mirabilis, Ag.” by Agassiz, shown of one-third the natural size in fig. 12, described and figured, zbzd. Egerton Coll. Fig. 13. ‘ qe, hs A GiB Same vy hag ie bee : aire, A\ \\ N \ - ==oo* Pe tal Ceratohyals of Gyrosteus mirabilis, one-third nat. size. [Nos. P. 2262 c, 43304. ] -euo {yoedse seuut ‘syrqnuw snajsotfhy jo eporavpovadns yysIy—9O] “SLA Is Is “YU TIX! ‘OZIS ‘d “ON] [¢9¢ 40 ‘qoadsv saqno ‘waswadiop yWeded BY} JO opOIAV[O YoT—"e] “Sy ‘peonpe [-p9cee “gq ON] ‘azIs ‘yeu YZXIS-ol0 qoadse seqno ‘s72qnsww snajsosh.H 30 S[PIAe[O IJe'T—"FI “SLT 4 vg ara ain Sh ‘\ \ in if AN SN AN ‘ V\i me \t \\ ACTINOPTERYGII. "CT “Sl "OT ‘SL AL CHONDROSTEIDA. P. 3356 m. Series of vertebral arches, each with a posterior ex- t the base and a truncated distal end which seems to have been originally invested with cartilage. The fossil probabl pansion a y represents the hemal arches of Gyrosteus mirabilis in the region of the caudal fin. Enniskillen Coll. oss @ 5 a oS ig en aa RE ive a § rot S58 cl b4 80 ae @r © a S sp q A Eq a R +> a O ae (2) "8 3 cs a, .4 5 Qn & eS D4 oO ws Fo ap 5 eel ce a To) DT os} (re) rain) AY closely- ird the natural described D, articulated and distally-bifurcating rays are well exhi- 9 b) The stout eular section, 7. Fnnskillen Coll i Be size in a 36, fig al fin displayed in irre th . cit. pp. 3: gured loc e Portion of caud shown of one and fi bited P. 3356 ¢ Bigs 7. [No. P. 3356 ¢.] Caudal fin-rays of Gyrosteus mirabilis; one-third nat. size. 42 ACTINOPTERYGII. P. 2262 e, P. 3358. Polished sections of similar rays; from Sands- end, near Whitby. Egerton § Enniskillen Colls. P. 3356 n. Series of unjointed rays, the longest piece preserved 0°5 in length, probably forming the anterior part of the pectoral fin. The foremost rays gradually increase in length, terminating successively on the anterior border ; and the two parallel rods of which each is composed are fused together at the pointed distal end. Enniskillen Coll. Several more imperfect bones of G'yrosteus mirabilis from the Enniskillen Collection are also registered under the general number P. 3356. All the typical examples of G'yrosteus are contained in an indurated matrix *; but evidence of a smaller Chondrostean, very probably of the same genus, is also found in a soft shale in the Whitby cliffs. The following are a few specimens :— P. 3357. Hyomandibular 0°18 in length. Enniskillen Coll. P. 3356 0. Crushed right clavicle, inner aspect, about 0:1 in depth. Enniskillen Coll. P. 2262d. Left supraclavicle, inner aspect, nearly 0°3 in maximum depth, differing from that of G. mirabilis in being com- paratively narrow. Egerton Coll. P. 3356 p. Undetermined bone. Enniskillen Coll. Family ACIPENSERIDA. Trunk elongate or elongate-fusiform ; tail heterocercal. External head-bones well developed, those of the cranial roof forming a con- tinuous shield, which comprises a median longitudinal series of azygous elements ; snout prominent and eye far forwards; mouth small, inferior, and suctorial, without teeth in the adult; no pre- maxilla; operculum present, but no branchiostegal rays. Squamation of trunk comprising few longitudinal series of overlapping bony scutes, with irregular intermediate small stellate ossifications ; the lateral rhombic scales and large fulcral scales on the upper caudal lobe robust. * This was probably obtained from the bed immediately above the Jet Rock (M. Simpson, Foss. Yorkshire Lias, ed. 2, 1884, p. xiii). ACIPENSERID &. 43 Genus ACIPENSER, Linneus. [Syst. Nat. ed. 10, 1758, p. 237.] External bones ornamented with tuberculations of ganoine. Jaws delicate, and minute pointed teeth present only in very young individuals ; spiracles present. A few slender ribs. Pectoral fins with a robust anterior ray or spine; pelvic, dorsal, and anal fins remote, the two latter opposed ; caudal fin inequilobate, extending to the extremity of the upper caudal lobe. Dermal scutes in five distinct series, one dorsal, two pairs lateral, not completely envelop- ing the caudal pedicle. Numerous scutes, pectoral spines, and fragments of bone indis- tinguishable from the corresponding parts of the existing Acipenser, are known from Tertiary formations; but no examples sufficing for specific diagnosis have hitherto been discovered. A brief enumera- tion of the known fossils is given below. Acipenser toliapicus, Agassiz, MS. 1844. Acipenser tohapieus, L. Agassiz, Poiss. Foss. vol. 11. pt. ii. p. 280 (name only). _ 1889. Acipenser tohapicus, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p26, pli. fig. 1 Type. Imperfect scutes; British Museum, A provisional name given to the earliest known scutes of Acipenser from the London Clay. The external surface is very deeply pitted, and the reticulations are nodose. Form. & Loc. Lower Eocene (London Clay): Isle of Sheppey. P. 3372. Two dorsal scutes intended by Agassiz to be the type specimens of the species, one labelled by that author, the other described and figured by the present writer, loc. cvt. Enniskillen Coll. P. 529. Somewhat larger scute, labelled by Egerton as a type speci- men. Egerton Coll. 37762. Well-preserved portion of another scute. Purchased, 1863. 24619. Imperfect left infraclavicle exhibiting very deep pits between the reticulations on the exposed outer face. Purchased, 1850. 44093. A less imperfect, larger example of the right infraclavicle 0-115 in length, showing the smooth inferior margin. Both in this and the previous specimen the external ACTINOPTERYGII. 44 Skeleton of Sturgeon (Acipenser). 1, posterior extremity of cartilaginous cranium beneath the head-plates; 2, upper jaw; 3, hyomandibular bone; 4, lower jaw; 6, gill-arches; 8, pectoral arch; a, neural arches and spines, placed above the notochord; b, hemal arches, placed below the notochord ; ¢, dorsal fin ; ¢, caudal fin; f, anal fin; g, pair of pelvic fins; 2, pair of pectoral fins; 7, ribs. ACIPENSERID &. 45 ornament has the appearance of not overlapping the superior margin; and there is a feeble superficial ridge extending downwards and backwards from the flexure of the bone, as in the existing species of Acipenser. Purchased, 1873. The following remains indistinguishable from Acipenser are also preserved in the Collection : — P. 5283. Fine lateral scute, noticed and figured in Proc. Geol. Assoc. vol. xi. 1889, p. 28, pl. 1. fig. 2; Lower Hempstead Beds, Hempstead, Isle of Wight. Presented by the Royal Society, 1887. P. 6475. Two portions of scutes and another fragment ; probably from the Hempstead Beds. Beckles Coll. 41892. Two portions of pectoral spines ; Upper Eocene, Hordwell, Hampshire. Purchased, 1870. P. 1533, P. 1533 a. Two imperfect pectoral spines and rolled frag- ments of two others, part of the ornament of one figured, loc. cit. pl. i. fig. 36; probably from the Hempstead Beds. Egerton Coll. P. 4946. Pectoral spine wanting distal extremity, resembling the York specimen figured, loc. cit. pl. 1. figs. 3, 3a; Hemp- stead Beds. Presented by John Edward Lee, Esq., 1885. The following remains indistinguishable from Acipenser have also been described :— Acipenser ornatus, J. Leidy, Proc. Acad. Nat. Sci. Philad. 1873, p-. 15, and Extinct Vert. West. Territ. (Rep. U.S. Geol. Surv. Territ.), vol. 1. pt. i. 1873, p. 350, pl. xxxii. fig. 58. —Miocene; Virginia. [Scute.] Avene sp., E. T. Newton, Vert. Forest Bed (Mem. Geol. Surv. 1882), p. 129, pl. xix. fig. 6; and Vert. Pliocene Dep. Britain (2d:d. 1891), p. 100.— Forest Bed Series ; Norfolk. [Cephalic plate; Museum of Practical Geology, London. | Acipenser sp., A. 8S. Woodward, Proc. Geol. Assoc. vol. xi. (1889), p. 28; Premier rayon de la dorsale d’un Poisson, ayant quelque rapport avec celui des Balistes, P. Gervais, Zool. et Pal. Frang. (1852), Explic. Planches, Poiss. Foss. p. 5, pl. Ixvui. fig. 33.—Lower Pliocene ; Montpellier, France. [Pectoral fin-spine. ] 46 ACTINOPTERYGII. Acipenser sp., A. S. Woodward, toe: cit. p. 29.—Red Crag; Suffolk. [Pectoral spines; York Museum. ] The dermal tubercles named Acipenser tuberculosus and A. molas- sicus by Probst are Selachian armour (see Part I. p. 89); and the so-called Acipenser cretaceus (A. Daimeries, Bull. Soc. Roy. Malacol. Belg. vol. xxvii. 1892, p. xvi) from the Senonian of Folx-les-Caves, Belgium, seems to be founded on the dermal plates of some fish related to Dercetis or Eurypholis. Family POLYODONTIDA. Trunk elongate or elongate-fusiform ; tail heterocercal. Bones of the cranial roof forming a discontinuous shield, with vacuities and with a median longitudinal series of small azygous elements on the rostral region ; snout much produced and eye far forwards; mouth large, with minute teeth in both jaws throughout life; no pre- maxilla; operculum and suboperculum present, but no branchio- stegal rays. Squamation of trunk rudimentary or absent; the lateral rhombic scales and large fulcral scales on the upper caudal lobe robust. Only two genera of this family are recognized among existing fishes, namely, Polyodon (or Spatularia) from the Mississippi, and Psephurus from Chinese rivers. Fossil remains are very rare, and only one definable extinct genus has hitherto been discovered. A fragmentary specimen, however, from the English Chalk may per- haps represent another member of the family. A detailed description of the skeleton of Polyodon is given by T. W. Bridge in Phil. Trans. 1878, pp. 683-733, pls. lv.-lvii. A figure of the skull is also published by R. H. Traquair, Ganoid Fishes Brit. Carb. Form. (Palzont. Soc. 1877), pl. vii. fig. 1 Genus CROSSOPHOLIS, Cope. [Amer. Nat. 1883, p. 1152 (Crassopholis). | External bones unornamented ; rostrum with small stellate bones. Dorsal and anal fins short-based and remote, the former arising in advance of the latter; caudal fin inequilobate, the upper lobe pre- dominant. Scales of trunk small and thin, each in the form of a small grooved disc with several posterior denticulations, arranged in oblique series, but not in contact; caudal fulcral scales numerous, broad at the base of the lobe, but becoming slender in its distal portion. POLYODONTIDA. 47 Crossopholis magnicaudatus, Cope. 1883. Crassopholis ata E. D. Cope, Amer. Nat. vol. xvii. p. 1153. 1885. Crossopholis magnicaudatils, E. D. Cope, zbzd. vol. xix. p. 1090. 1886. Cr ossopholis magnicaudatus, E. D. Cope, Mem. National Acad. Sci. vol. iii. p. 161, pl. with figs. 1-3. Type. Portion of trunk. The type species, with rostrum re; latively shorter than in Polyodon folium, and the operculum larger’ Bases of the teeth round and closely apposed. Dorsal fin-supports 16-18 in number, and rays probably 24. Scales subquadrate and more widely separated anterior to the dorsal fin than posterior to it. Measurements of type specimen :—Length from notch of caudal fin to line of origin of dorsal, 0°17; depth at origin of anal, 0-06; depth of caudai pedicle, 0-035; length of inferior caudal lobe, 0-11; depth and diameter of scales about 0:001 (Cope). Form/ § Loc. Eocene: Wyoming, U.S.A. Not/represented in the Collection. Genus PHOLIDURUS, A. 8S. Woodward. [Proc. Geol. Assoc. vol. xi. 1889, p. 31.] A provisional name applied to a Cretaceous Chondrostean fish known only by a portion of the tail. The caudal fulcral scales much resemble those of Psephurus, but are broader and flatter, less pointed, and evidently indicate a stout depressed fish. The caudal fin-rays are ornamented with ganoine. Pholidurus disjectus, A. S. Woodward. 1889. Pholidurus disjectus, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p- 31, pl. i. figs. 4, 5. Type. Portion of tail; British Museum. The type species, known only by the fragment mentioned below. Caudal fulcral scales very flat, with rounded and obtuse apex ; their exposed surface ornamented with thick ganoine in irregular dots and short wavy lines, more or less clustered, especially near the margin. Caudal fin-rays very robust, the superficial ganoine thick and rugose, not always completely covering the exposed faces of the successive joints. It is still uncertain whether or not the portion of a depressed rostrum described, loc. cit. p. 31, pl. i. fig. 6, belongs to this fish. Having made a renewed examination of the Jurassic Coelacanths at 48 ACTINOPTERYGII. Munich, the writer is now inclined to withdraw his comparison of this fossil with the supposed rostrum of those fishes (see supra, Pt. IT. p. 395). Form. & Loc. Senonian: Kent. 33221-24. Type specimen, being a portion of the tail described and figured, loc. cit.; Upper Chalk, Gravesend. The largest caudal fulcral scale measures 0°024 in maximum breadth, and 0-027 from the apex to the bifurcation of the base. Taylor Coll. Division B.—Baseosts rudimentary or absent in pelvic fins ; dermal rays of dorsal and anal fins equal in number to the endoskeletal supporting elements ; tail never hetero- cercal, usually abbreviate-heterocercal or homocercal, rarely diphycercal. Suborder II. PROTOSPONDYLI. ne Notochord persistent, or if more or less replaced by vertepre, the pleurocentra and hypocentra in part of the caudal region re- maining distinct and alternating even when fully developed; tail abbreviate-heterocercal. Mandible complex, with well-developed © - splenial rising into a coronoid process, which is completed by a distinct coronoid bone. Infraclavicular plates wanting in the pectoral arch; pectoral fin with more than five basals. Scales ganoid. In the living forms—air-bladder connected with the cesophagus in the adult, optic nerves not decussating, but forming a chiasma, and intestine with a spiral valve. Synopsis of Families. I. Mandibular suspensorium vertical or in- clined forwards and gape of mouth small. Trunk more or less deeply fusiform ; vertebrae not more than rings; teeth styliform or tritoral; fulcra large, and dorsal fin not extending more | than half the length of the trunk.. SEMIONOTID& (p. 49). Trunk elongate or elongate-fusiform ; vertebre not more than rings; teeth styliform ; fulcra variable, and dorsal fin extending at least half the length Meebo viral 0, ett. Aete W atie bole ciel MACROSEMIID& (p. 163). SEMIONOTIDA. 49: Trunk deeply fusiform or cycloidal ; no ossifications in notochordal sheath ; teeth tritoral; opercular apparatus reduced ; fulcra absent, and dorsal FE CMONSWICO 5 ea’ actin ae ee a ee PYCNODONTIDZ (p. 189.) II. Mandibular suspensorium inclined back- wards and gape of mouth wide. Trunk elongate or fusiform; vertebre very rarely more than incomplete rings ; marginal teeth large and conical, becoming minute on most of the inner dentigerous bones; premaxille in contact mesially ; fulcra large, and dorsal fin short .. EuGNaTHip™® (p. 285). Trunk elongate or elongate-fusiform ; vertebrae variable; often complete discs; marginal teeth large and conical, inner teeth mostly minute ; premaxille in contact mesially ; fulcra minute or wanting, and dorsal Ma variable im lenpth yest ss Amp (p. 360). Trunk elongate-fusiform ; notochord per- ~ sistent, sometimes with very feeble ossifications in the sheath ; ethmoid fused with the vomers ad forming a prominent rostrum, which sepa- rates the premaxille; teeth large and conical on part at least of all the dentigerous bones; fulcra minute or absent, fin-rays slender and closely set, and dorsal fin short .......... PACHYCORMID& (p. 374). Family SEMIONOTIDA. Trunk more or less deeply fusiform, rarely cycloidal. Cranial and facial bones all robust and opercular apparatus complete, but branchiostegals sometimes reduced; parietals meeting in the middle line ; mandibular suspensorium vertical or inclined forwards, and gape of mouth small; teeth styliform or tritoral, especially well-developed on the inner bones of the mouth, and with vertical successors. Notochord persistent, the vertebree never advancing beyond the annular stage. Fin-rays robust, the majority well- spaced, articulated and divided distally ; fulcra large ; dorsal fin not extending more than half the length of the trunk. Scales rhombic, except occasionally in the caudal region. The osteological characters of this family are best known in Lepidotus and Dapedius, and a detailed description of each of those genera is given below (pp. 78, 128). PART III. E 50 é ACTINOPTERYGII. Synopsis of Genera. I. Trunk regularly and deeply fusiform. (a) Teeth all styliform, or reduced within the mouth. Dorsal fin arising well in advance of anal; no enlarged ridge-scales .. Dorsal fin arising well in advance of anal; dorsal ridge-scales prominent Dorsal fin arising well in advance of anal; scales comparatively thin, and much the thinnest on caudal region ; no enlarged ridge-scales. . [Genus known only by detached scales, which are much deeper than broad, with a narrow overlapped margin, a large peg-and-socket articulation, and no sharp inner keel ; hinder border denticulated. Dorsal fin opposed to anal; dorsal and ventral ridge-scales prominent .. (6) Marginal teeth styliform; imner teeth stouter and mostly tritoral. [Genus known only by marginal teeth, of which crown is expanded to chisel- or gouge-shaped edge.... Dorsal fin arising well in advance of the anal, both these fins much elevated and fringed with fulcra which are scarcely enlarged at the base; angles of overlapped margin of scales not produced .. Dorsal fin arising well in advance of the anal, neither of these fins excessively elevated, but with a cluster of enlarged fulcra at the base; angles of overlapped mar- gin of scales produced forwards ; mo) Sular place remit lets ve II, Trunk much deepened, often irregular in form. Trunk very deeply fusiform or regu- larly cycloidal; teeth stout and styliform, clustered within the mouth; dorsal fin much extended and anal opposed to its hinder half; all scales rhombic, with feeble inner rib; ridge-scaJes in- conspicuous ...... afopetesene asthe dass Acentrophorus (p. 51). Sennonotus (p. 55). Aphnelepis (p. 64). Serrolepis (p. 65). | Pristisomus (p. 66). Sargodon (p. 67).| Colobodus (p. 68). Lepidotus (p. 77). Dapedius (p. 128). SEMIONOTIDZ. 51 Trunk irregularly cycloidal, with strongly-arched back; marginal teeth slender and styliform ; dor- sal and anal fins opposed, not much extended ; all scales rhom- - bic, with thick inner rib, very deep and narrow on flank; ridge- scales conspicuous ........0005 Cleithrolepis (p. 154). Trunk irregularly cycloidal, with strongly-arched back; dorsal fin much extended and anal opposed to its hinder portion; abdominal scales rhombic, with thick inner rib; caudal scales more or less eyclordal S41 iio eae oa Aetheolepis (p. 157). Trunk irregularly cycloidal, with ab- dominal protuberance; marginal teeth slender and styliform; dorsal fin much extended and anal op- posed to its hinder half; all scales rhombic, with thick inner rib, but those of caudal region compara- tively delicate ; ventral ridge- scales conspicuous ............ Tetragonolepis (p. 158). Genus ACENTROPHORUS, Traquair. (Quart. Journ. Geol. Soc. vol. xxxiii. 1877, p. 565.] Trunk fusiform. Teeth slender; opercular apparatus well- developed, with a narrow arched preoperculum. Fins small, with very large fulcra; dorsal fin short, opposed to the space between the pelvic pair and the anal; caudal fin symmetrical, slightly forked. Scales rhombic, smooth or feebly ornamented, the dorsal ridge- series inconspicuous ; the scales of the flank not much deeper than broad, and those of the ventral aspect nearly equilateral. All the fishes placed here were originally assigned to the genus Paleoniscus, and their distinctness was first pointed out by C. F. Liitken, Palzontogr. vol. xxii. (1873), p. 26, footnote. Acentrophorus varians (Kirkby). 1862. Paleoniscus varians, J. W. Kirkby, Ann. ae, Nat. Hist [3] vol. ix. p. 267, 1864, Paleoniscus var vans, J. W. Kirkby, Quart. enh Geol. Soe. vol. xx. p. 353, pl. xviii. fig. 2. 1877. Acentrophorus varians, R. H. Traquair, Quart. Journ. Geol. Soe. vol. xxxili. p. 565. BQ 52 ACTINOPTERYGII. Type. Imperfect fish ; Newcastle-upon-Tyne Museum. The type species, attaining a length of about 0°09. Head with opercular apparatus occupying slightly less than one-quarter of the total length ; maximum depth of trunk equalling about twice that of the caudal pedicle, and comprised four times in the total length. Head and opercular bones faintly rugose; operculum broader than deep. Dorsal fin with about 10, and anal with 8 rays. Scales unornamented, not serrated. Form. & Loc. Upper Permian (Magnesian Limestone): Durham. 36388-90. Two typical specimens, the first wanting the extremity of the snout and the paired fins, the second more imper- fect ; also a smaller fish; Fulwell Hill, near Sunderland. Presented by Sir Hedworth Williamson, Bart., 1862. P. 3481 a, b. Two fine specimens about 0:09 in length, somewhat fractured, but showing parts of all the fins; Fulwell Hill. In the second specimen the scales are distinctly shown to be smooth. Enniskillen Coll. P. 3481 c. Slightly smaller fish displaying portions of the median fins; Fulwell Hill. Hwuskillen Coll. P. 3481, P. 3483, P. 4342. Four more imperfect specimens, three being much smaller than the preceding; Fulwell Hill. One of the two specimens occurring on a single slab appears to exhibit traces of styliform teeth in the dentary, and enlarged anal scales in advance of the median fin. Enniskillen Coll. P. 1032. Fish about 0-065 in length and two smaller more im- perfect specimens; Fulwell Hill. Egerton Coll. P. 1032 a. The hinder abdominal and caudal region of two asso- ciated individuals; Fulwell Hill. The dorsal ridge-scales are shown to be relatively large, but not acuminate. Egerton Coll. 44210. Small well-preserved fish, wanting the extremity of the head and tail; Fulwell Hill. Purchased, 1873. Acentrophorus abbsi (Kirkby). 1862. Paleoniscus abbsit, J. W. Kirkby, Ann. Mag. Nat. Hist. [3] vol. ix. p. 268. 1864. Paleoniscus abbsit, J.W. Kirkby, Quart. Journ. Geol. Soc. vol. xx. p. 355, pl. xviii, fig. 3. 1877 Acentrophorus abbsii, R. H. Traquair, Quart. Journ. Gevl. Soc. vol. xxxili. p. 565, SEMIONOTID &. ie Type. Imperfect fish ; Newcastle-upon-Tyne Museum. A species about as large as the type, but more slender. Head with opercular apparatus occupying slightly less than one-quarter of the total length ; maximum depth of trunk equalling about twice that of the caudal pedicle and comprised at least five times in the total length. Head and opercular bones faintly rugose. Scales unornamented, not serrated, relatively larger than in the type species. Form. & Loc. Upper Permian (Magnesian Limestone): Durham. 44211. Fish about 0°06 in length, showing some of the supports of the anal and caudal fins, and an enlarged anal scale; Fulwell Hill, near Sunderland. Purchased, 1873. P. 3482. Imperfect remains of a fish about 0°085 in length; Fulwell Hill. Enniskillen Coll. P. 4342 a. Specimen as large as the first showing only fragments of the fins; Fulwell Hill. Enniskillen Coll. P. 4343. More imperfect smaller specimen ; Fulwell Hill. Enniskillen Coll. Acentrophorus altus (Kirkby). 1862. Paleoniscus latus, J. W. Kirkby (non Redfield), Ann. Mag. Nat. Hist. [3] vol. ix. p. 268. . 1864. Paleoniscus altus, J. W. Kirkby, Quart. Journ. Geol. Soe. vol. xx. p. 306, pl. xviii. fig. 1. 1877. Acentrophorus altus, R. H. Traquair, zbzd. vol. xxxili. p. 565. Type. Imperfect fish ; Newcastle-upon-Tyne Museum. A species about as large as the type, but more robust. Head with opercular apparatus occupying at least one-quarter of the total length ; maximum depth of trunk equalling about twice that of the caudal pedicle, and comprised only three times in the total length. Head and opercular bones faintly rugose; operculum as deep as broad. Scales unornamented, not serrated. Form. & Loc. Upper Permian (Magnesian Limestone): Durham. The only known examples of this species were obtained from the Old Quarry, Fulwell, and there are none in the Collection. Acentrophorus glaphyrus (Agassiz). 1835. Paleoniscus glaphyrus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 98, plex erfies. 12. 1850. Paleoniscus glaphyrus, W. King, Permian Foss. (Pal. Soc.), p. 224, pl. xxii. fig. 3 (? fig. 4). 54 _ ACTINOPTERYGII. 1855. Paleoniscus glaphyrus, F. M‘Coy, Brit. Paleeoz. Foss. p. 607. 1877. Acentrophorus (?) glaphyrus, R. H. Traquair, Quart. Journ. Geol. Soe. vol. xxxill. p. 562. Type. Imperfect fish; York Museum. Form and proportions as in the type species, but scales con- spicuously serrated. Form. & Loc. Upper Permian (Marl Slate): Durham and North- umberland. There are no typical examples of this species in the Collection ; but the undermentioned are probably to be regarded as smail (or young) specimens, according to Egerton (in King, Permian Foss. p. 225, pl. xxii. fig. 4) :— 35732. Imperfect trunk, exhibiting traces of serrations on the scales ; Marl Slate, probably from Midderidge, Durham. Purchased, 1860. P. 52. Fine specimen 0-043 in length, showing all the fins but not exhibiting any serrations on the scales preserved ; Marl Slate, Ferry Hill, Durham. Presented by Rev. Canon Greenwell, 1880. P. 355. Two similar but more imperfect fishes; Ferry Hill. Purchased, 1881. P. 5140. Elongated smaller specimen 0-035 in length ; Marl Slate, Cullercoats, Northumberland. Presented by William Dinning, Esq., 1886. 41317. A more imperfectly preserved small specimen, in counter- part; Ferry Hill. Purchased, 1869. A larger fish than any of the preceding, too imperfectly preserved for certain determination, but very much resembling Acentrophorus, is described by J. 8S. Newberry from the Trias of Chicopee Falls, Mass., U.S.A., under the name of Acentrophorus chicopensis (Foss. Fishes Trias. N. Jersey and Connecticut, 1888, p. 69, pl. xix. figs. 3, 4). The type specimens are preserved in Yale College Museum, New Haven, Conn., and there are no examples in the Collection. To this genus A. Fritsch also ascribes some fragmentary remains from the Lower Permian of Bohemia, under the name of Acentro- phorus dispersus (Fauna der Gaskohle, &c., Bohmens, vol. iii. 1894, p- 81, woode. no. 279, pls. cxili., cxiy.). SEMIONOTID A. 55 Genus SEMIONOTUS, Agassiz. [Neues Jahrb. 1832, p. 144.] Syn. Ischypterus, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. iii- 1847, p. 277. Trunk fusiform. Marginal teeth slender, conical, and somewhat spaced, inner teeth stouter; opercular apparatus well-developed, with a narrow arched preoperculum. Ribs ossified. Fin-fulera large. Paired fins small; dorsal fin large, arising at or behind the middle of the back and in part opposed to the relatively small anal ; caudal fin slightly forked. Scales smooth or feebly ornamented, and the narrow overlapped margin not produced at the angles ; flank-scales not more than twice as deep as broad, and those of the ventral aspect nearly as deep as broad ; the dorsal ridge-series of acuminate scales forming a prominent crest. . Semionotus bergeri, Agassiz. [Plate II. fig. 3.] 1832. Paleoniscum arenaceum, H. A. C. Berger, Verstein. Sandst. Coburg. Gegend. p. 18, pl. i. fig. 1. 1833. Semionotus spixi, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 8 (name only). 1833-86. Semionotus bergert, L. Agassiz, ibid. pp. 8, 224, pl. xxvi. figs. 2, 3. 1834. Semionotus bergert, L. Agassiz, Neues Jahrb. p. 380. 1848, Semionotus esox, H. A. OC. Berger, Neues Jahrb. p. 86. [Dis- torted fish; Royal Geological Museum, Gottingen. | 1851. Semionotus bergert, C. von Schauroth, Zeitschr. deutsch, geol. Ges. vol. ili. p. 405, pl. xvii. 1854, Semionotus, J. G. Bornemann, zbid. vol. vi. p. 612, pl. xxv. 1854. Semionotus bergert, H. A. C. Berger, Neues Jahrb. p. 321. (?) 1861. Semzonotus ee O. Fraas, Wiirtt. Jahresh. vol. xvii. pp. 93, 94, pl. i. fig. 6 1864. Neneatiotiis bergert, J. Striiver, Zeitschr. deutsch. geol. Ges. vol. xvi. p. 305, pl. xiii, figs. 1, 3, 4. Type. Imperfect fish ; University Geological Museum, Gottingen. The type species, a fish more than three times as long as its greatest depth, attaining a length of about 0:18. Trunk regularly fusiform, the depth of the caudal pedicle somewhat more than one- third as great as the maximum depth of the abdominal region. Head with opercular apparatus occupying nearly one-quarter of the total length; the external bones sparsely tuberculated. Pelvic fins arising nearly midway between the pectorals and the anal ; dorsal fin arising immediately behind the middle of the back, much 56 ACTINOPTERYGII. more than half as deep as the trunk at its point of origin and comprising about 16 rays; anal fin opposed to the hinder half of the dorsal, the longer rays when adpressed reaching to the base of the caudal. Scales smooth, except those of the middle of the flank, which are almost as broad as deep and crimped towards their serrated posterior border ; dorsal ridge-scales sharply pointed. Form. & Loc. Keuper: Coburg and Thuringia. P. 7399. Slab ofsandstone with three imperfect individuals, variously crushed, in counterpart ; Coburg. One specimen is shown of the natural size in Pl, II. fig. 3. The differences in the curvature of the dorsal margin are conspicuous and doubtless due entirely to accidental distortion. Some of the head and opercular bones are shown, ornamented with sparse tuberculations ; and part of the upper jaw of one individual exhibits a few stout conical teeth, which were not improbably arranged upon the vomer, while traces of spaced, slender, styliform teeth occur in the opposing lower jaw. Some of the fin-rays are well displayed, exhibiting the unjointed base and the very close articulations beyond. Purchased, 1884. P. 3623. Obscure remains of small specimen ; Coburg. Enniskillen Coll. Semionotus kapffi, Fraas. 1861. Semionotus kapffi, O. Fraas, Wurtt. Jahresh. vol. xvii. pp. 91, 95, pl. i. figs. 1-3. Type. Imperfect fishes ; Stuttgart Museum. A small species, about two and a half times as long as its maximum depth, attaining a length of about 0-1. Trunk deeply fusiform, the depth of the caudal pedicle not more than one-third as great as the maximum depth of the abdominal region. Head with opercular apparatus occupying nearly one-quarter of the total length; snout acutely pointed. Pelvic fins arising much nearer to the anal than to the pectoral fins; median fins as in the type species. Scales smooth and not serrated, those of the middle of the flank much deeper than broad ; dorsal ridge-scales produced into slender points. Form. & Loc. Middle Keuper: Wiirtemberg. 38654—58. Ten small slabs of sandstone with remains of several individuals ; Haslach, near Stuttgart. Purchased, 1864. P. 1545. Imperfect specimen, wanting the caudal extremity ; Haslach. ; Egerton Coll. SEMIONOTID, AY 38660. Several portions of sandstone with remains chiefly of this species ; Stuttgart. Purchased, 1864. 2845. Two specimens exhibiting portions of the squamation and the median fins of a large individual; Stuttgart. Van Breda Coll. Semionotus brodiei, Newton. 1887. Semitonotus brodiet, E. T. Newton, Quart. Journ. Geol. Soc. vol. xliii. p. 539, pl. xxii. figs. 1-7. Type. Imperfect fishes ; collection of Rev. P. B. Brodie. A small imperfectly known species, attaining a length of about 0-1. The maximum depth of the trunk equalling nearly half its length from the pectoral arch to the base of the caudal fin, and the caudal pedicle slender. Pelvic fins arising midway between the pectorals and anal, immediately in advance of the dorsal. Scales almost entirely smooth, a few with feeble traces of oblique ridges ; those of the anterior part of the flank serrated and about twice as deep as broad. The apparently great depth of the principal flank-scales in this species is probably exaggerated by crushing in the imperfect speci- mens hitherto discovered. Form. & Loc. Upper Keuper: Warwickshire. P. 5207. Imperfect distorted trunk, noticed and scales figured Joc. cit. p. 537, pl. xxii. fig. 7; Shrewley. Presented by Rev. P. B. Brodie, 1886. Semionotus altolepis, Deecke. 1889. Semionotus altolepis, W. Deecke, Paleeontogr. vol. xxxv. p. 120, pl. vi. fig. 10, Type. Nearly complete fish. A species attaining a length of about 0:12. Trunk regularly fusiform, the depth of the caudal pedicle about one-third the maximum depth of the abdominal region, Length of head with opercular apparatus nearly equal to the maximum depth of the trunk, and somewhat exceeding one-quarter of the total length of the fish; external bones ornamented with tubercles and ruge. Dorsal fin arising about the middle of the back, and the anal fin arising opposite its hinder extremity. Scales smooth, those of the flank in part about twice as deep as broad, and all the principal scales serrated. Form. & Loc. Muschelkalk : Perledo, Como, Italy. Not represented in the Collection. 08 ACTINOPTERYGII. Semionotus capensis, A. S. Woodward. 1888, Semionotus capensis, A. S. Woodward, Quart. Journ. Geol. Soc. vol. xliv. p. 138, pl. vi. figs. 1-5. Type. Nearly complete fishes; British Museum. A species attaining a length of about 0-18. Trunk regularly fusiform, with comparatively slender caudal pedicle. Length of head with opercular apparatus about equal to the maximum depth of the trunk, and contained four times in the total length of the fish ; external bones smooth. Pelvic fins arising nearly midway between the pectorals and the anal; dorsal fin arising about the middle of the back, behind the origin of the pelvic pair, and comprising 12 rays; anal fin arising opposite the hinder extremity of the dorsal, with about 8 rays, the longest when adpressed reaching to the base of the caudal. Scales smooth, none serrated, and those of the flank scarcely deeper than broad. Form. & Loc. Upper Karoo Formation (Stormberg Beds): Ficks- burg, Orange Free State, South Africa. P. 4089. The type specimen, being a slab partly in counterpart, with remains of four fishes. Presented by the Orange Free State National Museum, through Hugh Eaton, Hsq., M.D., 1883. P. 6861. Slab with remains of six fishes, partly in counterpart. Impressions of the styliform teeth are well shown in one specimen. Presented by H. Savory, Esq., 18938. P. 6943. Three specimens, one head displaying the styliform teeth in the premaxilla and some of the circumorbital bones in impression. Presented by David Draper, Esq., 1893. Semionotus fultus (Agassiz). 1833-36. Paleoniscus fultus, LL. Agassiz, Poiss. Foss. vol. ii. pt. i. pp. 4, 48, pl. viii. figs. 4, 5. 1841. Paleoniscus fultus, W. C. Redfield, Amer. Journ. Sci. vol. xl. p. 25. 1841. Palzoniscus macropterus, W. OC. Redfield, ibid. p. 25. 1847. Ischypterus fultus, Sir P. Egerton, Quart. Journ. Geol. Soc. Ol ihG o A 1850. Ischypterus fultus, Sir P. Egerton, 2id. vol. vi. pp. 8, 10. 1877. Ischypterus fultus, R. H. Traquair, bid. vol. xxxiil. p. 509. 1888. Ischypterus fultus, J. S. Newberry, Foss. Fishes Trias. N. Jersey and Connecticut (Mon. U.S. Geol. Surv. no. xiv.), p. 34, pl. vi. fioveZ epleavade die al!: 1888, Ischypterus macropterus, J. S. Newberry, ibid. p. 41, pl. xi. fig. 1. SEMIONOTIDZA. 59 Type. Imperfect trunk, wanting head. The type species of the so-called Ischypterus, attaining a length of about 0°2. Trunk regularly fusiform, the depth of the caudal pedicle more than one-third as great as the maximum depth of the abdominal region. Length of head with opercular apparatus about equal to the maximum depth of the trunk, and somewhat more than one-quarter of the total length of the fish. Pelvic fins arising nearer to the anal than tothe pectorals and immediately in advance of the dorsal; anal fin, with seven rays, partly opposed to the hinder half of the dorsal. Scales smooth and not serrated, those of the middle of the flank scarcely deeper than broad ; dorsal ridge- scales acuminate. Form. & Loc. Triassic: Massachusetts, Connecticut, and New Jersey, U.S.A. P. 1036. Imperfect fish; Durham, Connecticut. Egerton Coll. P. 1035. Fish with well-preserved squamation; Boonton, New * Jersey. Egerton Coll. P. 3511. Impression of trunk apparently deepened by distortion in the abdominal region; Massachusetts. Enniskillen Coll. P. 1017 a, b. Two small specimens, one wanting head, the other wanting caudal region; Sunderland, Mass. Lgerton Coll. P. 3511 a. Fragmentary remains, probably of this species ; Sunder- land. Enniskillen Coll. Semionotus tenuiceps (Agassiz). 1835-36, Hurynotus tenuiceps, L. Agassiz, Poiss. Foss. vol. ii. pt. i. pp. 159, 308, pl. xiv e. figs. 4, 5. 1837. Paleoniscus latus, J. H. Redfield, Ann. Lyceum Nat. Hist. New York, vol. iv. p. 38, pl. ii. 1837. Hurynotus tenuiceps, J. H. Redfield, zd:d. p. 39. 1841. Paleoniscus latus, W. C. Redtield, Amer. Journ. Sci. vol. xli. p. 25. 1841. Eurynotus tenuiceps, HK. Hitchcock, Geol. Massachusetts, vol. ii. p. 499, pl. xxix. figs. 1, 2. 1850. Ischypterus latus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. vi. p. 10. 1857. Eurinotus ceratocephalus, E. Emmons, Amer. Geology, pt. 6, p- 144, pl. ix a. 1860. Eurinotus ceratocephalus, E. Emmons, Man. Geology, ed. 2, p. 188, fig. 164. 60 ACTINOPTERYGII. 1877. Ischypterus latus, R. H. Traquair, Quart. Journ. Geol. Soc. vol. xxxili. p. 559. 1888. Ischypterus tenuiceps, J. S. Newberry, Foss. Fishes Trias. N. Jersey and Connecticut (Mon. U.S. Geol. Sury. no. xiv.), p. 32, pl. v. figs. 1-3, pl. vil. fig. 3. 1888. Ischypterus latus, J. S. Newberry, ibid. p. 46, pl. xiii. fig. 3. 1889. Allolepidotus americanus, W. Deecke, Paleeontogr. vol. xxxv. p. 114. Type. Imperfect fish ; Geological Society of London. A species attaining a length of about 0-2. Trunk with con- siderably arched dorsal border, the depth of the caudal pedicle more than one-third as great as the maximum depth of the abdominal region. Length of head with opercular apparatus less than the maximum depth of the trunk, and contained four times in the total length of the fish. Fins asin S. fultus. Scales smooth and not serrated, those of the middle of the flank in part twice as deep as broad; dorsal ridge-scales large and conspicuous, comparatively obtuse in large specimens. Form. & Loc. Triassic: Massachusetts, Connecticut, and New Jersey. 3854849. Two small fishes, imperfectly preserved; Sunderland, Mass. Purchased, 1864. P. 3511 b. Specimen about 0°18 in length ; Massachusetts. Enniskillen Coll. P. 1017-8. Four fragmentary specimens, displaying the deepened scales on the flank ; Sunderland, Mass. Egerton Coll. P. 7400. Fish 0°145 in length ; Connecticut. . Presented by Prof. C. U. Shepard. 38547. Two similar specimens ; Connecticut. Purchased, 1864. 28429. Slab with two specimens ; Connecticut. Mantell Coll. 26591. Middle portion of large fish; Connecticut. Presented by Dr. J. J. Bigsby, 1851. P. 3512. A very large imperfect specimen, doubtfully of this species ; Boonton, New Jersey. Enniskillen Coll. Semionotus alsaticus, Deecke. 1889. Semionotus alsaticus, W. Deecke, Paleontogr. vol. xxxv. p. 104, TE yy 10, Ile Type. Nearly complete fish; Strassburg Museum.” SEMIONOTID &. 61 ‘An elongated species, attaining a length of about 0°15; the depth of the caudal pedicle nearly equalling half the maximum depth of the abdominal region. Length of head with opercular apparatus slightly less than the maximum depth of the trunk, and contained five times in the total length of the fish; external bones coarsely rugose. Pelvic fins relatively large, nearer to the anal than to the pectorals ; dorsal fin arising behind the origin of the pelvic pair, about as deep as long, and the anal arising opposite its hinder extremity. Scales smooth, scarcely deeper than broad upon the flank. Form. & Loc. Bunter Sandstone : Wasselnheim, Alsace. Not represented in the Collection. Semionotus tenuis, A. 8. Woodward. 1890. Semronotus tenuis, A. S. Woodward, Mem. Geol. Surv. N.S. Wales, Palzont. no. 4, p. 31, pl. vi. fig. 3. Type. Imperfect fish; Geological Survey Museum, Sydney. An elongated species, attaining a length of about 0°13; caudal pedicle slender, its depth contained two-and-a-half times in the maximum depth of the abdominal region. Length of head with opercular apparatus not less than the maximum depth of the trunk, and equalling somewhat more than one-fifth of the total length of © the fish. Fin-fulera large and very slender; dorsal fin arising about the middle of the back, the length of the first ray equalling the depth of the trunk at its insertion; anal fin arising opposite the hinder extremity of the dorsal. Scales smooth, those of part of the flank twice as deep as broad. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. Not represented in the Collection. The following specimens are not specifically determined :— 38659. Imperfect head and abdominal region of a comparatively large and elongated fish with smooth scales; Keuper, Stuttgart. Purchased, 1864. P. 1546. Slab with imperfect remains of three small fishes ; Keuper, Coburg. Egerton Coll. The following species of Semionotus, all from Europe except the first, have been founded upon specimens which are mostly fragmentary and are not represented in the Collection :— _Semionotus australis, A. 8S. Woodward, Mem. Geol. Sury. N.S. Wales, Paleont. no. 4 (1890), p. 31, pl. vi. fig. 2.— 62 ACTINOPTERYGII. Lower Hawkesbury-Wianamatta Series ; Gosford, New South Wales. [Trunk, wanting head ; Geological Survey Museum, Sydney. | Semionotus elongatus, O. Fraas, Wirtt. Jahresh. vol. xvii. (1861), pp. 93, 95, pl.i. figs. 4, 5.—Middle Keuper; Stuttgart. [Distorted fish; Stuttgart Museum. | Semionotus gibbus, K. von Seebach, Zeitschr. deutsch. geol. Ges. vol. xviii. (1866), p. 7 (gibber, errore); W. Deecke, Pale- ontogr. vol. xxxv. (1889), p. 105.—Bunter Sandstone ; Bernburg, Anhalt. [Fragmentary trunk; University Geological Museum, Gottingen. | Semionotus gibbus, F. Bassani (non Seebach), Atti Soc. Ital. Sci. Nat. vol. xxix. (1886), p.37.—Triassic; Besano, Lombardy. [Nearly complete fish; Milan Museum. | Semionotus letticus, O. Fraas, Wiirtt. Jahresh. vol. xvii. (1861), p- 97, pl. i. fig. 8.—Upper Triassic (Lettenkohl); Hoheneck, Wirtemberg. [Imperfect fish; Stuttgart Museum. | Semionotus nilsson, L. Agassiz, Poiss. Foss. vol. ii. pt. i. (1837), p. 229, pl. xxviia. figs. 1-5; B. Lundgren, Kongl. Fysiogr. Sallsk. Minneskr. 1878, no. v. p. 32, pl. 11. fig. 79.—Rheetie ; Hoeganaes, Sweden. [Head and anterior portion of trunk ; Museum of Comparative Zoology, Cambridge, Mass., U.S.A. | Semionotus serratus, O. Fraas, Wiirtt. Jahresh. vol. xvii. (1861), p. 97, pl.i. fig. 7—Middle Keuper; Hiitten, Wirtem- berg. [Anterior portion of fish; Stuttgart Museum. | (? Colobodus.) Fragments of Semionotus have also been described from the Upper Keuper of Colwick Wood, Nottingham (K. T. Newton, Quart. Journ. Geol. Soc. vol. xliii. 1887, p. 539, pl. xxii. fig. 8), and from the Bunter Sandstone of Inzlingen, near Basle, Switzerland (W. Deecke, Paleontogr. vol. xxxv. 1889, p. 104, pl. vi. fig. 7: Basle Museum) ; and the present writer has examined characteristic specimens from the Rhetic probably of Bur Croweombe (Bath Museum) and Haps- ford Mill, Vallis, Somersetshire. Nearly complete fishes, variously crushed and distorted and some- times imperfectly preserved, have been described from the Trias of North America under the following names. They may be con- veniently referred to the genus Semionotus, and doubtless represent much fewer species than are here enumerated :— Ischypterus agassizi, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. vi. (1850), p. 10; J. 8. Newberry, Foss. Fishes Trias. SEMIONOTIDZ®. 63 N. Jersey & Connecticut (Mon. U.S. Geol. Surv. no. xiv. 1888), p. 30, pl. iii. fig. 1: Paleoniscus agassiziu, W. C. Redfield, Amer. Journ. Sci. vol. xli. (1841), p. 26.— Trias ; Boonton, New Jersey. Ischypterus alatus, J. 8. Newberry, op. cit. p. 37, pl. viii. figs. 1, 2'—Trias; Boonton. [Columbia College, New York.] Ischypterus brauni, J. S. Newberry, op. cit. p. 48, pl. xii. fig. 3, pl. xii. figs. 1, 2*: Palwoniscus latus, L. P. Gratacap (errore), Amer. Nat. vol. xx. (1886), p. 243, fig.—Base of Trias; Weehawken, New Jersey. Ischypterus elegans, J. 8. Newberry, op. cit. p. 37, pl. vii. fig. 2, pl. x. fig. 1, pl. xiv. figs. 1, 2*.—Trias ; Boonton. [Columbia College, New York. ] Ischypterus gigas, J. 8. Newberry, op. cit. p. 49, pl. xiv. fig. 3*.— Trias ; Boonton. Ischypterus Ae J. S. Newberry, op. ae pyoos) pls x. figs. 2, 3*.—Trias ; Boonton. Ischypterus lineatus, J. g. Newberry, op. cit. p. 40, pl. xi. figs. 1, 2'—Trias ; Boonton. [Columbia College, New York. | Ischypterus marshi, W. C. Redfield, Proc. Amer. Assoc. Adv. Sci. (Albany, 1856), pt. 2,p.188 (name only); J.S. Newberry, op. cit. p. 28, pl. ii. fig. 1.—Trias ; Sunderland, Massachu- setts. [Yale University Museum. | Ischypterus micropterus, J. S. Newberry, op. ct. p. 31, al. lv. figs. 1, 2, pl. xu. fig. 2*.—Trias ; Durham, Connecticut. Ischypterus minutus, J. 8. Newberry, op. cit. p. 48, pl. xiii. fig. 5°. —Trias; Durham. Ischypterus modestus, J. 8. Newberry, op. cat. p. 38, pl. ix. figs. 1- 3*.—Trias; Boonton. [Columbia College, New York. | Ischypterus ovatus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. vi. (1850), p. 10; J.S. Newberry, op. cit. p. 27, pl. i. fig. 1: Paleonscus ovatus, W. C. Redfield, Amer. Journ. Sci. vol. xli. (1841), p. 26: (?) Tetragonolepis, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. iii. (1847), p. 277, pl. ix. fig. 2.—Trias; Turner’s Falls, Mass., Boonton, and (?) Virginia. Ischypterus parvus, J. 8. Newberry (ew W. C. Redfield. MS.), op. cit. p. 45, pl. xiii. fig. 4*.—Trias ; Turner’s Falls. Ischypterus robustus, J. 8S. Newberry, op. cit. p. 36, pl. vi. fig. 1*. —Trias; Boonton. [Columbia College, New York. ] * These names were previously published without definition in Trans. New York Acad. Sci. vol. vi. (1888), p. 127. OE 64. ACTINOPTERYGII. The names of Semionotus balsami, brevis, dubius, inermis, and trotti* are given by C. Bellotti (in A. Stoppani, Studii Geol. e Paleont. Lombardia, 1857, pp. 422-427) to fishes of uncertain affinities from the Upper Trias of Perledo, Como. Another unsatisfactorily deter- mined species is also named Semionotus bellottii, E. Riippell, in A. Stoppani, zbzd. p. 425. It still remains to be proved that the so-called Archeosemionotus connectens (W. Deecke, Paleontogr. vol. xxxv. 1889, p. 121, pl. vi. fig. 3), from the Trias of Perledo, Como, is not founded on an imperfect example of Semionotus. The unique type specimen, in the Senckenberg Institute, Frankfort, has probably lost its squama- tion by accident. The imperfect trunk of a fish from the Upper Muschelkalk of the neighbourhood of Jena, apparently related to Semionotus and its. allies, is named Dolichopterus volitans by G. Compter, Zeitschr. f. Naturw. vol. lxiv. (1891), p. 41, pl. 1. figs. 1-6. It is described as characterized by much-enlarged pectoral fins, and by a compara- tively short dorsal opposed to an extended anal. Another imperfect fish, apparently of almost the same systematic position, from the Upper Muschelkalk of Elm, Brunswick, is described and figured without name by W. Dames, Paleont. Abhandl. vol. iv. (1888), p. 173, pl. xvia. fig. 10. Genus APHNELEPIS, A. 8. Woodward. Seems in forthcoming Mem. Geol. Surv. N.S. Wales, Paleeont. no. 9.] Trunk laterally compressed and deeply fusiform. Head of mode- rate size with acuminate snout, and more or less ornamented with rugee and tubercles ; marginal teeth small, stout, and almost conical, closely arranged; inner teeth nearly granular. Notochord per- sistent, sometimes with small hypocentra and pleurocentra in the caudal region; ribs long. Fulcra conspicuous on all the fins. Pectoral fins of moderate size, somewhat larger than the pelvic pair, which are well developed; dorsal and anal fins acuminate and short- based, the former almost or completely in advance of the latter; caudal fin forked. Scales all rhombic, thin on the abdominal, still thinner on the caudal region; those of the flank deeper than broad, those of the dorsal and ventral borders about as deep as broad; ridge-scales not enlarged. 1 Described as Lepidotus trotti by Balsamo-Crivelli, Ann. Polytecn. Milano, May 1839. SEMIONOTID&. 65: Aphnelepis australis, A. 8. Woodward. [ Described in forthcoming Mem. Geol. Surv. N.S. Wales, Palzont. no. 9, with drawings on pl. iii. figs. 1—4.] Type. Nearly complete fish ; Geol. Survey Museum, Sydney. The type species, attaining a length of about 0-2. Length of head with opercular apparatus contained about one-and-a-half times in the maximum depth of the trunk, and somewhat less than one- quarter of the total length of the fish ; the caudal pedicle one-third as deep as the abdominal region at its highest point, where the dorsal fin arises. Pelvic fins arising opposite the origin of the dorsal, and the latter completely in advance of the anal; dorsal rays about 14, anal rays 19 in number. Scales ornamented with coarse crimpings, which are slightly radiating and usually confined to the hinder half. Form. & Loc. Upper Hawkesbury-Wianamatta Series: Talbralgar, New South Wales. Not represented in the Collection. A large variety of Aphnelepis, perhaps identical with A. australis, is also described and figured, loc. cat. pl. ii. fig. 5. Genus SERROLEPIS, Quenstedt. [Handb. Petrefakt. 1852, p. 207. ] An indefinable genus founded upon detached flank-scales. These scales much deeper than broad, with a straight narrow overlapped margin, a large peg-and-socket articulation, and no sharp inner keel ; the exposed portion ornamented with transverse ridges, terminating in denticulations at the posterior border. A fragment of jaw, exhibiting a close series of stout styliform teeth, is described by Dames as having been found in association with the scales (Paleont. Abhandl. vol. iv. 1888, p. 172, pl. xiii. fig. 8). It may possibly pertain to the same genus. Serrolepis suevicus, Dames. 1852. Serrolepis, F. A. Quenstedt, Handb. Petrefakt. p. 207, pl, xvii. fie. 18. 1888. Serrolepis suevicus, W. Dames, Palzeont. Abhandl. vol. iv. p.171, pl. xiii. figs. 4-7 (? 8). Type. Isolated scales ; Tiibingen University Museum. The type species, known only by isolated scales, of which the largest measure about 0-015 in total depth, and are four times as deep as broad in their exposed portion. Posterior denticulations PART III. F 66 ACTINOPTERYGII. large, extended forwards as short, acute ridges; anterior half of the scale smooth or marked with finer transverse ridges. Form. & Loc. Upper Triassic (Lettenkohl): Wurtemberg. P. 7402. Two fragments of dolomite with scales and a thin tuber- culated bone; Comburg, near Hall. One scale is smooth n its anterior half. Purchased. Genus PRISTISOMUS, A. 8. Woodward. [Foss. Fishes Hawkesbury Series, Gosford (Mem. Geol. Surv. N.S. Wales, Palewont. no. 4, 1890), p. 32.] © Trunk deeply fusiform. Marginal teeth large, styliform, and in close series. Fin-fulera small. Paired fins moderately developed ; dorsal and anal fins remote, not much extended, the former partly opposed to the latter ; caudal fin robust, scarcely forked. Three or more series of the flank-scales vertically elongated; dorsal and ventral scales as broad as deep; a dorsal and ventral series of prominent, acuminate ridge-scales. Pristisomus gracilis, A. 8. Woodward. 1890. Pristisomus gracilis, A. S. Woodward, op. cit. p. 33, pl. v. fig. 1, pl. vi. fie. Uopl) avi, fiend: Type. Nearly complete fish ; Geol. Survey Museum, Sydney. The type species, attaining a length of about 0°12. Head with opercular apparatus occupying about one-quarter of the total length ; trunk gracefully fusiform, the maximum depth contained more than two-and-a-half times in the total length of the fish. Dorsal and anal fins almost of equal size, much elevated, and with a relatively short base-line. Form. & Loc. Lower Hocrdbne) Seca Series (Upper, Trias) : Gosford, New South Wales. P. 6275. Fish wanting paired fins. By exchange, 1890. P. 6277. Slab showing another specimen associated with P. crassus. By exchange, 1890. Pristisomus latus, A. 8. Woodward. 1890. Prstisomus latus, A. S. Woodward, op. cit. p. 35, pl. v. figs. 2-4. Type. Nearly complete fish ; Geol. Survey Museum, Sydney. A slightly larger species than the type, with somewhat deeper SEMIONOTID 67 trunk and smaller head. Dorsal fin considerably longer than the anal and not remarkably elevated. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6274. Two imperfect fishes. By eachange, 1890. Pristisomus crassus, A. 8S. Woodward. 1890. Pristisomus erassus, A. S. Woodward, op. cit. p. 36, pl. v. fies. 5-7. Type. Nearly complete fish; Geol. Survey Museum, Sydney. A species about as large as the foregoing, but with more robust and less deepened trunk. Head with opercular apparatus occupying at least one-quarter of the total length; maximum depth of trunk contained about three times in the total length of the fish. Dorsal fin considerably larger than the anal, as long as deep. Form. & Loc. Lower Hawkesbury-Wianamatta Series (Upper Trias): Gosford, New South Wales. P. 6276. Trunk showing dorsal and part of caudal fin. By exchange, 1890. P. 6277. Slab with nearly complete fish, associated with P. gracilis. By exchange, 2890. Genus SARGODON, Plieninger. [Wiirtt. Jahresh. vol. ii. 1847, p. 165.] An indefinable genus known only by the external incisive teeth. The dental crown is sharply separated from the long, cylindrical or nearly quadrangular root, and is chisel-like in shape. It seems probable that the fish possessing such teeth would also have tritoral teeth on the inner bones of the mouth. As originally suggested by Pleninger, it is, therefore, not unlikely that the small Rheetic teeth named Psammodus orbicularis (Meyer & Plieninger, Beitr. Pal. Wirttembergs, 1844, p. 117, pl. x. fig. 24), and others ascribed to Spherodus minimus (ibid. p. 117, pl. x. fig. 23, named by Agassiz, Poiss. Foss. vol. ii. pt. ii. 1844, pp. 216, 300), truly belong to Sargodon. Similar tritoral teeth have been described from the Rheetic of Leicestershire (A. 8. Woodward, Trans. Leicester Lit. & Phil. Soc., n. s. vol. i. pt. xi. 1889, p. 20), Somersetshire, and Gloucestershire (M. Browne, Rep. Brit. Assoc. 1891, p. 645), and some are preserved in the Collection from Aust Cliff, near Bristol (P.6069a. Presented by F. Harford, Esq., 1889). F2 68 ACTINOPTERYGII. Sargodon tomicus, Plieninger. 1847. Sargodon tomicus, T. Plheninger, Wiirtt. Jahresh. vol. iii. p. 165, pl. 1. figs. 5-10, 1858. Sargodon tomicus, F, A. Quenstedt, Der Jura, p. 35, pl. ii. figs. 34, 35 (? figs. 36-38). Type. Teeth ; Stuttgart Museum. The type species, known only by detached teeth, which sometimes measure 0°005 in the breadth and in the depth of the crown. Dental crown robust, arched from side to side and the concavity probably being innermost ; cutting-edge smooth, usually obliquely truncated by wear. Root not much compressed, usually nearly quadrangular in section, but with a shallow median longitudinal groove on its supposed inner face. Form. §& Loc. Rheetic: Wirtemberg and England. 41288. Tooth in bone-bed ; Axminster. Purchased, 1869. P. 7401. Three specimens; Aust Cliff, near Bristol. , History unknown. P. 3930. Fine tooth; Aust Cliff. Enniskillen Coll. Genus COLOBODUS, Agassiz. [Poiss. Foss. vol. i. pt. 11. 1844, p. 237.] Syn. Asterodon, G. von Minster, Beitr. Petrefakt. pt. iv. 1841, p. 140. Omphalodus, H. von Meyer, Neues Jahrb. 1847, p. 574. Nephrotus, H. von Meyer, Paleeontogr. vol. i. 1851, p. 243. Thelodus, KH. EH. Schmid, Nova Acta Acad. Ces. ae Vole xacix aes 9, 1861, p. 27 (in part). Eupleurodus, G €, Giinigh, Zeitschr. deutsch. geol. Ges. vol. Xxxvi. 1884, p. 142. Dactylolepis, H. Kunisch, cb2d. vol. xxxvii. 1885, p. 594. An imperfectly definable genus, not yet satisfactorily distinguished from Lepidotus. The form and proportions of the head and trunk, dentition, squamation, and the situation of the fins seem to be as in Lepidotus. In most species, however, the teeth are mammillated and more or less striated, while their arrangement has not yet been definitely proved to agree with that in the last-named genus; the overlapped border of the flank-scales is of uniform width, and not produced at the angles; while the dorsal and anal fins seem to be relatively more elevated than in Lepzdotus, with smaller and more regular fulera. The gular plate has not been discovered. The genus Colobodus was originally founded upon a fragment of dentition from the Muschelkalk of France, and the above state- SEMIONOTIDA. 69 ment of the characters of the trunk is based on the assumption that the nearly complete specimens of fishes from the Tyrol and Italy, recorded below under the names of C. ornatus and C. latus, are generically identical with the unknown fish to which the first- discovered example of dentition belongs. The name Colobodus is here preferred to that of Asterodon, because it seems to have been universally employed and is adopted by Professor W. Dames in his memoir giving the first satisfactory account of the genus (Paleont. Abhandl. vol. iv. 1888, p. 153). Colobodus hogardi, Agassiz. 1844. Colobodus hogardi, L. Agassiz, Poiss, Foss. vol. ii. pt. ii. pp. 287 244, 1852. Colobodus hogardi, P. Gervais, Zool. et Pal. Frang., Poiss., Explic. Planches, p. 13, pl. Ixxvii. fig. 15. 1853. Colobodus hogardi, C. G. Giebel, Zeitschr. naturw. Vereins Halle, vol. i. p. 326. 1888. Colobodus hogardi, W. Dames, Paleeont. Abhandl. vol. iv, p. 159. Type. Fragment of dentition ; Strassburg Museum. The type species, known only by portions of dentition. Teeth crowded and thus of irregular polygonal form, with feebly striated crown and an apical tubercle not surrounded by an annular indent. The type specimen was obtained from the Muschelkalk of Lunéville. Form. & Loc. Upper Muschelkalk: Lunéville, France. Letten- kohl: Wiurtemberg. Not represented in the Collection. Colobodus frequens, Dames. 1837. Gyrolepis albertii, H. B. Geinitz, Beitr. Kennt. Thiiring. Muschel- kalkeeb. p. 21, pl. ii. figs. 3 a, 6 (errore). 1844. Scales described and figured by Meyer and Plieninger, Beitr. Paleont. Wiirttembergs, p. 84, pl. xi. figs. 21-23, 25. 1851. Scales described and figured by H. von Meyer, Paleeontoger. vol. i. pp. 200, 248, pl. xxix. figs. 2, 4, 5, 10, 11, 14-16, 18-21, 23, 27-29 (? figs. 3, 6), pl. xxx1. figs. 35-41. 1852. Gyrolepis albertii, F. A. Quenstedt (errore), Handb. Petrefakt. p. 206, pl. xvii. figs. 6, 7, 12 (? fig. 8). 1861. Tholodus ' minutus, K. E. Schmid, Nova Acta Acad. Cees. Leop.- 1 The genus Tholodus was originally founded by H. von Meyer on a fragment of dentition from the Muschelkalk of Upper Silesia, which may be reptilian. The type species is 7. schmidi (H. von Meyer, in Schmid & Schleiden, Geogn. Verhilt. Saalthals Jena (1846), p. 87, and Palzontogr. vol. i. (1849), p. 199, pl. xxxi. figs. 27, 28). 70 ACTINOPTERYGIT, Car. vol. xxix. no. 9, p. 26, pl. iv. figs. 14,15. [Fragment of dentition. | 1861. Spherodus globatus, EK. EK. Schmid, 267d. p. 32, pl. iv. fig. 11. 1861. Thelodus levis, HE. HE. Schmid, zbid. p. 29, pl. iv. figs. 27-29. 1864. Lepidotus giebel, F. von Alberti, Ueberblick Trias, p. 210. 1865. Colobodus varius, H. Eck, Form. bunt. Sandst. u. Muschelk. Oberschlesien, pp. 67, 120 (errore). 1865. Gyrolepis alberti, H. Wek, tbid. pp. 71, 110, 122 (errore). 1872. Cololodus varius, H. Eck, Ridersdort u. Umgegend, pp. 94, 118 (errore). 1872. Gyrolepis alber tu, Hi. Eek, eded. pp. 101, 118 (er ia 1880. Colobodus varius, T. C. enees Aol. Mus. Teyler, vol. v. p. 126, pl. vii. fig. 27 (errore). 1880. Tetragonolepis triasicus, T. C. Winkler, cbid. p. 137, pl. viii. fig. 36. [Teeth; Wiirzburg University Museum. | 1888. Colobodus frequens, W. Dames, Paleeont. Abhandl. vol. iv. p. 156, pl. xii. figs. 4, 5, pl. xvi. 1891. Colobodus frequens, G. Compter, Zeitschr. f. Naturw. vol. Ixiv. p- 49, pl. i. figs. 7, 8. Type. Portion of squamation; School of Mines, Berlin. An imperfectly known species of moderate size. Scales smooth or ornamented with feeble, irregular, oblique striations, and the hinder margin with large, well-separated, long digitations. Teeth not crowded together, each with a conspicuously striated crown and an apical tubercle usually surrounded by a slight annular depression. Form. & Loc. Muschelkalk and Lettenkohl: Germany. P. 7403. Four scales; Muschelkalk, Bayreuth, Bavaria. Purchased. P. 1042 a. Scale; Bayreuth. Egerton Coll. Colobodus gogolinensis (Kunisch). 1885. Dactylolepis gogolinensis, H. Kunisch, Zeitschr. deutsch. geol. Ges. vol. xxxvil. p. 588, pl. xxiv. 1888. Colobodus gogolinensis, W. Dames, Paleeont. Abhandl. vol. iv. p. 158. Type. Anterior portion of fish; University Museum, Breslau. An imperfectly known species, with squamation closely resembling that of C. jfrequens, and the lower marginal teeth relatively more slender than in the last-named species. Scales smooth, the hinder margin with large, flattened, long digitations, truncated at the extremity and only separated by shallow grooves. Form. & Loc. Lower Muschelkalk: Upper Silesia. Not represented in the Collection. SEMIONOTID&. CL Colobodus varius, Giebel. 1848. Colobodus varius, C. G. Giebel, Neues Jahrb. p. 150, pl. ii. figs. 1-6 (in part). 1848. Gyrolepis albertu, C. G. Giebel, ibid. p. 152 (errore). 1848. Colobodus varius, C. G. Giebel, Fauna d. Vorw., Fische, p. 181 (in part). 1888. Colobodus varius, W. Dames, Paleont. Abhandl. vol. iv. p. 160, pl. xiv. fig. 2. Type. Fragment of dentition; School of Mines, Freiberg, Saxony. A species known only from fragments of dentition and detached scales. Teeth irregularly rounded, not crowded together, the crown of each conspicuously striated and with an apical tubercle surrounded by a slight annular depression. Scales ornamented with numerous and prominent oblique ridges terminating at the hinder margin in irregularly-produced and attenuated digitations. Form. § Loc. Lower Muschelkalk: Germany. P. 1042. Two scales; Bayreuth, Bavaria. Egerton Coll. P. 4625. Scale; Bayreuth. Enniskillen Coll. P. 7404. Coarsely-marked imperfect scale, either of this species or C. maximus ; Weimar. F Presented by C. Westendarp, Esq., 1884. Colobodus maximus, Dames. 1847. Pycnodus triasicus, H. von Meyer, Neues Jahrb. p. 574 (name only). 1847. Pycnodus splendens, H. von Meyer, zbid, p. 574 (name only). 1849. Pyenodus triasicus, H. von Meyer, Paleeontogr. vol. i. p. 237, pl. xxix. figs. 39, 40, 42-48. [Teeth.] 1849. Pycnodus splendens, H. von Meyer, 2bid. p. 239, pl. xxix. fig, 41. [ Teeth. |] 1852. Gyrolepis maximus, F. A. Quenstedt (errore), Handb. Petrefakt. p- 206, pl. xvii. fig. 14. [Scale ; Tiibingen University Museum. | 1857. Gyrodus picardz, C. Chop, Zeitschr. gesammt. Naturw. vol. ix. p- 180, pl. iv. fig. 5. ['Teeth.] 1861. Thelodus inflatus, EK. E. Schmid, Nova Acta Acad. Ces. Leop.- Car. vol. xxix. no. 9, p. 28, pl. iv. figs, 23-26. 1861. Spherodus compressus, EK. EK. Schmid, zed. p. 31, pl. iv. figs. 1-5. 1861. Spherodus rotundatus, E. K. Schmid, ibid. p. 32, pl. iv. figs. 6-10. 1865. Gyrolepis albertii, H. Eck (errore), Form. bunt. Sandst. u. Muschelk. Oberschlesien, p. 122. 1885. Gyrolepis maximus, F. A. Quenstedt (errore), Handb. Petrefakt. ed. 3, p. 322, fig. 102, pl. xxv. fig. 15. 1888. Colobodus maximus, W. Dames, Palzont. Abhandl. vol. iv. p. 162 pl. xii. fig. 3 (& P fig. 2), pl. xiii. fig. 2, pl. xiv. fig. 1, and (?) pl. xvia. fig. 9. 72 ACTINOPTERYGII. Type. Imperfect head and anterior scales; University Geological Museum, Gottingen. A large species known only by portions of the head and squama- tion. External head-bones ornamented with closely arranged ruge ; teeth resembling those of C. varius. Scales differing little from those of C. varius, but wanting the upper and lower almost free transverse ridges and having all the other ridges stouter than in the last-named species. Form. & Loc. Upper Muschelkalk and Lettenkohl: Germany. Not represented in the Collection. Colobodus chorzowensis (H. von Meyer). 1847. Omphalodus chorzowiensis, H. von Meyer, Neues Jahrb. p. 574. 1848. Colobodus (?) chorzowiensis, C. G. Giebel, Fauna d. Vorw., Fische, p. 466. 1851. Nephrotus chorzowensis, H. von Meyer, Paleeontogr. vol. i. p. 242, pl. xxviil. fig. 20. (Also scales described and figured zbed. pp. 251, 252, pl. xxix. figs. 30-37.) 1865. Colobodus chorzowensis, H. Eck, Form. bunt. Sandst. u. Muschelk. Oberschlesien, p. 66. 1865. Pleurolepis silesitacus, H. Eck, bid. p. 71. [ Scales. ] 1884, Eupleurodus sulcatus, G. Girich, Zeitschr. deutsch. geol. Ges. vol. xxxvi. p. 142, fig. 5. [Fragment of dentition; coll. of Herr Mocke, Kattowitz. | 1888. Colobodus chorzowensis, W. Dames, Palaont. Abhandl. vol. iv. p. 167, pl. xvi a. figs. 1-8. Type. Fragment of dentition. A species known only from fragments of dentition and detached scales. Teeth oval or irregularly rounded, not crowded together, the crown of each nearly smooth and with a large apical tubercle. Scales ornamented with a few very large oblique ridges, which do not bifurcate and often extend directly from the anterior to the posterior border. Form. § Loc. Lower Muschelkalk: Upper Silesia. Not represented in the Collection. Colobodus ornatus (Agassiz). 1832. Lepidotes ornatus, L. Agassiz, Neues Jahrb. p. 145. 1833-37. Lepidotus ornatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. pp. 9, 249, pl. xxxii. (?) 1844. Lepidotus speciosus, L. Agassiz (ex Munster, MS.), zbrd. p. 266, pl. xxxiv a. figs. 5-7. [Imperfect tail; Palseontological Museum, Munich. | SEMIONOTIDZ. 73 1850. Lepidotus acuttrostris, O. G. Costa, Atti Accad. Pontan. vol. v. p- 801, pl. viii. fig. 1 a. 1850. Lepidotus gigas, O. G. Costa (errore), ibéd. p. 808, pl. vill. fig. 3. 1857. Lepidotus? spinifer, C. Bellotti, in A. Stoppani, Studii Geol. e Paleont. Lombardia, p. 421. [Fragment ; Milan Museum. | 1862. Lepidotus acutirostris, O. G. Costa, Atti R. Accad. Sci. Napoh, vol. vi. Append. pp. 17, 44, pl. vil. fig. 3. 1862. Lepidotus sp., O. G. Costa, ibid. pp. 20, 42, pl. il. 1862. Semionotus sp., O. G. Costa, zbed. p. 48, pl. 111. 1862. Semionotus curtulus, O. G. Costa, ibid. pp. 20, 43, pl. iv. 1862. Urocomus picenus, O. G. Costa (errore), iid. pp. 27, 43, pl. vi. fir. laa. 1866. Lepidotus ornatus, R. Kner, Sitzungsb. k. Akad. Wiss., math.- naturw. Cl. vol. liv. pt. 1. p. 313, pl. 11. 1866. Lepidotus obesus, O. G. Costa, Atti R. Accad. Sci. Napoli, vol. iit. no. 12, p. 4, pls. 1., i. 1889. Semionotus spinifer, W. Deecke, Paleeontogr. vol. xxxv. p. 186. 1891. Lepidotus triumplinorum, A. de Zigno, Mem. R. Accad. Lincei, [4] vol. vii. p. 6, pl. i. [Nearly complete fish; University of Padua. | 1892. Lepidotus (Colobodus ?) ornatus, F. Bassani, Mem. Soe. Ital. Sci. [3] vol. ix. no. 3, p. 24. Type. Portions of fishes ; Stuttgart Museum. A species attaining a length of about 0-5. Trunk deeply fusiform, its maximum depth much greater than the length of the head with opercular apparatus, which occupies nearly one-quarter of the total length of the fish. External bones finely ornamented with tubercu- lations ; teeth smooth, not closely adpressed, those within the mouth oval or rounded. Pelvic fins arising opposite the origin of the dorsal fin, and much nearer to the ana! than to the pectorals; dorsal fin with about 24 rays, the anal less than half as large and opposed to its hinder portion. Scales smooth, but those of the flanks, except in the hinder half of the caudal region, with long and conspicuous posterior digitations; principal flank-scales scarcely deeper than broad. Horm. & Loc. Upper Triassic: Tyrol; Italy. 13444. Imperfect hinder portion of head with anterior portion of trunk ; Seefeld, Tyrol. The head and opercular bones, though very fragmentary, exhibit the characteristic tuber- culations ; some of the circumorbital bones are distinct, and the large upwardly-directed anterior process of the suboperculum is conspicuous. There are traces of large postclavicular scales; and there are prominent fulcra on the anterior ray of the pectoral fin. Purchased, 1836. 74 ACTINOPTERYGII. P. 1540, P. 4657. A somewhat smaller but nearly similar specimen, partly in counterpart; Seefeld. Egerton and Enniskillen Colls. 21375. Imperfect trunk, displaying the squamation and part of the tuberculated operculum; Seefeld. Part of a postclavicular scale is highly ornamented. Purchased, 1847. P. 1539. More imperfect portion of trunk; Seefeld. Hgerton Coll. P. 3622. Middle portion cf deepened trunk ; Seefeld. Enniskillen Coll. The following specimen may represent the young of C. ornatus:— P. 4706. Fragment of head and trunk of a very small fish, with extremely conspicuous ornamentation on the plan of that of C. ornatus; Seefeld. The fossil is associated with an imperfect Pholidophorus-like fish. Enmskillen Coll. Colobodus latus (Agassiz). 1833. Dapedius altivelis, L. Agassiz, Poiss. Foss. vol. 11. pt. i. p. 8 (un- defined). . , 1833-37. Semionotus latus, L. Agassiz, 2bid. pp. 8, 227, pl. xxvii. 1843. Semionotus pentland:, Sir P. Egerton, Proc. Geol. Soc. vol. iv. p. 183. [Caudal region; British Museum. | (?) 1848. Semionotus pustulifer, Sir P. Egerton, 267d. p.183. [Fragment of opercular apparatus and squamation; British Museum. | 1844. Lepidotus parvulus, L. Agassiz (ex Minster, MS.), tom. crt. p. 267, pl. xxxiva. figs. 8, 9. [Imperfect fish; Paleeontological Museum, Munich. | 1850. Lepidotus notopterus, O. G. Costa (errore), Atti Accad. Pontan. vol. v. pp. 803, 426, pl. viii. figs. 1 B, 4. 1850, Semionotus curtulus, O. G. Costa, bid. vol. v. p. 294, pl. vii. fig. 6, pl. vii. fig. 2. 1853-64. Lepidotus acutirostris, O. G. Costa, bid. vol: viii. pp. 76, 198, pl. ix. fig. 1, and Ittiol. Foss. Ital. p. 7, pl. i1. fig. 1. 1853-64. Semionotus curtulus, O. G. Costa, rid. vol. vill. pp. 78, 194, pl. xi. fig. 1, and Ittiol. Foss. Ital. p. 25, pl. 111. fig. 1. 1861. Semionotus latus, O. Fraas, Wurtt. Jahresh. vol. xvii. p. 85. 1862. Semionotus curtulus, O. G. Costa, Atti R. Accad. Sci. Napoli, Append. p. 48, pl. v. fig. 1. 1864. Semionotus curtulus, O. G. Costa, Atti Istit. Inc. Sci. Nat. Napoli, [2] vol. i. p. 288, pl. iti. fig. I. 1866. Semionotus latus, R. Kner, Sitzungsb. k. Akad. Wiss., math.- naturw. Cl. vol. liv. pt. 1. p. 319, pl. ii. fig. 5, pl. iv. SEMIONOTID 2. 79 1891. Lepidotus ragazzonii, A. de Zigno, Mem. R. Accad. Lincei, [4] vol. vii. p. 8, pl. ii. figs. 1, 2. [Nearly complete fish ; University of Padua. | 1892. Lepidotus (Colobodus ?) latus, F. Bassani, Mem. Soc. Ital. Sci. [3] vol. ix. no. 3, p. 24. Type. Portion of fish; Paleontological Museum, Munich. A species attaining a length of about 0°35; general proportions, teeth, and external ornamentation of bones asin C. ornatus. Scales smooth and without serrations, except in the lower half of the abdominal flank, where they are often marked with feeble oblique striations and pectinated at the hinder margin ; principal flank- scales considerably deeper than broad. Form. & Loc. Upper Triassic: Tyrol; Italy. 21377. Portion of trunk, with fragment of head; Seefeld, Tyrol. Purchased, 1847. P. 1104, P. 3622 a. Imperfect head and abdominal region of smaller fish, in counterpart ; Seefeld. Egerton and Enniskillen Colls. P. 604. Caudal region, showing anal and caudal fins, described by Egerton (ioc. ct. 1843) as the type specimen of Semionotus pentiandi ; Giffoni, province of Salerno, Italy. Egerton Coll. P. 602. Very imperfect fragment of opercular apparatus and flank- squamation probably pertaining to this species, described by Egerton (loc. cit. 1843) as the type specimen of Semionotus pustulifer ; Giffoni. } Egerton Coll. P. 1549. Portion of trunk of a small fish, perhaps young of this species ; Seefeld. The principal flank-scales are extremely finely serrated on their hinder margin, and the specimen bears the MS. name of Semionotus tenuiserratus, Egerton. Lgerton Coll, Scales of an undetermined species of Colobodus have been recorded from the Rheetic of Aust Cliff, near Bristol (M. Browne, Rep. Brit. Assoc. 1891, p. 645), and the undermentioned scale appears to be referable to this genus :— P. 7405. Rhombic scale 0-007 in depth, with a few superficial pittings tending to oblique elongation and at least four long slender digitations obliquely directed downwards ati its postero-inferior angle; Rhetic Bone-bed, Aust Cliff. Egerton Coll. 76 ACTINOPTERYGII. The following species have also been determined upon fragmentary evidence, but there are no examples in the Collection :— Oolobodus bronni: Asterodon bronnii, G. von Munster, Beitr. Petrefakt. pt.iv. (1841), p. 140, pl. xvi. fig.14 ; W. Dames, Paleont. Abhandl. vol. iv. (1888), p. 153: Colobodus varius, C.G. Giebel, Neues Jahrb. 1848, p. 152 (errore).— St. Cassian Beds; Tyrol. [Fragment of dentition; Pale- ontological Museum, Munich.|] The so-called Gyrolepis biplicatus (Minster, op. cit. p. 140, pl. xvi. fig. 15) may perhaps be the scale of this species. Colobodus scutatus, P. Gervais, Zool. et Pal. Franc. (1852), Poiss., Explic. Planches, p. 13, pl. lxxvii. fig. 16; .W. Dames, Paleeont. Abhandl. vol. iv. (1888), p. 166.—Muschelkalk ; Moselle, France. Colobodus sibiricus, A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol. iv. (1889), p.107: Palconiscus sibiricus, J. V. Rohon, Mém., Acad. Imp. Sci. 8t.-Pétersbourg, [7] vol. xxxvi. no. 13 (1889), p. 12, pl. ii. figs. 21, 22, 28.—Triassic (?) ; Kubekowa, Upper Jenissei, Siberia. [Scales; Imperial Academy of Sciences, St. Petersburg. | The fossils described under the following names may be fragments of the dentary bone of Colobodus, but they are as yet indetermin- able :— Charitodon glabridens, K. K. Schmid, Nova Acta Acad. Czs. Leop.- Car. vol. xxix. no. 9 (1861), p. 30, pl. i. fig. 41.— Muschelkalk ; Jena. Charitodon granulosus, HE. K. Schmid, ibid. p. 30, pl. 1. fig. 42.— Thid. Charitodon procerus, H. Eck, Form. bunt. Sandst. u. Muschelk. Oberschlesien (1865), p. 70, pl. ii. fig. 4.—Lower Mus- chelkalk ; (?) Chorzow. Charitodon tschudu, H. von Meyer, Palzontogr. vol. i. (1849), p. 205, pl. xxxi. figs. 22, 23: Charitosaurus tschudu, H. von Meyer, Neues Jahrb. 1838, p. 415. Figures also by Buttner, Rudera diluvii testes (1710), pl. x. fig. 6, and Knorr & Walch, Verstein. Suppl. pl. vii. fig. 2.— Muschel- kalk ; Querfurt and Esperstidt, Saxony. Hemilopas mentzeli, H. von Meyer, Neues Jahrb. 1847, p. 575, and loc. cit. (1849), p. 236, pl. xxviii. figs. 16, 17.—Mus- chelkalk ; Upper Silesia. SEMIONOTID A. 77 It is not improbable that the following species is also correctly placed here :— Lepidotus triasicus, F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxix. (1886), p. 38.—Keuper; Besano, Lombardy. - [Hinder portion of trunk; Milan Museum. | To this genus may also perhaps be referred the detached teeth from the Keuper of Tubingen, Wurtemberg, bearing the undefined name of Pycnodus priscus (lL. Agassiz, Poiss. Foss. vol. il. pt. ii. 1844, p. 199), and others described as Sphwrodus annularis (L. Agassiz, ibid. p. 211, pl. Ixxil. figs. 95-100). The origin of the latter is uncertain. The indefinable genus Cenchrodus (H. von Meyer, Neues Jahrb. 1847, p.574), founded upon a dentigerous bone, may perhaps be related to Colobodus, but its affinities are uncertain. Two species are recognized from the Muschelkalk of Upper Silesia, namely, Cen- chrodus goepperti and C. ottot (H. von Meyer, Joc. cit. p. 574, and Paleontogr. vol. i. 1851, pp. 243-247, pl. xxvili. figs. 18, 19). Genus LEPIDOTUS, Agassiz. [Neues Jahrb. 1832, p. 145 (Lepzdotes), and Poiss. Foss. vol. ii. pt. 1. 1833, pp. 8, 233.] Syn. Lepidosawrus, H. von Meyer, Paleeologica, 1832, p. 208. Spherodus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 1833, p. 15 (in art). Re conde, G. von Minster, Neues Jahrb. 1842, p. 38. Plesiodus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1863, p. 632. Prolepidotus, R. Michael, Zeitschr. deutsch. geol. Ges. vol. xlv. 1893, p. 729. Trunk fusiform and only moderately compressed. Marginal teeth robust, styliform; inner teeth stouter, often tritoral but smooth; opercular apparatus well developed, with a narrow arched preoperculum, but with few branchiostegal rays, and the gular plate wanting. Ribs ossified. Fin-fulcra very large, present on all the fins, biserial. Paired fins small; dorsal and anal fins short and deep, the former opposed to the space between the latter and the pelvic fins ; caudal fin slightly forked. Scales very robust, smooth or feebly ornamented ; flank-scales not much deeper than broad, with their wide overlapped margin produced forwards at the superior and inferior angles; scales of the ventral aspect nearly as deep as broad; dorsal and ventral ridge-scales usually incon- spicuous. 78 ACTINOPTERYGII. The chondrocranium in Lepidotus is well ossified, and the basi cranial axis is straight. The basioccipital exhibits on its posterior face a very deep conical fossa for the notochord; and the inferior aspect of the bone is marked by a broad longitudinal groove, with a flattened rim on each margin, probably indicating the backward extension of the basicranial canal (for the recti muscles of the eye) as far as the occiput. In one example of L. latifrons (no. P. 6841) there is also some appearance of one vertebral ring being fused with the basioccipital on its hinder face. The exoccipital forms a considerable part of the lateral wall of the brain-case, and is per- forated as usual by a large transversely-oval foramen for the exit of the vagus nerve. The pro-otic has a still larger extent than the exoccipital, and exhibits a deep oblique notch at its anterior margin for the passage of the fifth nerve. ‘The characters of the inter- orbital septum, pterotic and opisthotic bones are still unknown; and of the ethmoids it can only be said that they surround a pair of long closed canals for the passage of the olfactory nerves. The membrane bones of the cranial roof form a continuous shield, but do not extend backwards quite so far as the occipital border. There are two principal pairs of bones, the short parietals behind and the longer frontals forwards, not bilaterally symmetrical, but uniting in all directions by irregularly angulated sutures, which vary in different species. More anteriorly there would be nasals, but these are not satisfactorily known. The long and narrow squamosal element on each side reaches as far forwards as the anterior extremity of the parietals, but not so far backwards as the hinder margin of these bones. It is considerably overlapped by the supratemporal series of plates, and on the inner aspect there is an undetermined amount of connection with some of the ossified otic elements. Its surface for articulation with the upper end of the hyomandibular is clear, and a triangular walled area at the hinder end of its inner surface denotes the boundaries of the small temporal fossa. Postfrontal and prefrontal membrane bones are not differentiated from the circumorbital ring, and the cheek-plates are irregularly subdivided, being often different even on the two sides of the same head. The general plan of the cheek-plates, however, is distinct, there being a complete circumorbital ring, a semicircle of suborbitals, and a short deep series of preorbitals flanking the ethmoid region. The maxilla is a very delicate bone, deepest behind, tapering forwards, and terminating in front in an inwardly-directed process for articulation with the palatine; its oral margin is provided with a series of styliform teeth. The premaxilla is a smaller, stouter bone, also with a single series of styliform teeth, and bearing at its inner extremity a very large ne ek eee SEMIONOTID&. 79 ascending process which fits into a groove on the inferior aspect of the frontal bones. The base of the cranium is sheathed by a great parasphenoid bone and by the coalesced dentigerous vomers. The parasphenoid is narrowest at the origin of the large fan-shaped basipterygoid processes, expanding much behind and exhibiting a deep cleft in its hinder margin. It bears no teeth and is pierced mesially by a foramen for the passage of the internal carotids, which appears single on the lower face, but double on emerging above; the superior or attached face also shows the deep excavation forming the floor of the basicranial canal. The vomer is a stout thickened bone with crushing teeth, showing cavities in which the germ-teeth are formed; and the dentigerous bones of the palato- pterygoid arcade, closely connected with the vomer in front, exhibit a similar thickening. The hyomandibular is an elongated, laterally compressed bone, with its long axis slightly bent at the origin of the process of support for the operculum. It is somewhat strengthened by longitudinal ridges on the outer face, and the surface for attachment with the cranium is much extended. The bone is not pierced by any foramen. The symplectic element remains unknown, but the hinder border of the quadrate exhibits an inner surface evidently for union with it. The quadrate is slender for a fish with so powerful a dentition, and in the fine example of Lepidotus latifrons from the Oxford Clay (no. P. 6841) this element is of much interest as exhibiting a very different degree of ossification on the two sides. The metapterygoid bone is also comparatively delicate, but it shows a broad facette on its upward and anteriorly directed process, which may have articulated with some lateral element of the cranium. The hinder portion of Meckel’s cartilage is ossified as a robust articular bone, and to its outer face there is apposed a large plate, probably to be interpreted as angular. The coronoid region of the mandible is very deep, and the summit of the elevation is completed by a very small coronoid bone, shown in a Wealden specimen of Z. mantelli (no. P. 6342). The dentary bone, very deep in the coronoid region, becomes much narrower in its tooth-bearing portion; and its anterior half curves rapidly inwards to meet its fellow of the opposite side in a somewhat deepened symphysis. To the inner side of the dentary bone the robust splenial is articulated by a roughened face, and it also enters the mandibular symphysis ; whereas the dentary exhibits only one regular series of teeth, this element has several irregular series of a more tritoral character. The ceratohyal exhibits its ordinary hour-glass-shaped form, and is deepest behind. The hypohyals are a pair of very small triangular bones; and no evidence of an ossified glossohyal has hitherto been observed. 80 ACTINOPTERYGII. The teeth are hollow and the calcigerous tubes in the dentine radiate from the central cavity. The cap of enamel is thick, and when the germ of the successional tooth is first formed it lies in exactly the opposite direction to that of the functional tooth, thus making a revolution of 180° while the root of the old tooth is absorbed and it prepares to appear. The marginal teeth, forming a single series on the maxilla, premaxilla, and dentary, are com- paratively small and prehensile; those within are more robust and form a tritoral pavement. The latter are arranged with more or less reguiarity on the coalesced vomers, the pterygo-palatine arcade, and the splenial. In the earlier species all the teeth exhibit comparatively elongated pedicles, while in the later and more specialized forms the inner teeth are fixed on very short bases. The opercular apparatus is complete and there is a good series of branchiostegal rays, the uppermost very broad; but no indications of a gular plate have yet been discovered. The last-named fact is all the more remarkable, since in some of the other genera of Semionotide the gular plate is relatively large and robust. The preoperculum is a long narrow bone, exposed throughout its length and much bent forwards below. The operculum exhibits a sharp elevation on its inner face for articulation with the hyomandibular process; its upper border is overlapped by the supratemporal plates, and its lower border deeply overlaps the suboperculum. The latter element is almost sickle-shaped, with a very large upwardly-directed process at its antero-superior angle, and abruptly truncated in front for union with the large elongate- triangular interoperculum. The branchial arches are delicate and have only been observed in a fragmentary state. The gill-filaments are shown in the Oxfordian species to have been supported by a series of long slender rods, apparently quadrate in section, and each serrated on one margin; the gill-rakers are small, stout, and pointed, tipped with enamel, more or less falciform, and arranged in well-spaced series. The endoskeleton of the trunk is well ossified, but owing to the thickness of the squamation it is rarely seen and is as yet only imperfectly known. The notochord is persistent, and in the earlier and smaller species no ossifications have been observed in its sheath ; but in the large Wealden, and perhaps also in the large Oxfordian, species there are distinct indications of ring-vertebre, at least in the abdominal region. The rings are much deeper than broad, but in the few known specimens (e. g. nos. 2401, P. 1124, P. 6348 c) their precise characters are obscure, and it can only be stated that each ring appears to consist of four sectors, the lower pair bearing short processes for the support of the ribs. The right and left halves of SEMIONOTID.%: ° roll | the neural arches in the abdominal region are separate and not anchylosed with the neural spine; the ribs are long and slender, apparently extending to the ventral border. In the pectoral arch the clavicle is relatively much expanded, though pointed, below ; and it tapers irregularly above where over- lapped by the supraclavicle. Immediately behind the longitudinal bend in the element the outer surface is covered with a rugose thickening, marked with vermiculating rows of denticles of ganoine. The supraclavicle is narrow, about half as long as the clavicle, and firmly articulated at its thickened upper end with the small, almost club-shaped post-temporal. The basal bones of the pectoral fin are large and much elongated, slightly expanded at each end, and more than five in number. The pelvic fin-supports are unknown. Biserial fulcra are present on the anterior border both of the paired and median fins; and-the supports-of the dorsal and anal are much enlarged beneath them. The supratemporal plates vary much in arrangement in different species of Lepidotus, but they always overlap both the cranial roof- bones and the most anterior dorsal seales. In L. latifrons there is one not quite symmetrical pair of outer plates, occupying the space between the operculum, squamosal, and parietal on each side; and there are three symmetrically arranged plates, no larger than ordinary scales, apposed to the hinder margin of the parietals. In L. mantelli the supratemporals are in three pairs, the two outer ones corresponding to the single outer pair in L. latifrons. In L. elvensis, as already described by Quenstedt, the supratemporal series consists of a single pair of large plates, as in Amia. There is a series of postclavicular scales, but only two on each side are much enlarged. These two scales extend the whole depth of the flank, the uppermost being longest and narrowest. There are also three enlarged scales round the anus, which seems to have been mesially- placed ; their exposed portion is cycloidal, and the hinder margin usually serrated. Nearly all the other scales are in regular series, and those of the flank are united by a feeble peg- and-socket articulation ; a single row of scales, however, at the base of the dorsal, anal, and caudal fins does not conform to the regular flank-series, but is directly related to the fin-rays and fulcra. All the flank-scales are deeply overlapping, and most of them exhibit a forward production both of the antero-superior and antero-inferior angle; in some of those of the foremost series the overlapped portion is wider than the exposed area. The dorsal and ventral ridge-scales are never much enlarged; they are inconspicuous in the more robust species, but appear as a serrated ridge on the back in those which are more laterally compressed. PART III. G 82 ACTINOPTERYGII. The course of the sensory canals on the trunk can be traced by perforations and notches in the scales, which never produce a super- ficial ridge, There is one principal lateral line, as usual, and a second proceeds above on each side from the outer supratemporal to the origin of the dorsal fin, but apparently not beyond. The species of Lepidotus are numerous, and many are only imperfectly known. The following synopsis of those described below shows the nature of some of the specific characters :— I. Inner teeth on long pedicles, not much en- larged. Scales smooth. Parietals less than half as long as frontals, which are three times as long as broad and united by slightly wavy suture ; operculum two-thirds as broad as deep ; seales 1m part serrated!..........c5euss elvensis, p. 84, Ditto, but median frontal suture more wavy, parietals longer, and fish more elongated semuserratus, p. 85. Parietals at least half as long as frontals, which meet in a nearly straight median suture; operculum two-thirds as broad as deep; scales not serrated .......... gallineki, p. 87. Parietals half as long’ as frontals, which are twice as long as broad and united by deeply sinuous suture; operculum two- thirds as broad as deep ; principal flank- scales conspicuously denticulated ...... latefrons, p. 89. Parietals less than half as long as frontals, which are three times as long as broad and united by nearly straight median suture ; principal flank-scales conspicu- Ouchy dentiteulavedyta. cea tee macrocheirus, p. 90. Operculum twice as deep as its maximum breadth, which is contained more than three times in the length of the head; very few scales serrated, but those of lateral lime m@bkeledy:) pe stnarir etre ier. notopterus, p. 92. Parietals about one-third as long as frontals, which are three times as long as broad and united by nearly straight median suture; operculum somewhat less than twice as deep as its maximum breadth, which is contained nearly three times in the length of the head ; few scales in part serrated, but those of lateral line notched. minor, p. 94. II. Inner teeth on comparatively short pedicles, much enlarged. (a.) Scales smooth. Operculum nearly twice as deep as broad; SEMIONOTID. 83 inner teeth not excessively elarged, the majority oval and with apical tubercle ; principal flank-scales with few large denticulations at least in their lower half. leeds?, p. 99. Innermost splenial teeth excessively enlarged, round, without apical tubercle ........ affinis, p. 101. Operculum nearly twice as deep as its maximum breadth, which equals about one-third the length of the head; inner teeth not excessively enlarged, the majority oval and with apical tubercle; scales not serrated, but the postero- inferior angle more or less produced, and the hinder margin often with one or two notches immediately above this .... ungurculatus, p. 102. (6.) Scalesin part marked with radiating furrows. Majority of inner teeth oval, with apical tubercle, those of splenial in more than three irregular concentric series ...... levis, p. 103. Maximum width of operculum two-thirds as great as its depth, and equalling about one-third the length of the head; majority of inner teeth round, without apical tubercle, arranged on splenial in six or seven irregular concentric series........ palhatus, p. 103. Majority of inner teeth round, without apical tubercle, arranged on splenial in four or five irrecular concentric series ........ maximus, p. 105. (e) Scales smooth, but exhibiting nearly par- allel transverse grooves when abraded. Maximum width of operculum nearly two- thirds as great as its depth, and equal- line about one-third the length of the head ; principal flank-scales more or less coarsely serrated, sometimes crimped; dorsal ridge-scales inconspicuous ..... Maximum width of operculum about two- thirds as great as its depth, and equal- ling one-half the length of the head; principal flank-scales with two or three very large denticulations on the lower half of their posterior border; dorsal ridge-scales inconspicuous ............ degenhardti, p. 119. Scales with long slender posterior denticula- tions ; principal flank-scales considerably deeper than broad; dorsal ridge-scales CONSPICUOUS 2 se cc ee ss eee Seer ccw a hauchecornei, p. 119. mantell, p. 108. q¢2 84 ACTINOPTERYGII. Lepidotus elvensis (Blainville). 7 1818. Cyprinus elvensis, H. D. de Blainville, Nouv. Dict. d’Hist. Nat. vol. xxvii. p. 394. 1830. “Fossil fish,” G. Baker, Hist. Northampton, vol. i. p. 440, with plate. 1832. Lepidotes gas, L. Agassiz, Neues Jahrb. p. 145. 1833-37, Lepidotus gigas, L. Agassiz, Poiss. Foss. vol. ii. pt.1. pp. 8, 235, pls. xxviii., xxix. [Head, etc.; Stuttgart Museum. | 1843. Repidobus elvensis, F. A. Quenstedt, Flézgeb. Wtirttemb. p. 228. 1847. Lepidotus elvensis, F. A. Quenstedt, Ueber Lepidotus im Lias e, with plates. 1886. Lepidotus gigas, B. Thompson, Journ. Northampton. Nat. Hist. Soe. vol. iv. p. 27, with plate. Type. Nearly complete fish ; Paris Museum of Natural History. The type species, attaining a length of about 0°75. Head with opercular apparatus occupying about one-quarter of the total length ; maximum depth of trunk contained not much more than three times in the total length. External bones nearly smooth, but in part with sparsely-arranged coarse tuberculations ; parietal bones much less than half as long as the frontals, which are nearly three times as long as their maximum width, narrow in front, and united by a slightly wavy median suture; mandibular symphysis comparatively narrow. Marginal teeth acuminate, not less than three times as deep as broad. Operculum two-thirds as broad as deep, and its maximum breadth equalling somewhat less than one-half the length of the head. Fin-fulcra moderately developed; dorsal and anal fins deeper than long. Scales smooth, the principal flank-scales slightly deeper than broad, with a few coarse serrations upon the inferior half of the hinder border. Form. & Loc. Upper Lias: Bavaria, Wirtemberg, and N. France ; Somersetshire and Northamptonshire. P. 7406. Fish, wanting all the fins and the external surface of most of the scales and head-bones ; probably from Wiirtemberg. The cranial roof and all the facial bones of the right side, except those bordering the mouth, are well displayed ; and there are recognizable remains of the opercular apparatus and pectoral arch. 19662. Remains of head and trunk, displaying the circumorbitals, suborbitals, preoperculum, and interoperculum of the right side, with portions of the anal and caudal fins; Boll, Wiurtemberg. Purchased, 1845. P. 7407. Imperfectly preserved fish, wanting the anterior portion of the head and all the fins, except fragments of the _ SEMIONOTID. 85 - dorsal and pelvic fins which indicate their relative posi- tion; probably from Boll. P. 7408. Portions of small head and trunk in counterpart, dis- playing some of the marginal teeth, with indications of stouter teeth within; probably from Boll. P. 2054, P. 3529 b. Hinder portion of head and the squamation of the trunk somewhat scattered, with part of the caudal fin in counterpart; Ohmden. gerton & Enniskillen Colls. P. 2014. Fragmentary remains of head and trunk, wanting fins, exhibiting a coprolite in the abdominal region ; Ohmden, Wirtemberg. Egerton Coll. P. 3529-a. Very large specimen, displaying the squamation, remains of the paired fins, and the tubercular ornament of the cranial roof; Ohmden. Also a smaller, more imperfect fish ; probably from Boll. Enniskillen Coll. 32421. Head and remains of trunk with some well-preserved scales; Lacaine, Normandy.. Large portions of the man- dible and left maxilla are exhibited, and the opercular apparatus of the left side is nearly complete. Many of the anterior flank-scales are also well preserved, exhibiting a finer serration than most of those in the German speci- mens. Tesson Coll. 32422. Well-preserved portion of squamation of the abdominal region; Lacaine. Tesson Coll. 18992. Head and trunk with portions of paired fins, noticed by Agassiz, Poiss. Foss. vol. ii. pt. i. p. 235, and figured in Baker’s Hist. Northampton, p. 440; Upper Lias, Stowe-Nine-Churches, Northamptonshire. The perfo- rated series of scales of the superior lateral line is conspicuous. Miss Baker’s Coil, 18993-94. Two portions of squamation, the second with remains of the pectoral arch, opercular, and hinder facial bones ; Rothersthorpe, Northamptonshire. Miss Baker’s Coll. Lepidotus semiserratus, Agassiz. - 1822. “ Pikes,” Young & Bird, Geol. Yorkshire, p. 261, pl. xvi. figs. 7, 8. 1833. Lepidotus latissimus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 8 (undefined). [Scales: Paris Museum Nat. Hist.] 1833. Lepidotus umbonatus, L. Agassiz, ibid. p. 8 (undefined). 86 , ACTINOPTERYGII, 1837. Lepidotus semiserratus, L. Agassiz, ibid. p. 240, pls. xxix. a, b. 1849. Lepidotus semiserratus, W. C. Williamson, Phil. Trans. p. 441, pl. xl. figs. 3, 4. Type. Imperfect fishes ; Whitby and Scarborough Museums. An imperfectly known species, closely related to the typical L. elvensis, but apparently distinguished by its more elongated form, the maximum depth being contained four times in the total length. The parietal bones also seem to be relatively longer, and the sutures between both these elements and the frontals more wavy and sharply angulated. Form. & Loc. Upper Lias: Yorkshire °. All the following specimens were obtained from the cliffs near Whitby :— P. 7409. Imperfect fish about 0°55 in length, with the base of the caudal fin and fragments of the dorsal and paired fins. P. 2012. Larger specimen, exhibiting the ventral and partly lateral aspect, with portions of the paired and aual fins, but wanting the caudal. Lgerton Coll. P. 2012 a. Head and trunk, lateral aspect, with well-preserved squamation and remains of the paired fins. Some of the principal flank-scales are coarsely denticulated upon the lower half of their hinder border. The fulcra both of the pectoral and pelvic fins are prominent and, though im- perfectly preserved, appear to have been double. Egerton Coll. P. 3527. Imperfect fish, lateral aspect, about 0°6 in length, dis- playing the squamation. | Enniskillen Coll. P. 3528. Two specimens, ventro-lateral aspect, showing the enlarged scales in the anal region, with well-displayed remains of the caudal, anal, and paired fins. The smaller specimen also exhibits some of the marginal teeth of the upper jaw. Enniskillen Coll. P. 7410. Head of a large individual with some of the anterior scales and the base of the pectoral fins. The general form of the mandible and some of its styliform teeth are well exhibited. Purchased, 35556. A small head, with some of the anterior scales and the base of the pectoral fins.: Purchased, 1859. * Also recorded from Boll, Wiirtemberg, by F. A. Quenstedt, Flozgeb. Wirttemb, p. 2384, SEMIONOTIDA, 87 P. 1127. Imperfect skull and anterior squamation, the fractured cranial roof-bones exposed from above. Egerton Coll. P. 3528 a. Imperfect head, with some anterior scales and traces of the pectoral fins. The facial and cranial bones are sparsely tuberculated, and the coarseness of the serration of the scales varies considerably. The upper part of the broad hyomandibular is exposed on the right side; and there are remains of the dentition in both jaws. Enniskillen Coll. P. 5213, P. 5223. Two imperfect heads, with remains of the abdominal region. The sparse tuberculations upon the cranial and facial bones are well shown, and in the smaller specimen teeth are displayed. Presented by John Edward Lee, Esq., 1885. P. 6394. Imperfect head and lower portion of abdominal region. ) Beckles Coll. Lepidotus gallineki (Michael). 1893. Prolepidotus gallineki, R. Michael, Zeitschr. deutsch. geol. Ges. vol. xlv. p. 729, pls. xxxili., xxxiv. Type. Internal cast of imperfect head and trunk; Mineralogical Museum, University of Breslau. A species attaining a length of about 0°3; head with opercular apparatus occupying about one-quarter of the total length to the base of the caudal fin. External bones apparently almost smooth ; parietal bones antero-posteriorly elongated, at least half as long as the frontals, which meet in a nearly straight median suture; marginal teeth acuminate and inner teeth on elongated pedicles. Operculum two-thirds as broad as deep, and its maximum breadth less than one-half the length of the head. Fin-fulera moderately developed. Scales smooth and not serrated on the hinder margin. Form. & Loc. Rheetic: near Landsberg, Upper Silesia. Not represented in the Collection. Lepidotus tuberculatus, Agassiz. 1837-44. Lepidotus unguiculatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p: 254, pl. xxix. c. fig. 1 (non p. 251, pl. xxx. figs. 7-9). 1837-44. Lepidotus tuberculatus, L. Agassiz, 2bid. p. 256, pl. xxix. ¢. fig. 7. (?) 1844. Spherodus minor, L. Agassiz, cbed. pt. ii. p. 216 (name only). 1871. Lepidotus unguiculatus, J. Phillips, Geol. Oxford, p. 182, woode. xli. figs, 5-7. 88 ACTINOPTERYGII. — 1871. Pycnodus rudis, J. Phillips, eae 96 ACTINOPTERYGII. bones about one-third as long as the frontals, which are three times as long as their maximum width, narrow in front, and united by a nearly straight median suture; mandibular symphysis not much deepened or extended. Marginal teeth on much elongated pedicles, the crown obtusely conical in the lower jaw; inner teeth mostly larger and obtuse, but on moderately long pedicles. Fin-fulcra very large, the principal dorsal fulcra more than half as long as the anterior dorsal fin-rays ; pelvic fins arising midway between the pectorals and the anal; dorsal and anal fins deeper than long. Scales smooth, those of the flank coarsely serrated in the young, partly without serrations, partly with few irregular denticulations in the adult; scales of lateral line notched; dorsal ridge-scales acutely pointed and prominent. The large collection catalogued below seems to indicate that the individuals of this species grow stouter with age, besides losing the conspicuous serrations on the scales of the flank. A restoration of a typical fish is attempted in the accompanying fig. 22, of one-half the natural size, the only part remaining doubtful being the arrangement of the bones of the snout. A small fish from the Wealden of the Deister, Hanover, assigned to this species by C. Struckmann (Wealdenbild. Hannover, 1880, p. 86), has received the provisional name of Lepidotus struckmannt (W. Branco, loc. cit. p. 868, pl. vi. fig. 1). | Form. & Loc. Purbeckian: Dorsetshire. | The following specimens were all obtained from the neighbour- hood of Swanage :— ! 19006. Fine adult fish, with imperfect head, about 0°34 in length and 0°12 in maximum depth. The dorsal fin-fulcra are especially robust, four pairs having a separate insertion in advance of the anterior ray; and the principal flank- scales exhibit only feeble coarse denticulations in their inferior half. Purchased, 1845. 41157. Equally large individual, wanting the caudal and paired fins, displaying some of the ribs and median fin-supports, and the squamation of the left side from the inner aspect. Some of the left opercular and facial bones are also shown from within, and the mandibular ramus exhibits some of the splenial teeth on long pedicles posteriorly. | Purchased, 1868.. 42308. Somewhat larger fish, the squamation shown only in im- pression and some of the cranial and facial bones from: the inner aspect. Purchased, 1870. P. 5936. P. 6370. SEMIONOTID A. 97 Imperfect large head and trunk, with portions of the dorsal and pelvic fins. The tuberculated cranial roof is exposed, and the ventral portion of the abdominal squa- mation is especially well displayed. ‘The scales are not serrated, but the postero-inferior angle is acuminate. Purchased, 1889. Imperfect fish about 0°3 in length, exhibiting the tuber- cular ornament on the head-bones and operculum. Beckles Coll. 36080-81. Two specimens, 0°24 and 0:29 in length respectively. The smaller fish is shown partly from the lateral, partly from the dorsal aspect, and displays some of the head- bones and the squamation: a few of the principal flank- scales are observed to be coarsely, but feebly crenulated. The trunk of the larger fish is shown chiefly as an im- pression, though the greater part of the dorsal fin is preserved ; while in the head the left parietal and frontal, circumorbitals, and other bones are exposed from the inner aspect. Cunnington Coll. 45903. Imperfect small trunk, with remains of the head, displaying P. 4220. P. 4440. P. 2006. some of the ribs and the stout neural spines. Purchased, 1874. Large trunk, with remains of the head and part of the dorsal and caudal fins. A large portion of the squamation is well preserved, but none of the flank-scales exhibit denticulations. The dorsal fin-fulcra are unusually at- tenuated. Enniskillen Coll. Imperfect small trank displaying the fulcra of the dorsal and anal fins, and the long, curved ribs in the abdominal region. Enniskillen Coll. Small trunk, about 0°23 in length, with portions of all the fins, especially displaying the fulera. All the principal flank-scales of the abdominal region are coarsely though feebly serrated ; and this specimen forms the basis of the restoration of the trunk in fig. 22, p. 95. Egerton Coll. P. 2006 a. Head, abdominal region, and base of the tail’ of a similar fish, lateral aspect, with portions of the dorsal and paired fins. In the mandible the posterior teeth seem to be relatively small and arranged in more than one series ; and the margin of the upper jaw is shown to be formed by PART III, H 98 ACTINOPTERYGII. the premaxilla and maxilla, the latter element with a concayvely arched oral border and shaped as in L, latifrons. Below and behind the mandible there occur portions of the ceratohyal and epihyal; and the cranial roof-bones, besides the operculum, are shown to be tuberculated. The serration of the principal flank-scales is very con- Splcuous. Egerton Coll. 8047. Imperfect head and abdominal. region, equalling the pre- P. 6371. P 5591. P. 4441. P1148: ceding (P. 2006 a) in size. The tuberculations upon the cranial and facial bones are exhibited, and the clavicle is preserved behind. The removal of part of the squamation of the right side exposes the long, slender ribs and traces of the somewhat stouter neural arches, but no vertebral centra. Mantell Coll. Imperfect small fish shortened and deepened by crushing, and exhibiting serrated scales. Beckles Coll. Imperfect head and trunk of a slightly larger individual than no. 8047, apparently deeper and with non-serrated scales. The teeth exhibited are unusually stout, diminish- ing in size in the hinder portion of both jaws. Hlarford Coll. Imperfect head and abdominal region of a large fish, with the dorsal fin-fulera and relatively large scales. The imperfect coronoid bone is exposed in the mandible. Enniskillen Coll. Portion of a skull, vertically crushed and exposed from within, with some of the anterior dorsal scales shown from the inner aspect. The parietals and frontals are well shown, and the squamosal is preserved on the left side. The pair of supratemporal bones considerably overlaps the parietals; and between the two post-temporals there occurs a small median element, forming the first of the dorsal series of ridge-scales. Anteriorly the ascending process of each premaxilla is apposed to the inner face of the frontal bone of the same side; and the displaced left mandibular ramus shows that the splenial element, in addition to the dentary, bore teeth, The inner teeth are much stouter than those of the margin of the jaw; and they appear to be in three series on the anterior end of the splenial. The circumorbital and suborbital facial bones are also in part well displayed. Egerton Coll. SEMIONOTID A. 99 P. 6 374. Imperfect head showing cranial roof from within. Beckles Coll. 46419. Left frontal bone. Cunnington Coll. P. 1121. Larger left frontal bone. Egerton Coll. P. 7414. Smallpair of frontals, with three right circumorbitals. Enniskillen Coll. 21974, 24816. Three parasphenoid bones. Purchased, 1848, 1849. P. 1121 a. Parasphenoid. Egerton Coll. 48371. Right premaxilla, figured in Proc. Zool. Soc. 1893, pl. xlix. fig. 38; Middle Purbeck, Durdlestone Bay. Beckles Coll. P. 1119. Left premaxilla, with a series of five teeth. Hgerton Coll. P. 6373. Imperfect right mandibular ramus. Beckles Coll. 21974 a. Two small right dentary bones. Purchased, 1848. 36084. Larger left dentary, with a series of nine well-preserved teeth. Cunnington Coll. 40655, 46411. Two left dentaries, each exhibiting ten teeth. - Purchased, 1867, & Cunnington Coll. P. 6372. Imperfect small fish probably of this species, exhibiting scales with remarkably produced postero-inferior angle. Beckles Coll. Lepidotus leedsi, sp. nov. 1880. Lepidotus minor, R. Damon (errore), Geol. Weymouth, ed. 2 Suppl. pl. xi. fig. 12. Type. Portion of skeleton ; British Museum. An imperfectly known species of small or moderate size. External eranial bones rugose and marked with sparse, fine tuberculations ; opercular bones nearly smooth, with few patches of fine tubercula- tions. Dentary bone robust, but scarcely curved inwards, somewhat deepened by the sharp downward curve of its inferior border at the symphysis. ‘Teeth mostly oval in form, those on the inner bones robust, but elevated on pedicles and the crown sometimes with a median apex or tubercle; teeth of dentary bone obtuse and the pedicle somewhat tumid immediately below the crown; splenial teeth in about three irregular concentric series. Operculum nearly twice as deep as its maximum breadth, and not quite twice as broad at the lower as at the upper extremity; suboperculum somewhat — less than one-quarter as deep as the operculum, with very large H 2 100 ACTINOPTERYGII. antero-superior process. Scales large and smooth, those of the anterior portion of the flank with few large denticulations at least in their lower half; dorsal ridge-scales with slender acumination. Figs, 19-21. 192 Spl. - BoE eo a aja 21. fn a ine Ne 2D 0) Bs ¢ Ga Cc c) S: om me << An nies * Fig. 19.—Lepidotus macrocheirus; anterior half‘of right mandibular ramus from the outer and oral (@) aspects.—Oxford Clay; Peterborough. [No. P. 6839.]—d., dentary ; sp/., splenial. Fig. 20.—Lepidotus leedsi; left operculum (op.) and suboperculum (s.op.), outer aspect.—Oxford Clay; Peterborough. [No. P. 6837.] Fig. 20a.—Ditto ; imperfect right mandibular ramus, outer aspect, of same specimen, showing angular (ag.) and dentary (d.). Fig. 21.—Ditto ; left dentary, outer aspect, and lateral view of tooth (a),— Kimmeridge Clay; Weymouth. [No. 41964 c.] All these figures two-thirds nat. size. In this species the operculum is much larger in proportion to the mandible than in L. macrochewrus. Form. & Loc. Oxfordian: Huntingdonshire. Kimmeridgian : Dorsetshire. P. 6837. Type specimen, comprising the associated imperfect right mandibular ramus, squamosals, other cranial bones, epi- hyal, ceratohyals, left operculum and interoperculum, SEMIONOTID ®. 101 right and left suboperculum, post-temporals, supraclavicles, left clavicle, and numerous scales; Oxford Clay, Peter- borough. The operculum, suboperculum, and imperfect right mandibular ramus are shown of two-thirds the natural size in figs. 20, 20a. Leeds Coll. P. 6173—a. Two specimens of imperfect right dentary and splenial, showing the robust teeth on the latter element, the first specimen figured in Damon’s ‘ Geol. Weymouth,’ Suppl. pl. xi. fig. 12; Kimmeridge Clay, Weymouth. Damon Coll. P. 6173 b. Imperfect left dentary showing bases of teeth; Kimme- ridge Clay, Weymouth. Damon Coll. 41964 a-d. Fragment of upper dentition, detached teeth, imperfect left dentary with three complete teeth, and a small left dentary showing bases of teeth ; Kimmeridge Clay, Wey- mouth. The left dentary with teeth is shown of two- thirds the natural size in fig. 21. Purchased, 1870. 41964 e. Left operculum, much fractured, 0°115 in depth ; Kimme- ridge Clay, Weymouth. Purchased, 1870. 41178. Portion of squamation ; Kimmeridge Clay, Weymouth. Purchased, 1868. P. 1112. Fragmentary portion of squamation and some detached scales ; Kimmeridge Clay, Kimmeridge. Egerton Coll. P. 6174. Two scales, with fractured hinder margin, one figured by Damon, op. cit. pl. xii. fig. 10; Kimmeridge Clay, Wey- mouth. Damon Coll. Lepidotus affinis, Fricke. 1875. Lepidotus affinis, K. Fricke, Palzontogr. vol. xxii. p. 378, pl. xxi. fies. 2-6. Type. Fragments of dentition; University Geological Museum, Gottingen. A species of moderate size, known only by the dentition. Mar- ginal teeth styliform and slender ; inner teeth short, stout, smooth, and rounded. Splenial teeth in three irregular concentric series, the innermost excessively large; pterygo-palatine teeth relatively large, and in four irregular longitudinal series; vomerine dentition increasing in size backwards, the anterior teeth in about three 102 ACTINOPTERYGII. irregular longitudinal series, the largest posterior teeth comprising two pairs with one median tooth in advance. Form. & Loc. Upper Corallian and Kimmeridgian : Hanover ’. Not represented in the Collection. Lepidotus unguiculatus, Agassiz. 1829. “‘Schuppenhaut eines unbestimmbaren Reptils,” E. Riippell, Abbild. u. Beschreib. Verstein. Solenhofen, p. 11, pl. iv. 1832, Lepidosaurus, H. von Meyer, Palzologica, p. 208. 1833-37. Lepidotus unguiculatus, LL. Agassiz, Poiss. Foss. vol. ii. pt. 1. pp. 9, 251, pl. xxx. figs. 7-9 (non p. 254, pl. xxix. ¢. fig. 1). 1863. Lepidotus unguiculatus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys, Cl. vol. ix. p, 623. Type. Portion of squamation. So far as can be ascertained from the descriptions of Agassiz and Wagner, the fine specimen mentioned below pertains to L. wnguicu- latus and justifies the following diagnosis. A species attaining a length of about 0°8. Trunk robust, the length of the head with opercular apparatus equalling about two- thirds the maximum depth of the trunk, and occupying somewhat more than one-fifth of the total length of the fish. Maximum width of operculum slightly exceeding half its depth, and equalling about one-third the length of the head. External bones apparently smooth or sparsely ornamented. ‘Teeth short and stout and smooth, the majority oval in outline and with a well-defined median coronal tubercle or apex. Fin-fulcra very large on the dorsal fin, com- paratively small on the anal and lower lobe of the caudal fin; all the median fin-rays especially robust. Pelvic fins arising nearer to the anal than to the pectorals ; anal fin arising opposite the posterior extremity of the dorsal. Scales smooth, none serrated, but the postero-inferior angle more or less produced, and the hinder margin often with one or two notches immediately above this ; dorsal ridge- scales acutely pointed but inconspicuous. Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. 37022. Nearly complete fish 0°75 in length, with the right operculum removed and shown from the inner aspect above the head, and part of the abdominal squamation disturbed ; Solen- 1 Specifically indeterminable scales from the Kimmeridgian and Portlandian of N. France (Lepidotus fittoni, H. EH. Sauvage, errore, Catal. Poiss. Form. Second. Boulonnais, 1867, p. 18, pl. i. figs. 24, 25) are also ascribed to this species by H. HE. Sauvage, Bull. Soe. Géol. France, [3] vol. viii. (1880), p. 526. The so-called pharyngeals of Pycnodus dutertrei figured by Sauvage, loc. cit. 1867, pl. ii. fig. 9, are much like the splenials of L. affinis. SEMIONOTID.. 103 hofen. The head is much crushed and abraded, but a few tubercles remain upon the cranial roof and the mouth is opened to display the characteristic teeth. The anal and caudal fins are especially well preserved, the latter ex- hibiting its gently excavated posterior margin. Hiiberlein Coll. Lepidotus lzevis, Agassiz. 1837-44. Lepidotus levis, L. Agassiz, Poiss, Foss. vol. ii. pt. i. p. 254, pl. xxix. c. figs. 4-6. (P) 1846. Lepidotus subundatus, G. von Miinster (errore), Beitr. Petre- fakt. pt. vii. p. 37, pl. iii. fig. 16. [Detached scales and teeth ; Paleontological Museum, Munich. | 1860. Lepidotus levis, F. J. Pictet, Descript. Rept. & Poiss. Foss. Jura Neuchatelois, p. 26, pls. vi., vil. (?) 1875. Lepdotus levis, K. Fricke, Paleeontogr. vol. xxii. p. 377, plixxi. fig? 1. Type. Scale; Museum of Soleure, Switzerland. An imperfectly known species of moderate size. Teeth short and stout and smooth, the majority oval in outline and with a well- defined median coronal tubercle or apex ; splenial teeth apparently in more than three concentric series. Scales as in L. palliatus. The dentition described and figured as mandibular by Fricke seems to be more probably pterygo-palatine and exhibits four longitudinal series of teeth. Form. & Loc. Kimmeridgian: Switzerland. Upper Corallian and Lower Kimmeridgian: Hanover '. P. 3519. Limestone with fragmentary scales, probably of this species; Soleure. Enniskillen Coll. P. 1108. Four scales, labelled by Agassiz ; Soleure. Hgerton Coll. Lepidotus palliatus, Agassiz. im 1887, Lepidotus palliatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 255, pl. xxix. ¢ figs, 2, 3. 1833-44, Lepidotus radiatus, L. Agassiz, eid. pt. i. pp. 9, 256, pt. ii. p: 287, pl. xxx. figs. 2, 3. [Scales; Paris Museum of Natural Flistory. | ' Specifically indeterminable scales from the Upper Kimmeridgian and Portlandian of Boulogne are referred to this species by H. BH. Sauvage, Catal. Poiss. Form. Second. Boulonnais (Mém. Soc. Acad. Boulogne-sur-Mer, vol. 1. 1867), p. 16, pl. i, figs. 8-16, and Bull. Soc. Géol. France, [8] vol. vii. (1880), p. 525; also others from the Neocomian of Wassy, Haute Marne, by J. Cornuel, Bul), Soc. Géol. France, [3] vol. v. (1877) p. 607. 104 ACTINOPTERYGII. (?) 1863, Plestodus pustulosus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 638, pl. vil. 1867. Lepidotus palliatus, H. EH. Sauvage, Catal. Poiss. Form. Second. Boulonnais (Mém, Soc, Acad. Boulogne-sur-Mer, vol. ii.), p. 19, pl. i. figs. 19-23. 1867. Lepidotus radiatus, H. BK. Sauvage, zbid. p. 15 (in part). 1875. Lepidotus giganteus, K. Fricke, Paleontogr. vol. xxii. p. 381, pl. xxi. figs. 7-9. 1877. Lepidotus palliatus, H. E. Sauvage, Mém. Soc. Géol. France, [3] vol. d.mo. Lips, ple deren, 1880. Lepidotus palhatus, H. KE. Sauvage, Bull. Soc. Géol. France, [3] vol. viii. pp. 458, 524, pl. xiii. fig. 1. 1880. Lepidotus radiatus, H. E. Sauvage, aid. p. 524. (?) 1885. Lepidotus palliatus F. Bassani, Atti Soc. Ital. Sei. Nat. vol. xxviii. p. 157, pl. 11. a. figs. 14-16. Type. Detached scales British Museum. A species attaining a length of about 2 metres. Trunk very robust, and head with opercular apparatus occupying somewhat less than one-quarter of the total length of the fish. Maximum width of operculum two-thirds as great as its depth, and equalling about one-third the length of the head. External bones more or less rugose or tuberculated ; mandibular symphysis very robust, the dentary bone being much horizontally extended to support the large dentigerous splenial. All the teeth very short and stout and smooth, the inner and larger ones with gently rounded crown, the outer teeth more or less acuminate; splenial teeth in six or seven irregular concentric series, increasing in size within ; pterygo-palatine teeth in four or five longitudinal series, increasing in size within ; vomerine dentition increasing in size backwards, the anterior teeth very irregular, in about four or five longitudinal series, the largest posterior teeth comprising three successive pairs. Fin-fulera very large ; pelvic fins arising midway between the pectorals and the anal; dorsal fin remote, arising considerably behind the pelvic pair ; anal fin arising opposite the hinder extremity of the dorsal. The enamel of the scales comparatively thin, sometimes discontinuous, sometimes with few granulatious; principal flank-scales with a few broad ridges and furrows radiating from the centre to the hinder border, where they form indentations. In this definition, the statement of form and proportions is based upon the first specimen mentioned below. ‘The characters of the dentition are more clearly seen in the French specimens described by Sauvage. The left mandibular dentition is shown in Mém. Soe. Géol. France, [3] vol. i. no. 1, pl. i. fig. 1, and the vomerine dentition, ibid. pl. uu. fig. 11. The left pterygo-palatine dentition is shown SEMIONOTID &. 105 abid. pl. ii. fig. 10, and another fragment of the same is described and figured in Bull. Soc. Géol. France, [3] vol. viii. (1880), p. 458, pl. xiii. fig. 1. The maxilla and premaxilla are unknown. Form. & Loc. Upper Corallian: Witrtemberg. Kimmeridgian : N. France, 8S. England, Hanover, Bavaria. (?) Portlandian: Italy. P. 338. Plaster cast of a fine specimen 1°7 in length and about 0-65 in maximum depth, with imperfect fins ; Lithographic Stone, Solenhofen, Bavaria. The original fossil is a natural mould, preserved in the Paleontological Museum, Munich. Purchased, 1881. 32765, 33301. Detached teeth; Kimmeridge Clay, Boulogne. Purchased, 1859. 35762. Group of nine teeth; White Jura e, Schnaitheim, Wiirtem- berg. Purchased, 1860. 41402. A pair of squamosals, and part of another tuberculated bone, . apparently associated ; Kimmeridge Clay, Weymouth. Except upon the fragment, there is no tendency towards the arrangement of the tubercles in radiating series. Purchased, 1869. P. 3520-1. The two type scales, described and figured by Agassiz, loc. cit.; Kimmeridge Clay, Boulogne. Enniskillen Coll. 32474, 41616. Series of twelve scales ; Boulogne. Purchased, 1859. P. 1107. Imperfect large scale; Boulogne. Egerton Coll. 42364. Two imperfect scales, with very large overlapped area; Kimmeridge Clay, Weymouth. Purchased, 1870. P. 1110. Scale; Lithographic Stone, Pappenheim, Bavaria. Egerton Coll. 22486, 35760-61. Three scales, recorded under the name of Lepi- dotus radiatus by H. E. Sauvage, loc. cit. 1867, p. 16; White Jura e, Schnaitheim, Wiirtemberg. Purchased, 1848, 1860. Lepidotus maximus, Wagner. 1742. Figures of teeth by F. E. Briickmann, Cent. Epistol. itinerar. no. 1. 1746. Figure of tooth by P. Barrére, Pierres figurées, pl. ii. no 9. 1811. Figure of tooth by J. Parkinson, Organic Remains, vol. iii. pl. xix. fie. 6. 1838. Spherodus gigas, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 15. 106 ACTINOPTERYGII. 1839-44. Spherodus gigas, 11. Agassiz, abid. pt. il. p. 210, pl. Ixxiii. figs, 83-94. 1844, Spherodus neocomensis, L. Agassiz, ibid. p. 216. [ Teeth. |] 1839. Spherodus gigas, F. A. Roemer, Verstein. Norddeutsch. Oolithen- gebirges, Nachtr. p. 54. ; 1850. Spherodus gigas, J. Cornuel, Bull. Soc. Géol. France, [2] vol. vii. p. 703. 1851. Spherodus crassus, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p. 58. 1852. Lepidotus giganteus, F, A. Quenstedt, Handb. Petrefakt. p. 198, pl. xiv. fig. 18. [Scale; Tubingen University Museum. | 1852. Spherodus gigas, F. A. Quenstedt, ibid. p. 199, pl. xiii. fie, 42. 1853. Lepidotus giganteus, F. A. Quenstedt, Wurtt. Jahresh. vol. ix. p. 361, pl. vii. figs. 1-8. 1858. Lepidotus giganteus, F. A. Quenstedt, Der Jura, p. 780, pl. xcvi. figs. 1-4, 1858. Spherodus gigas, F. A. Quenstedt, bid. p. 780, pl. xevi. figs. 5-10, 1860. Spherodus gigas, F. J. Pictet, Descript. Rept. & Poiss. Foss. Jura Neuchatelois, p. 35, pls. viil., ix., pl. xvii. fig. 1. 1860. Spherodus neocomiensis, Pictet & Campiche, Foss. Terrain Crét. St. Croix, pit. p. (2,9). tae esa -O, (?) 1861. Tetragonolepis eximius, T. C. Winkler, Descript. Poiss. Foss. Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv.), p- 87, fig. 16. [Caudal fin; Haarlem Museum. | 1863. Lepidotus maximus, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. p. 629. 1863. Spherodus gigas, A. Wagner, ibid. p. 630. 1864. Spherodus yigas, 'Fhurmann & Etallon, Nouv. Mém. Soc. Helv. Sci. Nat. vol. xvii. p. 431, pl. lxi. fig. 17 (non figs. 18, 19). 1865. Spherodus gigantiformis, C. von Schauroth, Verstein. Herz, Naturaliencabinet Coburg, p. 155, pl. iv. fig. 15. [Tooth; Coburg Museum. | 1867. Lepidotus (Spherodus) giganteus, H. HK. Sauvage, Catal. Poiss. Form. Second. Boulonnais, p. 22. 1870. Spherodus gigas, G. G. Gemmellaro, Studii Paleont. Fauna Cale. a Terebratula janitor N. Sicilia, pt. 1. p. 6, pl. 11. figs. 1-14. 1870. Lepidotus maximus, K. A. von Zittel, Paleeontogr. Suppl. p. 22, Tolls ate tivegs I> . 1877. Lepidotus giganteus, J. Cornuel, Bull. Soc. Géol. France, [5] vol. v. p. 607. 1877. Lepidotus maximus, H. E. Sauvage, Mém. Soc. Géol. France, [3] Vol. 1. no. Lp. 7, pl. dates ree: 1879. Lepidotus maximus, H. EH. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol, xxxiil. pt. 1. p. 28. 1879. Lepidotus neocomiensis, H. EK. Sauvage, aid. p. 31, pl. il. figs. 7-10. 1883. Spherodus neocomiensis, W. Keeping, Foss. Neocom. Upware, p.-L, pleas fig. 4, SEMIONOTIDA. 107 1885. Lepidotusm axunus, F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxviii. pp. 80, 154, pl. ii. a. figs. 12, 13,j 1889. Lepidotus maximus, Etheridge & Willett, Quart. Journ, Geol. Soe. vol. xlv. p. 356, pl. xv. Type. Detached teeth; Museums of Oxford, Paris, and Stuttgart. The type species of the so-called genus Spherodus, attaining a length of probably not less than 2 metres, but known only from fragments. Teeth very broad and gently rounded, except towards the margin of the upper jaw, where they become obtusely conical ; teeth of mandible relatively large and arranged in four or five irregular concentric series. Principal flank-scales with a few broad ridges and furrows radiating from the centre to the hinder border, where they form feeble indentations ; superficial layer of ganoine comparatively: thin, sometimes discontinuous, sometimes with few granulations. This species as yet is only clearly distinguished from Lepidotus palliatus by the characters of the mandibular dentition, and some of the fragments entered above under the last-named species may belong to L. maximus. Form. & Loc. Upper Corallian: Wiirtemberg. Kimmeridgian : S. England, N. France, Switzerland, Tyrol, and Sicily. Portlandian: France, Italy, and Germany. Neocomian: Cambridgeshire, Berk- shire, and Bedfordshire (derived); Haute Marne, France; Switzer- land. P. 6723. Imperfect right splenial showing the arrangement of the dentition, with successional teeth, noticed in Quart. Journ. Geol. Soc. vol. xlv. p. 357, no. ili.; Kimmeridge Clay, Shotover, near Oxford. Presented by Henry Willett, Esq., 1892. P. 6724. Tooth with successor, in transverse section, figured zbid. pl. xv. fig. 3; Shotover. Presented by Henry Willett, Esq., 1892. P. 1677, P. 4658. Detached teeth; Tithonian formation, Trient, Tyrol. Egerton & Enniskillen Colls. 22482-83, 22488, 28506, 32754, 36148. Several detached teeth ; Corallian, Schnaitheim, Wiirtemberg. Purchased, 1847, 1848, 1859. 36148 a. Two abraded teeth associated with two successional teeth, each of the latter exhibiting a minute central coronal tubercle ; Schnaitheim. Purchased, 1859. P. 1679. Plaster cast of imperfect left palatine dentition ; Upper Jurassic, Switzerland. Egerton Coll. 108 ACTINOPTERYGII. P. 4659. Detached teeth; Soleure, Switzerland. Enniskillen Coll. P. 3. Two dental crowns; Favara Villabati, Sicily. Purchased, 1879. 30893, 32420. Several detached teeth, either of this species or Z. ee: Kimmeridge Clay, Mt. Lambert, Boulogne. Purchased, 1857. P. 1678, P. 4660. Six detached teeth; Kimmeridge Clay, Shotover, near Oxford. Egerton & Enniskillen Colls. P. 6172. Six smaller teeth ; Shotover. Damon Coll. P. 4661. Several detached teeth; labelled ‘“‘ Kimmeridge Clay, Christian Malford, Wiltshire.” Enniskillen Coll. 40467. Six teeth; Neocomian Bone-bed (derived from Kimmeridge Clay), Potton, Bedfordshire. Purchased, 1867. 49976. Four dental crowns; Potton. Presented by R. Inwards, Esq., 1879. 46382 a. Three dental crowns; Neocomian (derived), Farringdon, Berkshire. Cunnington Coll. 28395. Two dental crowns ; Farringdon. Mantell Coll. 40971. Seven dental crowns; Neocomian (derived), Upware, near Cambridge. Purchased, 1867. ZZ. 18 (Cracherode Catalogue). Dental crown. Cracherode Bequest. Lepidotus mantelli, Agassiz. 1826. Figure of marginal teeth by T. Webster, Trans. Geol. Soc. [2] vol. ii. pl. vi. figs. 5, 6. 1827. “Scales of a Vase form,” G. A. Mantell, Foss. ioe Forest, p. 58, pl. v. figs. 3, 4, 15, 16. 1833. Lepidotus nation tiene L.. Agassiz, Poiss. Foss. vol. ii. pt. i. p- 9. [Scales.] 1833-37. Lepidotus mantelli, L. Agassiz, bid. pt. i. pp. 9, 262, pl. xxx. figs. 10-15, pl. xxx. a. figs. 4-6, pl. xxx.6. fig. 2, pl. xxx.e. figs. 1-7. 1854-44. Lepidotus fittoni, L. Agassiz, wbed. pt. i. p. 265, pl. xxx. figs. 4-6, pl. xxx.a. (excl. figs. 46), pl. xxx. 0. (excl. fig. 2). [Portion of fish; British Museum. | 1836-44. Tetragonolepis mastodonteus, L. Agassiz, ibid. pt. i. p. 216, pl. xxii. e. figs. 5, 4 (mon fig. 5). 1841. Lepidotus mantelli, R. Owen, Odontogr. p. 69, pl. xxx. ng. 1, pl. xxxi. 1849. Lepidotus mantelli, W.C. Williamson, Phil. Trans. p. 444. 1854. Aechmodus mastodonteus, J. Morris, Catal. Brit. Foss. p. 317. SEMIONOTID &. 109 1854. Lepidotus fittoni, J. Morris, zbid. p. 331. 1854, Lepidotus mantelli, J. Morris, zbid. p. 332. 1860. Lepidotus fittont, J. HE. Lee, Geologist, vol. iii. p. 458, pl. xii. 1887. Lepidotus mantelli, W. Branco, Abh. geol. Specialk. Preussen u. Thiiring. Staaten, vol. vii. p. 345, pl. il. figs. 1, 2. 1890. Lepidotus mantelli, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 112. Type. Portion of fish; British Museum. A species attaining a length of about 1 metre. Trunk very robust, and head with opercular apparatus occupying about one- quarter of the total length of the fish. Maximum width of operculum nearly two-thirds as great as its depth, and equalling about one- third the length of the head; frontal profile very slightly bent and snout acute. External bones more or less rugose or tuberculated ; parietal bones much less than half as long as the frontals, which are three times as long as their maximum width, very narrow in front, and united throughout their length by a nearly straight median suture; mandibular symphysis very robust, the dentary bone being much horizontally extended to support the large denti- gerous splenial. Inner teeth very short and stout, the majority, when unworn, with a slightly acuminate crown, but always smooth; marginal teeth also robust ; splenial teeth in five (sometimes six) irregular concentric series increasing in size within; pterygo- palatine teeth in three (sometimes four) longitudinal series increasing in size within ; vomerine dentition increasing in size backwards, the anterior teeth very irregular, in about four longitudinal series, the largest posterior teeth comprising two pairs with one median tooth in advance. Ring-vertebre present in the adult. Fin-fulcra very large; pelvic fins arising nearer to the pectorals than to the anal ; anal fin arising opposite the hinder extremity of the dorsal. Scales smooth, those on the flanks often crimped towards their hinder border and more or less coarsely serrated, those of the lateral line deeply notched, and all showing oblique ridges when worn; prin- cipal flank-scales somewhat deeper than broad; dorsal ridge-scales inconspicuous but acuminate. Form. & Loc. Wealden: 8.E. England and N. Germany. » 2456. Hinder portion of head with part of the abdominal region, described and figured by Agassiz, tom. cit. p. 263, pl. xxx. c. fig. 1, and to be regarded as the type specimen; Heath- field. The drawing is very unsatisfactory, and there is no indication of the few coarse denticulations exhibited by some of the scales. The left hyomandibular and meta- 110 P. 6337. P. 6336. ACTINOPTERYGII. pterygoid are partly exposed, and the preoperculum appears to owe its peculiar form to crushing and fracture. The operculum and suboperculum are also much broken, but their true proportions seem to be as described by Agassiz. The uppermost postclavicular scale is con- spicuous, and there are traces of the elongated basal bones, besides the coracoid, at the origin of the pectoral fin. The fulcra on the latter are distinctly biserial, and the fin-rays are undivided except quite at the extremity. The obliquely-ridged structure of the scales can be faintly seen through the enamel, which is well preserved. Mantell Coll. A fine specimen, originally about 0-9 in length, wanting the extremity of the snout and the pectoral fins, but displaying part of the base of each of the other fins ; Hastings. The opercular and head-bones are coarsely tuberculated as in the type specimen, and the operculum is nearly similar in proportions ; but the preoperculum is shaped as in the so-called L. fittonz, and the suboperculum seems to have been nearly half as deep as the operculum. The pelvic fins arise considerably nearer to the position of the pectoral arch than to the anal, and both these fins display large fulcra; of the dorsal and caudal fins only insignificant fragments remain. The dorsal part of the abdominal region is crushed and displaced, but the greater part of the squamation is undisturbed, and the principal flank-scales exhibit a feeble pectination. Beckles Coll. Another fine specimen, equally large, wanting the paired fins but displaying the greater part of the anal and caudal ; Hastings. The operculum is as described in L. fittoni, but whether or not its comparative smoothness is due to abrasion, is uncertain ; the cranial and facial bones are irregularly rugose, not exhibiting sharp tuberculations. The dorsal fin is shown to have arisen at about the middle point of the back, but only the large anterior fulcra and two fragments of rays are preserved; the anal fin, with numerous more slender fulcra, seems to have been deeper than long; and the robust caudal fin-rays are shown to have been very closely articulated quite to their base. All the scales are smooth, but those on the anterior portion of the flank exhibit serrations, and each scale of the lateral line is conspicuously notched. ‘The perforations of the SEMIONOTID &. Tih scales for the dorso-lateral line are also seen as far as the origin of the dorsal fin; and the small ridge-scales, only preserved for a short distance behind the head, exhibit a comparatively blunt acumination. At the base of the dorsal and caudal fins one fringing row of scales is directly related to the fin-rays and fulcra, and does not conform to the regular flank-series of the trunk; at the base of the anal fin the squamation is lost. Beckles Coll. P, 4915. A more imperfect and fractured specimen, in counterpart ; P. 6338. Hastings Sands, Silver Hill, Hastings. The antorbital portion of the skull is wanting, but most of the cireum- orbital and suborbital bones are preserved and the former are larger than the latter. The preoperculum is coarsely rugose, while the operculum and suboperculum are closely and finely tuberculated; owing to fracture, the form of the operculum cannot be satisfactorily determined, but the proportions of the suboperculum seem to be as in the so- called L. fittoni, and its anterior ascending process is much more robust than in the type specimen of L. manéelli. Part of a pectoral fin is preserved, and the rays are shown to have been very closely articulated distally. Fragments of the dorsal and caudal fins and the imperfect squama- tion present no features worthy of special note. Dawson Coll. Head and greater portion of trunk, apparently much abraded, and showing only the origin of the dorsal fin; Hastings. The head-bones show traces of fine tubercula- tions besides the coarse rug, but the much-fractured operculum is smooth. The fluted structure of the scales is exposed by abrasion; the principal flank-scales are serrated ; and the dorsal ridge-scales do not exhibit traces of an acumination until beyond a considerable distance from the head. Beckles Coll. P. 6339-40. Two more imperfect, similarly abraded specimens; P. 5129. Hastings, Beckles Coll. Imperfect abraded head and portion of trunk, displaying the symphysis of the mandible and the lower extremity of the right clavicle; Horsham. The external head-bones are coarsely rugose and in part tuberculated; the oper- culum and suboperculum are rugose only, but seem to have been much abraded. ‘The ascending process of the 112 ACTINOPTERYGII. suboperculum is both broad and remarkably long. The teeth are partly acuminate, partly round; but it is probable that most of the latter owe their form to wear. The principal flank-scales are serrated, and the fluted structure is shown in all the scales from which the enamelled surface has been removed. Purchased, 1886. 90673 a. A much crushed and abraded head, with the anterior portion of the abdominal region, the type specimen of the so-called L. fittonz, figured by Agassiz, tom. cit. pl. xxx. a. fig. 1; Highfure, Billingshurst. The mandibular rami differ from those of the preceding specimen in having their inferior margin considerably curved downwards to a point at the symphysis. The openings in the scales of the dorsal region for sensory canals are not very regularly arranged. Presented by P. J. Martin, Esq., 1846. 43073. A much more imperfect, crushed specimen ; East Grinstead. Purchased, 1871. P. 6933. Fine example of the head and anterior abdominal region of a young individual, shown of one-half the natural size from the superior (a) and left lateral (6) aspects in the aecom- panying fig. 23; Hastings. The extremity of the snout is broken away, and only a doubtful fragment of bone appears to represent the maxilla (mw.) on the left side. The cranial roof-bones are in part coarsely rugose and ornamented with very fine tuberculations, mostly in radi- ating lines; the supratemporal plates (s.t.) are arranged in four pairs, the two innermost not quite symmetrical and representing the single pair in adults. The mandible is shown, partly smooth, partly with the characteristic coarse rugosity ; and the inferior border of the dentary bone (d.) is very sharply curved downwards to a point at the mandibular symphysis. The circumorbital (¢.0.), sub- orbital (s.o.), and opercular bones are well preserved on the left side; the first two series marked with a few large tubercles in their lower portion, more delicately ornamented above, and the opercular bones very finely granulated. The maximum width of the operculum (op.) is two-thirds as great asits depth, and its anterior margin is sinuous, exhibiting a considerable concavity above ; the maximum depth of the suboperculum (s.op.) is about half that of the operculum, and its anterior ascending SEMIONOTIDA. 113: process seems to be short and stout. The left clavicle (cl.) and supraclavicle (s.cl.) are also exhibited, and there are traces of large postclavicular scales (p.cl.) above and in front of the base of the pectoral fin. The scales of the flank are all strongly, but finely, serrated, and those of Fig. 23. SN Mm A yy, /\\' (OnE Lepidotus mantelli ; head from superior (a) and left lateral (0) aspecis, one-half nat. size— Wealden ; Hastings. [N.P. 6933.] ag., angular; c¢.o., circumorbitals; c/., clavicle; d., dentary; /r.. frontal; z.0p., interoperculum ; op., operculum; o7d., orbit; y.cl., postclavicular scale; p.op., preoperculum ; p.¢., post-temporal; pa., parietal ; s.c/., supra- clavicle ; s.o., suborbitals ; s.¢., supratemporals; sqg., squamosal. PART III. I 114 ACTINOPTERYGII. the lateral line are also deeply notched ; the dorsal ridge- scales are acuminate from the beginning, and many of the anterior dorso-lateral scales are very finely tuber- culated. Rufford Coll. P. 6341. Large head, somewhat fractured and abraded and wanting the rostral extremity ; Hastings. The external bones are all very coarsely rugose, without tuberculations; and the unworn teeth of the roof of the mouth are distinctly acuminate. The operculum has a sinuous anterior margin, and its depth is slightly more than twice that of the sub- operculum. At least six slender branchiostegal rays are fixed to the epihyal; the ceratohyal is long and much constricted mesially ; the hypohyal, shown on each side, and noticed in Proc. Zool. Soc. 1893, p. 563, is short and stout, with a deep transverse groove. Behind and below the head, the pointed and expanded inferior ends of the clavicles are well exhibited, and a few of the anterior scales remain. Beckles Coll. P. 6342. A smaller imperfect, abraded and fractured head, dis- playing in transverse section the structure of the jaws ; Hastings. The section of the rostrum and upper denti- gerous bones is described and figured in Proc. Zool. Soc. 1893, pp. 560, 562, pl. xlix. fig. 4, and the small coronoid bone of the mandible, shown on each side, is noticed, 2b7d. p- 563. Beckles Coll. P. 6343. A less imperfect, abraded head; Hastings. Beckles Coll. P. 6344-46. Six much abraded and fragmentary heads, one sliced to show the comparatively slight ossification of the inner elements of the cranium; Hastings. Beckles Coll. P,. 1124. Waterworn specimen of the cranium with some of the anterior scales and ring-vertebre ; Hastings. The ex- occipital and pro-otic bones are seen in contact, and the coarsely cancellated structure of all the inner bones is displayed. The supratemporal plates, of which the median pair are preserved, overlap the hinder border of the cranium. Egerton Coll, P. 7415. Hinder portion of head, with some anterior scales, showing the small, triangular post-temporal bone and part of the parasphenoid; Sussex. Transferred from the Old Indian Museum, 1880. * . SEMIONOTID&. TIS 2401. Hinder portion of head, with some anterior scales and ring-vertebre ; Sussex. The supratemporal plates are not in symmetrical pairs, but three on one side of the median line and two on the other. The operculum is coarsely tuberculated and the ascending process of the suboperculum is long and slender; but the anterior margin of the former is strongly sinuous. Mantell Coll. P. 6566. Parasphenoid bone, imperfect at each extremity, but showing the ascending lateral processes with superior bifurcation ; Hastings. Beckles Coll. 2399. Left frontal ascribed by Agassiz (tom. cit. p. 264, pl. xxx. b. fig. 2) to L. mantelli; Tilgate Forest. Manitell Coll. 2528. Right frontal ascribed by Agassiz (tom. cit. p. 264, pl. xxx. b. fig. 3) to the so-called L. fittoni ; Tilgate Forest. Mantell Coll, P. 7416-17. Left frontal and portion of right frontal; Hastings. Dawson Coll. 2217. Imperfect left operculum ; Tilgate Forest. Manitell Coll. 2219. Imperfect right suboperculum ; Tilgate Forest. Mantell Coll. 2209. Right preoperculum, inner aspect; Tilgate Forest. Maniell Coll. P. 7418. Right preoperculum ; Tilgate Forest. Enniskillen Coll. 2711. Ceratohyal; Tilgate Forest. Mantell Coll. 2326. Three portions of dentition figured by Agassiz, tom. cit. pl. xxx. a. figs. 4, 5, pl. xxx.c. figs. 2,3; Tilgate Forest. The first figure represents the greater part of the right mandibular dentition with the comparatively small series of teeth on the dentary bone; the second specimen is the middle portion of a vomer ; and the third specimen, shown in the two last-named figures, is the pterygo-palatine dentition apparently of the left side. Mantell Coll. 28412. Associated vomer, left pterygo-palatine, and right mandibular ramus of a large individual; Sussex. The vomer shows the characteristically-arranged five posterior teeth, with the smaller anterior teeth in four very irregular longitu- dinal series; the pterygo-palatine has a minute fourth outer series of teeth; the bases of six small teeth of the 12 116 ACTINOPTERYGII. single series in the dentary bone are exhibited in the mandibular ramus, and some of the outer splenial teeth are broken away. Mantell Coll. P, 3516. Fragmentary trunk with imperfect upper and lower dentition, much worn, and also the opercular apparatus ; Tilgate Forest. The pterygo-palatine teeth are in three series, and a few of the comparatively small dentary teeth are preserved. Enmskillen Coll. Lepidotus mantelli ; diagram of arrangement of teeth in upper (A) and lower (B) jaws, chiefly based upon specimens Nos. P. 3516 and P. 6363. d., dentary ; pt., pterygo-palatine ; sp/., splenial ; v., vomer. P, 3518. Rostral region of skull displaying vomerine and pterygo- palatine dentition; Hastings. Enniskillen Coll. P. 6363. Five portions of dentition, comprising a vomer with remarkably acuminate teeth, two left mandibular rami, SEMIONOTID®, 117 one right mandibular ramus, and a fragment; Hastings. The arrangement of the teeth of the vomer and one splenial is shown in fig. 24. Beckles Coll. P. 1126. Fragments of dentition; Sussex (?). Egerton Coll. 2327, 2841, 2844, 28412a. Fragments of dentition; Sussex. Mantell Colt. P. 4917. Right pterygo-palatine and two fragments; Hastings. Dawson Coll. P. 4995. Right dentary showing three marginal teeth ; Hastings. Presented by J. E. Tee Esq., 1885. 2524. Right clavicle, inner aspect; Tilgate Forest. Mantell Coll. P. 6362. Fragmentary trunk, with hinder extremity of head; Hastings. Beckles Coll. 23624. Crushed remains of head and anterior portion of trunk; Perch Hill, Brightling, Sussex. The imperfect meta- pterygoid and quadrate are shown in position on the left side, and the greater part of the hyomandibular is pre- served on the right. The left epihyal, ceratohyal, and hypohyal are displaced and well shown in series; and the uppermost, broad branchiostegal ray occurs immediately behind. The clavicles and some of the postclavicular scales are exposed ; and at the base of the pectoral fin on the right side there are five elongated basal bones. Presented by Rev. Joseph Gould, 1849. P. 6347. Anterior portion of trunk; Hastings. Beckles Coll. 2676. Hinder portion of trunk, apparently noticed by Agassiz, tom. cit. p. 263; Tilgate Forest. Mantell Coll. P. 6348 c. Fragment of trunk showing well-ossified ring-vertebre, with neural and hemal arches of the abdominal region; Hastings. The neural spine is not fused with the pedicles of the arch, and each ring as preserved seems to consist of four pieces. Beckles Coll. P. 469. Portion of squamation figured by Agassiz, tom. cit. pl. xxx. ¢. fig. 4; Tileate Forest. Egerton Coll. 36592. Portion of squamation ; Sussex. Dixon Coll. 40319. Portion of squamation, finely serrated ; Tunbridge Wells. Purchased, 1867. 118 ACTINOPTERYGII. 47984. Portion of squamation and some portions of the axial skele- ton ; locality unknown. Presented by the Hon. Robert Marsham, 1877. P. 1122. Portion of squamation, finely serrated; Tunbridge Wells. Egerton Coll. P. 3517 a—c. Three portions of squamation, the third being a large part of the caudal pedicle ; Hastings and Tilgate Forest. Enniskillen Coll. P. 5129 a. Portion of squamation ; Horsham, Sussex. Purchased, 1886. The Collection also comprises numerous detached scales and teeth from the Mantell and other Collections. Most of the following Wealden specimens may also probably belong to LZ. mantelli, but they cannot as yet be specifically deter- mined :— P. 6349. Abraded remains of small head and abdominal region, showing the neural arches and well-developed ribs; Hastings. The flank-scales are not serrated. Beckles Coll. 37240. Natural mould of hinder half of head and greater portion of trunk of a small fish; Rusthall Common, Tunbridge Wells. Purchased, 18638. P. 6739, P. 6739 a. Very small left premaxilla with five teeth and the base of a sixth, and wanting the ascending process ; also a still smaller right dentary with similarly slender teeth ; Hastings. Rufford Coll, 47504. Vomerine and right pterygo-palatine dentition; Isle of — Wight. The teeth are arranged as in LZ. mantell, but some exhibit coronal ruge radiating from the apex to a slight cingulum at the base. Purchased, 1876. 40539. Two portions of mandible with smooth teeth; Hastings Sands, Isle of Wight. Purchased, 1867. P. 1126 a-c. Three portions of mandible, with relatively small and numerous outer splenial teeth, all smooth; Isle of Wight. Lgerton Coll. P. 7097. Fragment of dentition; Brook, Isle of Wight. Purchased, 1894. SEMIONOTID 2, 119 P. 6363 a, b. Two portions of dentition, many of the teeth being relatively small and well spaced ; Hastings. Beckles Coll. P. 1123, P. 1125. Two waterworn portions of squamation ; Isle of Wight. Egerton Coll. P. 7419. Scales; Brook, Isle of Wight. Lepidotus degenhardti, Branco. 1885. Lepidotus degenhardti, W. Branco, Jahrb. preuss. geol. Landes- anst. 1884, p. 183, pl. viil., pl. ix. fig. 1. 1887. Lepidotus degenhardti, W. Branco, Abh. geol. Specialk. Preussen u. Thiring. Staaten, vol. vii. p. 380, pl. 1. 1887. Lepidotus degenhardti, var. dubia, W. Branco, ibid. p. 332, pl. i1- figs. 1-5. Type. Imperfect fish ; Geological Survey Museum, Berlin. A large species closely resembling LZ. mantelli, but apparently somewhat deeper in proportion to its length. Maximum width of operculum about two-thirds as great as its depth, and equalling one-half the length of the head; frontal profile very steep, slightly convex. External bones more or less rugose or tuberculated. Inner teeth short and stout, with a smooth and slightly acuminate crown. Fin-fulcra very large; pelvic fins arising midway between the pectorals and the anal; anal fin arising opposite a point con- siderably in advance of the hinder extremity of the dorsal. Scales showing a few oblique ridges beneath the enamel in their anterior half; principal flank-scales with two or three very large denticula- tions on the lower half of their posterior border; dorsal ridge-scales inconspicuous but acuminate. Form. & Loc. Wealden: Obernkirchen, Prussia. Not represented in the Collection. Lepidotus hauchecornei, Branco. 1887. Lepidotus hauchecornet, W. Branco, Abh. geol. Specialk. Preussen u, Thiiring. Staaten, vol. vii. p. 348, pl. iv. figs. 1, 2, pl. vii. fig. 1. Type. Imperfect fish, wanting the greater part of the caudal region; Geological Survey Museum, Berlin. A species of moderate size, attaining a length of about 0°5. Trunk deeply fusiform, and head with opercular apparatus occupying nearly one-quarter of the total length of the fish. External bones ornamented with very large, closely arranged tuberculations. Fin- fulera very large, but slender; pelvic fins arising midway between 120 ACTINOPTERYGII. the pectorals and the anal; anal fin arising opposite the hinder portion of the dorsal. Scales smooth, those of the flank with long, slender posterior denticulations, which are numerous and closely arranged on the anterior part of the abdominal region, fewer be- hind ; principal flank-scales considerably deeper than broad ; dorsal ridge-scales acuminate and conspicuous. Branco recognizes a variety of this species in which the most anterior scales exhibit only sparse denticulations, named ZL. hauche- corner var. paucidentata (loc. cit. p. 356, pl. v. fig. 1). To the same variety he also doubtfully assigns some fragments determined as L. fittoni by W. Dunker, Monogr. Norddeutsch. Wealdenbild. (1846), p. 63, pl. xiv., pl. xv. fig. 3. Form. & Loc. Wealden: Obernkirchen, Prussia. Not represented in the Collection. The following specifically indeterminable specimen exhibits scales much resembling those of LZ. hauchecorne: :— 28622. Opercular and pectoral region of a very large fish, with part of the abdominal squamation; Purbeck Beds, Swanage. The operculum measures 0°1 in maximum depth and 0:055 in maximum width, and is rugose though very sparsely tuberculated. It is more than four times as deep as the suboperculum, which is similarly rugose and exhibits the usual antero-superior ascending process. The serrations on the flank-scales are probably enlarged by imperfect preservation, but they must nevertheless have been origi- nally very conspicuous. Purchased, 1853. Lepidotus mawsoni, A. 8. Woodward. 1860. Lepidotus, Sir P. Egerton, inS. Allport, Quart. Journ. Geol. Soc. vol. xvi. p. 265, pl. xiv. figs. 5-18, pl. xv. figs. 1-4, pl. xvi. fies. 10-12. 1888. Lepidotus mawsont, A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol, i. p. 185. Type. Detached scales; British Museum. A large species known only from detached scales, teeth, and fragments. Scales much thickened and deeply overlapping; prin- cipal flank-scales with frequently discontinuous enamel, marked with a few broad ridges and furrows radiating from the centre to the hinder border, where they form feeble indentations; none of the scales serrated. Teeth, apparently of the same fish, rounded and comparatively small. Form. &¢ Loc. Cretaceous: Bahia, Brazil. SEMIONOTID A. i 4) | P. 5534, b. Two type scales described, loc. ct. 1888; Bahia, Presented by Joseph Mawson, Esq., 1888. P. 410, P. 412, P. 2280. Series of detached scales and teeth; Plataforma, Bahia. . Presented by Joseph Mawson, Esq., 1881, 1882. P. 7112. Twelve scales and two head-bones ; from beach between Plataforma and Itacaranha. Presented by Joseph Mawson, Esq., 1893. P. 7113. Scales ; Itacaranha. Presented by Joseph Mawson, Esq., 1893. P. 7114. Scales; Pedra Furada Bay, Montserrat. Presented by Joseph Mawson, Esq., 1898. P. 7118. Scales; various localities near Bahia. Presented by Joseph Mawson, Esq., 1893. P. 7341. Thirteen scales figured in Quart. Journ. Geol. Soc. vol. xvi. pl. xiv. figs. 6-12, pl. xv. figs. 1-4, pl. xvi. figs. 10-12. Presented by Samuel Allport, Hsq., 1894. P. 7343. Scales; Bahia. Presented by Samuel Allport, Esq., 1894. P. 7340. Head-bone figured as a crocodilian scute, loc. cit. 1860, pl. xvi. fig. 9; Bahia. Presented by Samuel Allport, Esq., 1894. P. 7342. Five head-bones; Bahia. Presented by Samuel Allport, Esq., 1894. P. 7344. Hyomandibular, remarkable for the thin laminar expan- sion of its hinder margin below the upper articulation ; Bahia. Presented by Samuel Allport, Esq., 1894. Lepidotus (?) pustulatus, sp. nov. Eblate VILE ne? i) Type. Associated scales ; British Museum. A large species known only by scales, some of which measure 0-035 in length in their exposed portion. Scales moderately robust, with a thin and sometimes discontinuous layer of enamel, marked with irregularly-arranged, large, round shallow pits; principal flank-scales exhibiting a few broad ridges and furrows radiating from the centre to the hinder border, where they form feeble digi- tations ; several scales much broader than deep. Form. §& Loc. Cenomanian: Kent. 122 ACTINOPTERYGII. P. 21, P. 6201-a. Numerous scales, various in form and state of preservation, discovered by J. Griffith and said to pertain to one fish, eight shown of the natural size in Pl. VIII. figs. la-h; Grey Chalk, Folkestone. Gardner Coll., and Purchased, 1890. P. 6201 b. Large triangular bone fractured at the margin, found in association with the above. The external surface is destitute of enamel and marked with large, rounded, radiating ridges, more or less tuberculated. Purchased, 1890. The following specimens are not specifically determinable, but appear to belong to Lepidotus :— P. 1105. Imperfect small smooth scales; Rhetic, Linksfield, Elgin, Egerton Coll. P. 2789. Tooth either of Lepidotus or Colobodus ; Rheetic, Axmouth, Devonshire. Enniskillen Coll. P. 1113. Scales; Kimmeridge Clay, Swindon, Wiltshire. Egerton Coll. P. 3619. Remains of trunk described as the type specimen of Senv- onotus manseli, Kgerton, Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Surv. 1872), no. 8, pl. viii. ; Kimmeridge Clay, Isle of Purbeck. Doubtfully ascribed to Heterolepidotus by K. A. von Zittel, Handb. Palzont. vol. ii. (1887), p. 205, and to Lepidotus by Woodward & Sherborn, Catal. Brit. Foss. Vert. (1890), p. 112. — Enniskillen Coll. P. 1541. Fragments of similar fish; Kimmeridge Clay, Isle of Purbeck. Egerton Coll. P. 2269. Plaster cast of imperfect fish about 0°9 in length, apparently related to Lepidotus palliatus; Lower Kim- meridgian (Lithographic Stone), Cirin, Ain, France. | Egerton Coll. 41800. Scale; Cambridge Greensand, Cambridge. Purchased, 1869. P. 7232. Nine scales ; Cambridge Greensand. Jesson Coll. 47217. Row of four prehensile teeth on bone; Gault, Folkestone. Gardner Coll. SEMIONOTID&. 123 46407. Two dental crowns; Upper Greensand, Warminster. Cunnington Coll. P. 5523. Small fragmentary scales and teeth; Lower Greensand, Godalming. Purchased, 1888. 46383. Dental crown; Lower Greensand, Seend, Devizes. Cunnington Coll. 47172. Group of imperfect scales; Jurassic, Nagpur, India. Presented by Rev. Stephen Hislop, 1876. P. 5156. Two teeth, type specimens of so-called Sphawrodus rugulosus described and figured by Sir P. Egerton, Quart. Journ. Geol. Soc. vol. i. (1845), p. 167, with woode. ; Cretaceous, Pondicherry, Madras. Egerton Coll. 47885 c. Similar tooth; Cretaceous, Pondicherry, Madras. Presented by the Hon. Robert Marsham, 1877. P. 7420. Extremity of tail of the form named Lepidotus temnurus by Agassiz (Edinb. New Phil. Journ. vol. xxx. 1841, p. 83, and Comptes Rendus, vol. xviii. 1844, p. 1010, misprinted lemnurus); Cretaceous, Serra de Araripe, Brazil. Purchased. P. 7111. Two fragments of squamation and detached scales of moderate size, exhibiting an ornament of few radiating grooves; Cretaceous, railway-cutting about two miles from Santa Amaro, Bahia, Brazil. Presented by Joseph Mawson, Esq., 1893. P. 7115. Less ornamented punctate scales; Cretaceous, near Lagoa Redonda Station, on the Bahia and San Francisco Rail- way, Timbo Branch, Brazil. Presented by Joseph Mawson, Esq., 1893. 32580. A much-abraded head and anterior abdominal region, showing ossified hypohyals in section; Oxfordian, Dives, Vaches-noires, Normandy. Tesson Coll. The following species have also been described, but most of them are unsatisfactorily defined, and they are not represented in the Collection :— Lepidotus aliaicus, J. V. Rohon, Bull. Soc. Imp. Nat. Moscou, n. s. vol. vi. (1892), p. 85, with figure.—Jurassic ; River Kenderlyk, Maikantschatschai Mountains, Altai Range, 124 ACTINOPTERYGII. Siberia. [Fish wanting head and extremity of tail; University Museum, Moscow. | | Lepidotus agassizi, F, A. Roemer, Verstein. Norddeutsch. Oolithen- gebirges, Nachtr. (1839), p. 53, pl. xx. fig. 36. Referred to Lepidotus minor by C. G. Giebel, Fauna d. Vorwelt, Fische (1848), p. 191.—Purbeckian (Serpulit); near Salzburg, Osterwald. [Imperfect fishes. | Lepidotus arenaceus, O. Fraas, Wirtt. Jahresh. vol. xvii. (1861), p- 97, pl. i. figs. 9-11.—Keuper (Bone-bed in Kiesel- sandstein); Hiitten, Wiirtemberg. ([Generically indeter- minable scales and jaw ; Stuttgart Museum. | Lepidotus beyrichi, W. Branco, Abh. geol. Specialk. Preussen u. Thiring. Staaten, vol. vii. (1887), p. 359, pl. iv. figs. 3, 4, pl. v.fig.2. (?) Lepidotus spinifer, W. Dunker, Programm Biirgerschiile Kassel, 1844, p.41. (?) Lepidotus spinifer= mantel, W. Dunker, Monogr, Norddeutsch. Wealdenbild. (1846), p. 63, pl. xv. fig. 9. Lepidotus fitton, W. Branco (errore), Jahrb. preuss. geol. Landesanst. 1884 (1885), p. 181, pl. ix. fig. 2.—Wealden; Obernkirchen. [ Portions of squamation ; (?=L. degenhardti.) | ; Lepidotus breviceps, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. x. (1854), p. 372, pl. xi. fig. 2.—Lower Jurassic (Kota Group); Deccan, India. [Imperfect head and scales ; Geological Society of London. | Lepidotus calcaratus, Sir P. Egerton, Palzont. Indica, [4] vol. i. no. 2 (1878), p. 3, pl. i. figs. 2, 3.—Lower Jurassic (Kota Group); Deccan, India. [Fragments of squama- . tion; Indian Museum, Calcutta. | Lepidotus deccanensis, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. vii. (1851), p. 273, pl. xv.—JZbid. [Trunk ; Geolo- gical Society of London. | Lepidotus decoratus, A, Wagner, Abh. k. bay. Akad., math.-phys. Cl. vol. ix (1863), p. 626, pl. vi. fig. 2.—L. Kimmeridgian (Lithographic Stone); Solenhofen. [Nearly complete fish ; Paleontological Museum, Munich. | Lepidotus dentatus, F. A. Quenstedt, Flozgeb. Wirttemb. (1843), p- 236, and Lepidotus im Lias ¢ (1847), pl. ii. fig. 3.— Upper Lias; Boll, Wiirtemberg. [Imperfect fish; Tiibin- gen University Museum. | Lepidotus eaiguus, O. G. Costa, Atti Accad. Pontan. vol. viii. (1864), p. 75, pl. xi. fig. 2; F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. (1882), p. 235.— Form. & loc. ? SEMIONOTID®. 125 Lepidotus frondosus, L. Agassiz, Neues Jahrb. 1832, p. 145, and Poiss. Foss. vol. ii. pt. 1. (1833-44), pp. 8, 268.—Upper Lias; Zell, near Boll. [Imperfect fish; Hartmann Coll. ] Lepidotus haydeni, J. Leidy, Proc. Acad. Nat. Sci. Philadelphia, vol. viii. (1856), p. 73.—Cretaceous (?); Bad Lands, Nebraska. [Scale.] Lepidotus intermedius, A. Wagner, Abh. k. bay. Akad., math.- phys. Cl. vol. ix. (1863), p. 627, pl. vi. fig. 3—L. Kim- meridgian (Lithographic Stone); Solenhofen. [Nearly complete fish; Paleontological Museum, Munich. | Lepidotus itiert, V. Thiolliere, Bull. Soc. Géol. France, [2] vol. xv. (1858), p. 783 (name only), and Poiss. Foss. Bugey, pt. ui. (1873), p. 15, pl. ii. (mame and figure only).—L. Kimmeridgian (Lithographic Stone); Cirin, Ain, France. [Imperfect head and anterior scales; Lyons Museum. | _ Lepidotus koeneni, W. Branco, Abh. geol. Specialk. Preussen u. Thiring. Staaten, vol. vii. (1887), p. 373, pl. viii. figs. 1— 4.—U. Kimmeridgian ; Kahleberg, near Echte. [Trunk, wanting head, paired fins, and caudal fin; Gottingen University Museum. | Lepidotus levigatus, H. E. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxill. pt. 1. (1879), p. 25.—Oxfordian ; Lézinnes, Yonne, France. [Trunk wanting fins, with hinder por- tion of head. | 3 Lepidotus lennieri, H. FE. Sauvage, Bull. Soc. Géol. Normandie, vol. xiv. (1892), p. 33, pl. i—Lower Kimmeridgian ; Cap de la Héve, Havre. [Imperfect fish. | Lepidotus longiceps, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. x. (1854), p. 371, pl. xii. fig. 1—Lower Jurassic (Kota Group); Deccan, India. [Fish wanting tail; Geo- logical Society of London. | Lepidotus longidens, J. Cornuel, Bull. Soc. Géol. France, [3] vol. v. (1877), p. 608, pl. xi. figs. 1, 2—Neocomian; Wassy, Haute Marne. [Fragment of marginal dentition. | Lepidotus mohimonti, T. C. Winkler, Mém. Soc. Roy. Sci. Liége, [2] vol. iv. (1874), appendix pp. 3, 4, pl. i—Upper Lias; Saint Mard, near Virton, Luxembourg. [Imperfect fish. ] (?=L. elvensis.) Lepidotus oblongus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. (1837-44), p. 259, pl. xxxiv. a. figs. 1-3; A. Wagner, Abh. k. bay. Akad., math.-phys. Cl. vol. ix. (1863), p. 625.—L. Kim- meridgian (Lithographic Stone); Solenhofen. [Frag- ments; Paleontological Museum, Munich. | 126 ACTINOPTERYGII. Lepidotus occidentalis, J. Leidy, Proc. Acad. Nat. Sci. Philadelphia, vol. vill. (1856), p. 73.—Cretaceous (?); Bad Lands, Nebraska. [Scales; Academy of Sciences, Philadelphia. | Lepidotus pachylepis, Sir P. Egerton, Palzont. Indica, [4] vol. i. no. 2 (1878), pt. 2, p. 2, pl. i+~-Lower Jurassic’ (Kota Group); Deccan, India. [Fragmentary head and trunk ; Indian Museum, Calcutta. | Lepidotus roemert, W. Dunker, Monogr. Norddeutsch. Wealden- bild. (1846), p. 65, pl. xv. fig. 10.— Wealden ; Bredenbeck, Deister. [Scale.] Lepidotus similis, C. G. Giebel, Fauna d. Vorwelt, Fische (1848), p. 191.—Lower Kimmeridgian (Lithographic Stone) ; Solenhofen. [Indeterminable fins ; Halle Museum. | Lepidotus splendens: Pholidophorus splendens, C. Struckmann, Wealdenbild. Hannover (1880), p. 87, pl. ii. figs. 2-4.— Purbeckian (Serpulit); Hanover. [Imperfect fishes. | Lepidotus striatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. (1833-44), pp- 9, 268, pl. xxxiv.a. fig. 4.—Chalk; Vaches Noires, Normandy. [Generically indeterminable squamation ; Paris Museum of Natural History. | Lepidotus undatus, L. Agassiz, Poiss. Foss. vol. 11. (1833-44), pt. i. pp. 9, 245, pt. 1. p. 287, pl. xxxili.—(?) Lower Lias; Lyme Regis, Dorsetshire. [Hinder portion of fish ; Paris Museum of Natural History. | Lepidotus unguiculatus-minor, F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. (1882), p. 236. Lepi- dotus minor, O. G. Costa (errore), Atti Accad. Pontan. vol. vii. (1853), p. 11, pl. iv. figs. 1,2. Lepidotus unguicu- latus, O. G. Costa (errore), ibid. vol. viii. Append. (1864), p. 111, pl. vii. figs. 2-5, 7-9.—Cretaceous ; Pietraroja, Naples. [Indeterminable scales. | Lepidotus virleti, L. Agassiz, Neues Jahrb. 1833, p. 475, and Poiss. Foss. vol. 11. pt. 1. (1833-44), pp. 9, 268.—‘* Upper Green- sand;” Morea. [Indeterminable scales, undescribed. | A restored figure of a large fish from the Upper Jurassic of Chaux-de-Fonds, Neuchatel, named Lepidotus crassus, is recorded by A. Jaccard (Bull. Soc. Sci. Nat. Neuchatel, vol. xvi. 1888, p. 44) as having been published in the ‘ Rameau de Sapin,’ the organ of the Club Jurassien, Neuchatel. The present writer has not been able to obtain this publication. Miscellaneous teeth, probably for the most part of the genus Lepidotus, have also been described under the following names :— SEMIONOTID 127 Spheerodus (?) cylindricoides, F. A. Roemer, Verstein. Norddeutsch. Oolithen-gebirges, Nachtr. (1839), p. 55.—Purbeckian ; Deister. Spherodus globulosus, Pictet & Campiche, Foss. Terrain Crét. St. Croix, pt. i. (1860), p. 73, pl. 1x. fig. 7.—Middle Gault ; St. Croix. [Tooth ; Campiche Coll. ] Spherodus hybridus, subannularis, submammillaris, subradiatus, and tetragonus, G. von Miinster, Beitr. Petrefakt. pt. vii. (1846), p. 89.—Corallian ; Lindnerberg, Hanover. Spherodus irregularis, L. Agassiz, Poiss. Foss. vol. 11. pt. il. (1844), p. 213, pl. Ixxili. figs. 74-81; G. von Munster, Beitr. Petrefakt. pt. vii. (1846), p. 39; W. Dunker, Monogr. Norddeutsch. Wealdenbild. (1846), p. 66, pl. xv. fig. 21.—U. Jurassic; Oelingerberg, near Osnabriick, and Lindnerberg, Hanover. Wealden; Schaumburg and Ravensberg.' [Paleontological Museum, Munich. ] Spherodus semiglobosus, W. Dunker, Monogr. Norddeutsch. Wealdenbild. (1846), p. 66, pl. xv. fig. 17.—Wealden ; North Germany. An indeterminable detached tooth, not of Lepidotus, from the Cenomanian (Plinerkalk) of Plauen, Saxony, is named Lepidotus plauensis? by C. H. Fischer, Allg. deutsch. Naturh. Zeit. n. s. volo ui. (1856), p. 137, fig. 1. The undefined name Lepidotus cottw is given by Agassiz (Poiss. Foss. vol. il. pt.1. 1844, p. 306) to unknown fossils from the ** Chalk ” of Hohenstein, near Schandau, Saxony. A plaster cast of a portion of Spherodont dentition in the Enniskillen Collection (P. 7422) is thus named, without reference to locality. Gyrolepidotus schnudtt (J. V. Rohon, Mém. Acad. Imp. Sci. St. Pétersbourg, [7] vol. xxxvi. no. 13, 1889, p. 8, pl. i. figs. 4, 10, 13, 14) from supposed Permian in the province of Jenissei, Siberia, is described as related to Lepidotus; but the type specimen in the Academy of Sciences, St. Petersburg, seems to the present writer to be most probably an imperfect example of a Paleoniscid. The same remark applies to Lepidopterus crassus (H. Pohlig, Festschr. 70ten Geburtst. R. Leuckarts, 1892, p. 63, pl. vii. fig. 3) from the Lower Permian of Thuringia, described as a link between Ambly- pterus and the Semionotide. 1 The Tertiary teeth noticed by Agassiz also under this name pertain to teleostean fishes, 128 ACTINOPTERYGII. Genus DAPEDIUS, Leach (emend. Agassiz). [Trans. Geol. Soc. (2) vol. 1. 1822, p. 45 (Dapedium), and Agassiz, Poiss. Foss. vol. ii. pt. i. 1835, p. 181.] Syn. Tetragonolepis, L. Agassiz (non Bronn), Poiss. Foss. vol. ii. pt. i. 1833-35, pp. 6, 181. Amblyurus, L. Agassiz, zbid. 1836, p. 220. Aichmodus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. x. 1854, p- 367. Omalopleurus, O, G. Costa, Ittiol. Foss. Ital. 1873, p. 59. Trunk much laterally compressed, cycloidal or very deeply fusi- form. Head comparatively small, with well-developed opercular bones arranged in an arched series; operculum deeper than the suboperculum ; preoperculum narrow and almost or completely covered by the suborbitals, but all the other external bones more or less ornamented with tuberculations of ganoine; a large gular plate present. Teeth robust, styliform, with simple, bifid, or mamilli- form apex, arranged in clusters within the mouth. Notochord persistent; ribs ossified. Fin-fulera large and uniserial. Paired fins small, and the pectorals situated well upon the flank; dorsal fin much elongated, arising about the middle of the back, and anal fin shorter, opposed to the hinder half of the dorsal; caudal fin slightly forked. Scales quadrangular, robust, ornamented with tubercles dorsally and ventrally, nearly smooth or similarly orna- mented on the flanks, and united by a peg-and-socket articulation at a slight rib-like thickening anteriorly ; scales of the flank deeper than broad, the others nearly equilateral, and the dorsal and ventral ridge-series inconspicuous, The chondrocranium of Dapedius is well ossified, and there seems to have been a complete, or nearly complete, interorbital septum. As seen in side view, the basicranial axis is sharply bent upwards in front of the otic region; and the basioccipital element is deep, much excavated behind for the notochord, and longitudinally erooved below for the basicranial canal. The divisions between the elements of the cranium and the situation of the foramina for the nerves have unfortunately not hitherto been distinguished ; but it is clear that there was an ossified supraoccipital, with a vertical median ridge behind, and there are robust ossifications in the pre- frontal and postfrontal regions. The ethmoidal region terminates in front in a small blunt process, pierced transversely by a large foramen ; it expands on each side, in advance of and below the pre- frontal, into a great mass sheathed by the vomer. The olfactory nerve evidently passed through a foramen observable between the ao) SEMIONOTID &. 129: 06% sy + SA l setetes <4 KR HAI) Dapedius politus, outline restored. PART III. & 130 ACTINOPTERYGII, prefrontal and ethmoid, there being no elongation of this foramen into a canal; and Dapedius thus differs from Amia while agreeing with Lepidosteus in the course of the olfactory nerves across the orbital cavity. The membrane-bones of the cranial roof form a continuous shield, without vacuities; but a narrow rim of the cranium projects behind the covering thus formed. In young individuals the paired parietals, frontals, and squamosals are dis- tinct, and this condition sometimes persists in the adult; but more usually these principal roof-bones soon become fused into a con- tinuous plate. Immediately in advance a pair of short and broad nasals meets in the middle line; and there is a small median plate enveloping the ethmoid in front. The premaxille are separate, small and short, apparently without any ascending process ; the maxilla is a long stout bone, with a slight spatulate expansion posteriorly, and bounded above in its hinder two-thirds by a small, narrow supramaxilla. A complete ring of circumorbital plates surrounds the eye; and there is also an incomplete suborbital series, reaching from the squamosal to the hinder end of the maxilla, while one isolated plate occurs immediately below the nasal opening, above the suture between the maxilla and premaxilla. The parasphenoid is imperfectly known, but does not appear to have been dentigerous ; the vomer, which is probably single, is furnished with a dense cluster of comparatively large teeth. The hyomandibular is elon- gated and much laterally compressed, with a considerable expansion above, but contracted in its lower half into a narrow bar with nearly parallel anterior and posterior edges. The symplectic and quadrate are unknown, and the palato-pterygoid arcade can only be described as delicate, with large teeth on its inferior margin, smaller tuber- cular teeth on its inner face. The mandible is remarkably short and deep, with a coronoid elevation, comprising distinct dentary, splenial, articular, and probably coronoid elements. The dentary bears only the marginal series of teeth, and its postero-superior portion is smooth and toothless where overlapped by the maxilla ; the splenial is less deep, but more robust anteriorly, entering the mandibular symphysis and bearing a cluster of teeth, which become minute granules behind as the bone rises into the coronoid. The angular bone is deep, fixed to the outer face of the articular, and uniting with the dentary in a conspicuously zig-zag suture. Not- withstanding the prominence of the superficial ornament, the course of the sensory canals can scarcely be traced ; but a groove for the transverse commissure on the parietals and squamosals is seen, and a nearly vertical groove occurs on the angular bone. The opercular apparatus is complete, but the preoperculum is 131 SEMIONOTIDA. "potoysoa ‘snepadng Jo yuNy Jo UOJ PEYsopug. — : ea i 132 ACTINOPTERYGII. only exposed on the cheek in its lower portion. The suboperculum exhibits a feeble ascending process at its antero-superior angle; and the interoperculum is relatively large. There are about six broad branchiostegal rays; and a large broadly-oval gular plate, marked by a V-shaped groove for the sensory canal, occurs in front, In the axial skeleton of the trunk the notochord must have been persistent, and no traces of ossifications in its sheath have been detected. The neural and hemal arches, however, are all well ossified at least superficially, and only the thickness of the squa- mation prevents their being frequently displayed. Throughout the trunk as far as the middle of the caudal region, the neural spines are not fused with their corresponding arches, this fusion taking place only in the hinder half of the tail. The first few neurals are especially robust, expanded at their upper end, though not sup- porting the stout ridge-scales, and directly apposed to their arches ; the remaining neurals are more slender, taper below, and slightly overlap their arches. The ribsin the abdominal region form a regular series, but do not reach the ventral border; the hmal spines in the caudal region are fused with their corresponding arches, are sharply bent backwards, and exhibit a small trianguJar expansion anteriorly at their base. There are no intermuscular bones. All the fins bear uniserial fulcra of moderate size; but the two halves of the fin-rays at least in the median fins seem to be loosely apposed. ‘The number of the fin-supports in the dorsal is proved to equal exactly that of the rays, and there is no fusion of supports at its origin. The paired fins are small and delicate, but nothing worthy of note is known in reference to the supports. There is a large post-temporal plate on each side articulated with the supra- clavicle; and the long, arched clavicle exhibits its anterior margin sharply bent inwards. The scales in Dapedius have a broad peg-and-socket articulation, but no sharply thickened rib on the inner face. The azygous ridge- scale are not acuminate, except at the origin of the anal fin, where a few are enlarged. Most of the minor characters of Dapedius are very variable, and it is thus difficult to subdivide the genus into well-defined species. In the majority of forms, the scales are tuberculated only in the anterior dorsal and ventral regions; rarely the tuberculations extend over the flank. One group of species has the marginal teeth bi- cuspid, while another group has the same teeth unieuspid; but in observing this character it must be remembered that the former teeth when seen in side view may easily be mistaken for the latter. There are also tolerably constant differences in the form of the trunk, SEMIONOTID 2. 133 though allowance must be made for the fact that this sometimes deepens as the individual becomes aged. On the whole, the most satisfactory classification of the species represented in the Collection appears to be as follows :— I. Scales smooth on flanks. (a) Marginal teeth bicuspid. Ornament very coarse, often ruge ; scales finely serrated ........ Br iia ane politus (p. 133). Variety with more closely pectinated SOMOS esas ene ane sab tae aed pees radvatus (p. 137). Ornament coarse, few or no ruge ; scales MOLPSCLPALEH felt) .seetavcte) caeeap ser sa! « orbis (p. 137). Small feebly ornamented variety of the SEUNG, ete aes) eats caste gees «aS « dorsalis (p. 138) Ornament fine and sparse; scales not SORNA LOO ays terhal) yet aouguena ake Epa p sl cies colet (p. 140). (6) Marginal teeth unicuspid. Ornament coarse, sometimes rugee; scales SOMIUC Out stent n wosyiayh. alezo/a mabey eh oes es punctatus (p. 142). More elongated species, with similar ornament but more slender teeth; Scales\motiserrated Nani ai. foie oui pholidotus (p. 145). Still more elongated species, similarly ornamented; flank-scales scarcely deeper than broad, not serrated.... celatus (p. 147). II. Scales all tuberculated. Trunk about as deep as long, four-and-a- half times as deep as the caudal pedicle; teeth bicuspid ; scales serrated ...... granulatus (p. 148). Equally deep trunk with more slender CamdalmpedtCler. rasa Aweteerthe / si ocbevatere magnevillet (p. 151). Dapedius politus, Leach. 1822. Dapedium politum, Leach, Trans. Geol. Soc. [2] vol. i. p. 45, pl. vi. figs. 1-4. 1832. Dapedium politum, L. Agassiz, Neues Jahrb. p. 148. - 1835-36. Dapedius politus, L. Agassiz, Poiss. Foss. vol. ii. pt, 1. p. 185, plexccyanio, 1 1835-44. Tetragonolepis confluens, L. Agassiz, ibid. p. 199, pl. xxiii. a. fig. 1. [Head; British Museum. | 1835-48. Tetragonolepis speciosus, L. Agassiz, ibid. p. 199, pl. xxiii. d. [ Nearly complete fish; British Museum. | 1836-44. Tetragonolepis letosomus, L. Agassiz, 2bid. p. 202, pl. xxill. a. fig. 3. [Immature fish ; British Museum. | 1852. Dapedius politus, ¥. A. Quenstedt, Handb. Petrefakt. p. 202. 1854, Dapedius politus, J. Morris, Catal. Brit. Foss. p. 324. 134 ACTINOPTERYGII. 1854, Aichmodus confluens, levosomus, speciosus, J. Morris, zbid. pp. 316, 317. - 1869. Aichmodus orbicularis, J. Morris, Geol. Mag. vol. vi. p. 337, pl. x. [Nearly complete fish ; W. H. Huddleston Coll. j 1890. Dapedius letosomus, orbicularis, politus, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, pp. 58, 59. Type. Imperfect fish. The type species, attaining a length of about 0-4. Maximum depth of trunk about equal to its length (exclusive of the caudal fin) and four times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying about one-quarter of the total length; the external bones in the adult ornamented with very coarse tuberculations, closely arranged, more or less flattened or even hollowed on the operculum, and often fused into short vermiculating ridges. Marginal teeth robust, partly unicuspid, partly bicuspid. Pelvic fins arising midway between the pectorals and the anal; dorsal fin with 30, and anal fin with 18 rays. Scales nearly smooth, with few minute transverse strize and sparse puncta- tions; the hinder border delicately serrated. The small specimens named Dapedius leiosomus differ from the typical D. politus in their somewhat more elongated form and im the sparseness of their tubercular ornament; but they are proved to be immature by the non-fusion of the parietal, frontal, and squamosal bones. The Collection seems to exhibit every gradation between these fishes and the large specimens commonly named Tetragonolepis confluens. Form. & Loc. Lower Lias: Dorsetshire. All the following specimens were obtained from the Lower Lias of Lyme Regis, Dorsetshire :— P. 3555. Head of large individual, with pectoral fin and anterior abdominal scales; the type specimen of the so-called Tetragonolepis confluens described and figured by Agassiz, loc. cit. Enniskillen Coll. P. 3550 a. Remains of head and abdominal region of a similar fish. Enniskillen Coll. P. 3556. Imperfect fish 0°39 in length, with displaced facial bones and wanting the anal fin. ‘The ornament upon the oper- cular and facial bones is relatively as coarse as in the preceding specimen, but there is less tendency towards the fusion of the tubercles. The tuberculations upon the dorsal ridge-scales and the adjoining series are to a considerable extent fused into longitudinal rugze. Enniskillen Coll. SEMIONOTID 135: 173 (Mantell Cat.). Remains of a fish 0°37 in length, showing only fragments of the fins. Mantell Coll. P. 1575. Imperfectly preserved fish about 0°375 in length; with portions of all the fins. Egerton Coll. 18988. Head and much fractured trunk of a fish about 0°36 in length. The tuberculations are fused into ruge. Purchased, 1845. P. (3567. Type specimen of the so-called Tetragonolepis speciosus, described and figured by Agassiz. Enniskillen Coll. 48012. Somewhat smaller but better preserved specimen, showing broad bicuspid teeth in both jaws, and with the tubercular ornament of the head, opercular bones, and dorsal ridge- scales rarely passing into ruge. The characters of the squamation are well exhibited. Purchased, 1877. P. 3554a. Imperfect trunk and hinder portion of head of a fish about 0°30 in length. Enniskillen Coll. P. 4399. Imperfect crushed and abraded specimen about 0°32 in length, exhibiting a remarkable smoothness of part of the opercular bones. Enmiskillen Coll. P. 3550. Fish 0°32 in Jength, with imperfect fins and abraded squamation, showing both bicuspid and unicuspid teeth. The fin-fulera are well exhibited. Enniskillen Coll. 35790. Specimen of the same size with caudal fin and well-preserved squamation. The head is much crushed, and there is scarcely any tendency towards a fusion of the superficial tuberculations. Purchased, 1860. 39846. Specimen slightly smaller than the last, wanting the greater part of the median fins. The superficial tuberculations are rarely fused into short ruge. Purchased, 1866. P. 4230, P. 4398. Two similar but more imperfectly preserved specimens. Enniskillen Coll. P. 3539. Imperfect head of an equally large fish, showing jaws and dentition. Enniskillen Coll. P. 3538. Another head, with extremely coarsely marked opercular apparatus. The ethmoidal plate and premaxille are figured in Proc. Zool. Soc. 1898, pl. 1. fig. 4. Enniskillen Coll. 136 ACTINOPTERYGII. 41158. Fish about 0°22 in length, with imperfect head and displaced opercular bones. Purchased, 1868. 19005. Similar fish, with imperfect snout. Purchased, 1845. P. 1572, P. 1576, P. 1582-85. Imperfect fish about 0°21 in length, the head and trunk of a similar specimen wanting the squamation of the caudal region, the head and abdominal region of another fish, and three small specimens about 0-17 in length. - Egerton Coll. P. 3552. Three imperfect fishes 0°19-0°2 in length. Enniskillen Coll. 44858. Specimen 0:2 in length with well-preserved squamation but imperfect head and fins. Presented by Benjamin Bright, Esq., 1873. 38530. Specimen of similar size, more imperfect. Purchased, 1864. P. 6. Well-preserved fish 0°195 in length, wanting the greater part of the paired fins. Purchased, 1879. P. 6335. Similar specimen with paired fins, Beckles Coll. 44160. Fish 0:185 in length, displaying the fins. Purchased, 1873. P. 3548. Slightly smaller but similar specimen. Lnniskillen Coll. 38106. More imperfect fish 0°165 in length. Purchased, 1864. P. 3534. Type specimen of the so-called Tetragonolepis levosomus described and figured by Agassiz, loc. cit. Enniskillen Coll. P. 1554 a, P. 1588 a. Two imperfect small fishes, 0°13 and 0-11 in length respectively, the second exhibiting scales in the dorsal region resembling those of D. radiatus. Ligerton Coll, 30864. Imperfectly preserved fish about 0:13 in length. Purchased, 1856. P. 3535 a, b, P. 3537. Three small specimens 0°115 to 0-12 in length, the third showing some pectinated scales in the anterior part of the dorsal region. Ennskillen Coll. 39867. Specimen 0:11 in length, displaying pelvic and median fins. Purchased, 1866. P. 4879. Comparatively well-preserved fish showing some denticu- lated scales. Purchased, 1885. 30862. Stout specimen 0-098 in length. Purchased, 1856. SEMIONOTIDZ. 137 P. 3537 a. Somewhat smaller and more elongated fish. Enniskillen Coll. P. 6178. Imperfect much elongated fish 0-075 in length, in counter- part. Purchased, 1890. Dapedius radiatus (Agassiz). 1836-44. Tetragonolepis radiatus, L. Agassiz, Poiss. Foss. vol. i. pt. i. p- 201, pl. xxiii. a. fig. 2. 1854. Aichmodus radiatus, J. Morris, Catal. Brit. Foss. p. 317. Type. Imperfect head and trunk; British Museum. A small species or variety differing only from the young of D. politus (so-called D. leiosomus) in the prominence of the pectina- tions and crenulations on all the flank-scales. Whether or_not this character is due to the superficial abrasion of the scales, still remains to be determined. Form. & Loc. Lower Lias: Lyme Regis, Dorsetshire. P. 468. Type specimen. Egerton Coll. 28716. Head and lower portion of the trunk of an equally orna- mented fish. Purchased, 1853. 35559. A partially distorted specimen 0°115 in length, with crenu- lated scales. Purchased, 1855. 35722. Another feebly ornamented specimen 0°145 in length, wanting the greater part of the head and ventral region. Purchased, 1859. P. 1564. A specimen much resembling the type, but with more feebly ornamented scales and exhibiting more of the trunk. Egerton Coll. P. 3537 b. Small comparatively elongated fish 0-088 in length, with ornate scales. Enniskillen Coll. Dapedius orbis, Agassiz. 1836. Dapedius orbis, Iu. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 218, pl. xxv. d. 1849. Dapidius orbis, W. C. Williamson, Phil. Trans. p. 445. Type. Fish, wanting tail. A large species attaining a length of about 0-45. Maximum depth of trunk nearly equal to its length (exclusive of the caudal fin) and about four times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying somewhat less than one- 138 ACTINOPTERYGII. quarter of the total length of the fish; the external bones orna~ mented with numerous coarse, rounded tuberculations not fused into ruge. Marginal teeth very stout and obtuse, the majority slightly bifid. Scales comparatively thick and nearly smooth, with few sparse punctations and extremely delicate transverse striz ; hinder border not serrated. Form. & Loc. Lower Lias: Leicestershire. The following specimens were all obtained from Barrow-on-Soar:— P. 7423-24. Two fine large specimens, much fractured but exhibit- ing the principal characters of the species. Purchased, P. 7425. A smaller more imperfect fish displaying one of the pelvic fins and some teeth. Purchased. P. 7426. Very imperfectly preserved head and trunk with traces of the fins. Part of the dentition is conspicuous, the tubercles on some of the head-bones are shown in impression, and a few of the hemal spines are exposed at the base of the caudal fin. Purchased. P. 3549-a. Two small specimens, the second wanting the caudal fin and the greater part of the head, but displaying the orna- ment on some of the suborbital and opercular bones, many well-preserved scales, and the dorsal and anal fins. Enniskillen Coll. 18789. Portion of small head and trunk showing the depth of the dorsal fin. Purchased, 1845. Dapedius dorsalis (Agassiz). 1836. Tetragonolepis dorsalis, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 211, plex. figs. (2. pl exites aioe 1836. Tetragonolepis momlfer, L. Agassiz, zbid. p. 212, pl. xxi. a. figs. 2-5. [Fish, wanting head ; Bristol Museum. | 1844. Tetragonolepis striolatus, L. Agassiz, eid. p. 804 (name only). [British Museum. | 1854. Aichmodus dorsalis, J. Morris, Catal. Brit. Foss. p. 316. 1854. Dapedius monilifer, J. Morris, ibid. p. 324. 1890. Dapedius dorsalis, Woodward & Sherborn, Catal. Brit. Foss, Vertebrata, p. 58. 1890. Dapedius monilifer, Woodward & Sherborn, 762d. p. 59. 1890. Dapedius dorsalis, M. Browne, Trans. Leicester Lit. & Phil. Soc. n. 8., vol. ii. p. 202. Type. Nearly complete fish; British Museum. SEMIONOTID HE. 1389 A small species attaining a length of about 0°2. Form variable, but maximum depth of trunk usually less than its length (exclusive of the caudal fin) in the proportion of about 6 to 7, and equalling approximately three and a half times the depth of the caudal pedicle. Head with opercular apparatus occupying nearly one-quarter of the total length of the fish; the external bones almost smooth, with very few small sparse tubercles, and the operculum also exhibiting reticulated markings. Marginal teeth bicuspid and robust. Scales smooth, and the hinder border not serrated. The young of Dapedius orbis being as yet unknown, it still remains uncertain whether or not the small fishes described as D. dorsalis should be thus interpreted. Form. & Loc. Lower Lias: ‘‘ Gloucestershire” and Leicestershire. P. 7421. Type specimen figured by Agassiz, loc. ct. pl. xxi. figs. 1, 2; said to have been “found in limestone near Byrford, Gloucestershire.” Possibly the locality intended is Burford Signet, Oxfordshire, where the Lower Lias occurs. Old Collection. P. 467. Impression of fish imperfect dorsally, figured by Agassiz, loc. cet. pl. xxi. a. fig. 1 ; labelled “ Gloucester.” Egerton Coll. P. 15538, P. 3532. Typical specimen in counterpart, labelled by Agassiz, and showing bicuspid marginal teeth ; Barrow- on-Soar, Leicestershire. Lgerton & Enniskillen Colls. P, 1552. A much fractured fish, the maximum depth of the trunk 0:077 and its length (without caudal fin) 0-088 ; Barrow- on-Soar. Egerton Coll. P. 1552 a. A large specimen 0-2 in length, having the trunk as deep as long; Barrow-on-Soar. Tubercles occur on the cranial roof, and there are bicuspid teeth in the jaw. Egerton Coll. P. 3530 x, P. 3531. Comparatively deep-bodied fish, 0-13 in length, in counterpart; Barrow-on-Soar. One side of the speci- men is labelled ‘“ Tetragonolepis monilifer, Agass.,” the other “ Tetragonolepis striolatus, Agass.,” both in Agassiz’ handwriting. Enniskillen Coll. P. 3530. Four specimens variously imperfect ; Barrow-on-Soar. Enniskillen Coll. 140 ACTINOPTERYGII. 19430-31. A small trunk with opercular bones, in counterpart ; Barrow-on-Soar. Maximum depth of trunk 0:049, and length (without caudal fin) 0:06. Presented by the Earl of Aylesford, 1845, 40176. A very small fish displaying the reticulations on the oper- culum ; Barrow-on-Soar. Purchased, 1866. P. 7432. Small distorted fish ; probably from Barrow-on-Soar. Presented by Edward Gibson, Esq. P. 4424. Greater portion of small fish with well-preserved pectoral fin; Barrow-on-Soar. | Enniskillen Coll. Dapedius colei, Agassiz. 1835. Dapedius colei, L. Agassiz, Poiss, Foss. vol. ii. pt. i. pp. 195, 217, pl. xxv. 6. figs. 1-7, pl. xxv. c. Type. Imperfect head and trunk; British Museum. A species nearly equalling D. »olitus in size. Maximum depth of trunk about equal to its length (exclusive of the caudal fin) and four times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying nearly one-quarter of the total length ; the external bones feebly ornamented with fine, sparse, rounded tubercles, usually arranged on the cranial roof on the radiating lines of growth. Marginal teeth very robust, and the majority bifid. Scales smooth, comparatively thin, rarely exhibiting punctations, and apparently not serrated. This species seems to be satisfactorily defined, but in the case of fragmentary and abraded specimens it is not always possible to distinguish between those that may be placed here and examples of D. punctatus, D. orbis, or immature D. granulatus. Form. & Loc. Lower Lias: Dorsetshire. ry The following specimens were all obtained from the neighbourhood of Lyme Regis :— P. 3545. Type specimen described and figured by Agassiz, loc. cit. p- 195, pl. xxv.b. The lower marginal teeth appear to be all bifid, and the right hyomandibular bone is well exposed. The specimen is much abraded, and the opercular bones are thus unusually smooth, while the lines of growth of some of the scales are rendered conspicuous. Enniskillen Coll. P. 7427. A nearly complete but much fractured fish, described and figured by Agassiz, loc. cit. p. 217, pl. xxv. c. Old Collection. SEMIONOTID A, 141 38529. Imperfect and much abraded large fish, wanting the caudal fin. Purchased, 1864. 39350. Specimen 0°35 in length, much abraded but displaying some of the teeth. Purchased, 1864. 37785. A smaller fish exhibiting relatively large tubercles on the dorsal and ventral scales, these extending far upon the flank behind the upper portion of the operculum. Purchased, 1863. P. 1569-70. Two specimens about 0°36 in length, the first much abraded and wanting the dorsal region of the trunk, the second exhibiting the extension of the tubercles upon the flank-scales as noted in no. 37785. Egerton Coll. P. 3546, P. 3558. Three imperfect specimens, one showing the left pectoral fin. Enniskillen Coll. Fig. 27. Dapedius colet ; facial bones of left side. [No. P. 3538 a.] ag., angular ; ¢.o., cireumorbitals; d., dentary; etk., dermo-ethmoid ; Z.0D 5 interoperculum ; mz., maxilla; m., narial opening; za., nasal ; ord., orbit : pmc., premaxilla; p.op., preoperculum ; s.0., suborbitals. 35789. A small fish 0:275 in length, somewhat abraded and broken. Purchased, 1860, P. 6397. A more imperfect small specimen. Beckles Coll. 142 ACTINOPTERYGII. P. 4431. Much abraded and distorted head and trunk, showing marginal teeth, probably of this species. Enniskillen Coll. — 40651. Imperfect head displaying dentition, with left pectoral fin and some anterior scales. Purchased, 1867. P. 1557. Imperfect head with opercular apparatus. gerton Coll. P. 1561. Portion of head and dentition. Egerton Coll. P. 3538 a. Jaws, cheek-plates, and bones round the narial opening in natural position, shown of the natural size in fig. 27. Enniskillen Coll. Dapedius milloti, Sauvage. 1891. Dapedius millott, H. E. Sauvage, Bull. Soc. Sci. Yonne, vol. = pt. . p. 36, pl. ii. Type. Nearly complete fish, apparently abraded. A species attaining a length of about 0°3. Maximum depth of trunk nearly equal to its length (exclusive of the caudal fin) and four times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying one-third of the length to the base of the caudal fin; external bones apparently smooth. Scales all smooth. (Sawvage.) Form. & Loc. Upper Lias: Vassy, Yonne, France. Not represented in the Collection. Dapedius punctatus, Agassiz. 1835. Dapedius punctatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 192, pl. xxv. a., pl. xxv. figs, 6 d, 7-9. 1833-39. Tetragonolepis leachit, L. Agassiz, tbid. pp. 7, 208, pl. xxiii. d. [Head ; British Museum. | 1848. Tetragonolepis striatus, H. G. Bronn (ex Agassiz, MS.), Index Paleeont. p. 1261. 1849. Pholidotus leachit, W. C. Williamson, Phil. Trans. p. 444. 1852. Dapedius punctatus, F. A. Quenstedt, Handb. Petrefakt. p. 202, pl. xvii. fig. 2 (in part). 1858. Dapedius punctatus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. ix. p. 275, pl. xi. fig. 2. 1854, Aichmodus leachi, J. Morris, Catal. Brit. Foss. p. 516. 1854. Dapedius punctatus, J. Morris, bid. p. 324. (?) 1858. Dapedius leachtt, F. A. Quenstedt, Der Jura, p. 207 » pl, xxlbe. figs. 3, 4. pl. xxxii. fig. 7. 1890, Devens leacht and D. punctatus, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, pp. 58, 59. Type. Nearly complete fish; Oxford Museum. SEMIONOTIDZ. 1438 A species equalling D. politus in size. Maximum depth of trunk somewhat less than its length (exclusive of the caudal fin) and a little more than three times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying nearly one- quarter of the total length of the fish; the external bones orna- mented with rounded, sharply defined tuberculations of moderate size, sometimes elongated, rarely fused into short ruge. Marginal teeth large and unicuspid. Scales smooth, with few sparse punc- tations; the hinder border delicately serrated, the serrations becoming especially conspicuous in the middle of the caudal region. The form of the operculum is apparently not constant, but in most of the specimens assigned to D. punctatus it is relatively narrower and deeper than in the type species. Form. & Loc. Lower Lias: Dorsetshire. Upper Lias: Wirtem- berg. Unless otherwise stated, the following specimens were all obtained from the neighbourhood of Lyme Regis :— 19486. Imperfect head and trunk, wanting the greater part of the fins, but displaying the squamation. Purchased, 1845. 35793. Well-preserved fish with imperfect fins. The operculum measures 0:045 in maximum depth and 0:03 in maximum width; the upper end is arched forwards, rounded, and tapering, and many of the superficial tuberculations are elongated. Purchased, 1860. 36258. Another fine specimen relatively more elongated (apparently by distortion). The operculum is less deep in proportion to its breadth than in no. 35793, and there is more ten- dency to the elongation of the superficial tuberculations. The tubercles upon the cranial roof exhibit frequent fusion into continuous series. Purchased, 1862. P. 3554. Nearly complete fish 0°39 in length, with an operculum of the same form as no. 35793, more sparsely tuber- culated. The marginal teeth are unicuspid, and very long though robust. The scales of the lateral line exhibit erescentic perforations ; and there are traces of a superior lateral sensory canal, not perforating the scales it traverses, but passing through pairs of elongated tubercles. Enniskillen Coll. P. 2053. Imperfect large specimen in septarian nodule, labelled Tetragonoleprs leacht by Agassiz. Egerton Coll. 144 ACTINOPTERYGII. P. 6396. Much fractured large specimen showing the characteristic operculum and teeth, and traces of the superior lateral line. Beckles Coll. P. 3566. Fish 0°32 in length, with comparatively broad operculum. Enniskillen Coll. 37774. Imperfect fish about 0°33 in length. Purchased, 1863. 40089. Fish 0°3 in length, with abraded and fractured head-bones, but displaying the marginal teeth. Purchased, 1866. 42435. Head and anterior flank-scales, the type specimen of Tetra- gonoleprs leacht described and figured by Agassiz, Joc. cit. The relatively large size of the tubercles upon the bones of the snout is well shown. Presented by Kenneth Murchison, Esq., 1872. 44859. Remains of head and anterior flank-scales. Presented by Benjamin Bright, Esq., 1873. P. 350. Head and abdominal region of a small individual probably of this species. Tuberculations are almost absent upon the suboperculum and the lower portion of the operculum, perhaps in consequence of abrasion; and some of the large unicuspid teeth are conspicuous. Very large median scales occur in front of the anal fin, and the vertical series of flank-scales above the base-line of this fin are slightly reflexed forwards. Purchased, 1881. 41214. Small fish 0°245 in length, with comparatively feeble ornament, and displaying large unicuspid teeth in the mandible. Purchased, 1868. P. 3570. More imperfect small specimen. Enniskillen Coll. P. 7428. Much abraded small specimen probably of this species. 18514. Imperfect head and trunk of a fish about 0°35 in length, displaying the operculum and facial bones, the marginal teeth, and a large portion of the squamation ; Upper Lias, Boll, Wirtemberg. Purchased, 1844. P. 1592. Head vertically crushed and wanting the extremity of the snout; with some of the anterior dorsal and dorso-lateral scales. Egerton Coll. P. 3540. Small head with dentition. Enniskillen Coll. 39144. More imperfect small head with dentition. Bowerbank Coll. SEMIONOTID ®. 145: 36883. Head wanting mandibular ramus and facial bones of the left side, displaying those of the right side from within. The outer teeth are the largest, with a simple obtuse apex, and many of the inner teeth are either indented or slightly bifid. The vomer exhibits relatively large stout teeth, and the outer edges of the pterygoid arcade and splenial are similarly armed; but on the inner face of the two latter elements the teeth are merely small tubercles, The epihyal is much contracted at its proximal end, and the ceratohyal is remarkably short and deep. | Purchased, 1862. P. 1589. Remains of mandible and portions of surrounding bones. Lgerton Coll. ‘Dapedius angulifer (Agassiz). 1832-33. Tetragonolepis trail, L. Agassiz, Neues Jahrb. 1832, p. 147, and Poiss. Foss. vol. ii. pt. i. p. 7. 1835-36. Tetragonolepis angulifer, L. Agassiz, ibid. p. 213, pl. xxii. 1854. A’chmodus angulifer, J. Morris, Catal. Brit. Foss. p. 317. Type. Nearly complete fish. A species attaining a length of about 0°5. Maximum depth of trunk not quite equal to its length (exclusive of the caudal fin) and somewhat more than three and a half times as great as the depth of the caudal pedicle. Marginal teeth unicuspid. Scales of flank smooth, none much deeper than broad, and each marked externally with a triangular depression of which the base coincides with the hinder border while the apex is turned forwards. (Agassiz.) Form. & Loc. Lower Lias: Stratford-on-Avon, Warwickshire. Known only by the unique type specimen, which cannot now be traced. Dapedius pholidotus, Agassiz. 1832. Tetragonolepis pholidotus, L. Agassiz, Neues Jahrb. p. 147. (?) 1832. Tetragonolepis heteroderma, L. Agassiz, zbid. p. 147. 1833-44. Tetragonolepis pholidotus, L. Agassiz, Poiss. Foss. vol. ii, pt. 1. ps4 200, pb xt e. fia. 2. (?) 1833-44. Tetragonolepis heteroderma, L. Agassiz, ibid. pp. 7, 206, pl. xxiil.e. fig. 1. [Portion of squamation; Hartmann Coll.] 1843. Tetragonolepis pholidotus, F. A. Quenstedt, Flozgeb. Wiirttemb. p- 238. 1852. Dapedius pholidotus, F. A. Quenstedt, Handb. Petrefakt. p. 203, pl. xvii. figs. 1, 3-5. 1854. Aichmodus pholidotus, J. Morris, Catal. Brit. Foss. p. 317. PART III. L 146 ACTINOPTERYGII. 1858. Dapedius pholidotus, F. A. Quenstedt, Der Jura, p. 228, pl. xxxi. figs. 1-7. 1860. Tetragonolepis pholidotus, A. Wagner, Sitzungshb. k. bay. Akad. Wiss. p. 41. Type. Imperfectly preserved fish ; Stuttgart Museum. A small species, attaining a length of about 0°-25-0-3. Maximum depth of trunk three-quarters as great as its length (exclusive of the caudal fin) and equalling nearly four times the depth of the caudal pedicle. Head with opercular apparatus occupying one- quarter of the total length of the fish; the external bones ornamented with numerous large, rounded tuberculations, sometimes fused into short rugee on the cranial roof and facial bones. Marginal teeth unicuspid and comparatively slender. Scales smooth or faintly wrinkled in the anterior half, and the hinder border not serrated ; tuberculations absent on all the ventral scales except the ridge- series, where they are represented chiefly by elongated ruge. Form. & Loc. Upper Lias: Wiirtemberg and Normandy. 36049. Typical specimen about 0:275 in length, wanting the bones on the exposed left side of the head, the paired fins, the dorsal fin, and the greater part of the anal fin; Lias e, Metzingen, near Reutlingen. Purchased, 1861. P. 1574 a, P. 1563 b, c, P. 1573. A similar specimen showing the marginal teeth and part of the cranial roof; also two very imperfect fishes wanting the dorsal region and a fragmentary small specimen ; Ohmden, near Boll. Egerton Coll. P. 3568-9. Three large fishes with imperfect fins, all showing part of the dentition and one well displaying the squamation ; also remains of a small head, with the impression of some anterior scales and a pectoral fin; Ohmden. Enniskillen Coll. P. 4401. Another imperfect large fish, exhibiting an inner view of the left opercular and branchiostegal apparatus; Ohmden. Enniskillen Coll. 18512. Head and the greater part of the squamation of, a large individual; Ohmden. Some of the teeth and the super- ficial ornament are well shown. Purchased, 1844. 19660-61. Two very imperfect fishes, exhibiting part of the super- ficial ornament and a large portion of the squamation ; Boll, Purchased, 1845. SEMIONOTID A. 147 22525. Remains of head and abdominal region, with the pectoral fin and some of the superficial ornament in impression; Boll. Purchased, 1848. P. 1563 d. Portion of squamation ; Boll. Egerton Coll. The following specimens bear the specific name of Dapedius ovalis (Tetragonolepis ovalis, L. Agassiz, Poiss. Foss. vol. i. pt. 1. 1836, p. 209, pl. xxi. fig. 3), and were also referred to the genus Aichmodus by Egerton (J. Morris, Catal. Brit. Foss. 1854, p. 317). They seem to differ only from D. pholidotus in the slightly more elongated form of the trunk, and are regarded as constituting a variety of this species by Quenstedt (Handb. Petrefakt. 1852, p- 203). P. 1563 a. Type specimen of D. ovals described and figured by Agassiz, loc. cit.; Boll. Egerton Coll. P. 3572. Head and trunk of a fish about 0°22 in length, wanting the caudal pedicle and fin, labelled by Agassiz; Ohmden. Enniskillen Coll. P. 1563 e. Specimen 0°17 in length, chiefly shown as an impression ; Boll. Egerton Coll. P. 3571. Impression of slightly larger fish, labelled by Agassiz ; Ohmden. Enmskillen Coll. 32448. Fine specimen about 0°145 in length to the base of the caudal fin, wanting the greater part of the fins; Upper Lias, Curcy, Normandy. The parietal, frontal, and squamosal bones are separate. , Tesson Coll. Dapedius czlatus, Quenstedt. 1858. Dapedius caelatus, F. A. Quenstedt, Der Jura, p. 226, pl. xxviii. fies. 1, 2. 1860. Tetragonolepis caelatus, A. Wagner, Sitzungsh. k. bay. Akad. Wiss. p. 40. Type. Nearly complete fish ; Tubingen University Museum. An elongated species, attaining a length of about 0-45. Length of trunk (exclusive of the caudal fin) one and a half times as great as its maximum depth, and the latter equalling thrice the depth of the caudal pedicle. Head with opercular apparatus occupying somewhat less than one-quarter of the total length of the fish; the external bones ornamented with very coarse rounded tubercles, usually fused into short rugz, which are directed nearly horizontally L2 148 ACTINOPTERYGII. on the opercular and cheek-plates. Teeth robust, unicuspid in the marginal series of the mandible. Tubercles on the dorsal and ventral scales very coarse and usually fused into ruge; the scales of the flank scarcely deeper than broad, not serrated, and covered with smooth enamel, which exhibits a coarse rugosity or digitation towards the anterior border. Form. & Loc. Upper Lias: Wirtemberg. 19659. Fish about 0°43 in length, with very imperfectly preserved head and abdominal region, but displaying the general form and proportions and some of the scales; Boll. Purchased, 1845. 19659 a. More imperfect fish, in counterpart, exhibiting the squa- mation, the operculum and suboperculum, remains of some of the head-bones, and the lower marginal teeth ; | Boll. Purchased, 1845. P. 7429. Similar specimen with well-preserved scales and opercular bones. Purchased. P. 2015-6. Two imperfect specimens. Egerton Coll. Dapedius granulatus, Agassiz. 1835. Dapedius granulatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 190, pl. xxv, figs. 2-6. 1836-48. Tetragonolepis pustulatus, L. Agassiz, tbid. p. 201, pl. xxiii. c. [Anterior portion of fish ; British Museum. | 1849. Dapidius granulosus, W. C. Williamson, Phil. Trans. p. 445, pl. xl. figs. 5, 6. 1854. Achmodus pustulatus, J. Morris, Catal. Brit. Foss. p. 317. 1888. Dapedius cycloides, W. Deecke, Mittheil. Comm. Geol. Landes- Unters. Elsass-Lothringen, vol. i. p. 209, pl. iii. [Nearly complete fish ; collection of Herr First, Ruprechtsau, near Strassburg. | 1890. Dapedius granulatus, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 58. Type. Imperfect head and anterior abdominal region; Oxford Museum. The largest known species, attaining a length of 0°6. Maximum depth of trunk equalling or slightly exceeding its length (exclusive of the caudal fin) and about four and a half times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying one-quarter of the total length of the fish; the external bones ornamented with numerous coarse, rounded tuberculations, very rarely fused into ruge. Marginal teeth stout, the majority SEMIONOTID %. ~ 149 obtuse and slightly bifid. Scales of the abdominal and part of the caudal region all ornamented at least in their anterior half with coarse tuberculations, which are often flattened, closely arranged, and in part fused into rugz; hinder border conspicuously serrated in young specimens, smooth or nearly so in adults. The type specimen of the so-called D. cycloides was obtained from the ‘“ Angulatus-kalk” of Steinburg, near Zabern, Lower Alsace. . Form. & Loc. Lower Lias: Dorsetshire and Alsace-Lorraine. All the following specimens were obtained from the neighbour- hood of Lyme Regis, Dorsetshire :— P. 3561. Type specimen of the so-called Tetragonolepis pustulatus, described and figured by Agassiz, loc. cit. Remains of the head and anterior abdominal squamation are shown, but teeth are wanting. Enniskillen Coll. 19004 a. Remains of the head and greater portion of the trunk of a large fish probably about 0°6 in length. From the Johnson Collection, noticed by Agassiz, op. cit. vol. ii. Biat p. 201. Purchased, 1845. 40351. Large specimen, much elongated by distortion and dis- playing the caudal fin. Purchased, 1867. P. 5937. Fine specimen 0:55 in length, showing the obtuse, bifid marginal teeth. The scales are not serrated, and many of the tubercles on the flank are fused into short ruge. Purchased, 1889. P. 3563. Well-preserved fish about 0-475 in length. As in the former specimen, none of the scales exhibit serrations. Enniskillen Coll. P. 3564. An equally large imperfect fish displaying the dorsal and caudal fins. The tuberculations upon the cranial roof and flank-scales are partially fused into short ruge. Enniskillen Coll. P. 3564 a. Imperfect head and trunk wanting the dorsal region; the ornament consisting of rounded tubercles, rarely fused except on the ridge-scales. Enniskillen Coll. P. 3562. Imperfect and distorted remains of the head and abdominal region of an equally large fish. Enniskillen Coll. P. 3564 b. Fragmentary trunk with skull. Enniskillen Coll. P. 1577. Fine specimen 0°42 in length. Egerton Coll. 150 ACTINOPTERYGII. 35791. More imperfect fish of the same size, exhibiting some of the flank-scales from the attached face. Purchased, 1860. P. 420. Much-broken and abraded fish, equally large. Presented by F. Seymour Haden, Esq., 1882. 36046. Imperfect head and anterior scales of a similar fish. Purchased, 1861. P. 3544, P. 3565. Two specimens about 0-4 in length, the first wanting the greater part of the fins, the second having lost much of the scale-ornament by abrasion. Enniskillen Ooll. 32494. Similar fish much crushed and distorted in the dorsal portion. Purchased, 1857. P. 7430. Imperfectly preserved fish 0°35 in length, wanting the greater part of the dorsal and anal fins. Purchased. P. 1578. Equally large specimen, somewhat abraded and distorted, but with well-preserved median fins and the lower mar- ginal teeth. . Egerton Coll. 40650. A smaller specimen, shortened by crushing, displaying the fulcra of the right pelvic fin. Purchased, 1867. P. 1579. Small head and trunk, much abraded, without fins. Egerton Coll. P. 6063. Remains of branchiostegal rays, the left clavicle, and a well-preserved portion of the anterior ventro-lateral squa- mation of a large fish, showing the partial fusion of the ornamental tubercles into rugee. Presented by F. Harford, Esq., 1889. 35794. Abraded remains of the head and abdominal region of a small individual, probably about 0°27 in length, exhibiting the serration of the hinder margin of the scales. Purchased, 1860. P. 4400. Well-preserved head and abdominal region of a small individual. Enniskillen Coll. P. 1555. Much abraded and fractured small head and abdominal region, remarkable for the fineness of the granulation on the opercular bones. Egerton Coll. SEMIONOTID®. 151 Dapedius magnevillei, Agassiz. 1833-36. Tetragonolepis magneville, L. Agassiz, Poiss. Foss. vol. i1. pt. 1. pp. 7, 214, pl. xxiv. 1852. Dapedius magneville, F. A. Quenstedt, Handb. Petrefakt. p. 203. Type. Nearly complete fish; Caen Museum. A species of moderate size. Maximum depth of trunk equal to its length (exclusive of the caudal fin) and about six times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying much less than one-quarter of the total length of the fish; the external bones ornamented with distinct tuberculations. All the scales, except those towards the end of the tail, ornamented with sparsely arranged tubercles. Form. & Loc. Upper Lias: Normandy. P. 7431. Very imperfectly preserved fish, about 0°33 in length; said to have been obtained from Caen, but probably from Curcy. Tesson Coll. As already pointed out (A. 8. Woodward, Ann. Mag. Nat. Hist. [6] vol. i. 1888, p. 356), vertically crushed specimens of Dapedius form the basis of the so-called genus Amblyurus (L. Agassiz, Poiss. Foss. vol. ii. pt. i. 1836, p. 220). A single species, A. macro- stomus (Agassiz, ibed. p. 220, pl. xxv.e¢), is founded upon specimens from the Lower Lias of Lyme Regis, now in the Oxford Museum ; and the following are similar fossils which can only be generically determined :— 35564, 35788. Two crushed and distorted fishes showing ventral aspect, the first small, the second large and displaying bifid teeth ; Lower Lias, Lyme Regis. Purchased, 1860. 36338. Another example, ventral aspect, wanting tail but showing bifid teeth ; Lyme Regis. Purchased, 1862. P. 1562. Similar specimen, showing paired fins and uniserial fulcra ; Lyme Regis. Egerton Coll. P. 3574. Two more fragmentary specimens, ventral aspect, showing the caudal fin; Lyme Regis. Enniskillen Coll. P. 2024. More imperfect smaller example, labelled by Agassiz ; Lower Lias, Street, Somersetshire. Egerton Coll. The following fragmentary specimens of Dapedius, though also specifically indeterminable, are of interest as illustrating anatomical characters or showing the distribution of the genus :— 152 P. 1587. ACTINOPTERYGII. An imperfect much elongated fish, displaying the neural and hemal arches of the trunk and the pelvic fin-supports, partly used in the restoration, fig. 26, p. 131; Lower Lias, Lyme Regis. Egerton Coll. P, 3542-a. Two fragmentary heads, with some anterior scales, P. 3541. P. 1535. displaying the mandible, &c., from below; Lyme Regis. Enniskillen Coll. Fine cranium, described and figured by the present writer in Proc. Zool. Soc. 1893, p. 564, pl. 1. fig.3; Lyme Regis. Enniskillen Coll. Laterally-compressed cranium showing vomerine teeth, with anterior neural arches of trunk exhibiting the separate, distally expanded neural spines; Lyme Regis (?). The spines, so far as preserved, are directly apposed to, and do not overlap, the neural arches. kigerton Coll, P. 1537 a. Very small cranium, side view; Lyme Regis. Egerton Coll. P. 1589 a. Imperfect right maxilla, premaxilla, and dentary ; Lyme P. 3551. P. 4877. P. 1536, P. 4423. Regis. Ligerton Coll. More remains of jaws; Lyme Regis. Enniskillen Coll. Fine right mandibular ramus, inner aspect, showing both dentary and splenial entering the symphysis; Lyme Regis. The splenial teeth are mammillated. Purchased, 1885. P.1557a. Two more imperfect left mandibular rami; Lyme Regis. As in the previous specimen, the splenial has the appearance of being forked behind and rising into the coronoid process. Egerton Coll. Imperfect small fish displaying the axial skeleton of the trunk; Lyme Regis. The neural spines are free as far as the middle of the caudal region, but then become fused with the corresponding arches. The ribs, though robust, do not extend to the ventral border of the trunk. The heemal spines in the caudal region meet their supporting arches at a considerable angle, are fused with them, and exhibit a small triangular expansion anteriorly below the point of union. Ennskillen Coll. P. 1556 a. Portion of trunk showing ribs, neural arches, and the inner aspect of the squamation ; Lyme Regis. Egerton Coll. SEMIONOTID% 153 P. 1592. Anterior fragment of fish displaying broad, ornamented dorsal ridge-scales, each apparently the result of the fusion of about three pairs of scales with the median one ; Lyme Regis (?). ) Egerton Coll. P. 515. Fragment of squamation labelled Dapedius micans by Agassiz and intended to be the type specimen of that species, named in list in Poiss. Foss. vol. ii. pt. i. (1844), . p- 304; Upper Lias, Whitby. The scales are abraded and exhibit slight transverse ruge. Egerton Coll. P. 1591. Fragment probably of the same species, showing scales and remains of highly-ornamented head-bones, on which the tubercles are considerably fused into ruge; Whitby. Two imperfect large teeth seem to have been simply pointed. Egerton Coll. P. 3536. Fragment apparently of similar squamation, labelled Dapedius micans by Agassiz; Whitby. Hnniskillen Coll. P. 3543. Imperfect small trunk with part of the coarsely tubercu- lated opercular apparatus ; Upper Lias, Ilminster, Somer- setshire.- The scales are nearly smooth, without tubercu- lations or posterior serrations. Enniskillen Coll. The following species have also been founded upon fragmentary specimens, but there are no examples in the Collection :— Dapedius alpinus, G. G. Winkler, Neues Jahrb. 1886, vol. 1. p- 20, pl. i. fig. 6—-Rheetic ; Linggries, Bavarian Alps. [Fragment of head and abdominal scales.] (? Colobodus.) Dapedius bouei: Tetragonolepis bouei, L. Agassiz, Poiss. Foss. vol. ii. pt. i. pp. 7, 210 (1833-36), pl. xi. fig. 1.— Rhetic ; Seefeld, Tyrol. [Indeterminable fragment. ] Dapedius costai, F. Bassani, Mem. Soc. Ital. Sci. [3] vol. ix. (1892), no. 3, p. 9: Omalopleurus speciosus, O. G. Costa, Ittiol. Foss. Ital. (1873), p. 59, pl. v. fig. 1—Triassic: Guiffoni, near Naples. [Imperfect head and abdominal region ; Geological Museum, University of Naples. ] Dapedius egertoni, W. H. Sykes, Quart. Journ. Geol. Soc. vol. ix. (1853), p. 352 ; Sir P. Egerton, Paleont. Indica, ser. iv. vol.i. no. 2 (1878), p. 6, pl. ii. figs. 3-5: ichmodus eger- toni, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. x. (185+), p. 367.—Lower Jurassic (Kota Formation); Kota, Deccan, India. [Fragments ; Geological Society of London. | 154 ACTINOPTERYGII. Dapedius jugleri, F. A. Roemer, Verstein. Norddeutsch. Oolithen- Geb., Nachtr. (1839), p. 53, pl. xx. fig. 35.—Upper Lias ; Werther, Westphalia. [Head and anterior scales. | Dapedius notabilis: Tetragonolepis notabilis, A. Wagner, Sitzungsb. k. bay. Akad. Wiss. 1860, p. 40 (footnote): Dapedius punctatus, F. A. Quenstedt (errore), Der Jura (1858), p. 226, pl. xxvii. figs. 4-12, pl. xxviii. figs. 3, 4, pl. xxix. figs. 1, 2.—Upper Lias; Wiirtemberg. [Fragments ; Tiibingen University Museum. | Dapedius olifex, F. A. Quenstedt, Der Jura (1858), p. 89, pl. xi. figs. 18-26.—Upper Lias; Wirtemberg. [Skull and fragments ; Tubingen University Museum. | The undefined name Dapedius arenatus was given by Agassiz (Poiss. Foss. vol. ii. pt. i. 1844, p. 304) to an unknown fossil from the Lower Lias of Lyme Regis. An imperfect example, apparently of D. colei, in the Egerton Collection (P. 1568), is thus labelled by him. Here may also perhaps be placed the teeth from the Lower Lias of Lyme Regis recorded under the undefined name of Spherodus mocrodon, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. (1844), p. 216 (name only). An imperfectly defined Upper Jurassic genus, closely related to Dapedius, is named Heterostrophus* (A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1863, p. 614), and is known by a single species, H. latus (A. Wagner, ibid. p. 615), from the Lower Kimmeridgian (Lithographic Stone) of Solenhofen, Bavaria. The type specimen is preserved in the Paleontological Museum, Munich, and measures about 0-33 in length to the base of the caudal fin. The external bones and scales are smooth, and the comparatively stout and small inner teeth are marked on the crown with radiating grooves. Fragmentary evidence probably of a similar fish from the Oxford Clay of Peterborough is preserved in the collection of Alfred N. Leeds, Esq., Eyebury. Genus CLEITHROLEPIS, Egerton. (Quart. Journ. Geol. Soc. vol. xx. 1864, p. 3.] Trunk much laterally compressed, very deep, and the dorsal border strongly arched. Head comparatively small, with well- developed opercular bones arranged in an arched series ; operculum 1 Printed Heterostichus in Gelehrte Anzeig. k. bay. Akad. Wiss. 1860, p. 93. SEMIONOTID®. 155 much less deep than the suboperculum, the preoperculum narrow and almost covered by the suborbitals ; the external bones more or less ornamented with superficial tuberculations of ganoine. Mar- ginal teeth styliform, in close regular series. J in-fulcra large and uniserial. Pectoral fins large, situated well upon the flank, pelvic fins smaller ; dorsal and anal fins remote and opposite, not much elongated; caudal fin forked. Scales quadrangular, robust, very deep on the flank, more or less tuberculated, and the anterior border strengthened by a robust inner rib, which forms the peg-and-socket articulation; the series between the dorsal and anal fins sharply turned forwards for a short space above and below; dorsal and ventral ridge-scales conspicuous. Cleithrolepis granulatus, Egerton. 1864. Cleithrolepis granulatus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. xx. p. 3, pl. 1. figs. 2, 3. 1890. Cleithrolepis granulatus, A. S. Woodward, Mem. Geol. Surv. N.S. Wales, Palzeont. no. 4, p. 39, pl. vii., pl. vill. figs. 2, 3. 1890. Cleithrolepis granulatus, O. Feistmantel, zdcd. no. 3, p. 75, pl. xxix. fig. 8. Type. Nearly complete fish. The type species, attaining a length of about 0°15. Maximum depth of trunk about equal to its length (exclusive of the caudal fin) and somewhat more than four times as great as the depth of the caudal pedicle. Head with opercular apparatus occupying less than one-fifth of the total length of the fish, and its height at the anterior margin of the operculum contained slightly more than two-and-a-half times in the maximum depth of the trunk; depth of operculum only half that of the suboperculum, which is twice as deep as broad. External bones and scales finely and closely tuber- culated. Pelvic fins arising midway between the pectoral and anal fins; dorsal fin, with about 17 rays, arising at the commencement of the posterior third of the trunk ; anal fin arising more posteriorly but terminating at the same point, and comprising not more than 12 rays. Flank-scales very deep, some of those of the lateral line five or six times as deep as broad, none serrated on the hinder border; the vertical series on the caudal region rapidly narrowed ; ridge-scales apparently not crenulated. Each ventral ridge-scale is shown in several specimens to consist of a right and left half, apparently meeting at a very obtuse angle in the median line; and it is thus evident that the lower portion of the abdomen was broad during life. The fish is, indeed, of so remarkable a form that the fossilized examples are very variously 156 ACTINOPTERYGII. distorted, and it is difficult to determine its original shape and pro- portions. The accompanying woodcut (fig. 28) is probably almost correct. H UC ONT Ss) jeez, _ \ | CU pW SI Cleithrolepis granulatus, restored. A unique specimen with remarkably deepened trunk, found in association with this species, is provisionally named Clezthrolepis altus (A. 8. Woodward, loc. cit. p. 42, pl. viii. fig. 4). Form. & Loc. Upper Trias (Lower Hawkesbury-Wianamatta Series): New South Wales. P. 6280. Four imperfect specimens; Gosford. By exchange, 1890. P: 6281. Slab exhibiting imperfect specimens in association with Pristisomus, &e.; Gosford. — By exchange, 1890. Cleithrolepis extoni, A. 8. Woodward. 1888. Cleithrolepis extoni, A. S. Woodward, Quart. Journ. Geol. Soc. vol. xliv. p. 141, pl. vi. figs. 6, 7. Type. Imperfect fish ; British Museum. A species apparently resembling the type in form and proportions, but differing in the relative size of the opercular bones. ‘Tubercu- lations on head and opercular bones fine and sparse ; operculum two- thirds as deep as the suboperculum, which is nearly as broad as deep. Form. & Loc. Upper Karoo Formation (Stormberg Beds): Orange Free State. P. 5455. The type specimen, described and figured Joc. cit. p. 141, pl. vi. fig. 6; Rouxville. . Presented by Hugh Exton, Esq., M.D., 1888. SEMIONOTID 2%. 157 P. 5455 a. Imperfect head with opercular apparatus, and fragment of trunk with pectoral fin, described and figured «bid. p- 141, pl. vi. fig. 7. Presented by Hugh Exton, Esq., M.D., 1888. The imperfectly known genus Dipteronotus (Egerton, Quart. Journ. Geol. Soc. vol. x. 1854, p. 369) appears to be closely related to Cleithrolepis, but is distinguished at least by its much-elongated dorsal fin, which is broken in the type specimen, and was originally described by Egerton as double. A single species, D. cyphus, is determined by Egerton (Joc. czt. p. 369, pl. xi.) from the Keuper of Bromsgrove, Worcestershire, the type and only known specimen being now preserved in the Museum of Practical Geology, London. Genus AE THEOLSEPIS, A. 8. Woodward. (Described in forthcoming Mem. Geol. Surv. N.S. Wales, Paleont. no. 9. | Trunk deep and laterally compressed. Head small, and external bones more or less tuberculated. Notochord persistent, apparently © without ossifications in the sheath. J in-fulcra well developed. Pectoral fins placed laterally; pelvic fins of moderate size; dorsal and anal fins extended, acuminate in front, and both remotely situated; [? caudal fin not forkedj. Scales of abdominal region thick, much deeper than broad on the flank, quadrate in form, deeply overlapping, with large peg-and-socket articulation, and an anterior inner longitudinal keel; the scales of this form gradually passing into those of the caudal region, which are very thin, deeply imbricating, and more or less oval in shape. Scale-ornament con- sisting of tubercles. Aetheolepis mirabilis, A. 8. Woodward. 1893. Aetheolepis, A. 8S. Woodward, Natural Science, vol. iii. p. 449, woode. [Described in forthcoming Mem. Geol. Surv. N.S. Wales, Paleeont. no. 9. | Type. Nearly complete fish ; Museum of Geol. Surv. N.S. Wales, Sydney. The type species, attaining a length of about 0:17. Length of trunk from the pectoral arch to the base of the caudal fin equalling scarcely more than three-quarters of the maximum depth; the dorsal margin gibbously curved, the ventral margin more regularly arched. Head with opercular apparatus occupying slightly more - than one-quarter of the total length of the fish to the base of the 158 ACTINOPTERYGII. caudal fin. Pelvic fins arising much nearer to the anal than to the pectorals ; the dorsal fin, with about 24 rays, arising considerably in advance of the middle point of the back and extending nearly to the base of the caudal fin; the anal fin, with 17 rays, opposed to the hinder two-thirds of the dorsal, and the length of its foremost ray equalling nearly half of the maximum depth of the trunk. The thickened abdominal squamation terminating abruptly at a line joining the origin of the dorsal and anal fins. Form. & Loc. Upper Hawkesbury- Wianamatta Series: Talbralgar, New South Wales. Not represented in the Collection. Genus TETRAGONOLEPIS, Bronn. [Neues ahrb. 1830, p. 30. | Syn. Pleurolepis, F. A. Quenstedt, Handb. Petrefakt. 1852, p. 214. Homeolepis, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. 1860, p. 92. Trunk much laterally compressed, cycloidal or very deeply fusiform, and the abdominal region relatively large, protuberant ventrally. Head comparatively small, with well-developed oper- cular bones arranged in an arched series; preoperculum narrow; the external bones in part ornamented with superficial tubercula- tions of ganoine. Marginal teeth styliform, in close regular series. Notochord persistent, apparently with pleurocentra and hypocentra ; ribs short but ossified ; neural spines fused with their supporting arches throughout, and both neurals and hemals in caudal region with laminar expansion on anterior border. Fins consisting of distally bifurcating rays; paired fins small, the pectorals situated at about the middle of the flank, the peivic fins remote; dorsal fin much elongated, arising about the middle of the back, and anal fin shorter, opposed to the hinder half of the dorsal; caudal fin only slightly, if at all, forked. Scales quadrangular, very deep on the flank, smooth, rugose, or tuberculated, and the anterior border strengthened by a robust inner rib, which forms the peg- and-socket articulation; caudal scales much thinner than those of the abdominal region ; ventral ridge-scales conspicuous, serrated. Tetragonolepis semicincta, Bronn. [Plate ITI. fig. 1.] 1880. Tetragonolepis semicinctus, H. G. Bronn, Neues Jahrb. p. 30, plat, tiste2. 1882. Tetragonolepis semicinctus, L. Agassiz, Neues Jahrb. p. 147. Ser baa f . SEMIONOTIDA. 159 1835, Tetragonolepis semicinctus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p: 196; plissaikifies. 2,3. 1842. Tetragonolepis subserratus, G. von Minster, Neues Jahrb. p. 97. [Imperfect fish ; Paleontological Museum, Munich. | 1843. . Tetragonolepis semicinctus, F. A. Quenstedt, Flézgeb. Wiirttemb. p. 240. 1852. Pleurolepis semicinctus, F, A. Quenstedt, Handb. Petrefakt. p- 214. 1853. Tetragonolepis subserratus=T. semicinctus (?), Sir P. Egerton, Quart. Journ. Geol. Soc. vol. ix. p. 277, pl. xi. fig. 3. 1853. Tetragonolepis cyclosoma, Sir P. Egerton, zbid. p. 278. [Imperfect fish; British Museum. | 1858. Tetragonolepis semicinctus, F. A. Quenstedt, Der Jura, p. 229 , pl. xxix. fig. 5. 1860. Pleurolepis semicincta, A. Wagner, Gelehrte Anzeig. k. bay Akad. Wiss. vol. 1. p. 94. 1883. Pleurolepis semicinctus, F. A. Quenstedt, Handb. Petrefakt. ed. 3, p. 325. 1892. Tetragonolepis semicinctus, O. M. Reis, Geogn. Jahresh. 1891, poo; ie, 11. Type. Fish, imperfect anteriorly. The type species, attaining a length of about 0-1. The maximum depth of the trunk five times as great as the depth of the caudal pedicle, and contained one-and-a-half times in the total length of the fish; the greatest depth of that portion of the trunk below the vertebral axis equalling about three times that of the portion above the axis. Head with opercular apparatus occupying nearly one- quarter of the total length; external bones feebly tuberculated ; marginal teeth slender. Scales smooth, or with slight ruge following the concentric lines of growth, the hinder border serrated ; those of the flanks very deep, and the ventral ridge-scales finely denticu- lated. The best figure of this species hitherto published is given by Quenstedt, Der Jura, pl. xxix. fig. 5. Form. & Loc. Upper Lias: Wiirtemberg and Bavaria. 16369. Imperfect head and trunk with remains of the paired fins; Ohmden, near Boll, Wiirtemberg. The squamation is almost entirely removed in the caudal region, and some of the laminar appendages of the neural spines are shown. Purchased, 1842. 22524. Similar specimen wanting all the fins, but displaying some of the teeth ; Boll. Appearances in the axial skeleton of the trunk suggest either that the neural and hemal 160 ACTINOPTERYGII. arches were much expanded or that small ossifications were developed in the notochordal sheath. Purchased, 1848. 19663-64. A large distorted fish imperfect dorsally, in counterpart Boll. Part of the abdominal squamation is displayed. Purchased, 1845. P. 1595, P. 3625 a. Imperfect head and the lower portion of the abdominal region, in counterpart ; Boll. Egerton § Enniskillen Oolls. P. 3625 b,c. Two typical specimens showing the feeble character of the squamation in the caudal region; Boll. ‘The first specimen displays the median fins, and is shown of the natural size im 2) Til ties. Enniskillen Coll. 22531. A small fish 0-065 in length, with remains of all the fins; Boll. Like No. 22524, this specimen also appears to exhibit pleurocentra and hypocentra in the caudal region. Purchased, 1848. P. 1596. Small specimen about 0:05 in length, labelled 7. subser- ratus by Egerton; Banz, Bavaria. Egerton Coll. P. 1593, P. 3626. Two very imperfect small specimens, the second wanting the caudal region and the first wanting also the head, labelled 7’. cyclosoma in Egerton’s handwriting and evidently to be regarded as the types of that species ; from Banz and Ohmden respectively. Egerton & Enniskillen Colls. Tetragonolepis discus, Egerton. 1853. Tetragonolepis discus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. ix. p. 278, pl. xi. fig. 5. 1860. Plewrolepis discus, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. p. 96. Type. Head and trunk ; collection of Rev. P. B. Brodie. A smaller species than the type, nearly similar in proportions, but with a less protuberant abdominal region; the greatest depth of that portion of the trunk below the vertebral axis less than three times as great as that of the portion above the axis. Scales smooth, or with slight rugz following the concentric lines of growth, the hinder border not serrated ; those of the abdominal flank relatively broad ; ventral ridge-scales very finely serrated. Form. & Loc. Upper Lias: Gloucestershire. “AS a z - arin Be SEMIONOTID 2. 161 P. 1594. A small fish wanting the caudal region, showing the position of the pelvic fins; Dumbleton. Egerton Coll. P. 3624. Two specimens of the abdominal region, one also ex- hibiting the opercular apparatus and pectoral fin; Dum- bleton. Enniskillen Coll. P. 7039. Fragment of abdominal squamation ; Dumbleton. Purchased, 1894. Tetragonolepis oldhami, Egerton. 1878. Tetragonolepis oldhami, Sir P. Egerton, Paleont. Indica, [4] vol. i. pt. i. p. 3, pl. i. fig. 1. Type. Fish wanting head and caudal region; Indian Museum. Calcutta. A species attaining a length of about 0°15, with trunk apparently less deepened than in the type; the greatest depth of that portion of the trunk below the vertebral axis equalling about twice that of the portion above the axis. Cranial roof closely tuberculated, facial and opercular bones apparently smooth. Ventral ridge-scales tuberculated and sharply serrated. Form. & Loc. Lower Jurassic (Kota Group): Deccan, India. Not represented in the Collection. Tetragonolepis drosera, Egerton. 1852. Pleurolepis, sp., F. A. Quenstedt, Handb. Petrefakt. p. 215. 1853. Tetragonolepis droserus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. ix. p. 278, pl. xi. fig. 4. 1858. Tetragonolepis einctus, F. A. Quenstedt, Der Jura, p. 230, pl. xxix. figs. 6,7. [Nearly complete fish; Tiibingen Tne Museum. | 1860. Homeolepis drosera, A. Wagner, Gelehrte Anzeig. k. bay. Akad, Wiss. vol. 1. p. 97. Type. Imperfect fish ; British Museum. A large species, attaining a length of about 0°3, and somewhat more elongated than the type. Head with opercular apparatus occupying about one-quarter of the total length; the external bones closely granulated. Scales ornamented with numerous gra- nulations, rarely fused into short ruge; the hinder border not serrated. This species is regarded by Wagner as the type of a distinct genus, Homeolepis, said to be separated from Tetragonolepis by the much less protuberant character of the ventral region, the relatively PART III. M 162 ACTINOPTERYGII. lower position of the pectoral fin, and by the greater number of scales in the vertical series below the vertebral axis. A somewhat deeper form than the typical fish is also named by Weer var. orbiculata. Form. § Loc. Upper Lias: Wiurtemberg. 20563. The type specimen described by Egerton, loc. cit.; Boll. Purchased. Fragmentary specimens have also been described under the following names, but there are no examples of these species in the Collection :— Tetragonolepis analis, Sir P. Egerton, Paleeont. Indica, [4] vol. i. pt. ii. (1878), p. 5, pl. iii. fig. 1.—Lower Jurassic (Kota Group); Deccan, India. [Ventral part of trunk; Indian Museum, Calcutta.] (? Cleithrolepis.) Tetragonolepis rugosus, Sir P. Egerton, ibid. p. 6, pl. i. fig. 2.— Ibid. [Portion of squamation; Indian Museum, Cal- cutta. | Tetragonolepis mimor : Homeolepis minor, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. vol. 1. 1860, p. 100.—Upper Lias; Boll, Wiirtemberg. [Nearly complete fish; Pale- ontological Museum, Munich. | Indeterminable fragments, probably not of this genus, have also been named as follows :— Tetragonolepis dubius, G. von Minster, Beitr. Petrefakt. pt. iv. (1841), p. 140. —Muschelkalk ; Esperstadt, Thuringia. [ Seale. | Tetragonolepis ? obscurus, G. yon Miinster, zbcd. p. 140, pl. xvi. fig. 18.—St. Cassian Beds; Tyrol. [Tuberculated bone. | Tetragonolepis quadratus, T. C. Winkler, Archiv. Mus. Teyler, vol. v. (1880), p. 136, pl. viii. fig. 35.—Muschelkalk ; Hochberg, Wiirzburg. [Scale. ] An indeterminable specimen from a so-called Jurassic horizon at Bogoslowsk, Siberia, is described by G. Fischer de Waldheim under the new generic and specific name of Prionoplewrus bronni (Bull. Soc. Imp. Nat. Moscou, vol. xxv. 1852, pt. 1. p. 171, pl. ii. figs. 4-6). The description is unsatisfactory, and whether or not the fossil is related to Tetragonolepis remains to be determined. MACROSEMIID &. 16 Family MACROSEMIID&. Trunk elongate or elongate-fusiform, more or less laterally com- pressed. Cranial and facial bones moderately robust or delicate, and opercular apparatus complete; mandibular suspensorium ver- tical or inclined forwards, and gape of mouth small ; marginal teeth styliform, inner teeth similar or tubercular. Notochord persistent, the vertebre never advancing beyond the annular stage. Fin-rays robust, the majority well-spaced, articulated and divided distally ;. fulera variable; dorsal fin elongated, usually extending at least half the length of the trunk. Scales rhombic. The cranial osteology of the Macrosemiide is as yet very un- satisfactorily known, the only illustration of importance hitherto published being that of the skull of Macrosemius by K. A. von Zittel, reproduced below (fig. 29). The basicranial axis is always. straight and nearly parallel with the hinder portion of the cranial roof; there is no interorbital septum; the cleft of the mouth is horizontal, and the rostrum does not project beyond the mandible. Fig. 29. Macrosemius latiusculus ; head and opercular apparatus, left lateral aspect (after Zittel), ar., angular ; br., branchiostegal rays; c/., clavicle; d., dentary ; hy., cerato- hyal ; mx., maxilla; 0., orbit; op., operculum; p.op., preoperculum ; pa., parietal region ; pl., pterygo-palatine arcade; pmz., premaxilla ; psph., parasphenoid ; gu., quadrate ; s.op., suboperculum ; sp/., splenial ; vo., vomer. In Macrosemius the sclerotic of the eye is ossified, and the cheek- plates seem to have been very delicate. The mandibular suspen- sorium is inclined so much forwards that the articulation of the quadrate (qu.) is beneath the front margin of the orbit (0.). The M2 164 ACTINOPTERYGII. pterygo-palatine arcade (pl.) bears at least one series of large, well- spaced conical or styliform teeth; and there is a cluster of similar teeth on the vomer (vo.). The maxilla (mw.) is elongated, tapering in front ; and the premaxilla ( pmz.) is very short, with a slender ascending process. The mandible is much deepened in the coronoid region, and von Zittel recognizes dentary (d.), splenial (spl.), and angular (ar.) elements. In the hyoid arch, the epihyal, cerato- hyal, and hypohyal bones are well ossified. The opercular apparatus is complete; the suboperculum (s.op.) exhibiting an ascending process at its antero-superior angle, and the large inferior limb of the preoperculum (p.op.) being much turned forwards. The bran- chiostegal rays (br.) are few, well-spaced, constricted at their point of attachment and much expanded in their distal portion. A gular plate has only been observed in Ophiopsis and Eusemius. The ossifications in the notochordal sheath do not advance beyond the stage of unconstricted rings; and Vetter * has observed completed annular pleurocentra and hypocentra alternating in the caudal region of Ophiopsis. The ribs are ossified, though usually delicate and not extending quite to the ventral border of the fish; and the neural spines are fused with their supporting arches both in the abdominal and caudal regions. The basals in the pectoral fin of Ophiopsis are not less than nine in number (PI. III. fig. 3); and the pelvic fin-supports are irregularly hour-glass shaped, the proximal end exhibiting the widest expansion. There is one series of enlarged postclavicular scales especially well shown in Histionotus; and the dorsal fin-rays in this genus seem to be equal in number to the vertical series of regular flank- scales beneath them’. There are enlarged ridge-scales on the caudal pedicle, which attain an extreme development on its ventral border in Macrosemius. Synopsis of Genera. I. Dorsal fin single. Back nearly straight and dorsal fin occupy- ing from one-half to two-thirds of its length; caudal fin forked; fulcra on all median fins; squamation complete and flank-scales scarcely if at alldeepened.. Ophzopsis (p. 165). 1 Mitth. k. mineral.-geol. Mus. Dresden, pt. iv. (1881), p. 56. 2 See figure of Histionotus angularis by J. C. Mansel-Pleydell, Geol. Mag. {8] vol. vi. (1889), pl. vii. MACROSEMITIDA. Back elevated and angulated anteriorly, the dorsal fin extending from the angula- tion almost to the caudal fin, which is deeply forked ; uniserial fulera on both paired and median fins; squamation complete and flank-scales deepened ., Back nearly straight, and dorsal fin extend- ing almost its whole length; squama- tion apparently complete, the flank- scales very large and much deepened... Back nearly straight, and dorsal fin extend- ing almost its whole length; caudal fin not forked, rounded ; fulcra only on the caudal fin; scales thin, wanting dorsally and ventrally, those of the flank scarcely deepened and the vertical series dicho- tomous above; much-enlarged ridge- scales on lower border of caudal pedicle. Back nearly straight, and dorsal fin extend- ing almost its whole length ; (?) no anal fin; squamation robust and complete, but irrecular, the flank-scales not much if at all deepened, the vertical series apparently sometimes dichotomous dorsally and ventrally .............. II. Dorsal fin subdivided into two parts. Vertebral rings feeble or absent; anterior portion of dorsal deeper than the pos- terior portion ; squamation complete .. Vertebral rings robust; anterior portion of dorsal with comparatively widely spaced rays, not deeper than the posterior por- tion ; squamation complete 165 Histionotus (p. 173). Legnonotus (p. 176). Macrosemius (p. 176). Petalopteryx (p. 181). Propterus (p. 183). Notagogus (p. 186). Genus OPHIOPSIS, Agassiz. [Neues Jahrb. 1834, p. 385.] Trunk much elongated, gradually tapering from the occiput back- wards or the dorsal margin only slightly arcuate; head large or of moderate size. Marginal teeth acutely pointed. Notochord invested with delicate ring-vertebre ; ribs ossified. Bifurcation of dorsal fin-rays variable ; fulcra often absent on paired fins and usually confined to the base of the median fins. Paired fins relatively large; dorsal fin ordinarily extending about half the length of the back, high in front, low behind; anal fin small; caudal fin forked. Scales covering the whole of the trunk, in regular series, united by 166 ACTINOPTERYGII. peg-and-socket articulation, and often pectinated at the hinder border; the scales of the middle of the flank scarcely deeper than broad, few of the ventral scales much broader than deep; no enlarged ridge-scales. | This is the least specialised genus ascribed to the Macrosemtiide, and may be regarded as a link between this family and that of the Eugnathide. Ophiopsis procera, Agassiz. 1844. Ophiopsis procerus, L, Agassiz, Poiss. Foss. vol. il. pt. i. p. 289, pl. xlviii. fig. 1. 1851. Ophiopsis procerus, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p. 60. 1863. Ophiopsis procera, A. Wagner, tbid. vol. ix. p. 653. Type. Imperfectly preserved fish; Palzontological Museum, Munich. The type species, attaining a length of about 0:3. Length of head with opercular apparatus equalling the maximum depth of the trunk, and occupying about one-fifth of the total length of the fish ; maximum depth of trunk twice as great as the width of the caudal pedicle. External ornament of head and opercular bones consisting of small, sparse tuberculations ; teeth small. Dorsal fin occupying nearly half the length of the back, and comprising about 25 distally- bifurcated rays, of which the anterior are much elongated, while the others rapidly become much shortened; pelvic fins arising slightly in advance of the middle point between the pectorals and the caudal. Scales large and smooth, with delicately pectinated hinder border except towards the end of the caudal region. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. 37029. Full-sized specimen with imperfect head and fins, in counter- part; Solenhofen. The tuberculation of the head and opercular bones and post clavicular plates is distinct; and the closely arranged, slightly constricted, smooth ring- vertebre are well shown. The greater part of the squamation is also displayed. Hiberlein Coll. P. 6939. Another fine specimen 0:25 in length, displaying all the fins except the anal, and with well-preserved squamation ; Hichstadt. By exchange, 1893. MACROSEMIID 167 Ophiopsis attenuata, Wagner. [Plate IIT. figs. 2, 3.] 1863. Ophiopsis attenuata, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 655. 1873. Ophiopsis attenuata, V. Thiolliére, Poiss. Foss. Bugey, pt. ii. p. 19, pl. viii. fig. 2. Type. Trunk of fish; Palzeontological Museum, Munich. Form and proportions as in the type species, but the fish not attaining so large asize. External head-bones and opercular bones smooth; dorsal fin-rays mostly, if not all, undivided ; scales deli- eately serrated, not pectinated. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia, and Ain, France. P. 1093. P. 3609. P. 1090. Fish of the form ascribed to this species by Thiolliére ; Cirin, Ain, France. The head is shown only in impression, and the dorsal fin is very imperfect. Egerton Coll. Small individual 0-075 in length, wanting the anal fin shown of the natural size in Pl. III. fig. 2; Kelheim, Bavaria. The opercular elements and the fins are espe- cially well exhibited, but no fulcra are preserved except at the base of the caudal fin. Enniskillen Coll. More imperfect example of a similar fish, displaying the paired fins; Kelheim. The outer aspect of the left pectoral fin is represented of three times the natural size in Pl. IIL. fig. 3. Several elongated basal cartilages (6) are indicated, the hindermost one being much larger than the others, with its upper extremity more inclined forwards. Above the basal: lobe is an enlarged scale (a), apparently of the postclavicular series; and the fin-rays are about 12 or 13 in number. Egerton Coll. Ophiopsis zqualis, Wagner. 1863. Ophiopsis equalis, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. p. 656, Type. Nearly complete fish ; Paleontological Museum, Munich. A species attaining a length of about 0-2. Length of head with opercular apparatus exceeding the maximum depth of the trunk and contained about four-and-a-half times in the total length of the sh ; maximum depth of trunk twice as great as the width of the 168 ACTINOPTERYGII. caudal pedicle. Dorsal fin extending about half the length of the back ; pelvic fins arising much nearer to the pectorals than to the caudal. Scales of moderate size, smooth and delicately serrated. A fish from the Lithographic Stone, described as intermediate between this species and O. attenuata, is named O. intermedia by Wagner, loc. cit. p.657. The type specimen is a well-preserved fish in the Paleontological Museum, Munich. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. «P. 7176. Fish 0°135 in length, much crushed, the dorsal fin and squamation shown only inimpression ; Hichstadt. Granu- lar teeth are exhibited apparently on the splenial and pterygoid bones ; and about 12 branchiostegal rays are shown in series. The length of the pectoral fin-rays: appears to be nearly equal to the depth of the back of the head. Purchased, 1894.. Ophiopsis tenuiserrata (Agassiz). 1844. Pholidophorus tenuiserratus, L. Agassiz (ex Munster, MS.),. Poiss. Foss. vol. il. pt. 1. p. 276, pl. xxxviil. fig. 3, pl. xlii. fig. 4. 1851. Ophiopsis serratus, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p.62. [Imperfect fish ; Palzeontological Museum,. Munich. | . 1863. Ophiopsis serrata, A. Wagner, iid. vol. ix. p. 654. 1881. Ophiopsis serrata, B. Vetter, Mittheil. k. mineral.-geol. Mus.. Dresden, pt. iv. p. 55. Type. Imperfect fish; Woodwardian Museum, Cambridge. A robust species, attaining a length of 0°18. Head with oper- cular apparatus occupying nearly one-fifth of the total length ;. maximum depth of trunk twice as great as the width of the caudal pedicle and contained five times in the total length of the fish. Fin-fulcra very slender, present on paired fins. Dorsal fin occupy- ing slightly less than half of the back and comprising 25 rays, mostly bifurcated, of which the anterior three are extremely elon- gated (their length exceeding the depth of the trunk) and the others rapidly become much shortened posteriorly; pelvic fins. arising considerably in advance of the middle point between the pectorals and caudal. Scales smooth, those of the flank finely serrated and partly pectinated at the hinder margin, except towards the extremity of the caudal region. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. MACROSEMIID &. 169 P. 1077. Nearly complete trunk wanting the head; Kelheim. The dorsal fin is especially well preserved, and the squamation of the left side is shown from the inner aspect. Egerton Coll. P. 3599. Imperfect caudal region figured by Agassiz, loc. cit. pl. xxxvill. fig. 3; Kelheim. Enniskillen Coll. P. 3602. Small specimen wanting extremity of head and tail; Kelheim. Enniskillen Colt. Ophiopsis guigardi, Thiollicre. 1873. Ophiopsis guigardi, V. Thiolliére, Poiss. Foss. Bugey, pt. i. pl. vii. (fig. only). Type. Nearly complete fish; Lyons Museum. A species attaining a length of about 0°3. Length of head with opercular apparatus equal to the maximum depth of the trunk and contained about five-and-a-half times in the total length of the fish; maximum depth of trunk twice as great as the depth of the caudal pedicle. Fin-fulcra slender, extending up the anterior ray of each median fin. Dorsal fin less than half as long as the back, much elevated in front, arising at the beginning of the second third of the trunk. Scales relatively large and smooth. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Cirin, Ain, France. Not represented in the Collection. | Ophiopsis penicillata, Agassiz. 1844. Ophiopsis penicillatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p- 290, pl. xxxvi. figs. 2-4. ~ Type. Nearly complete fish; British Museum. A robust species of moderate size. Head with opercular appa- ratus occupying slightly less than one-quarter of the total length ; Maximum depth of trunk twice as great as the width of the caudal pedicle and contained five times in the total length. External head- bones conspicuously tuberculated ; teeth long and slender. Dorsal fin arising at the end of the anterior third of the back, half as long as the trunk, comprising not less than 25 rays, mostly bifurcated, of which the longest do not equal the depth of the trunk at their point of insertion; pelvic fins arising slightly in advance of the middle point between the pectorals and the caudal. The scales of this species are described by Agassiz as smooth and 170 ACTINOPTERYGII. non-denticulated ; but in the type and only known specimen none of the scales of the flank are exposed from the outer aspect, their hinder border being thus obscured. Form. & Loc. Purbeck Beds: (?) Dorsetshire. P. 7433. Type specimen ; probably from the neighbourhood of Swanage. Old Collection. Ophiopsis breviceps, Egerton. 1852. Ophiopsis breviceps, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains (Mem. Geol. Surv.), dec. vi. no. 6, pl. vi. Type. Nearly complete fish ; Museum of Practical Geology. A robust species of small size, attaining a length of about 0°12. Head with opercular apparatus occupying slightly less than one- quarter of the total length; maximum depth of trunk twice as great as the width of the caudal pedicle and contained nearly four- and-a-half times in the total length. Head and opercular bones coarsely ornamented with tubercles and rugze; teeth elongate- conical. Dorsal fin comprising not less than 35 rays and occupying the greater part of the hinder two-thirds of the trunk, not so deep as the trunk at its point of origin ; pelvic fins arising almost at the middle point between the pectorals and the caudal. Scales smooth and somewhat concave externally, with a coarsely serrated hinder horder. Form. & Loc. Purbeck Beds: . Wiltshire. P. 3608. A typical specimen with scattered squamation and head- bones, and the fins only shown in impression ; Wockley. near Tisbury. The premaxille exhibit an upwardly- ascending extension, and the outer aspect of an operculum shows the coarsely rugose character of the surface-orna- ment. The vertebree, as usual, are very delicate. Enniskillen Coll. 46410. Imperfect hinder two-thirds of the trunk, with remains of dorsal fin ; near Tisbury. Cunnington Coll. P. 583. Fragmentary specimen labelled by Egerton as the counter- part of the original of his fig. 2, loc. cit.; Wockley, near Tisbury. Egerton Coll. P. 1094. Two specimens exhibiting vertebrae, scales, and other fragments ; Wockley. Egerton Coll. MACROSEMIID&. 171 Ophiopsis dorsalis, Agassiz. _ 1844. Ophiopsis dorsalis, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 291, ; pl. xxxvi. fig. 5. Type. Nearly complete fish; British Museum. A much elongated species, attaining a length of 0°16. Head ‘with opercular apparatus occupying one-fifth of the total length ; maximum depth of trunk twice as great as the width of the caudal pedicle, and contained somewhat more than six times in the total length. Head and opercular bones externally rugose. Dorsal fin comprising not less than 35 rays and occupying the greater part of the back, not so deep as the trunk at its point of origin; pelvic fins arising slightly in advance of the middle point between the pectorals and caudal. Scales smooth and somewhat concave exter- nally, those of the flank finely serrated on the hinder border, those of the caudal region often irregularly punctated. Form. & Loc. Purbeck Beds: Dorsetshire. P. 466. Type specimen ; probably from Swanage, erroneously described by Agassiz as from the Lower Oolite of North- ampton. — Egerton Coll. P. 7496. A more imperfectly preserved specimen, in counterpart ; Swanage. | Purchased. Ophiopsis flesheri (Agassiz). 1844. Pholidophorus flesherti, LL. Agassiz, Poiss. Foss. vol. i. pt. i. p- 281, pl. xxxvii. fig. 8. 1887. Ophiopsis fleshert, K. A. von Zittel, Handb. Paleont. vol. ii. p27. Type. Nearly complete fish ; imperfect counterpart in British Museum. A much elongated species, attaining a length of 0-2. Head with opercular apparatus occupying one-fifth of the total length; maxi- mum depth of trunk twice as great as the width of the caudal pedicle, and contained seven times in the total length. Dorsal fin occupying about half the length of the back, and apparently much elevated in front; pelvic fins arising slightly in advance of the middle point between the pectorals and caudal. [Scales apparently serrated. | Form. & Loc. Inferior Oolite: Northamptonshire. 47138. Portion of counterpart of the type specimen, extending from the back of the head to the middle of the caudal region; from the railway-tunnel near Blisworth. The 172 ACTINOPTERYGII. squamation being exhibited almost entirely in impression, it is difficult to determine with certainty whether or not the scales are serrated. Sharp Coll. Ophiopsis lepturus (Bellotti). 1857. Pholidophorus lepturus, C. Bellotti, in A. Stoppani, Studii Geol. e Paleont. Lombardia, p. 429. 1889. Ophiopsis lepturus, W. Deecke, Paleeontogr. vol. xxxv. p. 122, pl. vi. fig. 4. Type. Nearly complete fish. A small species, about 0:08 in length, differing from the typical forms in the prominence of the upper caudal lobe and the absence of vertebral rings. Length of head with opercular apparatus ex- ceeding the maximum depth of the trunk and contained about four times in the total length of the fish; maximum depth of trunk twice as great as the width of the caudal pedicle. Dorsal fin fringed with conspicuous fulcra, comprising 15 rays, arising imme- diately behind the anterior third of the trunk and occupying about half of the back. Scales relatively small, in from 42 to 44 vertical series. Specimens from the Senckenberg Museum, Frankfurt, are de- scribed by Deecke. Form. & Loc. Muschelkalk : Perledo, Como, Italy. Not represented in the Collection. The following species are imperfectly known and not represented in the Collection :— Ophiopsis altivelis, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. p. 657.—Lower Kimmeridgian (Litho- graphic Stone); Kelheim, Bavaria. [Hinder portion of fish ; Palzeontological Museum, Munich. | Ophiopsis bellottu, W. Deecke, Paleontogr. yol. xxxy. (1889), p- 124: Mothosomus bellotin, F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxix. (1886), p. 37.—Keuper; Besano, Lombardy [Nearly complete fish; Milan Museum. | Ophiopsis macrodus, V. Thiolliére, Ann. Soc. Sci. Phys. & Nat. Lyon, [2] vol. iii. (1850), p. 148, and Poiss. Foss. Bugey, pt. i. (1873), p. 19.—Lower Kimmeridgian (Lithographic Stone); Cirin, Ain, France. [Nearly complete fish ; Lyons Museum. | A unique specimen from the Lithographic Stone of Eichstidt, Bayaria, now in the Dresden Museum, differs only from the typical MACROSEMIID@. 173 Ophiopsis (according to the description) in the non-bifurcated character of all the dorsal fin-rays. It is the type of the genus and species Husemius beate, B. Vetter, Mittheil. k. mineral.-geol. Mus, Dresden, pt. iv. (1881), p. 51, pl. i. fig. 3. The length of the head with opercular apparatus considerably exceeds the maximum depth of the trunk and is contained little more than three-and-a-half times in the total length of the fish. The dorsal fin comprises about 32 rays; and 11 free supports are described in advance of this. The principal flank-scales are delicately sculptured, exhibit from 4 to 6 strong denticulations on the posterior margin, and are deeper than broad; there are about 44 dorso-ventral series. The published notices of Ophiopsis muenstert (G. von Munster, Neues Jahrb. 1834, p. 385; L. Agassiz, Poiss. Foss. vol. i1. 1844, pt. 1. p. 292, pt. 11. p. 289; A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. 1851, p. 60) leave the systematic position of this species doubtful. According to Wagner’s description, the ver- tebral centra are well ossified ; according to a figure by von Zittel, who names the species [sopholis muensteri (Handb. Paleeont. vol. 111. 1887, p. 216, fig. 230), the head is indistinguishable from that of Eugnathus. The type specimen, obtained from the Lithographic Stone of Kelheim, Bavaria, is an elongated fish wanting the pelvic, dorsal, and anal fins; it is preserved in the Paleontological Museum, Munich. The genus Macrepistius (EK. D. Cope, Journ. Acad. Nat. Sci. Philad. [2] vol. ix. 1894, p.441), so far as known, appears to differ from Ophiopsis only in having all the teeth tumid at the apex, ex- cept those of the premaxille and the opposing portion of the dentaries. The type species is M. arenatus (E. D. Cope, ibid. p. 441, pl. xix. fig. 2) from the Neocomian of Glen Rose, Texas, probably attaining a length of about 0-3. The head and opercular bones are ornamented with tubercles, which become confluent on the hinder part of the parietals. The operculum is twice as deep as broad and three times as large as the suboperculum. ‘The dorsal fin originally comprised not less than 32 rays. The scales are irregularly pitted, but not serrated on the hinder margin. Genus HISTIONOTUS, Egerton. [Ann. Mag. Nat. Hist. [2] vol. xiii. 1854, p. 434.] Head large, snout acute; the dorsal margin of the trunk rising above the head to an angulation from which the body gradually tapers backwards. Marginal teeth much elongated, closely ar- ranged. Notochord invested with delicate ring-vertebre. Fins . Le ACTINOPTERYGII. consisting of distally bifurcating rays, all with large A-shaped fulera ; pectoral fins much larger than the pelvic pair; dorsal fin arising at the angulation of the back, extending to the caudal pedicle, high in front, becoming low behind; anal fin small; caudal fin forked. Scales covering the whole of the trunk, in regular series, united by peg-and-socket articulation, and more or less pec- tinated at the hinder border; the scales of the middle of the flank and of the dorsal region much deeper than broad, with more or less convex hinder border ; those of the ventral region at least as broad as deep; postclavicular scales very large; the ridge-scales of the caudal pedicle not much enlarged. Histionotus angularis, Egerton. 1854-55. Histionotus angularis, Sir P. Egerton, Ann. Mag. Nat. Hist. [2] vol. xiii. p. 454, and Figs. & Descript. Brit. Organic Remains (Mem. Geol. Surv.), dec. vii. no. 5, pl. v. 1889. Histionotus angularis, J. C. Mansel-Pleydell, Geol. Mag. [3] vol. vi. p. 241, pl. vii. Type. Fish, wanting tail; British Museum. The type species, attaining a length of about 0-2. Length of head with opercular apparatus very slightly exceeding its maximum depth, and occupying about one-quarter of the total length of the fish ; length of the trunk equalling twice its maximum depth, and the dorsal angulation measuring approximately 148°. The head and opercular bones externally ornamented with fine, closely arranged ruge ; the large postclavicular plates similarly ornamented. Fin- rays stout and smooth ; pectoral fins scarcely twice as large as the pelvic pair, and the latter arising in advance of the middle point of the trunk; dorsal fin consisting of at least 25 rays. Pectinations of the scales delicate and confined to their hinder margin, but con- spicuous in all regions of the trunk. Form. & Loc. Purbeck Beds: Dorsetshire and Wiltshire. P. 577. Type specimen, described and figured by Egerton, loc. cit. ; Swanage, Dorsetshire. The impression of the caudal region is much less distinct than indicated in the published figure, in which the anal fin is erroneously extended. Ligerton Ooll. P. 3614. Crushed head and trunk, wanting the greater part of the caudal region; Swanage. Enniskillen Coll. P. 5935. Small fish somewhat distorted and with imperfect fins, but displaying the bifurcation of the caudal; Swanage. MACROSEMIID &. a7 Part of the cranial roof is shown, and some of the superior circumorbital bones are preserved. Purchased, 1889. P. 3614. Part of a trunk with displaced squamation, showing some ring-vertebre: immediately behind the position of the pelvic fins; Swanage. - Enniskillen Coll. 46421. Imperfect head and portion of trunk ; Tisbury, Wiltshire. Cunnington Coll. Histionotus oberndorferi, Wagner. 1863. Histionotus oberndorfert, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 650, pl. iii. 1887. Histionotus oberndorfert, K. A. von Zittel, Handb. Paleont. vol. iii. p. 218, fig. 231. Type. Imperfect fish, wanting caudal region ; Palzontological Museum, Munich. An imperfectly known species, differing from H. angularis in the more acute angulation of the dorsal margin and in the more coarsely serrated character of the scales. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. 49135. Plaster cast of type specimen; Kelheim. Purchased, 1878. Histionotus falsani, Thiollicre. 1873. Histionotus falsani, V. Thiolliére, Poiss. Foss. Bugey, pt. ii. p- 14, pl. v. fig. 1. Type. Much-fractured fish ; Lyons Museum. A species about equalling the type in size, but the maximum depth of the trunk considerably exceeding half its length, and the head with opercular apparatus at least as deep as long. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Cirin, Ain, France. Not represented in the Collection. An imperfect small fish in the Dresden Museum, from the Bavarian Lithographic Stone, is also regarded as indicating a dis- tinct species, Histionotus parvus, by B. Vetter, Mittheil. k. mineral.- geol, Mus. Dresden, pt. iv. (1881), p. 48, pl. ii. fig. 5. 176 ACTINOPTERYGII. Genus LEGNONOTUS, Egerton. [Ann. Mag. Nat. Hist. [2] vol. ii. 1854, p. 485.] Trunk gradually tapering from the occiput backwards or the dorsal margin only slightly arcuate. Marginal teeth very long and much crowded. Dorsal fin extending almost the whole length of the back, and all the rays, except perhaps anteriorly, distally bifurcating. Scales apparently covering the whole of the trunk, in regular series, those of the middle of the flank much deeper than broad. Lateral line forming a conspicuous ridge. Legnonotus cothamensis, Egerton. 1854-55. Legnonotus cothamensis, Sir P. Egerton, loc. cit. p. 435, and Figs. and Descript. Brit. Organic Remains (Mem. Geol. Surv.), dec. vili. no. 7, p. 4, pl. vii. figs. 9-12. Type. Imperfect trunk; Bristol Museum. The type species, attaining a length of about 0:06. Marginal teeth bluntly pointed; operculum ornamented with large, flattened tubercles. Dorsal fin comprising about 30 rays. Scales compara- tively large, smooth, but coarsely serrated; principal scales of lateral line about two-thirds as broad as deep. Form. & Loc. Rheetic (Cotham Marble): Aust Cliff, Gloucester- shire. P. 1092. Three small slabs exhibiting portions of jaws associated with a mass of scales, bone-fragments, and ring-vertebree. Egerton Coll. Genus MACROSEMIUS, Agassiz. [Neues Jahrb. 1834, p. 387.] Syn. Disticholepis, V. Thiolliére, Ann. Soc. Sci. Phys. & Nat. Lyon, [2] vol. iii. 1850, p. 136, and Poiss. Foss. Bugey, pt. ii. 1873, p. 14, | Trunk gradually tapering from the occiput backwards; head large, snout acute. Teeth much elongated, closely arranged. Notochord persistent, without ring-vertebre; ribs ossified. Fins consisting of very robust, bifurcating rays, without fulcra except in the caudal; pectoral fins much larger than the pelvic pair; dorsal fin arising immediately behind the occiput and extending con- tinuously to the caudal pedicle; anal fin small; caudal fin rounded. Scales thin and more or less pectinated, with peg-and-socket articu- lation, and apparently wanting towards the dorsal margin; scales MACROSEMIID. 177 of the middle of the flank relatively large, becoming smaller both dorsally and ventrally, in the former case by dichotomy of the vertical series; about four very large ridge¢scales on the ventral border between the anal and caudal fins. Macrosemius rostratus, Agassiz. [Plate IIT. fig. 4.] 1834. Macrosemius rostratus, L. Agassiz, Neues Jahrb. p. 388 (name only). _ 1844. Macrosemius rostratus, L. Agassiz, Poiss. Foss. vol. ii. pt. 11. p. 150, pl. xlvii. a. fig. 1. 1851. Macrosemius rostratus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. p. 73. 1863. Macrosemius rostratus, A. Wagner, zbid. vol. ix. p. 647. 1863. Macrosemius insignis, A. Wagner, ibid. vol. ix. p. 648, pl. ii. [ Fish, wanting tail; Paleeontological Museum, Munich. | Type. Nearly complete fish ; Royal Bohemian Museum, Prague. The type species, attaining a length of about 0°3. Head with opercular apparatus somewhat longer than its maximum depth and occupying about one-quarter of the total length of the fish; the maximum depth of the trunk exceeding twice the width of the caudal pedicle. Rays of dorsal fin very long and comparatively slender, without denticles, and about 38-40 in number; the length of those of the hinder portion of the caudal region greater than the depth of that part of the trunk. Pelvic fins arising well in advance of the middle point between the pectoral and caudal fins, and the anal arising shortly behind. Scales conspicuously pectinated. Closely related to this fish, if not specifically identical, is a trunk from the Lithographic Stone of Kelheim, said to be slightly deeper in proportion to its length but not otherwise distinguished from the typical I. rostratus. It is described as the type of MV. latiusculus by A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. (1851), p. 74; and a head is figured under the same name by K. A. von Zittel, Handb. Paleont. vol. iii. (1887), p. 218, fig. 232 (copied above, fig. 29, p. 163). The original specimens are pre- served in the Paleontological Museum, Munich. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. 37051. Fine specimen 0-275 in length, in counterpart, displaying some of the teeth, a few ribs, the dorsal and caudal fins, and the greater part of the squamation ; Solenhofen. Héberlein Coll. PART III. N 178 ACTINOPTERYGII. P. 7177. Another fine specimen 0°165 in length, displaying ribs and all the fins, as shown in PI. III. fig. 4; Hichstadt. The pelvic fin-supports are seen in impression, much con- stricted near the distal end, much expanded proximally. Purchased, 1894. 37094. Distorted fish, imperfectly preserved but showing the pectinated squamation ; Solenhofen. Hldberlein Coll. P. 956. Imperfect head and abdominal region, showing the paired fins; Kelheim. Egerton Coll. P. 955, P. 3616. Imperfect trunk 0°07 in length, in counterpart, with displaced squamation, showing ossified ribs and dorsal fin-supports with expanded distal ends ; Kelheim. The scales are finely serrated. ; Egerton and Enniskillen Colls. Macrosemius dumortieri (Thiollicre). 1858. Disticholepis dumortiert, V. Thiolliére, Bull. Soc. Géol. France, [2] vol. xv. p. 783 (name only). 1873. Disticholepis dumortiert, V. Thiolliére, Poiss. Foss. Bugey, pt. 11. p. 15, pl. vi. fig. 1. 1883. Disticholepis dumortiert, H. EK. Sauvage, Bull. Soc. Géol. Hisudes [3] vol. xi. p. 479. Type. Nearly complete fish; Lyons Museum. A species of moderate size. Head with opercular apparatus somewhat longer than its maximum depth, and occupying about one-quarter of the total length of the fish ; the maximum depth of the trunk nearly three times as great as the width of the caudal pedicle. Rays of dorsal fin about 32 in number, denticulated on their posterior border and stout but not expanded; the length of those of the caudal region scarcely if at all exceeding the depth of that part of the trunk. Pelvic fins arising slightly in advance of the middle point between the pectoral and caudal fins, and the anal arising shortly behind. Scales conspicuously pectinated. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. P. 4684. Imperfect impression of a typical fish; Cirin. Purchased, 1884. Macrosemius fourneti (Thiollicre). 1850. Disticholepis fourneti, Ann. Soc. Sci. Phys. & Nat. Lyon, [2] vol. il. p. 136. MACROSEMIID B. 179 1854. Disticholepis fourneti, V. Thiolliére, Poiss. Foss. Bugey, pt. 1. 1. viii. i873. Disticholepis fourneti, V. Thiolliére, zbzd. pt. i. p. 15. Type. Nearly complete fish; Lyons Museum. A large species attaining a length of about 0°3. Head with opercular apparatus longer than its maximum depth, and occupying about one-quarter of the total length of the fish; maximum depth of the trunk scarcely more than twice as great as the width of the caudal pedicle. Rays of dorsal fin about 34 in number, very stout, and denticulated on their posterior border; those of the hinder half of the fin somewhat expanded distally, and their length not ex- ceeding the depth of the caudal region of the trunk. Pelvic fins arising almost midway between the pectoral and caudal fins, and the anal arising shortly behind. Scales usually covered with fine striz extending from the delicate pectinations of the hinder border. This is the type species of the so-called Disticholepis, which is regarded by Wagner (Gelehrte Anzeig. k. bay. Akad. Wiss. 1860, p-. 402) as doubtfully distinct from Macrosemius. It is not improbable that the fish from Cirin, erroneously ascribed by Thiolliére (op. cit. pt. 1. p. 14, pl. v. fig. 2) to Macrosemius rostratus, is a small example of this species. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. 3 P, 4685. The greater portion of the trunk, with the dorsal and caudal fins, of a large individual chiefly shown in im- pression ; Cirin. Purchased, 1884. P, 4685 a. Imperfect impression of a fish 0-2 in length, showing all the fins; Cirin. Purchased, 1884. P. 1091. Hinder abdominal and caudal regions of a small indi- vidual, much fractured; Cirin. Distinct denticles of ganoine are seen upon the posterior border of some of the hinder dorsal fin-rays. Egerton Coll. Macrosemius pectoralis, Sauvage. 1883. Macrosemius pectorals, H. K. Sauvage, Bull. Soc. Géol. France, [3] vol. xi. p. 477, pl. xii. fig. 17. Type. Nearly complete fish ; counterpart in British Museum. A very small species, attaining a length of about 0°055. Head with opercular apparatus considerably longer than its maximum depth, and occupying about one-third of the length of the fish to the base of the caudal fin; caudal pedicle very slender, its width N 2 180 ACTINOPTERYGII. considerably less than one half the maximum depth of the abdo- minal region. Vertebral rings well ossified. Dorsal fin arising opposite the fourth or fifth vertebra, with about 26 rays, which are not expanded, but bifurcate distally at least in its hinder half. Pelvic fins arising midway between the pectoral and caudal fins, and the anal, with 6 or 7 rays, shortly behind. Squamation very thin. Form. & Loc. Portlandian: Meuse, France. P. 7359. Counterpart of type specimen; Upper Portlandian (“ La Garde”), Savonnicres-en-Perthois, Meuse. The vertebral rings are shown to be complete and well ossified, and the neural arches throughout the trunk, the hzmal arches in the caudal region, besides all the fin-supports, are especially robust. The present writer cannot distinguish more than 26 dorsal and 7 anal fin-rays. The hinder- most dorsal rays are clearly proved to bifurcate. Traces of the extremely delicate flank-scales occur above the pelvic fins. Purchased, 1894. Macrosemius andrewsi, A. 8. Woodward. 1895. Macrosemius andrewsi, A. S. Woodward, Geol. Mag. [4] vol. ii. p. 148, pl. vii. fig. 3. Type. Nearly complete fish; British Museum. A very small species, about 0:035 in length, closely similar to the preceding but with relatively stouter caudal region. Separate hypocentra and pleurocentra in notochordal sheath. Dorsal fin with about 25 slender rays, arising above the fifth pair of ribs. Pelvic fins arising about midway between the pectoral and caudal fins, and the anal, with 7 or 8 rays, shortly behind. Squamation very thin. Form. & Loc. Purbeckian: Wiltshire. P. 6303. The type specimen, in counterpart, described and figured loc. cit.; Middle Purbeck, Teffont. Presented by Rev. W. R. Andrews, 1890, The following specimens may perhaps indicate a species of Macro- semius from the Stonesfield Slate, while two premaxille and a maxilla figured by J. Phillips (Geol. Oxford, 1871, p. 180, woode. xl. figs. 8, 9) may pertain to the same fish; these specimens, however, are insufficient for determination. P. 3617. Dentigerous bone, probably maxilla, named Macrosemius brevirostris by Agassiz (Poiss. Foss. vol. i. pt. 1. 1844, MACROSEMIID 2. 181 p- 166), described and figured by the present writer in Proc. Geol. Assoc. vol. xi. (1890), p. 293, pl. ii. fig. 9; Stonesfield Slate, Stonesfield. Enniskillen Coll. P. 957. Left dentary with eight teeth, probably of the same species ; Stonesfield. Egerton Coll. The following species is only imperfectly defined and is not represented in the Collection :— Macrosemius helene, V. Thiolliére, Ann. Soc. Sci. Phys. & Nat. Lyon, [2} vol. ii. (1850), p. 135, and Poiss. Foss. Bugey, pt. ii. (1878), p. 14, pl. vi. fig. 2; H. E. Sauvage, Bull. Soc. Géol. France, [3] vol. xi. (1883), p. 478.— Lower Kimmeridgian (Lithographic Stone); Cirin, Ain, France. [Imperfect small fish; Lyons Museum. | Genus PETALOPTERY&X, Pictet. [Poiss. Foss. Mt. Liban, 1850, p. 20.] Syn. Aphanepygus, F. Bassani, Verhandl. k. k. geol. Reichsanst. 1879, p. 162. as Trunk much elongated, gradually tapering from the occiput backwards; head small, snout acute. Teeth much elongated, closely arranged ; suborbital plates subdivided into numerous small tessere. Fulcra absent, except on the caudal fin; pectoral fins much enlarged; dorsal fin consisting of unbranched rays, arising shortly behind the occiput and extending continuously to the caudal pedicle ; [anal fin apparently absent; caudal fin scarcely if at all forked]. Squamation robust and extending over the whole trunk, the flank-scales not much (if at all) deepened, but all more or less irregular, and the vertical series apparently sometimes dichotomous dorsally and ventrally. Petalopteryx syriacus, Pictet. 1850. Petalopteryx syriacus, F. J. Pictet, Poiss. Foss. Mt. Liban, p. 22, pl. iu. fig. 1. 1866. Petalopteryx syriacus, F. J. Pictet & A. Humbert, Nouv. Rech. Poiss. Foss. Mt. Liban, p. 54. 1882. Petalopteryx syriacus, F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. p. 268. Type. Nearly complete fish; Geneva Museum. The type species, attaining a length of about 0°16. Maximum depth of trunk contained nearly four-and-a-half times in its length 182 ACTINOPTERYGII. from the pectoral arch to the base of the caudal fin, and exceeding twice the width of the caudal pedicle. Suborbitals subdivided into small hexagonal plates, ornamented with granulations. Dorsal fin comprising more than 45 rays, its anterior portion elevated and as deep as the trunk at its point of origin. Principal flank-scales deeper than broad, smooth, and very finely denticulated on the posterior border. (Pictet.) Form. &§ Loc. Upper Cretaceous: Mount Lebanon, Syria. Not represented in the Collection. Petalopteryx dorsalis, Davis. 1887. Petalopteryx dorsalis, J. W. Davis, Trans. Roy. Dublin Soc. [2] vol, iii. p. 627, pl. xx. fig. 4. Type. Fish with imperfect fins; British Museum. A small species, attaining a length of 0-075. Length of head with opercular apparatus exceeding the maximum depth and con- tained six times in the total length of the fish to the base of the caudal fin; maximum depth of trunk contained nearly six times in its length from the pectoral arch to the base of the caudal fin, and twice as great as the width of the caudal pedicle. Tesserz on cheek very small, elongated antero-posteriorly, and smooth. [Fins imperfectly known, but] pelvic pair comprised within the first third of the trunk. Scales very small and irregular, all apparently at least as broad as deep, smooth, and not serrated on the posterior margin. | Form. & Loc. Upper Cretaceous: Mount Lebanon, Syria. P. 4755. Type specimen described and figured by Davis, loc. cit. ; Hakel. The lower dentition and the cheek-plates are especially well shown in the head; the branchiostegal rays are robust though filiform. There is no evidence as to the nature of the vertebral axis, owing to the thickness of the squamation. The fins are too imperfect for de- scription, and it is impossible to determine whether or not the anal is wanting by accident. The caudal fin-rays distinctly bifurcate once. Except in the posterior half of the caudal region, there is evidence of the dichotomy of the vertical series of scales both dorsally and ventrally ; and, as noted by Davis, some of the small scales near the pectoral fins appear to be rounded. Lewis Coll. MACROSEMIID A. 183 Petalopteryx elegans (Bassani). 1879. Aphanepygus elegans, F. Bassani, Verhandl. k. k. geol. Reichs- anst. p. 163. 1882. Aphanepygus elegans, F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. p. 197, pl. 1. figs. 1-9. Type. Fish with imperfect fins; Austrian Geological Survey Museum, Vienna. The type species of the so-called genus Aphanepygus, attaining a length of about 0-12. Length of head with opercular apparatus exceeding the maximum depth and contained about five times in the total length of the fish to the base of the caudal fin. Tessere on cheek very small, quadrangular and often antero-posteriorly elongated. Dorsal fin comprising at least 75 rays, the longest of which are as deep as the maximum depth of the trunk; pelvic fins arising just beyond the end of the first quarter of the trunk. Scales small and irregular, smooth, not serrated on the posterior margin, and the majority broader than deep. (Bassant.) Form. & Loc. Upper Cretaceous: Island of Lesina, Dalmatia. Not represented in the Collection. Genus PROPTERUS, Agassiz. [Neues Jahrb. 1834, p. 386. ] Syn. Rhynchoncodes, O. G. Costa, Atti Accad. Pontan. vol. v. 1850, p. 317. Trunk irregularly fusiform, the dorsal margin more or less bent at the origin of the dorsal fin; head large, snout acute. Teeth long and slender. Notochord invested at least in part with very delicate pleurocentra and hypocentra or ring-vertebree. ins consisting of distally bifurcating rays; paired fins of moderate size, without fulera; median fins very large, the dorsal extending more than half the length of the back and divided into two portions, the anal fin short and deep, and the caudal deeply forked; dorsal fin with basal fulecra, the anal and caudal fringed with fulcra. Scales covering the whole of the trunk, in regular series, united by peg- and-socket articulation, and usually pectinated or denticulated at the hinder border; the principal flank-scales somewhat deeper than broad, none of the ventral scales much broader than deep; no en- larged ridge- scales. Propterus microstomus, Agassiz. 1834. Propterus microstomus, L. Agassiz, Neues Jahrb. p. 386. 1833-44. Notagogus xietent, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. 184 ACTINOPTERYGII. pp. 10, 293, pl. xlix. fig. 1. [Imperfect fish; Paleeontological Museum, Munich. | 1844. Propterus microstomus, L. Agassiz, zbid. p. 296, pl. 1. figs. 6-8. 1851. Notagogus zietent, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p. 65. 1851. Propterus microstomus, A. Wagner, bid. p. 66. 1851. Propterus gracilis, A. Wagner, ibid. p. 68. [Imperfect fish ; Paleontological Museum, Munich. } 1868. Propterus microstomus, A. Wagner, loc. cit. vol. ix. p. 645. Type. Fish, wanting part of caudal fin ; Paleontological Museum, Munich. The type species, attaining a length of about 0:09. Length of head with opercular apparatus about equalling the maximum depth of the trunk and contained slightly more than four times in the total length of the fish; the dorsal border gently arched and the maximum depth of the trunk two-and-a-half times as great as the width of the caudal pedicle. Length of the first dorsal fin-ray equalling the depth of the trunk at its point of insertion; the short-based anal fin opposed to the hindermost rays of the dorsal. Scales finely denticulated. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. Not represented in the Collection. Propterus speciosus, Wagner. [Plate III. fig. 5.] 1851. Propterus speciosus, A.Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p. 67, pl. iv. fig. 1. 1863. Propterus speciosus, A. Wagner, loc. cit. vol. ix. p. 644. Type. Imperfect fish; Paleontological Museum, Munich. A species attaining a length of about 0°15. Proportions as in the type species, but the dorsal border irregularly arched, sharply rising above the occiput and bent at the origin of the dorsal fin. The anterior and posterior portions of the dorsal fin comprising about 16 and 13 rays respectively; pelvic fins arising well in advance of a point mid-way between the pectorals and the caudal ; the short-based anal fin opposed to the hindermost rays of the dorsal. Scales finely denticulated. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. 37088, 37935. Two fine specimens, in counterpart, exhibiting the principal characters of the species ; Solenhofen. The first is shown of the natural size in Pl. III. fig. 5. Haberlein Coll. MACROSEMIID 2. 185 37099. A large fish, 0°18 in length, with imperfect head and fins, probably of this species ; Solenhofen. Héberlein Coll. -P. 5547. A small fish; Eichstidt. By exchange, 1888. Propterus elongatus, Wagner. 1863. Propterus elongatus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 645. Type. Fish, wanting squamation; Paleontological Museum, Munich. A species briefly described as differing only from P. speccosus in the more slender proportions of the trunk, which tapers more rapidly behind. Form. &¢ Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. Not represented in the Collection. Propterus scacchii (Costa). [Plate IIT. fig. 6.] 1850. Rhynchoncodes scacchi, O. G. Costa, Atti. Accad. Pontan. vol. v. pools, pl. v. fig. 5. Type. Nearly complete fish ; seeemee Museum, Naples. The type species of the so-called genus Rhynchoncodes, of small size, attaining a length of about 0-06. Length of head with opercular apparatus exceeding the maximum depth of the trunk and contained about three-and-a-half times in the total length of the fish; the dorsal border gently arched and the maximum depth of the trunk about three times as great as the width of the caudal pedicle. Length of the first dorsal fin-ray nearly equalling the depth of the trunk at its point of insertion. Form. & Loc. Upper Jurassic: Naples. P. 3613. Specimen 0:055 in length, displaying the general form of the fish but much abraded, shown of the natural size in Pl. III. fig. 6; Torre d’Orlando, near Castellamare, Naples. Each part of the dorsal fin seems to have com- prised about 10 rays, and the anal fin, with only 6 rays, exhibits large fulcra along its anterior border resembling those of the caudal fin. Enniskillen Coll. To the genus Propterus, perhaps also to the species P. scacchii, may be referred two small imperfect fishes from the Upper Jurassic of Torre d’Orlando (errore “ Pietraroja”) described under the name 186 ACTINOPTERYGII. of Rhynchoncodes macrocephalus, O. G. Costa, Atti Accad. Pontan. vol. vill. (1864), p. 102, pl. ix. figs. 10, 11. They have already been placed in this genus by F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. (1882), p. 239. The so-called Propterus serratus, Minster MS. (L. Agassiz, Poiss. Foss. vol. ii. pt. 1. 1844, p. 296), from the Lithographic Stone of Bavaria (type in Berlin Museum), is undefined. Genus NOTAGOGUS, Agassiz. | Poiss. Foss. vol. ii. pt. i. 1833-44, pp. 10, 293. ] Syn. Blenniomoeus, O. G. Costa, Atti Accad. Pontan. vol. v. 1850, p- 319. Calignathus, O. G. Costa, eid. vol. vil. 1855, p. 37. A genus scarcely distinguished from Propterus, differing only in the non-elongation of the anterior rays of the dorsal fin, which are very widely spaced, and in the less deeply forked character of the caudal fin. The vertebral rings also appear to be more robust than in Propterus. Notagogus pentlandi, Agassiz. [Plate III. figs. 7, 3.] 1833-44. Notagogus pentlandi, L. Agassiz, Poiss. Foss. vol. i. pt. 1. pp. 10, 294, pl. xlix. fig. 2. 1833-44, Notagogus latior, L. Agassiz, cbid. pp. 10, 294, pl. xlix. fig. 3. [ Distorted fish; Paris Museum of Natural History. | 1850. Notagoyus pentlandi, O. G. Costa, Atti Accad. Pontan. vol. v. p. 312, pl. v. fig. 2, pl. vil. fig. 5. 1850. Notagogus erythrolepis, O. G. Costa, ibid. p. 514, pl. iv. figs. 6, 7. 1850. Notagogus minor, O. G. Costa, zbid. p. 315, pl. v. fig. 4. 1850. Blenniomoeus longicauda, O. G. Costa, ibid. p. 319, pl. vi. fig. 2. 1850. Blenniomoeus brevicauda, O. G. Costa, ibed. p. 321, pl. v. fig. 3. 1853. Blenniomoeus major, O. G. Costa, ibid. vol. vii. p. 34, pl. il. fies. 4-6. 1864. Notagogus pentlandi, O. G. Costa, ibid. vol. vill. p. 72, pl. xii. fig. 5. 1864. Notagogus crassicauda, O. G. Costa, ibid. p. 74, pl. xii. figs. 6, 7. 1864. Blenniomoeus longicauda, O. G. Costa, wid. p. 99. 1864. Notagogus erythrolepis, O. G. Costa, bid. p. 102, pl. x1. fig. 11. 1864. Notagogus gracilis, O. G. Costa, zbid. p. 108, pl. xi. fig. 8. 1882. Notagogus pentlandi, F, Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. pp. 287, 239. Type. Nearly complete fish; British Museum. A species attaining a length of about 0°15, but usually smaller. MACROSEMIID.. 187 Length of head with opercular apparatus considerably exceeding ~ the maximum depth of the trunk and equalling half its length to the base of the caudal fin; width of caudal pedicle somewhat less than half the maximum depth of the trunk, which tapers gradually from a point close to the occiput. Dorsal fin arising at the end of the first quarter of the back, and its anterior portion twice as much extended as the hinder portion ; the first comprising about 14 rays, very widely spaced and all shorter than those of the second portion, which are more closely arranged and only 10 in number. Anal fin, with large fulcra and about 6 rays, as deep as the second portion of the dorsal and arising slightly behind the origin of the latter. Scales very finely crenulated. This is commonly regarded as the type species of Wotagogus. Form. & Loc. Upper Jurassic: Naples. 117. Type specimen ; Torre d’Orlando, near Castellamare. Purchased, 1837. P. 2065. Finer specimen 0:14 in length, shown of the natural size in Pl]. III. fig. 7; Torre d’Orlando. Egerton Coll. P. 6866. Impression of a large fish distorted at the lower margin of the abdominal region, apparently the counterpart of the type specimen of the so-called N. latior; Torre d’Orlando. Presented by Walter Crouch, Esq., 1893. P. 1097. Three imperfect young specimens, the largest about 0:06 in length, exhibiting the internal skeleton of the trunk ; Torre d’Orlando. The middle portion of the vertebral axis of one specimen is shown of three times the natural size in Pl. III. fig. 8. The pleurocentra and hypocentra are observed to be distinct posteriorly, but soon fused together in the abdominal region. Egerton Coll. Notagogus denticulatus, Agassiz. 1844. Notagogus denticulatus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p: 294, pl. 1. figs. 1-5, pt. ii. p. 289. 1851. Notagogus denticulatus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. p. 65. 1863. Propterus denticulatus, A. Wagner, zbid. vol. ix. p. 646. 1881. Notagogus denticulatus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 48. Type. Nearly complete fish; Paleontological Museum, Munich. A species attaining a length of about 0:1. Proportions of head and trunk asin WN. penilandi, except that the trunk in the abdo- 188 ACTINOPTERYGII. minal region is slightly deeper. Anterior portion of dorsal fin nearly twice as much extended as the second portion, both about equally elevated and the first three rays of each more approximated than the others; the anterior portion with about 13 rays, the pos- terlor portion with not less than 11 or 12 rays, which are somewhat less widely spaced. Anal fin arising opposite the middle of the hinder portion of the dorsal. Scales conspicuously denticulated, except those of the pectoral region, which are more or less cycloidal. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. P. 3610-11. Two specimens, the first with imperfect head, the second very fragmentary and chiefly in impression; Kel- heim, Bavaria. Enniskillen Coll. P. 1089. Another imperfect specimen exhibiting the rounded scales in the pectoral region ; Kelheim. | Egerton Coll. P. 1090. Small fish about 0:055 in length, probably young of this species; Kelheim. Egerton Coll. Notagogus inimontis, Thiollicre. 1850. Notagogus Imi montis, V. Thiolliére, Ann. Soc. Sci. Phys. & Nat. Lyon, [2] vol. iii. p. 187. 1858. Notagogus tunismontis, V. Thiolliére, Bull. Soc. Géol. France, [2] vol. xv. p. 783 (name only). 1878. Notagogus inimontis, V. Thiolliére, Poiss. Foss. Bugey, pt. i. p. 15, pl. vi. fig. 3. 1893, Notagogus inimontis, H. E. Sauvage, Bull. Soc. Hist. Nat. Autun, vol. vi. p. 428. Type. Nearly complete fish ; Lyons Museum. A species doubtfully fee from NV. denticulatus, but described by Sauvage as separated by its relatively larger teeth and steeper facial profile of the head. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. P. 4692. Trunk without head; Cirin, Ain. Purchased, 1884. Notagogus macropterus, Vetter. 1881. Notagogus macropterus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 46. Type. Fish, wanting caudal fin; Dresden Museum. A species closely related to NV. denticulatus, described as differing PYCNODONTID &.- 189 in the more arched form of the back, deeper trunk, and the remarkable development of the pectoral, dorsal, and anal fins. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ba- varia. Not represented in the Collection. A fish from the Lithographic Stone of Cirin, Ain, France, much resembling the two preceding species, is named NV. margarite, Thiolliére (Bull. Soc. Géol. France, [2] vol. xv. 1858, p. 783), and figured without description in Thiolliére, Poiss. Foss. Bugey, pt. ii. (1873), pl. vi. fig. 4. Either to the Macrosemiide or to the Semionotidze may also per- haps be referred the problematical Triassic genus Orthurus (R. Kner, Sitzungsb. k. Akad. Wiss., math.-naturw. Cl. vol. lili. 1866, p. 163). The trunk is comparatively elongated and is almost or quite scale- less on the flanks. A few of the inner teeth are enlarged and tritoral. There is little or no ossification in the notochordal sheath, and the ribs are extremely delicate. The pectoral fins are large and the pelvic fins remote; the dorsal fin has an extended base-line but is not acuminate, and the anal is relatively very small; the caudal fin is truncated, not forked. A few undivided and unarti- culated rays occur at the origin of the dorsal and caudal fins, but ordinary fulera are absent. All the fin-rays are delicate, and those of the dorsal and anal fins, though articulated, are not branched more than once. An elongated large scale occurs in front of the anal fin. The type species, O. sturz (Kner, loc. cit. p. 163, pl. ii. fig. 1), is founded on a unique specimen from the Keuper of Raibl, Carinthia, in the Museum of the Austrian Geological Survey, Vienna. Another form from the “ Hauptdolomit” of Lumezzane, Lombardy, is also described by W. Deecke, Paleeontogr. vol. xxxv. (1889), p. 186, pl. vii. fig. 9. Family PYCNODONTIDA. Trunk deeply fusiform or cycloidal. Cranial bones robust, and a median occipital plate separating the parietal elements; facial bones delicate or wanting; opercular apparatus reduced to a small operculum, large preoperculum, and not more than two branchio- stegal rays ; mandibular suspensorium much inclined forwards and gape of mouth small; teeth prehensile on the premaxilla and dentary, wanting on the maxilla (if this bone be present) and the pterygo- palatine arcade, tritoral on the single vomer and the splenials ; all rh PET Gh 190 ACTINOPTERYGII. the teeth apparently without vertical successors. Notochord per- — sistent, destitute of ossifications in its sheath, Fin-rays robust, the majority well-spaced and articulated; fulcra absent, except — perhaps quite at the base of the caudal fin; dorsal and anal fins more or less extended. Scales rhombic when present, frequently wanting on the whole or part of the caudal region; almost in- variably strengthened by the inner rib on their anterior margin and united by a peg-and-socket articulation in connection there- with. The cranial osteology of the Pycnodont fishes is as yet very imperfectly known. ‘The little information available suggests that there was as much variation in this group as in certain aberrant tribes of modern fishes, such as the Plectognaths and Gymnodonts ; and in any general description it is therefore necessary to state precisely in which: genus or genera several of the characters have been observed. When this statement is not made in the following account, the character in question has been met with very widely and may be regarded as normal in the family. The best-preserved specimens hitherto obtained are those of Mesturus leedsi from the Oxford Clay of Peterborough. The laterally-compressed examples of Gyrodus and Mesodon, from the Lithographic Stone of Bavaria and France, are also important; while the unique specimen of Ano- mocodus willett: from the Sussex Chalk (see p. 263) reveals for the first time the pterygo-palatine arcade. The chondrocranium is well ossified and always completely covered with membrane-bones, there being no vacuities in the cranial roof. The basicranial axis is more or less parallel with the roof behind the angulation of the frontal profile, and is then bent sharply downwards to the dentigerous oral face of the vomer ; while the latter is finally directed in a plane almost parallel with the first. The axis of the skull as a whole is directed downwards and forwards, making a considerable angle with the axis of the trunk. Of the chondrocranial elements, only the postfrontal (sphenotic), mesethmoidal, and supposed basisphenoidal bones have hitherto been clearly observed. The postfrontal in Mesturus is small and does not appear on the cranial roof; nor is there any external ornamented plate fused with its outer face. Its lower extremity meets the basipterygoid process of the parasphenoid in a deeply interdigitating suture; while its posterior outer face takes part in the facette for the upper end of the hyomandibular. The meseth- moid is always conspicuous as a deep thin lamina extending torwards from the anterior border of the orbital cavity and articulating below a reek PYCNODONTID &. 191 with the median ridge on the superior aspect of the coalesced vomers : it can be distinguished from this plate by the arrangement of its structural fibres, which are directed downwards and forwards instead of horizontally, and it never projects in advance of the vomers in the rostrum. There is no ossified interorbital septum. It is evident from several specimens, notably Anomeodus willetti and Mesturus leedsi, that the base of the cranium bears a delicate, laminar, median vertical keel extending as far forwards as the orbit ; but the only precise information concerning the basicranial axis has been obtained from specimens of Mesturus leedsi. The basiocci- pital is unknown, but a detached element, evidently chondrocranial, in no. P. 6834 recorded below, fits well on the hinder margin of another bone in the same fossil which is proved to be parasphenoid. It may therefore be determined as basisphenoid, and is noteworthy as occupying a considerable length of the basicranial axis. It is longer than broad, exhibits a median longitudinal keel below, and is narrowest at its hinder end; while the lateral margins form sharp edges, each apparently notched near its anterior end, and a pair of large foramina pierce the bone obliquely near its middle. The parasphenoid is remarkable for its shortness, not extending backwards beyond the front edge of the supposed basisphenoid. The main part of the bone is short, stout, and broad, with a median longitudinal keel below ; and its basipterygoid processes are short, with the very coarsely dentated articular end already mentioned. At the front extremity of the otic region this broad bone is abruptly truncated, its inferior keel terminates in a roughened pointed knob, and the element continues merely as a narrow slender median bar across the region of the orbit; towards the front of the orbit in many fossils a vertical median lamina is observed to rise gradually on its superior face to meet the ascending plate of the coalesced vomers. The latter form one very stout, bilaterally symmetrical bone extending to the anterior end of the rostrum, where they are overlapped by the small premaxille. The arrangement of the membrane-bones (or dermal plates) of the cranial roof is not quite constant, and there is much irregularity especially in the superficial elements covering the ethmoidal region. As shown by Mesturus (fig. 30), the posterior median element of the roof is bilaterally symmetrical and unpaired, and may therefore be named supraoccipital (s.occ.). The frontals (fr.) are the largest plates, always conspicuous and readily identified between the orbits, and varying in length according to the shape of the head. The otic region is covered by a single plate, which forms the postero- lateral angle of the roof and meets the frontal anteriorly, entering 192 ACTINOPTERYGII. to some extent the superior border of the orbital cavity; this in our nomenclature is evidently the squamosal (sq.). In the majority of Pycnodonts, the space between the supraoccipital, frontal, and squamosal elements is occupied on each side by a single parietal Fig. 30. orb tr fr SUM [res COE Mesturus leedsi; diagram of bones ot cranial roof, superior aspect, from a specimen in jthe collection of Alfred N. Leeds, Esq., Eyebury.—Oxford Clay ; Peterborough. eth., ethmoidal plates; jfr., frontal; m.eth., median ethmoidal plate; orb., orbit; sg.,squamosal ; s.oce., supraoccipital; s.¢., supratemporal; 2, plates in parietal region. plate ; while this plate in' Mesodon, Microdon, Stemmatodus, Ceelodus, Paleobalistum, and Pycnodus exhibits a large posteriorly-directed process with digitate extremity, arising about the middle of its hinder margin and extending immediately beneath the scales of the trunk. In Mesturus leedsi, however, the parietal region is occupied hy two or more irregular plates on each side (v); and neither in this genus nor in Gyrodus is there any posteriorly-directed process. The ethmoidal plates, as shown in Mesturus leedsi, are most remark- able (eth.). The region in advance of the frontals is covered with polygonal tesseree, which extend even over the smooth premaxille ; PYCNODONTIDA. 193 and these tessere frequently fuse together. One median plate thus formed extends backwards between the anterior ends of the frontals, and these elements are sometimes entirely separated by it ; moreover, this median series is even continued further back by another azygous plate (m.eth.) which meets (or is fused with) the supraoccipital. The arrangement of azygous median plates in the cranial roof of Mesturus leedsi is thus suggestive of the corresponding plates in Acipenseroid fishes. In Coccodus ail the elements of the cranial roof are fused into one continuous shield. The cheek-plates are small, thin, and apparently without any very definite arrangement. In Mesturus aud G'yrodus one plate larger than the remainder, bounding the upper jaw, may be the maxilla; but it is delicate and toothless. The premaxille are a pair of small, deep and narrow bones, moderately thick, resting upon the anterior extremity of the vomer, and covered with the ethmoidal dermal plates. The postero-external border of each is notched, as if for the opening of the nasal capsule. The sclerotic capsule is often ossified. The hyomandibular is a long narrow lamina about twice as broad above as in its lower half, with a posterior process near its upper end for the support of the operculum (Pl. XVI. fig. 3, hm.) ; but nothing is known of its connections below. The pterygo-palatine arcade is delicate and toothless, and is shown both in Anomaodus willettc and Mesturus leedsi to have been directly fused for a considerable distance with the edge of the basicranial axis. The thickened articular end of the quadrate is turned forwards so that the facette for the mandible is in a vertical plane; and this facette is irregularly oval, deeper than broad, and slightly concave. The free border of the ectopterygoid is concavely arched; and there is not much doubt that a distinct symplectic element was apposed to the hinder margin of the quadrate, though this still remains to be definitely proved. The two rami of the mandible are separate at the symphysis, and in Mestwrus leedsi each is observed to consist of five elements. The proximal end of the meckelian cartilage is distinctly ossified as an articular bone; and there is a very large splenial element within, while three more delicate splints appear without. The splenial is much the largest and stoutest bone in the jaw, meeting its fellow of the opposite side at the symphysis and well covered with a pavement of teeth on its oral face. It is exposed on the outer aspect of the entire margin of the ramus behind the short oral border of the dentary, and rises pos- teriorly into a large coronoid process. The dentary is comparatively insignificant, thin, deep and narrow, meeting its fellow at the PART III. 0 194 ACTINOPTERYGII. symphysis, and bearing a row of prehensile teeth. An angular plate, though not extending upwards quite to the oral border, completes the posterior part of the outer face of the mandibular ramus ; and its hinder ascending portion meets a small coronoid bone, with which it frequently becomes fused. The hyoid elements are not satisfactorily known, though in Mesturus verrucosus a short and deep ceratohyal with a small hypohyal is evidently observed (Pl. XVimion chi y ne The opereular and branchiostegal apparatus is remarkably reduced. The operculum is relatively small, deep, and narrow, truncated above where it meets the postero-lateral edge of the cranial roof, and tapering below to a point. This bone has hitherto been named “supraclavicle,” but its true nature is indicated both by a specimen of Gyrodus heaagonus (Pl. XVI. fig. 3) and by one of Mesturus leedsi (no. P. 6834), The preoperculum (commonly termed ‘“‘ operculum”) is very large, triangular in shape and much expanded below; its mode of attachment to the mandibular sus- pensorium is indicated in the specimens both of Anomeodus willetti and Gyrodus hexagonus already referred to. The suboperculum and interoperculum are wanting; and only two branchiostegal rays have been observed immediately below the preoperculum in Mesturus leedsi and in Gyrodus frontatus (Pl. XVI. fig. 2). In Gyrodus and Mesturus the space between the rami of the mandible is completely covered with small polygonal tesseree, there being no gular plate. On the branchial arches, long and slender calcified gill-filaments, more or Jess denticulated, are often observed. Teeth are confined to the vomer, splenial, premaxilla, and dentary. They are all hollow, with a short base firmly anchylosed to the supporting bone; and the present writer has never observed any provision for replacement. The only suspicion of such an arrange- ment is afforded by the Oxfordian specimens of Mesturus leedsi. The teeth of the premaxilla and dentary are prehensile and arranged in a single series ; those of the vomer and splenial are tritoral and form an extended pavement. Anteriorly the teeth of these pave- ments are nearly equal in size and do not exhibit any very definite arrangement; but posteriorly as a rule they soon become differ- entiated and disposed in regular longitudinal series of more or less different sizes. Appearances suggest that the splenial and vomerine elements are continually being lengthened by growth behind, the only new teeth obtained during the life of the animal being those added in this manner. If so, it is much the same kind of growth as that which takes place in the dentition of the Cochliodontid and Myliobatidee among Elasmobranchs: the only differences being due =a PYCNODONTID®. 195 to the presence of a bony base in the one case and its absence in the other. Moreover, in comparing the detached vomers and splenials of Pycnodonts, the smaller specimens cannot be compared as a whole with the larger ones—they must be compared only with that portion of the latter which happens to be of corresponding size. The notochord is always persistent, and no ossifications which can be ascribed to its sheath have hitherto been observed. The neural and hemal arches, however, are invariably well-ossified, and their bases are so much expanded that they sometimes (Palco- balistum, Pycnodus) completely encircle the notochord. Libs are present ; and those of Gyrodus and Paleobalistum are distinctly observed to exhibit the laminar expansion so characteristic of the neural spines throughout the trunk and of the hemal spines in the caudal region. This expansion is commonly confined to the anterior edge of each spine, but in Gyrodus and Paleobalistumn it occurs both anteriorly and posteriorly ; and in the last-mentioned genus the laminz of adjacent spines are actually united for a considerable length in a jagged suture. The neural spines in the abdominal region extend to the dorsal margin of the fish, and are often thickened apparently for the support of the ridge-scales. The heemal spines supporting the caudal fin are also more or less expanded, but never fused together. No intermuscular bones have been seen. The precise mode of suspension of the pectoral arch to the cranium still remains to be discovered; but the clavicle is well known, and some specimens of Gyrodus appear to exhibit a supra- clavicle extending towards the back of the cranial roof. The clavicle is much vertically elongated, tapering above, and with a spatulate expansion below ; a very small surface is exposed on the flank of the fish. There is no infra-clavicle. The scapula and coracoid cannot yet be described, but the pectoral fin is attached just above the inferior expansion of the clavicle. The base of this fin forms a little lobe, distinctly covered with thin rounded scales in Gyrodus; and a single series of seven or eight basals can be readily counted in specimens both of Gyrodus and Palcobalistum, while some vacant space may have been occupied by still more of these elements. The pelvic fins, though often quite rudimentary, are exhibited in all the genera of which the trunk is satisfactorily known. The rays of the dorsal and anal fins are equal in number to their supports, which are more numerous than the vertebral arches in the same region; but each fin-ray is sometimes liable to be subdivided into its right and left halves by crushing, and there 02 196 ACTINOPTERYGII. is then a false appearance of multiplicity of rays. All the rays are more or less articulated, and they also usually bifurcate; but there are no traces of fulera, unless a few short, undivided basal rays at the origin of the caudal fin are placed in this category. The scales are all quadrangular and somewhat deepened on the flank. Their anterior margin is strengthened by a vertical inner rib, which forms a peg-and-socket articulation to unite the scales of each transverse (vertical) series; and there is one exceptional instance (Mesturus) in which this union is still further strengthened by an interlocking jagged suture of the superposed upper and lower margins. ‘The series are for the most part regular; but in Mesturus there are a few, short, irregular intercalary series both dorsally and ventrally, while in this genus, Gyrodus, and Palwobalistum there is a fine subdivision of the scales at the base of the dorsal and anal fins. When the squamation degenerates on the caudal region, it does not appear to pass through the stage represented in the Dapedioid genus Aetheolepis (see p. 157); the rhombic scales seem to disappear directly without first becoming cycloidal, for remnants of their anterior thickened rib are often observed on the otherwise naked tail. The “lateral line ” extends along the flank from the outer supratemporal to the middle of the caudal pedicle ; and there is also always an upper canal passing along the top of the flank to the origin of the dorsal fin. The ridge-scales are usually small and inconspicuous; but in Palwohalistum and Pycnodus those of the ventral ridge appear to have considerably extended limbs. The hinder end of the abdominal cavity is nearly always marked by a long, curved bone, extending from a slight expansion at the ventral border just in advance of the anal fin, and tapering to a point immediately below the notochordal axis. In Gyrodus (Pl. XVI. fig. 2, v) this has much the aspect of an azygous internal bone (as described by B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. 1881, p. 36); while in Celodus, Paleobalistum and Pycnodus it appears rather asa great paired dermal scute (as described by J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. 1856, pp. 216, 221,241). The elementis certainly not an enlarged support of the anal fin, and has no connection with the pelvic fins. It must still remain problematical. In arranging the genera of Pycnodonts, the presence or absence of scales on the caudal region cannot be regarded as of prime importance, owing to the uncertainty of the character in some degree in Microdon and in a greater degree in Palcobalistum. Specialization seems to result chiefly (1.) in the strengthening of the backbone by the inteflocking of its arches; (ii.) in the reduc- PYCNODONTID &. 197 tion of the tritoral teeth to a fixed arrangement in regular longi- tudinal series ; and (ii1:) in the obliteration of the indent for the meckelian cartilage on the attached face of the splenial bone. Very rarely (Coccodus, Xenopholis) a spinous dermal armour is also developed. Finally, we venture to recognize one case of degeneracy of the tritoral dentition (Anomeodus).: Synopsis of Genera. J. Neural and hemal arches of axial skeleton of trunk not expanding sutiiciently to encircle the notochord. (a.) Number of longitudinal series of teeth on splenial bone inconstant; caudal fin rounded ; no dermal spines. Vomerine teeth in five longitudinal series, sometimes irregular laterally ; splenial dentition comprising one regular principal series, with three or more outer series and one or two inner series, usually irregularly arranged ; * scales tuberculated, confined to region in advance of median fins .......... Mesodon (p. 199). [Splenial dentition as in Mesodon, but usually much more irregularly ar- ranged, and the principal longitudinal series not well-differentiated; the splenial bone much stouter, and with a remarkably deep symphysial facette; HslMlnOwn -. 0. 2.8. yest. gett Athrodon (p. 215).] Vomerine teeth in three regular longitu- dinal series, with irregular interme- diate series; splenial dentition with two regular series separated by small teeth, and flanked within by other small teeth ; scales covering whole of trunk, united above and below with JAR EEC SL LIRES BR Cinean inne a Sori Mesturus (p. 218). (4.) Number of longitudinal series of teeth on splenial bone constant; caudal fin forked ; no dermal spines. Vomerine teeth in five longitudinal series, the inner lateral pairs regularly alter- nating with the widely-spaced median teeth; splenial teeth in four regular series ; Squamation confined almost or completely to region in advance of BISCIAD Is Sours Sores wae gttehs oe a Microdon, p. 221). 198 ACTINOPTERYGII. Vomerine teeth in five, and splenial teeth in four regular longitudinal series ; scales covering whole of trunk, and none united with jagged sutures .... Vomerine teeth in five, and splenial teeth in three regular longitudinal series ; squamation confined to region in advance of median tins; caudal fin scarcely forked). waseeee es ees Oral surface of vomer convex from side to side, and teeth in five regular longi- tudinal series; splenial teeth in three series, the outer sometimes in part subdivided, the inner sometimes irregularly supplemented ; squamation confined to region in advance of medial 11s Co: ceperiect meee eer one (c.) Splenial dentition comparatively degene- rate, restricted to a space well within outer margin, and number of longitu- dinal series inconstant ; no dermal spines. Vomerine teeth irregular, in from three to five longitudinal series; squamation confined to region in advance of median ins: -.. spa bieeyes ee serie c (d.) Abnormal genera with median occipital spine, and more or less spinous pectoral arch. Vomerine teeth apparently in five, and splenial teeth in three regular longi- tudinal series ; clavicular spines large ; Scalles wattle: cus i) pare ae Imperfectly known, but greater portion of trunk covered with large, rhombic, keeled Seutes:\.40r y eeee eee ee II. Neural and hemal arches of axial skeleton of trunk expanding and completely encir- cling the notochord. Vomerine teeth in five, and splenial teeth in three regular longitudinal series; caudal pedicle very short, and fin fan-shaped ; Squameation variable (1), crore reas Dentition asin Paleobalistum ; caudal pedicle slender and fin slightly forked ; squama- tion confined to region in advance of LE CUVATA HAIRS acces so iia a ib ale koin a leet ate tae Gyrodus (p. 233). Stemmatodus (p. 248). Coelodus (p. 249). Anomeodus (p. 258). Coccodus (p. 266). Aenopholis (p. 269). Paleobalistum (p. 270). Pycnodus (p. 275). ee ee PYCNODONTIDZA. 199 Genus MESODON, Wagner’. [Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. 1851, p. 56.] Syn. (?) Typodus, F. A. Quenstedt, Der Jura, 1858, p. 781. Trunk discoidal, not produced at the caudal pedicle. Head and opercular bones externally ornamented with granulations; cleft of mouth very oblique; teeth smooth, or with feeble indentation and ruge; vomerine teeth arranged in five longitudinal series, the lateral pairs being often irregular; splenial dentition comprising one principal series of teeth with three or more outer series and one or two inner series, usually irregularly arranged. Neural and hzmal arches of axial skeleton not sufficiently expanded to meet round the notochord. Fin-rays robust, closely articulated, and much divided distally. Pelvic fins present; dorsal and anal fins deep throughout their extent, the former occupying the hinder half of the back, and the latter somewhat shorter; caudal fin fan- shaped, having a convex hinder margin, and arising immediately between the posterior extremities of the dorsal and anal fins. Scales robust, ornamented with granulations, and occupying only the anterior half of the trunk. Of this genus many species are known only by the dentition, and in that case they cannot be satisfactorily defined. The form of the teeth is especially variable, but the number and relative proportions of the several series appear to be sufficiently constant for noting in provisional definitions. Mesodon macropterus (Agassiz). [Plate XVI. fig. 1.] 1834-44. Gyrodus macropterus, L. Agassiz, Poiss. Foss., Feuill. p. 18, and vol. ii. pt. ii. p. 301. 1851. Mesodon macropterus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. pp. 49, 56, pl. iv. fig. 2. 1856. Mesodon macropterus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 202. 1862. Mesodon macropterus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 849. 1887. Mesodon macropterus, K. A.von Zittel, Handb. Paleont. vol. ii. p- 247, fig. 261. Type. Nearly complete fish ; Palzeontological Museum, Munich. The type species, attaining a length of about 0°16. Maximum 1 This name having gained universal acceptance, we adopt it, notwith- standing its preoccupation among Mollusca by Mesodon, Rafinesque, 1819. 200 ACTINOPTERYGII. depth of the trunk nearly equal to the length of the head and trunk without caudal fin ; distance from frontal angulation to hinder margin of preoperculum equalling about one-quarter of the total length of the fish. [Dentition imperfectly known, but] teeth smooth, some indented, and those of the principal mandibular series at least twice as broad as long. Dorsal and anal fins equally elevated, the latter with about 30 rays and four-fifths as long as the former, which has 35 rays. Squamation covering less than half of the trunk; ridge-scales coarsely serrated, each on the ventral aspect with about six points. It seems probable that the so-called Mes.don gibbosus * is founded upon a small, distorted fish of this species. The original specimen is in the Paleontological Museum, Munich, and was obtained from the Lithographic Stone of Kelheim. ‘Three other small fishes from Hichstadt, in the same Museum, also probably the young of M. macropterus, bear the name of M. pulchellus (A. Wagner, loc. cit. vol. ix. 1862, p. 351). Another dwarf variety, from the Middle Purbeck of Teffont, Wiltshire, is named M. macropterus, var. parvus (A. 8S. Woodward, Geol. Mag. [4] vol. ii. 1895, p. 147, pl. vu. fig. 2). Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. P. 5546. Well-preserved fish 0-14 in length, shown of two-thirds the natural size in Pl. XVI. fig. 1; Eichstiidt. As shown in side view, the basicranial axis is bent sharply downwards at the front of the orbit (0.) to the dentigerous vomer (v.); and some of the sutures in the cranial roof can be dis- tinguished. The limits of the supraoccipital (s.occ.), squamosal (sq.), and parietal ( pa.) plates are quite clear, and the latter element bears a large process (a) on its hinder margin, this directed backwards and subdivided into digitations at the extremity. The operculum (op.) and preoperculum (p.op.) are imperfect, but their relative proportions and characteristic radiating markings are seen. Some of the long hour-glass-shaped basals (6.) in the pectoral fin can also be observed. There are no scales on the caudal region, and the endoskeleton is thus well exposed. By exchange, 1888. 1 A. Wagner, Abk. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. (1851), pp. 52, 56, pl. iii. fig. 2. Gyrodus gibbosus, L. Agassiz, Poiss. Foss. vol. ii, pt. ii. 1844, p. 236 (name only, ex Minster, MS.). A distorted specimen of Mesodon from the Lithographic Stone of Cir, Ain, France, is also described under the same specific name by V. Thiolliére, Poiss. Foss. Bugey, pt. ii. (1878), p. 13, pl. ii. fig. 12. PYCNODONTID®. 201 37109. Imperfectly preserved similar fish, the head in counterpart and displaying part of the left splenial dentition; Solen- hofen. There are traces of the tubercular ornament on the scales, and the serration of the ventral ridge-scales is conspicuous. Haberlein Coll. P. 1628. Portion of caudal region of a somewhat larger fish; — Kelheim. Egerton Coll. 37107. Small, nearly complete specimen, 0-07 in length, in counter- part; Solenhofen. The premaxille are shown, and the course of the dorsal “lateral line” is conspicuous on the squamation to the origin of the dorsal fin. Hdberlein Coll. Mesodon daviesi, A. S. Woodward. 1890. Mesodon daviest, A. S. Woodward, Proc. Zool. Soc. 1890, p. 351, pl. xxviii. fig. 5. Type. Nearly complete fish ; British Museum. A species attaining a length of about 0°25. Maximum depth of the trunk somewhat less than the length of the head and trunk without caudal fin; distance from frontal angulation to hinder margin of preoperculum scarcely exceeding one-fifth of the total length of the fish. [Dentition imperfectly known, but] teeth smooth, some indented, and those of the principal mandibular series at least twice as broad as long. Dorsal and anal fins equally elevated, the latter with 29 rays and four-fifths as long as the former, which has 38 rays. Squamation not covering more than half of the trunk. Form. & Loc. Purbeckian: Dorsetshire. 41387, P. 6381. Type specimen, with incomplete counterpart ; Purbeck Beds, Swanage. Purchased, 1869, and Beckles Coll. P. 7454. Remains of head and abdominal region, doubtfully of th species; Swanage. The principal teeth of the mandible are more transversely elongated than those in the type specimen. Mistory unknown. P. 6383. Portion of caudal region of small fish, probably young of this species; Swanage. Beckles Coll. The following specimen agrees with the type of Mesodon daviese in the form and proportions of the trunk, but the head is relatively as long as in Mesodon macropterus. The difference is probably due to crushing. 202 ACTINOPTERYGII. P. 4381. Nearly complete fish 0°13 in length, wanting the paired fins; Purbeck Beds, Swanage. Eaniskillen Coll. Mesodon simus, Sauvage. 1893. Mesodon simus, H. E. Sauvage, Bull. Soc. Hist. Nat. Autun, vol. vi. p. 441. Type. Nearly complete fish. A species described by Sauvage as closely resembling WM. daviesi, but differing in the somewhat more elongated form of its trunk. Form. & Loc. Lower Kimmeridgian: Orbagnoux, Ain, France. Not represented in the Collection. Mesodon comosus, Thiollicre. 1858. Mesodon comosus, V. Thiolliére, Bull. Soc. Géol. France, [2] vol. xv. p. 783 (name only). 1873. Mesodon comosus, P. Gervais, in V. Thiolliére, Poiss. Foss. Bugey, pt. ii. p. 13, pl. 11. fig. 1. Type. Fish, wanting head ; Lyons Museum. A species as large as M. daviesi, distinguished from all known forms by its remarkably short and deep dorsal and anal fins. Dorsal fin with about 27, anal fin with not less than 22 rays, Squamation covering much more than half of the trunk. Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Cirin, Ain, France. Not represented in the Collection. Mesodon liassicus (Egerton). 1854, Pycnodus lassicus, Sir P. Egerton, Ann. Mag. Nat. Hist. [2] vol. xiii. p. 486. 1855. Pycnodus liassicus, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains (Mem. Geol. Sury.), dec. viii. no. 10, pl. x. 1856. Mesodon liassicus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 202. Type. Imperfect fish; British Museum. An imperfectly known small species, about 0°13 in length. Maximum depth of the trunk less than the length of the head and trunk without caudal fin. Teeth smooth. Ornamentation of scales and external bones consisting of closely arranged, large, flattened tubercles. Form. & Loc. Lower Lias: Leicestershire, Somersetshire, and Gloucestershire. 19864. Type specimen ; Barrow-on-Soar, Leicestershire. Purchased, 1846. ‘ PYCNODONTID 2. - 203 P. 1336. Smaller imperfect head and trunk, wanting the greater part of the fins ; Tarnhill, Tewkesbury, Gloucestershire. Egerton Coll. P. 5127. Very small imperfect trunk, with abraded scales showing the tubercular ornament in part; Langport, Somerset- shire. Purchased, 1886. Mesodon rugulosus (Agassiz). 1825. Figure by C. Prevost, Ann. Sci. Nat. vol. iv. pl. xviii. fig. 18. 1837. Pycnodus trigonus, W. Buckland, Geol. & Mineral., ed. 2, vol. ii. p. 45, pl. xxvil. ec. fig. 3. 1839-44, Pycnodus rugulosus, Lu. Agassiz, Poiss. Foss. vol. ii. pt. il. p. 194, pl. Ixxii. a. fig. 23. 1839-44. Gyrodus trigonus, L. Agassiz, ibid. p. 232, pl. lxix. a. fig. 19. [Vomer; British Museum]?. | 1840. Pycnodus rugulosus, R. Owen, Odontography, pl. xxxiv. fig. 1. 1844. Microdon trigonus, L. Agassiz, Tableau Gén. Poiss. Foss. p. xlil. (name only), 1844. Pycnodus parvus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 199 (name only). [Mandibular dentition; British Museum. |] 1844. Pycnodus trigonus, L. Agassiz, zbid. p. 199 (name only). 1844. Pycnodus latirostris, L. Agassiz, ibid. p. 199. [Mandibular dentition ; British Museum. | (?) 1871. Pyenodus rugulosus, J. Phillips, Geol. Oxford, p. 179, woodc. ex. te I, 1871. Gyrodus trigonus, J. Phillips, ibid. p. 179, woode. xxxix. fig. 7. 1889. Mesodon rugulosus, A. 8. Woodward, Geol. Mag. [3] vol. vi. p. 404. 1889. Mesodon trigonus, A. 8S. Woodward, thd. p. 454. 1890-92. Mesodon rugulosus, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p. 298, pl. ili. figs. 23-27, and zbrd. vol. xii. p. 239, pl. iv. figs. 2-4. Type. Vomerine dentition ; Oxford Museum. A species of large size, known only by the head. External bones ornamented with coarse granulations, closely arranged ; maximum width of preoperculum exceeding half itsdepth. Teeth ornamented with a feeble rugosity radiating from an annular apical indentation, soon removed by abrasion; outline of teeth usually regularly rounded. Vomerine teeth closely arranged, those of the median series considerably broader than long and their breadth about equal to that of the two lateral series; an incomplete supplementary * A vomer from the Bathonian of Pernigotti, Verona (de Zigno Collection, University of Padua), is also recorded under this name by F. Bassani, Atti Soe. Ital. Sci. Nat. vol. xxviii. (1885), p. 161. 204 ‘ACTINOPTERYGII. series of small teeth occurring on each side. Splenial teeth closely arranged, those of the principal series considerably broader than long, flanked within by one irregular row of small round teeth and externally by three series, of which the outermost scarcely exceeds the innermost in size. Form. & Loc. Bathonian: Northamptonshire, Oxfordshire, and Gloucestershire; Normandy '. 38554. Imperfect large vomer ; locality unknown. Purchased, 1864. 42274. Smaller vomerine dentition, less abraded ; locality unknown. Baugh Coll. 35498. Vomerine dentition 0°02 in length ; Stonesfield Slate, Stones- field. Purchased, 1860. / P. 1648-a. Similar specimen and one smaller; Stonesfield. Egerton Coll. 32550. Plaster cast of imperfect vomerine dentition; Great Oolite, Caen, Normandy. Lesson Coll. P. 3779. Small vomerine dentition described and figured by Agassiz, loc. cit., as the type specimen of Gyrodus trigonus ; Stones- field. Enniskillen Coll, P. 521. Smaller specimen noticed by Agassiz, loc. cit., and figured in Proc. Geol. Assoc, vol. xi. (1890), pl. iii. fig. 265 Stonesfield. Egerton Coll. P. 4387. Right splenial dentition, much broken ; Stonesfield. Enniskillen Coll. 1370 (Sloane Catalogue). Smaller specimen, right side; Witney, Oxfordshire. Sloane Coll. P. 1666 c. Smaller right splenial ; Stonesfield. Egerton Coll. P. 522. Small right splenial dentition, labelled “ Pycnodus parvus, Ag.,” in Agassiz’ handwriting, described and figured in Proc. Geol. Assoc. vol. xi. (1890), p. 299, pl. i. fig. 23; Stonesfield. Egerton Coll, P. 3780-81. Slightly larger examples of the right and left splenial dentition, the first labelled ‘‘ Pycnodus latirostris, Agass.,” 1 A very similar though not identical dentition is also known from the Kimmeridgian of Hanover (K. Fricke, Palzontogr. vol, xxii. 1875, p. 362, pl. xix. figs. 6, 7). | PYCNODONTIDZ. 205 in Agassiz’ handwriting, described and figured in Proc. Geol. Assoc. vol. xi. (1890), p. 299, pl. iil. fig. 27 ; Stones- field. Enniskillen Coll. P. 1666. Similar splenial dentition of left side; Stonesfield. Egerton Coll. P. 3734. Four more imperfect small examples of the splenial den- tition ; Stonesfield. Enniskillen Coll. Mesodon bucklandi (Agassiz). 1833-44. Pycnodus bucklandi, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p- 16, pt. ii. p. 192, pl. lxxii. a. fig. 15 (non figs. 16-22). 1839-44. Pycnodus didymus, L. Agassiz, zbed. p. 198, pl. lxxii. a. figs. 24, 25. [Mandibular dentition; British Museum. | 1839-44. Pycnodus ovalis, L. Agassiz, ibid. p. 195, pl. lxxil. a. fig. 5. [ Vomerine dentition ; Bristol Museum. |] 1840. Pycnodus bucklandi, R. Owen, Odontogr. pl. xxxiv. fig. 2. 1840. Pycnodus didymus, R. Owen, 26d. pl. xxxiv. fig. 3. 1844. Pycnodus obtusus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 199 (name only). [Vomer; British Museum. | 1871. Pycnodus bucklandi, J. Phillips, Geol. Oxford, p. 179, woode. xxxix. figs. 4, 5. 1871. Pycnodus didymus, J. Phillips, abd. p. 179, woode. xxxix. fig. 6. 1885. Mesodon bucklandi, F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxviil. p. 160. 1889. Mesodon bucklandi, A«S. Woodward, Geol. Mag. [3] vol. vi. p. 404. 1890. Mesodon bucklandt, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p- 297, pl. ii. figs. 20-22. Type. Vomerine dentition ; Oxford Museum. A species of large size, known only by the dentition. Teeth smooth, often irregular in outline, the rounded contour being. fre- quently interrupted by angulations. Vomerine teeth well spaced ; those of the median series, except quite anteriorly, less than twice as broad as long, but their breadth exceeding that of the two lateral series; teeth of the inner lateral series much larger than those of the outer series, not regularly alternating; a few small scattered teeth also occurring irregularly between the median and inner lateral series. Splenial teeth well spaced, those of the principal series almost twice as broad as long, flanked within by a single row of small rounded teeth and externally by three regular series, of which the second only equals the innermost row in size, while the first is slightly larger, and the third (or outermost) much larger than all except the principal series. 206 ACTINOPTERYGII. Form. & Loc. Bathonian: Oxfordshire, Wiltshire, and North- amptonshire ; (?) 8. Bartolomeo, Verona, Italy. P. 1640. Vomerine dentition figured in Proc. Geol. Assoc. vol. xi. pl. ii. fig. 20; Stonesfield Slate, Stonesfield. Egerton Coll. P. 1646. More imperfect large specimen ; Stonesfield. Egerton Coll P. 525. Fragment of similar dentition, the undescribed type specimen of Pycnodus obtusus, Agassiz, figured in Proc. Geol. Assoc. vol. x1. pl. ii. fig. 22 ; Stonesfield. Egerton Coll. P. 3739. Portion of smaller vomerine dentition; Forest Marble, Atford, near Bath. Enniskillen Coll. P. 1647. Portion of still smaller specimen; Stonesfield. Egerton Coll. 39776. Small vomerine dentition, the teeth more closely arranged than usual; Stonesfield. Purchased, 1862. 47982. Vomerine dentition 0:018 in length ; Stonesfield. Presented by the Hon. Robert Marsham, 1877. P. 3733. Smaller specimen; Stonesfield. Enniskillen Coll. P. 3732. Left splenial dentition, the type specimen of Pycnodus didymus, described and figured by Agassiz, loc. cit. ; Stonesfield. Enniskillen Coll. P. 3736. Similar specimen, fractured and in counterpart; Stones- field. Enniskillen Coll. P. 1641. Slightly smaller right splenial dentition, showing only the bases of the teeth; Stonesfield. Egerton Coll, P. 1649, P. 1666 a, b. Five small examples of the splenial dentition, one in counterpart ; Stonesfield. Egerton Coll. P. 1652. Imperfect left splenial dentition apparently of this species, labelled ‘* Pycnodus Hugu, Ag.,” by Agassiz ; Stonesfield. Ligerton Coll. The following scales are referable either to this or to the preceding species :— P. 520, P. 3776-77. Type specimens of the so-called Gyrodus per- latus, Agassiz (Poiss. Foss. vol. . pt. 11. 1844, p. 236), PYCNODONTID#. 207 being four scales, of which the first two are described and figured by the present writer in Proc. Geol. Assoc. vol. ix. (1890), p. 297, pl. 11. figs. 30, 31; Stonesfield Slate, Stonesfield. Egerton & Enniskillen Colts. Mesodon'‘tenuidens, A.S. Woodward. 1890. Mesodon tenuidens, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p- 300, pl. ii. fig. 29 (erroneously named Jatedens in text). Type. Right splenial dentition ; British Museum. A small species known only by the splenial dentition. Teeth finely rugose, with a transversely elongated apical pit; all or nearly all the teeth broader than long. Principal teeth on splenial bone at least twice as broad as long, arched, and inwardly tapering ; this series flanked within by one row, and externally by four rows of small teeth passing forwards into two rows. Form. & Loc. Bathonian: Oxfordshire. 47983. Type specimen; Stonesfield Slate, Stonesfield. Presented by the Hon, Robert Marsham, 1877. _ Mesodon levior, Fricke. 1846. Pycnodus didymus, G. von Minster (errore), Beitr. Petrefakt. pt. vu. p. 41, pl. i. fig. 26, pl. iil. fig. 6. (?) 1864. Pycnodus hug, H. Credner (errore), Zeitschr. deutsch. geol. Ges. vol. xvi. p. 244, pl. xi. fig. 7. 1875. Mesodon levior, K. Fricke, Paleeontogr. vol. xxii. p. 364, pl. xix. figs. 9-12, pl. xx. figs. 1, 2. Type. Splenial dentition. A species of moderate or large size, known only a the dentition. Teeth irregularly rounded in outline, with an apical pit very shallow in the principal series, and with feeble radiating ruge. Vomerine teeth closely arranged; those of the median series not much broader than long, and their breadth about equalling that of the two lateral series; outer lateral series scarcely smaller than the inner, and often flanked by an incomplete supplementary row of minute teeth. Teeth of principal series on splenial bone much broader than long and inwardly tapering; flanked within by one continuous and one incomplete series of small teeth; and flanked externally by three series, of which the inner equals the outer in size, and the median is sometimes in part duplicated. Form. & Loc. Upper Corallian and Kimmeridgian : Hanover." 1 The fragments from the Kimmeridgian and Portlandian of N. France ascribed to this species by Sauvage (Bull. Soc. Géol. France, [8] vol. viii. 1880, p- 529, pl. xix. fig. 4) appear to be incorrectly determined. 208 ACTINOPTERYGII, P. 3749. Vomerine dentition with comparatively nafrow median teeth ; Coral Rag, Lindnerberg, Hanover. Enniskillen Coll. P. 5950. Vomer, partly fractured, showing some of the unworn rugose teeth ; Coral Rag, Holzen, Eschershausen. Purchased, 1889. P. 7438. Fragments of two large vomers; Kimmeridgian, Lan- genberg. Purchased, 1895. P. 5951. Right splenial; Holzen. Purchased, 1889. P. 7436. Associated splenials ; Langenberg. Purchased, 1895. Mesodon granulatus (Minster). 1846. Pyenodus granulatus, G. von Miinster, Beitr. Petrefakt. pt. vii. p- 44, pl. ii. figs. 11, 12. 1846. Pycnodus juglert, G. von Minster, thd. p. 42, pl. iii. figs. 8-10. [Fragments of dentition ; Paleontological Museum, Munich. | (?) 1846. Pycnodus nicoleti, G. von Munster (errore), bid. p. 42. 1858. Pyknodus granulatus, F. A. Quenstedt, Der Jura, p. 782, pl. xevi. fio. 20. 1875. Mesodon granulatus, K. Fricke, Paleontogr. vol. xxii. p. 359, pl. xviii, pl. xix. figs. 1-5. (?) 1880. Mesodon granulutus, H. E. Sauvage, Bull. Soc. Géol. France, [3] vol. vill. p. 528, pl. xix. fig. 3. Type. Detached teeth ; Natural History Museum, Berlin. A large species, imperfectly known. External bones and scales ornamented with very coarse granulations. Teeth feebly rugose, those of the lateral series with an apical pit, and soon becoming smooth by abrasion; outline of teeth often irregularly rounded. Vomerine teeth sparsely arranged, those of the median series con- siderably broader than long, and their breadth equalling or slightly exceeding that of the two lateral series. Splenial teeth more closely arranged, those of the principal series often twice as broad as long, flanked within by one row of small round teeth and ex- ternally by three series, of which the median is the smallest (some- times partly duplicated) and the outer about equal in size to the inner series. This definition is based upon the researches of Fricke. Form. & Loc. Corallian and Kimmeridgian: Hanover, Wiirtem- berg, S. England, and (?) N. France. P. 1655. Portion of left splenial dentition; Corallian, Lindner- berg, Hanover. Egerton Coll. PYCNODONTID @. 209 P. 5102. More nearly complete specimen ; Lindnerberg. Presented by J. EH. Lee, Esq., 1885. 28506. Portion of left splenial dentition; Coral Rag, Schnaitheim, Wirtemberg. Purchased, 1847. 40636. Right splenial bone with much-worn teeth, doubtfully assigned to this species; Coral Rag, Weymouth. Purchased, 1867. P. 3786 d. Small right splenial closely resembling the specimen figured by Fricke, loc. cit. pl. xix. fig. 3; Kimmeridge Clay, Weymouth. Enniskillen Coll. P. 6748. Abraded portion of similar left splenial; Kimmeridge Clay, Weymouth. Purchased, 1892. P, 3741. Portion of small right splenial dentition; probably from the Coral Rag of Weymouth. Enmskillen Coll. Mesodon nicoleti (Agassiz). 1844. Pycnodus nicolett, L. Agassiz, Poiss. Foss. vol. i. pt. ii. p. 192, pl. Ixxi. fig. 14. 1860. Pycnodus nicoleti, F. J. Pictet, Rept. & Poiss. Foss. Jura Neu- chatelois, p. 55, pl. xii. figs. 1-3. 1879. Pycnodus nicoleti, H. KH. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. XxXxiil. pt. 1. p. 33, pl. 11. fig. 6. Type. Imperfect splenial dentition. A large species, known only by the dentition of the lower jaw, which appears to differ from that of M/. granulatus merely in the greater length of the principal teeth as compared with their breadth. Future discoveries must determine whether the two supposed species are truly distinct. None of the specimens in the Collection show more than one inner series and three outer series of small teeth on the splenial bone. Form. & Loc. Kimmeridgian: Switzerland; Yonne, France, - (?) Portlandian: Germany. P. 1644. Imperfect left splenial dentition, much worn ; Soleure. Egerton Coll. P. 3740. Two similar specimens; Soleure. Enniskillen Coll. P. 5292. Portion of left splenial dentition, showing the rugosity on one of the principal teeth ; Soleure. Presented by Her Grace the Duchess of St. Albans, 1876. PART III. P 210 ‘ ACTINOPTERYGII. P. 7437. Left splenial either of this or the preceding species ; Portlandian (zone of Ammonites gigas), Duingen, Harz. Purchased, 1895. Mesodon damoni, A. 8. Woodward. 1860. Pyenodus bucklandi, R. Damon (errore), Geol. Weymouth, Suppl. pl. vii. fig. 9. 1890. Mesodon, sp., Woodward & Sherborn, Catal. Brit. Foss. Verte- brata, p. 121. 1890. Mesodon damoni, A. S. Woodward, Geol. Mag. [3] vol. vii. p. 158. 1898. Mesodon damon, A.S. Woodward, cbzd. vol. x. pl. xvi. fig. 6. Type. Left splenial dentition ; British Museum. A large species, known only by the dentition of the lower jaw. Teeth rounded or closely arranged, smooth or very feebly rugose, without an apical pit. Teeth of principal series on splenial bone almost or quite twice as broad as long; teeth of the inner series considerably larger than any of the outer series, flanked within also by an irregular, incomplete row of small teeth; those of the outer Serles arranged in four irregular rows, variable in size, but the innermost and outermost usually the largest. Form. & Loc. Portlandian: Dorsetshire. P. 6165. Left splenial bone, the type specimen ; Portland. Damon Coll. P. 6180. Right and left splenial dentition, partly fractured, in slab of limestone ; Upway, near Weymouth. Damon Coll. P. 1642-3. Imperfect right and left splenials ; near Weymouth. Egerton Coll. P. 3738. Right splenial; near Weymouth. Enniskillen Coll. P. 4678. Fragmentary left splenial ; Ridgway near Weymouth. Presented by C. Westendarp, Hsq., 1884. Mesodon gigas (Agassiz). 1742. Dent de Dentato, L. Bourguet, Traité des Pétrifications, p. 78, pl. lvui. fig. 396. 1833-44. Pycnodus gigas, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 17 pt. 11. p. 191, pl. lxxi. fig. 13, pl. Ixxi. a. figs, 56-58. 1839. Pycnodus gigas, F. A. Roemer, Verstein. Norddeutsch. Ooli- thengeb., Nachtr. p. 54. 1860. Pycnodus gigas, F. J. Pictet, Rept. & Poiss. Foss. Jura Neu- chatelois, p. 46, pls. x., xi., pl. xviii. fig. 2. y) PYCNODONTID &. 2i-4 Type. Portions of splenial dentition ; Stuttgart Museum. The largest species hitherto discovered, known only by the splenial dentition. Teeth rounded and closely arranged, smooth or feebly rugose, with traces of a shallow apical pit only in the lateral series. Teeth of principal series at least twice as broad as long, scarcely if at all arched, and almost equally blunt at each extremity; imner series very small and irregular; outer teeth in four irregular series, largest and broader than long or reniform in the innermost of these, smallest in the second and third series, which are especially irregular. Form. § Loc. Kimmeridgian : Switzerland; N. Germany ’. P. 3742. Imperfect right splenial bone, with teeth of principal and first outer series; Neuchatel. Enniskillen Coll. P. 3743. Plaster cast of a nearly similar specimen, left side; Soleure. Enniskillen Coll. 28379. Imperfect right splenial dentition, of small size, doubtfully referable to young of this species; Soleure. The prin- cipal teeth are more arcuated than usual and nearly three times as broad as long; the inner teeth are minute; the second outer series of teeth is relatively larger than in the typical adult dentition. Purchased, 1853. P. 7440. Imperfect left splenial, with remains of dentary externally ornamented with fine tubercles ; Langenberg, Hanover. Purchased, 1895. Mesodon affinis (Pictet). 1860. Pyenodus affinis, F. J. Pictet (ex Nicolet, MS.), Rept. & Poiss. Foss. Jura Neuchatelois, p. 50, pls. xii., xii. b¢s, pl. xix. fig. 1. Type. Splenial dentition ; Neuchatel Museum. A species somewhat smaller than JZ. gigas, also known only by the mandibular dentition, which closely resembles that of the last- named species, differing (1) in the relatively larger size of the inner series of teeth, which is sometimes duplicated, and (2) in the relatively smaller size and rounded form of the teeth in the inner- most of the outer series. Form. & Loc. Kimmeridgian : Switzerland. * Detached teeth from the Kimmeridgian and Portlandian of Boulogne have also been assigned to this species by H. E. Sauvage, Catal. Poiss. Form. Second. Boulonnais (1867), p. 25; others from the Diceraskalk of Kelheim, Bavaria, by M. Schlosser, Palzeontogr. vol. xxviii. (1881), p. 58, pl. vil. figs. 4,5; others from the Tithonian of Verona, by F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxviii. (1885), p. 158, pl. ii. a. figs. 10, 11. P2 PAA ACTINOPTERYGII. P. 3745. Fragmentary right splenial bone; Soleure. Enniskillen Coll. The following portions of dentition appear to belong to the genus Mesodon, but are specifically undetermined :— 1370 a (Sloane Catalogue). Fragment of splenial dentition; Great Oolite, Witney, Oxfordshire. Sloane Coll. P. 3737. Fragment of splenial labelled “Gt. Oolite, Gibraltar, near Oxford,’ but much resembling the Portlandian Mesodon damont. Enniskillen Coll. 36141. Imperfect left splenial; Forest Marble, Atford, near Bath. Purchased, 1859, 36145. Well-preserved left splenial dentition, with only two com- plete outer series of teeth; Forest Marble, Stanton, Gloucestershire. Cunnington Coll. 46338. Imperfect left splenial with very smooth teeth; Forest Marble, Atford, near Bath. Cunnington Coll. 47139. Portion of small vomerine dentition ; Great Oolite, Buttock’s Booth, Northampton. Sharp Coll. 40353. Fine vomer with remarkably rounded teeth, the inner lateral series comparatively small and with minute inter- calary teeth (Pl. XVII. fig. 1); Great Oolite, Caen, Normandy. Purchased, 1867. 22659. Portion of large right splenial dentition ; Coral Rag, Schnait- heim, Wurtemberg. Purchased, 1848. 41869. Imperfect vomer with well-spaced teeth, those of the median series not much wider than long; Kimmeridge Clay, Wey- mouth. Purchased, 1869. P. 6169. Imperfect left splenial, figured by R. Damon, Geol. Wey- mouth, ed. 2 (1880), Suppl. pl. ix. fig. 11; Kimmeridge Clay, Weymouth. Damon Coll. P. 4391. Portion of small splenial ; Kimmeridgian, Soleure, Switzer- land. Enniskillen Coll. 30870. Portion of vomer with closely arranged teeth, those of the median series nearly twice as broad as long; Portland Stone, Ridgway, near Weymouth. Purchased, 1856. 21349. Left splenial dentition, with principal teeth much elongated transversely ; Purbeck Beds, Swanage. Purchased, 1847. PYCNODONTID&. 213 P. 3757. Another specimen with more numerous flanking teeth ; Purbeck Beds, Swanage. Enniskillen Coll. 35577. Portion of left splenial apparently of a large species of Mesodon, with numerous small lateral teeth ; Lias, Camer- ton, near Bath. The bone measures about 0:025 in maximum width, and the teeth of the pee series are somewhat broader than long. Presented by Hugh Owen, Esq., 1859. The following species have also been founded on portions of dentition, of which there are no examples in the Collection :— Mesodon autissiodorensis: Pycnodus autissiodorensis, H. KE, Sau- vage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiii. pt. 11. (1879), p. 38, pl. 1. fig. 6—Neocomian; Yonne, France. [Right splenial. | Mesodon bathonicus, H. E. Sauvage, Bull. Soc. Géol. France, [3] vol, vili. (1880), p. 527, pl. xix. fig. 1. Pycnodus affinis, H. E. Sauvage, Catal. Poiss. Form. Second. Boulonnais (1867), p. 26, pl. u. fig. 6 (errore)—Bathonian ; Mar- quise. [Imperfect left splenial ; Boulogne Museum. | _ Mesodon bolonensis, H. KE. Sauvage, loc. crt. (1880), p. 527. Pyc- nodus boloniensis, H. E. Sauvage, op. cit. (1867), p. 27, pl. i. fig. 4. Pycnodus juglert, H. EH. Sauvage, bid. (1867), p. 27, pl. 1. fig. 5 (errore).—Bathonian ; Marquise. [Portion of right splenial; Boulogne Museum. | Mesodon diastematicus, E. D. Cope, Journ. Acad. Nat. Sci. Philad. [2} vol. ix. (1894), p. 443, woodc. fig. 5.— Lower Cre- taceous; Texas. [Vomer of uncertain genus. | Mesodon dumblei, K. D. Cope, ibid. p. 444, pl. xx. fig. 7. Miero- dus dumbelu, EK. D. Cope, Proc. Amer. Phil. Soc. vol. xxx. (1892), p. 128.—Lower Cretaceous; Texas [left splenial. | Mesodon dutertrer, H. E. Sauvage, Bull. Soc. Géol. France, [3] vol. vill. (1880), p. 528 (in part). Pycnodus dutertrei, H. E. Sauvage, Catal. Poiss. Form. Second. Boulonnais (1867), p. 31, pl. i. fig. 7 (non pp. 38, 45, pl. ii. figs. 8, 9 =vomer of Gyrodus and splenials of Lepzdotus).—Port- landian; N. France. [Left splenial; Boulogne Museum. | Mesodon gervaisi, H. KE. Sauvage, Bull. Soc. Géol. France, [3] vol. vill. (1880), p. 527. Pycnodus gervuisi, H. EK. Sauvage, Catal. Poiss. Form. Second. Boulonnais (1867), p. 29, pl. ii. fig. 2, and Bull. Soc. Géol. France, [3] vol. viii. (1880), OA ACTINOPTERYGII. p. 461, pl. xiv. figs. 2, 3.—Bathonian ; Marquise. [Right splenial ; Boulogne Museum. | Mesodon heckeh, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. (1862), p. 345, pl. 1. fig. 5.—Lower Kimmeridgian (Lithographic Stone); Solenhofen, Bavaria. [Imperfect dentition in fragmentary fish ; Palzeontological Museum, Munich. | Mesodon morinicus, H. EK. Sauvage, Bull. Soc. Géol. France, [3] vol. viii. (1880), p. 528, pl. xix. fig. 2.-—Portlandian ; N. France. [Portion of left splenial; School of Mines, Paris. | Mesodon pusillus, K. Fricke, Paleontogr. vol. xxii. (1875), p. 367, pl. xix. fig. 14, pl. xx. figs. 3, 4. -Kimmeridgian ; Hanover. [Upper and lower dentition. | Mesodon radiatus: Gyrodus radiatus, L. Agassiz, Poiss. Foss. vol. 1. pt. 11. (1844), p. 232, pl. lxix. a. fig. 20.—Bathonian ; Caen, Normandy. [Vomer. | Mesodon robustus : Pycnodus robustus, J. Cornuel, Bull. Soc. Géol. France, [3] vol. viii. (1880), p. 159, pl. iu. fig. 22.—Neo- comian ; Saint Dizier, Creuse. [Portion of left splenial ; Cornuel Collection. | Mesodon sauvagei: Pycnodus sauwaga, F. J. Pictet, Mém. Soe. Linn. Normandie, vol. xvi. no. 1 (1872), p. 19, pl. i. fig. 5; J. Cornuel, Bull. Soc. Géol. France, [3] vol. x1. (1883) p. 18, pl. i. figs. 1-3.—Portlandian; Haute Marne. [Vomer ; Royer Coll. ] An undescribed right splenial of Mesodon, with very irregular teeth, from the Jurassic of Mejdel Shems, near Caesarea Philippi, is preserved in the Museum of the Syrian Protestant College, Beyrout. Indeterminable detached teeth and miscellaneous portions of jaws with widely spaced teeth, apparently of MJesodon, are recorded from the Neocomian of Europe under the name of Pycenodus coulon ; but the specific characters even of the dentition are not as yet defined. ‘The name has been given to detached teeth from Neu- chatel (L. Agassiz, Poiss. Foss. vol. 11. pt. ui. 1844, p. 200, and P. de Loriol & V. Gilliéron, Mém. Soc. Helvét. Sci. Nat. vol. xxiii. 1869, no. 5, p. 5, pl. 1. figs. 5-7); detached teeth from Sainte Croix, Switzerland, and Dept. Ain, France, and an imperfect splenial from Auxerre, France (Pictet & Campiche, Foss. Terrain Crét. St. Croix, pt. i. 1860, p. 57, pl. vii. figs. 5-17, with reference to P. Gervais, Zool. et Pal. Franc. 1852, pl. lxix. fig. 22); other detached teeth from Piedmont (KE. Sismonda, Mem. R. Accad. Sci. Torino, [2] vol. xix. 186], p. 455, pl. i. figs. 1-11); an imperfect PYCNODONTIDZ. 215 splenial from Yonne, France (H. EK. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiii. pt. ii. 1879, p. 35, pl. il. fig. 5); an imperfect splenial from the Lower Neocomian of Ville-sur-Saulx, Meuse, France (J. Cornuel, Bull. Soc. Géol. France, [3] vol. viii. 1880, p. 158, and ibid. [3] vol. xi. 1883, p. 24, pl. i. fig. 10); and frag- ments from the phosphates of Cambridgeshire and Bedfordshire (W. Keeping, Foss. Neocom. Upware, 1883, p. 82, pl. i. fig. 5). To Mesodon may also probably be referred the portions of vome- rine dentition from the Corallian of Schnaitheim, Wiirtemberg, described under the names of Typodus annulatus and splendens by F. A. Quenstedt, Der Jura (1858), p. 781, pl. xevi. figs. 16-18. A fragment of a similar vomer is ascribed to Spherodus by F. A. Quenstedt, Handb. Paleeont. (1852) p. 214, pl. xvi. fig. 9. The undefined name of Pycnodus tristychius (L. Agassiz, Poiss. Foss. vol. 1. pt. 11. 1844, p. 199) seems to have been given to an English Jurassic jaw of Mesodon, probably from the Stonesfield Slate. The type specimen was originally in the Bristol Museum. The following form of dentition seems to be related to Mesodon, but is not represented in the Collection :— Gyronchus oblongus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. (1844) p. 202, pl. Ix. a, figs. 10, 11. Gyronchus (Scaphodus) oblongus, L. Agassiz, ibid. vol. i. (1844), p. xlii. Sca- phodus heteromorphus, J. Morris (‘ex Agassiz, MS.”), Catal. Brit. Foss. (1854), p. 344; A. 8. Woodward, Proc. Geol. Assoc. vol. x1. (1890), p. 301, pl. i. figs. 33, 34. Mesodon oblongus, Woodward & Sherborn, Catal, Brit. Foss. Vertebrata (1890), p. 120.—Stonesfield Slate ; Stonesfield. [Vomer; Bristol Museum. | Genus ATHRODON, Sauvage. [Bull. Soc. Géol. France, [3] vol. vii. 1880, p. 530. ] Anamperfectly definable genus, known only by the splenial bone, which much resembles that of Mesodon, but is considerably stouter and exhibits a remarkably deep symphysial facette. Splenial teeth as in Mesodon, but usually much more irregularly arranged, and the principal longitudinal series not well differentiated. . Athrodon douvillei, Sauvage. 1880. Athrodon douville, H. E. Sauvage, Bull. Soc. Géol. France, [3] vol. vill. p. 530, pl. xix. fig. 5. Type. Left splenial ; School of Mines, Paris. ' The type species. Splenial bone longer than broad, with very 216 ACTINOPTERYGII. small, widely spaced teeth, mostly circular and conspicuously mamumillated, disposed in from 7 to 10 irregular longitudinal series, somewhat enlarged towards the symphysial margin of the bone. The dentition of the type specimen measures 0-019 in maximum width and 0-045 in length. Form. & Loc. Lower Portlandian: Boulogne. Not represented in the Collection. Athrodon intermedius, A. 8S. Woodward. 1893. Athrodon intermedius, A. 8S. Woodward, Geol. Mag. [3] vol. x. p. 434, pl. xvi. fig. 1. Type. Left splenial dentition; British Museum. Splenial bone comparatively elongated, with large, closely arranged teeth, mostly smooth and nearly circular, a few exhibiting an apical pit with feebly crimped margin, disposed in about 5 or 6 irregular longitudinal series, the largest forming a principal series near the symphysial margin of the bone. Form. § Loc. Purbeckian: Aylesbury, Buckinghamshire. 40314. The type specimen, described and figured loc. cit. ‘The dentition measures 0-017 in maximum width and 0-03 in length. Purchased, 1867. Athrodon crassus, A. 8. Woodward. 1893. Athrodon crassus, A.S. Woodward, Geol. Mag. [3] vol. x. p. 489, pl. xvi. fig. 3. Type. Right splenial with abraded dentition; Woodwardian Museum, Cambridge. Splenial bone short and broad, with large, widely-spaced teeth, mostly circular, disposed in about four irregular longitudinal series, largest near the middle of the bone. The dentition of the type specimen measures 0°02 in maximum width and 0:04 in length. Form. & Loc. Cenomanian: Cambridge. Not represented in the Collection. Athrodon jessoni, A. 8. Woodward. 1895. Athrodon jessoni, A.S. Woodward, Geol. Mag. [4] vol. 11. p. 208. pl. vii. fig. 1. Type. Right splenial; British Museum. Splenial bone very robust, but narrower than in A. crassus, with PYCNODONTID.E. A large, closely-arranged teeth, mostly circular, all smooth, disposed in three nearly regular longitudinal series. Anteriorly the three series are about equal in size; posteriorly the median teeth are slightly the larger. Form.'& Loc. Cenomanian: Cambridge. P. 7238. The type specimen, described and figured loc. cit.; Cam- bridge Greensand, Cambridge. The dentition measures 0-02 in maximum width and 0-04 in length. Jesson Coll. The following form of vomer may belong either to Athrodon or to Mesodon :— P. 7186. Imperfect vomerine dentition, shown of the natural size in Pl. XVII. fig. 2; Portland Stone, near Weymouth. The teeth are widely spaced on a transversely-convex surface, and arranged in seven series. All are smooth, but much worn; and even the principal median teeth are scarcely broader than long. Purchased, 1894. P. 3750. Left lateral teeth of a similar vomer; Portland Stone, near Weymouth. Enniskillen Coll. The following species have also been founded on detached splenial bones, of which there are no examples in the Collection :— Athrodon bolomensis, H. KE. Sauvage, Bull. Soc. Géol. France, [3] vol. vill. (1880), p. 531, pl. xix. fig. 6.—Lower Kim- meridgian ; Brecque-recque, Boulogne. [School of Mines, Paris. | Athrodon profusidens, A. 8. Woodward, Geol. Mag. [3] vol. x. (1893), p. 485. Pycnodus profusidens, J. Cornuel, Bull. Soc. Géol. France, [3] vol. v. (1877), p. 609, pl. xi. figs. 3-6. Mesodon profusidens, A. Gaudry, Enchain. Monde Anim., Foss. Second. (1890), p. 164, fig. 262.—Neocomian ; Wassy, Haute Marne. Athrodon tenuis, A. 8S. Woodward, loc. cit. (1893), p. 435, pl. xvi. fig. 2—Lower Senonian; Lonzée,near Gembloux, Belgium. [Brussels Royal Museum of Natural History.] Athrodon wittei, H. E. Sauvage, loc. cit. (1880), p. 531. Mesodon witter, K. Fricke, Paleontogr. vol. xxii. (1875), p. 364, pl. xix. fig. 15.—Lower Kimmeridgian ; Hanover. An imperfect vomerine dentition from the Cambridge Greensand, in the Woodwardian Museum, Cambridge, is also not improbably referable to Athrodon (A. 8. Woodward, loc. cit. 1893, p. 435, pl. xvi. fig. 4). 218 ACTINOPTERYGII. Genus MESTURUS, Wagener. [Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1862, p. 338. ] Trunk discoidal, abruptly produced into a small and short caudal pedicle. Head and opercular bones externally ornamented with granulations; teeth with a crimped and usually indented coronal apex ; vomerine teeth arranged in three principal series, with a varying number of irregular, small, intercalated series; splenial dentition comprising one principal series of teeth, with about two inner and several outer irregular series of smaller teeth. Fin-rays robust, closely articulated, and much divided distally. Pelvic fins present ; dorsal and anal fins deep throughout their extent, not specially elevated in front, and the former occupying about the hinder half of the back; caudal fin fan-shaped, having a sinuously convex hinder margin, and nearly surrounding the short caudal pedicle. Scales robust and covering the whole of the trunk; their upper and lower margins united by interlocking digitations, and their external surface tuberculated. Mesturus verrucosus, Wagner. [Plate XV.] 1862. Mesturus verrucosus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 338, pl. iii. fig. 1. Type. Nearly complete fish ; Palzeontological Museum, Munich. The type species, attaining a length of about 0°5. Maximum depth of trunk considerably exceeding its length from the scapular arch to the base of the caudal pedicle, and head with opercular apparatus occupying nearly one-third of the total length of the fish (including caudal fin). [Dentition unsatisfactorily known, but] the teeth of the outermost series on the splenial little inferior in size to those of the principal series. Dorsal fin with 32 rays, arising at the middle of the back behind its highest point; [anal fin incompletely known]. Tubercular ornamentation of the scales fine and closely arranged compared with that of the head-bones, except in the anterior half of the lateral line, where the tubercles form a series of irregular excrescences. All the principal scales exhibiting fine structural lines radiating backwards from a point on their anterior margin, beneath the tubercular ornamentation. The vertical series of scales irregularly bifurcating towards the whole of the dorsal margin and towards the caudal half of the ventral margin. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. PYCNODONTID.. 219 49147. Plaster cast of type specimen ; Hichstadt. Purchased, 1878. 37023. A fine specimen, in counterpart, with crushed head and wanting part of the ventral margin; Solenhofen. The best side of the fossil is shown of one-half the natural size in Pl. XV. fig. 1, with some parts restored from the opposite side. The bones of the cranial roof are shown to be especially thick and marked with a relatively coarse tubercular ornament. The facial bones are remark- ably delicate and finely tuberculated, exhibited as very irregular large tesserzee below the orbit, and represented by the remains of one long narrow plate (#) above the upper jaw. The sclerotic of the eye is ossified (sel.). The margin of the vomer (vo.) is exposed in the upper, aud that of the splenial (sp/.) in the lower jaw, both of these bearing stout teeth on moderately elongated pedicles ; and the external face of the mandible is com- pleted by the tuberculated dentary (d.) and angular (ag.) plates. The postero-superior portion of the mandible, however, is obscured by the thin facial bones. Still further below the skull are two elements which seem to be identifiable as ceratohyal (ch.) and hypohyal (hy.); both very small, and the former remarkably deepened behind. Among the remains of branchial and branchio- stegal apparatus, the calcified gill-filaments (fig. 1 a) are especially conspicuous, each exhibiting a widely spaced series of very fine denticles on its upper margin. Frag- ments of the operculum (op.) indicate that this plate was as coarsely tuberculated as the cranial roof; so also, in part at least, was the preoperculum (p.op.), which is dis- played almost entirely from its imner aspect, and seems to be bounded below in the counterpart of this fossil by one or perhaps two branchiostegal rays. Below the oper- cular apparatus are observed very small, tuberculated, imbricating scales, which are more or less lozenge-shaped and broader than deep, and extend as a covering between the rami of the mandible. The neural spines (n.) of the vertebral axis are exhibited enveloped in the squamation, those in the abdominal region thickened and extending almost or quite to the dorsal ridge. As shown by im- pressions in the counterpart, they are about 30 in number to the base of the caudal pedicle. Immediately behind the opercular apparatus are remains of the clavicle, orna- mented with large tubercles on its lower expansion (cl.) ; 220 ACTINOPTERYGII. and in the short lobe at the base of the pectoral fin there are portions of the long, hour-glass-shaped supporting cartilages ( p.b.), which were probably not less than nine in number. Thirty-five rays can be distinctly observed in the pectoral fin on the counterpart, and there may have been afew more; about five of the foremost rays gradually increase in length and seem to have been un- divided, while the remainder are divided and sparsely articulated distally. The region which would support the pelvic fins is broken away, and the anterior portion of the anal fin is similarly destroyed. The dorsal and caudal fins, however, are very satisfactorily preserved. The dorsal is borne on 31 or 32 supports, and seems to be slightly the deepest at its middle; there are two short and stout basal rays (or a ridge-scale and a ray) in front, undivided, and the second somewhat longer than the first ; then three gradually lengthening rays succeed, each arti- culated but not branching; and the remainder of the fin consists of 28 well-spaced rays, each very stout, closely articulated, widened, and dichotomously branching from a point quite close to its base. The anal fin-rays are similar, as also are those forming the middle part of the tail. The caudal fin is fan-shaped, surrounding the hinder half of the pedicle, and having a sinuously convex posterior border. Its marginal rays above and below are simple, and gradually increase in length, while the fifth or sixth is the first exhibiting articulations. All the principal characters of the squamation are displayed, and the scales of the whole of the flank are shown to be united above and below by the characteristic jagged suture (fig. 16). The fine lines radiating beneath the tubercular ornament from a point on the anterior margin of many scales are apparently a structural feature; the radiation being exhibited also to some extent on the inner face of some scales exposed near the ventral border. The vertical flank-series become irregular as they approach the dorsal margin throughout the trunk, and towards the ventral margin in the caudal region. Intercalary vertical series (ic.) of variable length are thrust between them. At the base of the dorsal and anal fins they are subdivided into very small, irregularly lozenge-shaped scales; and the arrangement of the small scales on the caudal lobe is also not very regular. A few narrow scales, likewise not con- PYCNODONTID&. 221 formable with the vertical flank-series, are observed at the base of the lobe of the pectoral fin; while those of the gular and branchiostegal region have already been noticed. Haberlein Coll. Mesturus leedsi, sp. nov. Type. Imperfect head and trunk; collection of Alfred N. Leeds, Esq., Eyebury. A larger species than WM. verrucosus, with more coarsely and sparsely tuberculated scales, which do not exhibit any radiating lines. No enlarged tubercles on the course of the lateral line. Premaxilla with three, dentary with four prehensile teeth. Vome- rine and splenial teeth smooth, exhibiting a shallow apical indenta- tion with a crimped margin, very rarely also with a slight median tubercle ; shape of indentation varying with that of the tooth, and the hinder portion of its crimped border not infrequently wanting. Oral surface of vomer flat, with outer lateral teeth not much inferior in size to those of the median series; inner lateral teeth less than half as large as these, very irregular and much supple- mented behind. Splenial dentition comprising one principal longi- tudinal series of teeth, all oval and about as large as the median yomerine teeth, but with long axis oblique; outermost series regular and similar, but rather smaller; one regular rew of round teeth about half as large, and an innermost irregular row of still smaller teeth, within the principal series; two similar rows of small teeth also interposed between the latter and the outermost series, but these again irregularly supplemented in the hinder two- thirds of the bone. Form. & Loc, Oxfordian : Huntingdonshire. P. 6834. Associated series of bones isolated from matrix; Oxford Clay, near Peterborough. In the nomenclature here adopted the series comprises the parasphenoid, basi- sphenoid, right postfrontal, right and left squamosal, portion of right frontal, right and left operculum, and other fragments. Leeds Coll. Genus MICRODON, Agassiz}.~ [Poiss. Foss. vol. 11. pt. i. 1833, p. 16, pt. 11. 1844, p. 204.] Trunk deeply fusiform, often almost discoidal, with a slender abbreviated caudal pedicle. Head and opercular bones ornamented 1 This name having gained universal acceptance, we adopt it, notwithstanding its preoccupation among Diptera by Microdon, Meigen, 1803. 222 ACTINOPTERYGII. with reticulating ruge and pittings; teeth smooth, sometimes feebly indented in the lateral series; vomerine teeth in five longi- tudinal series, the inner lateral pairs regularly alternating with the widely spaced median teeth; splenial teeth in four series, the innermost being relatively small, and the second the largest or principal series. Neural and hemal arches of axial skeleton of trunk not expanding sufficiently to encircle the notochord. Fin- rays robust, closely articulated, and much divided distally. Pelvic fins present; dorsal and anal fins very high and acuminate in front, rapidly becoming low and fringe-like behind, the former occupying at least the hinder half of the back and the latter somewhat shorter, arising more posteriorly; caudal fin forked. Scales ornamented with reticulating ruge or pittings, and covering only the anterior half of the trunk in advance of the median fins, though some- times partly extended over the middle of the flank of the caudal region. Microdon elegans, Agassiz. 1833-44. Microdon elegans, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 16, pt. i. p. 205) pl. Txix. b: (?) 1889. G'yrodus laticauda, G. von Munster, Neues Jahrb. p. 679. 1848. Microdon notabilis, G. von Minster, Beitr. Petrefakt. pt. vi. p- 55, pl. ii. fig. 2. [Mandibular dentition; Paleontological Museum, Munich. | 1851. Pycnodus elegans, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. pp. 33, 36. | 1851. Pycnodus notabilis, A. Wagner, ibid. vol. vi. pp. 37, 57, pl. iii. fig. 3. 1862. Microdon elegans, A. Wagner, zbid. vol. ix. p. 348, (?) 1862. Microdon nanus, A. Wagner, zbid. vol. ix. p. 344. [Immature fish; Paleontological Museum, Munich. | 1887. Microdon elegans, K. A. von Zittel, Handb. Palzeont. vol. iii. p. 246, fig. 259. Type. Nearly complete fish ; Paleontological Museum, Munich. The type species, attaining a length of about 0-3. Maximum depth of trunk equalling about four-fifths of the length of the head and trunk without caudal fin; head with opercular apparatus occupying slightly more than one-quarter of the total length of the fish. Splenial teeth closely arranged; those of the principal series somewhat broader than long and truncated at each end ; innermost teeth and those of the inner flanking series about equal in size, very small and sometimes longer than broad ; outermost teeth irregularly quadrate, longer than broad, about half as large as the principal “TMs on, ; De PYCNODONTID A. ODS teeth. Vertebral axis at origin of dorsal fin midway between the dorsal and ventral borders of the fish. Dorsal fin with more than 50 rays, occupying considerably more than half of the back, much more elevated than the anal fin, which has 45 rays, and the length of which equals about three-quarters that of the dorsal. Ridge- scales coarsely serrated; flank-scales delicate, marked with feeble rugs, which are mostly transverse. A small fish in the Paleontological Museum, Munich, not improbably young of this species, is named Microdon nanus, A. Wagener, loc. cit. vol. ix. (1862) p, 344. Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. 37369. Plaster cast of type specimen; Kelheim. Purchased, 1863. P. 1626, P. 3764. Fine large specimen partly in counterpart, showing remains of the pelvic fins ; Solenhofen. Egerton and Enniskillen Colls. P. 1631. Caudal region, with nearly complete caudal fin; Kelheim. igerton Coll. P. 3765. Imperfect caudal fin ; Kelheim. Enniskillen Coll. Microdon radiatus, Agassiz. 1839-44. Microdon radiatus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p08. pl. bax. fies. 1; 2. 1840. Microdon radiatus, R. Owen, Odontography, p. 73, pl. xliii. fig. 1. Type. Imperfect fishes. | A much smaller species than the type, nearly similar in general form and proportions, but with relatively deeper abdominal region. Principal series of splenial teeth wider than the two outer series, of which the outermost is considerably the largest. Ridge-scales with three or four coarse serrations, of which the hindermost is a large denticle; flank-scales robust, marked with prominent rugee which are mostly transverse and radiating. The laminar expansions on the neural and hemal arches are well shown in several specimens recorded below, proving that their absence in the original fossils examined by Agassiz was accidental. The neural spines are remarkably robust in the abdominal region. Form. & Loc. Purbeckian: Dorsetshire. All the following specimens were obtained from the neighbour- hood of Swanage :— 19013. Fish 0°105 in length, wanting the pelvic fins and the greater part of the dorsal and anal fins. Purchased, 1844. 224 ACTINOPTERYGII. 28443. Two more imperfect specimens, somewhat larger. One displays the posterior process of the parietal, arising beneath the outer layer of this bone. Cunnington Coll. 44844. Fish 0°13 in length, wanting most of the fins but displaying part of the ornamented squamation. In this, as in the other specimens, the scales seem to have been much more robust in the ventral than in the dorsal region. Presented by Benjamin Bright, Esq., 1873. 46333. Well-preserved trunk and cranium of a slightly larger fish, with portions of the pelvic and median fins. Cunnington Coll, P. 1627. Four specimens in various states of preservation, two displaying the splenial dentition, and one the hyo-mandi- bular bone. Egerton Coll. P. 5592. Remains of head and trunk, displaying scales and splenial dentition. Harford Coll. 22403. Remains of small head and trunk, displaying the ridge- scales. Purchased, 1848. P. 7455. Cranium in side view. History unknown. 33481. Right splenial dentition. Purchased, 1858. The following specimens of vomerine dentition from Swanage may pertain to Microdon radiatus, but they are relatively large. They differ from the corresponding dentition of M. pagoda only in the relatively smaller size of the outer paired teeth :— 21974. Vomerine dentition preserved for a length of 0°019. Purchased, 1848. P. 6820. A somewhat larger specimen. Purchased, 1892. Microdon bernardi (Thiollicre). 1854. Pycnodus bernardi, V. Thiolliére, Poiss. Foss. Bugey, pt. i. p. 17, with plate. 1856. Microdon bernardi, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 201. 1860. Microdon bernardi, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. vol. 1. p. 396. Type. Nearly complete fish ; Lyons Museum. A species as large as the type species. Maximum depth of trunk equalling about two-thirds of the length of the head and trunk PYCNODONTID A. 225 without caudal fin; rostrum prominent, and head with opercular apparatus occupying somewhat less than one-quarter of the total length of the fish. Vertebral axis at origin of dorsal fin midway between the dorsal and ventral borders of the fish. — Principal series of mandibular teeth much wider than the two outer series, of which the innermost is insignificant. Dorsal fin occupying con- siderably more than half of the back, much more elevated than the anal fin, which is also shorter. Ridge-scales delicate on the back, robust but feebly serrated on the ventral border; flank-scales ornamented with delicate radiating ruge. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France, and (?) Bavaria. P. 1635. A typical specimen in counterpart, much disturbed ; Cirin, Ain. Egerton Coll. P. 4693. Imperfect trunk ; Cirin. | Purchased, 1884. 49132. Plaster cast of a small fish, probably of this species; Kel- heim, Bavaria. Purchased, 1878. Microdon wagneri (Thiollicre). 1854. Pycnodus wagneri, V. Thiolliére, Poiss. Foss. Bugey, pt. 1, p. 23, with figure. 1856. Microdon wagnert, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 201. 1860. Microdon wagneri, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. vol. 1. p. 396. Type. Nearly complete fish ; Lyons Museum. A species resembling the type in size, general form, and pro- portions, and apparently only differing in the extension of the squamation over the middle of the flank of the anterior half of the caudal region. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. P. 1636. A fine specimen 0°25 in length preserved in impression and wanting the rostral portion of the skull; Cirin. The ribs of the scales originally on the flanks of the caudal region are indicated ; and the form of the hinder part of the trunk suggests that the figured type specimen has been somewhat distorted by crushing in that region. Egerton Coll. PART III, Q 226 ACTINOPTERYGII. P. 4694. Imperfect fish, displaying the expansion at the inferior end of the problematical bone (? ridge scute) at the hinder extremity of the body-cavity ; Cirin.. Purchased, 1884. -Microdon egertoni (Thiollire). 1854. Pycnodus egertoni, V. Thiolliére, Poiss. Foss. Bugey, pt. i. p. 24, with figure. 1856. Microdon egertoni, J. J. Heckel, Denkschr. k.'Akad. Wiss. math.-naturw. Cl. vol. xi. p. 201. 1860. Microdon egerton, A. Wagner, Gelehrte Anzeig. k. bay. Akad. vol. 1. p. 896. Type. Nearly complete fish ; Lyons Museum. A small form of Microdon, not yet satisfactorily distinguished from the type species. It is stated to differ in not exhibiting an angulation of the frontal profile and in having fewer vertebre : but the first character may be due to imperfect preservation, and the second is difficult to observe with certainty. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. P. 1637. Imperfect, crushed specimen 0°13 in length, shown for the most part in impression; Cirin. Egerton Coll. P. 4695. Slightly larger specimen displaying the pelvic and median fins, but wanting the greater part of the head; Cirin. Purchased, 1884. Microdon sauvanausi (Thiolliére). | 1850. Pycnodus sauvanausi, V. Thiolliére, Ann. Soc. Sci. Phys. & Nat. Lyon, [2] vol. ii. p. 181. 1854. Pycnodus sauvanausii, V. Thiolliére, Poiss. Foss. Bugey, pt. i. p. 15, with plate. 1856. Miorotton sauvanausit, J. J. Heckel, Denkschr. k. Akad. Wikis math.-naturw. Cl. vol. xi. p. 201. Type. Nearly complete fish; Lyons Museum. A large species attaining a length of about 0-6. Maximum depth of trunk apparently equalling about half of the length of the head and trunk without caudal fin; head with opercular apparatus occupying somewhat more than one-quarter of the total length of the fish. Each premaxilla with two chisel-shaped teeth; [other teeth imperfectly known]. Scales apparently confined to the most anterior part of the trunk. A fish from Cirin described as intermediate beeweee this and the « ca oe PYCNODONTID. 227 following species is named Microdon intermedius, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. vol. 1. (1860), p. 398. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Cirin, Ain, France. Not represented in the Collection. Microdon itieri (Thiollicre). 1850. Pycnodus itiert, V. Thiolliére, Ann. Soc. Sci. Phys. & Nat. Lyon, [2] vol. iii. p. 182. 1854. Pycnodus ttiert, V. Thiolliére, Poiss. Foss. Bugey, pt. i. p. 22, with plate and woodcut of dentition. 1856. Microdon itiert, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl. vol. xi. p. 201. 1860. Microdon itiert, A. Wagner, Gelehrte Anzeig. k. bay. Akad. Wiss. vol. 1. p. 396. Type. Nearly complete fish; Lyons Museum. A moderately elongated species attaining a length of about 0°5. Maximum depth of trunk contained three times in the length of the head and trunk without caudal fin; head with opercular apparatus occupying only about one-fifth of the total length of the fish. Vome- rine teeth closely arranged ; those of the median series much broader than long; those of the inner paired series elongated and their axis oblique, each pair alternating with the median teeth but scarcely pressed between these; outer teeth irregularly quadrate, about as broad as long, and very closely arranged. Splenial teeth (according to Thiolliére’s diagram) much spaced; those of the principal series two or three times as broad as long, rounded at each end; those of the innermost series minute, and those of the two flanking series somewhat broader than long, the outer twice as large as those of the inner flanking row. Dorsal fin occupying about half of the back, and anal fin more than two-thirds as much extended as this. Scales apparently confined to the most anterior portion of the trunk. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Cirin, Ain, France. Not represented in the Collection. Microdon hugii (Agassiz). [Plate XVII. fig. 3.] 1833-44. Pyenodus hugii, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 17, pt. ii. p. 195, pl. lxxii. a. figs. 49-54. 1846. Pyenodus bucklandi, G. von Minster (errore), Beitr. Petrefakt. pt. vil. p. 40, pl. iii. figs. 5a, 6. 1846. Pyenodus preusst, G. von Miinster, zbid. p. 45, pl. ii. fig. 25. (Splenial; Paleontological Museum, Munich. } a2 228 ACTINOPTERYGII. 1852. Pycnodus hugi, F. A. Quenstedt, Handb. Petrefakt. p. 218, pl. xvi. fig. 10. 1856. igeie hugit, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl, vol. xi. p. 201. (?) 1858. Pyknodus hugii, F. A. Quenstedt, Der Jura, p. 781, pl. xcvi. fies. 30, 31. 1860. Pycnodus hugu, F. J. Pictet, Rept. & Poiss. Foss. Jura Neu- chatelois, p. 56, pl. xiii. figs. 4-8, pl. xix. fig. 2. (?) 1860. Pycnodus notabilis, F. J. Pictet (? errore), zbid. p. 58, pl. xiv. figeade 1864. ical irregularis, H. Credner (errore), Zeitschr. deutsch. geol. Ges. vol. xvi. p. 244, pl. xi. fig. 5. 1875. Microdon hugu, K. Fricke, Paleontogr. vol. xxii. p. 37], pl. xx. fies. 10-16. 1880. Microdon hugu, C. Struckmann, Wealdenbild. Hannover, p. 90, pl. iii. fig. 8. Type. Portions of mandibular dentition; Soleure Museum. A large species, known only by the dentition. Vomerine denti- tion [according to Fricke] very narrow, and the teeth of the median and inner paired series widely spaced; median teeth of irregularly rounded form, scarcely broader than long ; those of the inner paired series irregularly triangular or quadrangular, antero-posteriorly elongated ; those of the outer paired series narrowest and much elongated antero-posteriorly. Splenial teeth closely arranged ; those of the principal series about twice as broad as long and more or less truncated at their outer end; those of the innermost series and of the inner flanking series relatively small and about equal in size; those of the outermost series larger than the latter, though less than half as large as the principal teeth, slightly elongated transversely and truncated at the inner end. The largest known splenial dentition measures about 0-05 in length, and the irregular subdivision of some of the teeth is frequently observed. Form. & Loc. Corallian and Kimmeridgian: Hanover, Wurtem- berg, an Switzerland. Portlandian: Hanover ; (?) alsoS. England. Purbeckian: Hanover. P. 1654a, b. Left splenial dentition, somewhat broken, and another abnormal fragmentary specimen ; Kimmeridgian, Soleure, Switzerland. Egerton Coll. P. 7443. Left splenial; Kimmeridgian, Sohlewerke, Hanover. Purchased, 1895. P. 2297. Imperfect small left splenial dentition ; Portlandian, Hanover. Presented by Mrs. Burton, 1882. PYCNODONTID 2. 229 P. 1650, P. 3748. Right and left splenial dentition, of small size ; Corallian, Lindnerberg, Hanover. Egerton and Enniskillen Colls. 30871. Left splenial dentition, probably of this species, shown of the natural size in Pl. XVII. fig. 3; Portland Stone, Weymouth. Purchased, 1856. Microdon minutus (Minster). 1846. Pycnodus minutus, G. von Minster, Beitr. Petrefakt. pt. vii. p- 41, pl. i. fig. 7. 1875. Microdon minutus, K. Fricke, Paleontogr. vol. xxii. p. 369, pl. xx. figs. 5-9. Type. Fragment of mandibular dentition; Paleontological Museum, Munich. A species of moderate size, known only by the dentition. On the vomer [according to Fricke] the teeth of the principal series much transversely elongated, comparatively closely arranged; those of the inner paired series minute or aborted ; those of the outer paired series small and irregularly rounded. Splenial teeth closely arranged ; those of the principal series at least twice as broad as long; those of the innermost series round and minute; those of the inner flanking series much transversely elongated, relatively large, and those of the outer flanking series smaller, either round or slightly elongated transversely. Form. & Loc. Kimmeridgian: Hanover; Switzerland. P. 3747. Left splenial dentition; Lindnerberg, Hanover. Enniskillen Coll. P. 3746 a. Portion of larger right splenial dentition; Soleure, Switzerland. Enniskillen Coll. Microdon quincuncialis (Blake). 1875. Pycnodus quincuncialis, J. F. Blake, Quart. Journ. Geol. Soc. vol. xxxi. p. 2238. 1880. Pyenodus quincuncialis, R. Damon, Geol. Weymouth, ed. 2, Suppl. pl. xi. fig. 10. 1890. Microdon quincuncialis, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 122. Type. Vomerine dentition ; British Museum. A species of large size. Inner vomerine teeth sparsely arranged, those of the principal series not much broader than long, and the paired teeth very irregular in size and form, with few supplementary 230 ACTINOPTERYGII. minute teeth; teeth of the outer paired series closely arranged, longer than broad, and truncated externally. Form. & Loc. Kimmeridgian: Dorsetshire. P. 6170. Type specimen; Lower Kimmeridge Clay, Weymouth. Damon Coll. P. 6749. Imperfect right splenial dentition probably of this species, though possibly an abnormal example of Gyrodus cocco- derma, exhibiting the principal teeth of a very irregular form, scarcely broader than long, and the inner flanking series slightly larger than the outer series; Weymouth. Purchased, 1892. 47965. Larger imperfect specimen of the same form of splenial dentition ; Coral Rag, Wheatley. Presented by the Hon. Robert Marsham, 1877. Microdon pagoda (Blake). 1880. Pycnodus pagoda, J. F. Blake, Quart. Journ. Geol. Soc. vol. xxxvi. p. 228, pl. x. fig. 10. 1889. Microdon payoda, A.S. Woodward, Geol. Mag. [3] vol. vi. p. 454. Type. Vomerine dentition. A species of small or moderate size, known only by the vomerine dentition, which is somewhat arched from side to side. Teeth of the median or principal series at least twice as broad as long ; those of the inner pair about half as large as the latter, with tendency to oblique elongation; those of the outer paired series much smaller, irregular in shape and size, and not much truncated ex- ternally. Form. & Loc. Portlandian: Dorsetshire. 40640 a. Vomerine dentition; Portland Stone, near Weyinoiln \ Purchased, 1867. P. 4678. Smaller specimen; Ridgway Quarry, near Weymouth. Presented by C. Westendarp, Esq., 1884, P. 7187. Another small vomer; near Weymouth. Purchased, 1894. Microdon biserialis, A. 8. Woodward. 1844, Pycnodus biserialis, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 199 (name only). 1890. Mesodon biserialis, A.S. cae Proc. Geol. Assoc. vol. x1. p- 300, pl. ii. fig. 28. Type. Left splenial dentition British Museum. PYCNODONTID&. 951 A species of small or moderate size, known only by the splenial dentition. Teeth closely arranged; those of the innermost series minute and round; those of the principal series about twice as broad as long; teeth of the inner flanking series broader than long and: larger than those of the outermost row, which are rounded. Form. & Loc. Bathonian : Oxfordshire. P. 523. Type specimen ; Stonesfield Slate, Stonesfield. Egerton Coil. Microdon (?) discoides (A. 8. Woodward). 1844. Pycnodus discoides, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 199 (name only). 1890. Mesodon discordes, A. 8. Woodward, Proc. Geol. Assoc. vol. xi. p- 800, pl. iii. fig. 32. Type. Imperfect vomer ; British Museum. A species doubtfully ascribed to Microdon, known only by the unique vomer recorded below. Vomerine teeth round and well spaced; those of the median series not much exceeding the outer lateral teeth in size; inner paired teeth only about half as large as the others. Form. & Loc. Bathonian: Oxfordshire. P. 524. Type specimen, described and figured loc, cit. 1890; Great Oolite, Little Gibraltar, near Oxford. Eyerton Coll. The following specimens of Mesodon are not specifically deter- mined :— , P. 7444. Vomer ; sae eo Langenberg, Hanover. Purchased, 1895. P. 3756. Vomer resembling Microdon in its anterior half, but the inner - lateral teeth not interposed between the median teeth in its hinder half; Purbeckian, Swanage. Enniskillen Coll. The following species of Microdon have also been founded upon portions of dentition, but there are no examples in the Collection :— ~ Microdon coralli: Pycnodus coralli, H. E. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiii. pt. ii. (1879), p. 32, pl. ii. fig. 2.—Upper Corallian; Tonnerre, Yonne, France. [Right splenial ; Cotteau Collection. | Microdon distantidens: Pycnodus distantidens, F. J. Pictet, Rept. et Poiss. Foss. Jura Neuchatelois (1860), p. 67, pl. xv. 232 ACTINOPTERYGII. fig. 6.— Kimmeridgian ; Chaux-du-Milieu, Neuchatel. [Portion of vomer; Neuchatel Museum. | Microdon formosus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl. vol. xi. (1856), p. 201. Pycnodus formosus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. (1851), p. 40, pl. iii. fig. 4. Lower Kimmeridgian (Diceras- kalk); Oberau, near Kelheim, Bavaria. [Portion of right splenial ; Paleontological Museum, Munich. | Microdon irreqularis: Pyknodus irregularis, F. A. Quenstedt, Der Jura (1858), p. 781, pl. xevi. fig. 32 1.—Upper Corallian ; Schnaitheim, Wirtemberg. [Portion of vomer; Tiibingen University Museum. | Microdon (?) minor ; Pycnodus minor, F. A. Roemer, Verstein. Norddeutsch. Oolithengeb., Nachtr. (1839), p. 54, — Portlandian ; Galgenberg, near MHildesheim, Hanover. [Splenial. | Microdon vicinus: Pycnodus viemus, J. Cornuel, Bull. Soc. Géol. France, [3] vol. xi. (1883), p. 20, pl.i. figs. 8, 9.—Port- landian; Ville-sur-Saulx, Meuse. [Splenial.] An undefined species of Microdon is also indicated by imperfect jaws from the Lower Kimmeridgian of Orbagnoux, Ain, France (Pycnodus sp., H. E. Sauvage, Bull. Soc. Hist. Nat. Autun, vol. vi. 1893, p. 443, pl. ix. fig. 2). The genus has been erroneously recorded from the Cretaceous. The so-called Microdon nuchalis (F. Dixon, Geol. Sussex, 1850, p-. 369, pl. xxxii. fig. 7) 1s founded upon an imperfect example of a teleostean fish from the Chalk of Sussex, now in the British Museum (Platax ? nuchalis, A. 8. Woodward, Ann. Mag. Nat. Hist. [5] vol. xx. 1887, p. 342). Microdon occipitalis (F. Dixon, op. cit. p- 369, pl. xxxii*. fig. 2) is a name given to a generically indeter- minable fragment of a Pycnodont from the Chalk of Lewes, in the Brighton Museum. Microdon? pulchellus (J. W. Davis, Trans. Roy. Dublin Soe. [2] vol. il. 1887, p. 501, pl. xxiv. fig. 3), from the Upper Cretaceous of Sahel Alma, Mt. Lebanon, is a teleostean fish. The type specimen is now in the Edinburgh Museum. An indeterminable fossil from the Cretaceous of Pietraroja, Naples, is named Microdon simplex, O. G. Costa, Atti Accad. Pontan. vol. viii. (1864), p. 112, pl. ix. fig. 7. ' An Eocene fossil from Bavaria, certainly not of this species is recorded under the same name by K. Schafhautl, Sid-Bayerns Leth. Geogn. (1865), p. 246 pl. lxv.c. fig. 16. PYCNODONTIDZ. 233 Genus GYRODUS, Agassiz. [Poiss. Foss. vol. ii. pt. i. 1833, p. 16, and pt. 1. 1844, p. 2238.] Syn. Stromateus, H. D. de Blainville, Nouv. Dict. d’Hist. Nat. vol. xxvii. 1818, p. 333. Trunk deeply fusiform or discoidal, with a slender abbreviated caudal pedicle. Head and opercular bones ornamented with tubercles; cheek and gular region covered with small, imbricating, cycloidal scales; teeth more or less rugose and mammillated, those of the vomer in five, and those of the splenial in four regular series. Neural and hemal arches of axial skeleton of trunk not expanding sufficiently to encircle the notochord. Fin-rays robust, closely arranged, articulated and divided distally. Pelvic fins present ; dorsal and anal fins low and fringe-like, except in front where they rise to an elevated point, these two fins arising at about the same point and not extending in advance of the hinder half of the trunk ; caudal fin deeply forked, with slender lobes. Scales tuberculated or rugose, covering the whole of the trunk. | Gyrodus macrophthalmus, Agassiz. 1833. Microdon abdominalis, L. Agassiz, Poiss. Foss. vol. ii. pt.i. p. 16. 1839-44. Gyrodus macrophthalmus, L. Agassiz, ibid. vol. ii. pt. ii. pp. 224, 301, pl. lxvii. 1839-44. G'yrodus rugosus, L. Agassiz (ex Miinster MS.), zbed. p. 227, pl. lxix. [Nearly complete fish ; Paleontological Museum, Munich. | 1842. Gyrodus m@eandrinus, G. von Miinster, Neues Jahrb. p. 45. [ Ditto. ] 1851. Gyrodus macrophthalmus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. p. 28. 1851. Gyrodus rugosus, A. Wagner, ibid. pp. 29, 45, 56. 1851. Gyrodus meandrinus, A. Wagner, ibid. p. 30. 1862. Gyrodus macrophthalmus, A. Wagner, ibid. vol. ix. p. 336 (in part). 1862. Gyrodus rugosus, A. Wagner, zbid. vol. ix. p. 337. 1862. Gyrodus dichactinius, T. C. Winkler, Descript. Poiss. Foss. Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv.), p. 67, fig. 12. [Nearly complete fish ; Teyler Museum, Haarlem. |] 1881. Gyrodus macrophthalmus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 20 (in part), 1887. Gyrodus macrophthalmus, K. A. von ae Handb. Paleeont. vol. ili. p. 239, fig. 251. Type. Nearly complete fish ; Paleontological Museum, Munich. The type species, attaining a length of about 0:3. Maximum 234 ACTINOPTERYGII. depth of trunk not exceeding its length from the scapular arch to the base of the caudal fin, and head with opercular apparatus occupying one-third of the total length exclusive of the caudal fin. [Dentition unsatisfactorily known but] principal teeth exhibiting two crimped rings on crown. Dorsal fin occupying the hinder half of the back, and its maximum elevation equalling about one-fourth of the depth of the trunk at its insertion. Scales towards the dorsal margin conspicuously tuberculated, the others marked with a coarse reticu- lation. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. P. 1620, P. 3771. Nearly complete fish 0:19 in length, partly in counterpart, wanting the greater part of the dorsal and anal fins; Kelheim. Egerton and Enniskillen Colls. P. 3766. Portion of trunk of a large fish, probably of this species ; Kelheim. Enniskillen Coll. P. 1621. Imperfect anterior portion of small fish, probably of this species ; Kelheim. Egerton Coll. Gyrodus hexagonus (Blainville). [Plate XVI. fig. 3.] 1818. Stromateus hexagonus, H. D. de Blainville, Nouv. Dict. d’Hist. Nat. vol. xxvii. p. 334. 1833-44. Microdon hexagonus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 16, pt. il. pp. 184, 206, pl. Ixix.e. figs. 4, 5. 1833-44. Microdon analis, L. Agassiz, ibid. pt.i. p. 16, pt. i. p. 207, pl. lxix.c. tig. 3. [Nearly complete fish ; Palzeontological Museum, Munich. | 1844. Gyrodus analis, L. Agassiz, zbid. pt. ii. p. 300. 1851. Gyrodus hexagonus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. pp. 32, 40, 44, pl. ui. fig. 1. 1851. Gyrodus lepturus, A. Wagner, ibid. vol. vi. pp. 31, 56. [Imperfect fish ; Paleontological Museum, Munich. | 1852. Gyrodus rugosus, F. A. Quenstedt (errore), Handb. Petrefakt. pil, plixvities 1% 1862. Gyrodus hexagonus, A. Wagner, loc. cit. vol. ix. p. 334. 1881. Gyrodus macrophthalmus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 20 (in part.) 1887. Gyrodus hexagonus, K. A. yon Zittel, Handb. Paleeont. vol. iii. p- 241, fig. 252. Type. Nearly complete fish and fragment; Paleontological -Museum, Munich, and British Museum. A species, so far as known, closely similar to the type, only differing in the relatively greater protuberance of the abdominal OTT eS a iF Fi he Pgh PYCNODONTIDZ. 235 region, and in the simpler mammillation of the teeth. The maxi- mum depth of the trunk exceeds its length. A relatively large specimen from the Lithographic Stone of Solenhofen, in the Munich Museum, is regarded by Wagner (oe. cit. 1862, p. 335) as probably a distorted example of this species, but in case it happens to prove distinct is provisionally named G. turgzdus. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. P. 3774. Fragment figured by Agassiz, loc. cit. pl. Ixix.c. fig. 4, as one of the type specimens; Solenhofen. Part of a pectoral] fin shows seven basals, and this is evidently not the complete series. A calcified gill-filament exhibits the sparse denticles on one side as in Mesturus. Enniskillen Coll. 37108. Nearly complete fish, partly crushed and fractured, but displaying the relations of the hyomandibular (Am.) to the operculum (op.) and preoperculum (p.op.) as shown in Pl. XVI. fig. 3; Solenhofen. Hiberlein Coll. 37813. Smaller nearly complete fish, in counterpart; Solenhofen. Haberlean Coll. 37814. A more imperfect specimen 0°175 in length, in counter- part; Solenhofen. A detached tooth resembles the form described by Agassiz in G. macrophthalmus. Hiberlen Coll. 37106. Imperfect fish 0-14 in length, in counterpart; Solenhofen. Hiaberlein Coll. P. 1623, P. 1623 a, P. 2098. Two imperfect small specimens and the scattered remains of a larger fish; Solenhofen. No. P. 1623 shows the feebly serrated abdominal ridge-scales, and no. P. 2098 displays the splenial dentition. Egerton Coll. P. 3769, P. 3772-73. Four imperfect examples of the trunk; Kelheim. Enniskillen Coll. Gyrodus frontatus, Agassiz. [Plate XVI. fig. 2.] 1839-44. Gyrodus frontatus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. pp- 226, 301, pl. Lxviii. 1840. Gyrodus gracilis, G. yon Miinster, Beitr. Petrefakt. pt. iii. p. 128, pl. vin. fig. 2. [Immature fish ; Paleontological Museum, Munich, and Woodwardian Museum, Cambridge. ] 236 ACTINOPTERYGII. 1851. Gyrodus frontatus, A. Wagner, Abh. k. bay. Akad. Wiss., math. phys. Cl. vol. vi. pp. 29, 55. 1851. Gyrodus gracilis=“Microdon hexagonus,” A. Wagner, tbid. p. 32. (?) 1852. Gyrodus medius, F. A. Quenstedt, Handb. Petrefakt. p. 211, pl. xvi. fig. 2. [Imperfect fish ; Tubingen University Museum. | 1862, Gyrodus macrophthalmus, A. Wagner, ibid. vol. ix. p. 336 (in part). 1862. Gyrodus gracilis, A. Wagner, ibid. vol. ix. p. 338. 1881. Gyrodus macrophthalmus, B. Vetter, Mittheil. k. mineral, -geol. Mus. Dresden, pt. iv. p. 20 (in part). 1887. Gyrodus Ve, K. A. von Zittel, Handb. Palzont. vol. iii. p- 242, fig. 254. 1893. Gyrodus Frontatus, H. E. Sauvage, Bull. Soc. Hist. ee Autun, vol. vi. p. 440. Type. Nearly complete fish ; British Museum. A species resembling G'. hewagonus in form and _ proportions, but differing in having the tubercular ornament of the scales, without reticulations, extending over the ventral half of the fish. The reticular ornament of the scales in G'yrodus evidently results from the connection of scattered tubercles by slight ridges. Such a modification may be produced during the growth of the fish, and in that case the so-called Gyrodus gracilis is probably the young stage of G. macrophthalmus and G. hewagonus as well as that of G. frontatus. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria, and Ain, France (Sauvage). P. 2096. Type specimen; Kelheim. Little can be seen of the scale-ornament of the ventral half of the fish, but the few traces remaining exhibit scattered tubercles without reticulation. Egerton Coll. 22515. Remains of a smaller specimen; Solenhofen. Purchased, 1848. P.3770. Fish originally about 0°115 in length, wanting the anterior half of the head and the caudal fin; Kelheim. The characteristic expansions on the neural and hemal spines of the caudal region are conspicuous, as described in the next specimen. Six orseyen basal cartilages are observed in the lobe of the pectoral fin, which is covered with thin round scales. Enniskillen Coll. P. 2097. Fine specimen 0:075 in length, shown of the natural size in Pl. XVI. fig. 2; Kelheim. The coarse tubercular ornament of the cranial roof is shown, while the hinder margin of the frontal (fr.) and the boundaries of the PYCNODONTID#. 937 squamosal (sq.) are obscurely indicated. The position of the jaws is shown by remains of the bones and traces both of the prehensile and tritoral teeth. The so-called ossified sclerotic (scl.) of the very large eye is also pre- served, and seems to exhibit a few minute granulations. A few of the small polygonal tessere (¢.) covering the cheek can be seen immediately below a fragment of the parasphenoid ; and the whole of the gular region as far back as the clavicle is invested with similar tessere (¢.) bearing sparse tuberculations. A few traces of the cal- cified gill-filaments (g.f.) remain at the back of the cheek ; while the right operculum and preoperculum are exposed from the inner aspect. The operculum (op.) is indented on the front margin at its point of suspension from the hyomandibular; the preoperculum (p.op.) is thickened at the upper end and exhibits delicate structural fibres radiating from a point at about the middle of its anterior margin. Immediately below the preoperculum are two branchiostegal rays (67.), and in front of these appear fragments of bone perhaps of the hyoid arch. The axial skeleton of the trunk is well shown and is noteworthy for the form of the expansions on the neural (n.) and heemal (h.) spines of the caudal region. Each expansion is triangular, contracting at the base, widening distally, and almost—though not quite—confined to the anterior margin of the spine. Similar expansions appear to occur at least on the hindermost neural spines of the abdominal region. The lobe of the pectoral fin (p.) is distinctly covered with small thin scales, each ornamented with a tubercle; and a cluster of elongated basal cartilages is preserved. The lower expansion of the clavicle (cl.) terminates in a point at the ventral border of the fish. The slender pelvic bones (plv.) are imperfectly shown at the base of the fragmentary pelvic fins. The median fins exhibit no features worthy of special remark; but just in advance of the origin of the anal the problematical bone (#) marking the posterior limit of the abdominal cavity is well displayed. Fine serrations, or acuminate tubercles, are observed on the dorsal and ventral ridge- scales; and the courses of both “ lateral lines” are con- spicuous. Egerton Coll. P. 3768. More imperfect smaller specimen, in counter- part, displaying the scaly lobe of the pectoral fin and six 238 ACTINOPTERYGII. of its basal cartilages; Kelheim. The supposed sclerotic seems to exhibit a few sparse and fine granulations as in the last specimen. Egerton and Enniskillen Colls. P. 3768 a. Very small, immature fish, wanting the caudal region ; Kelheim. Though much crushed, this specimen is in- teresting as exhibiting a thickened har behind the operculum, extending from the normal upper limit of the clavicle to the back of the cranium, thus probably a supraclavicle. Seven basals are preserved in the pectoral fin. Enniskillen Coll. Gyrodus circularis, Agassiz. 1833. Spherodus rhomboidalis, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p- 15 (undefined). 1834-44. Gyrodus cireularis, L. Agassiz, Poiss. Foss., Feuill. p. 18 (name only), and vol. ii. pt. 11. p. 300. 1834-44. Gyrodus punctatissimus, L. Agassiz, ibd. Feuill. p. 18 (name only), and vol. ii. pt. ii. p. 301. [Fragment of fish; Paleontological Museum, Munich.] (=Microdon gigas, Agass. MS.) 1834-44. G'yrodus rhomboidalis, L. Agassiz, ibid. Feuill. p. 18 (name only), and vol. ii. pt. ii. p. 300. [Imperfect fish ; Paleontological Museum, Munich. } 1836. Gyrodus multidens, G. von Minster, Neues Jahrb. p. 581. [Imperfect head ; Palzeontological Museum, Munich. | 1845. Gyrodus wmbilicus, Mandelslohe, Wiirtt. Jahresh. vol. 1. p. 158, fig. 2. 1851. Gyrodus circularis, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p. 10, pl. i. fig. 1. 1851. Gyrodus rhomboidals, A. Wagner, aid. vol. vi. p. 19, pl. i. fig. 2. 1851. Gyrodus multidens, A. Wagner, 162d. vol. vi. p. 23, pl.i. figs. 3, 4. 1851. Gyrodus punctatissimus, A. Wagner, wid. vol. vi. p. 27. 1855. Gyrodus umbilicus, O. Fraas, Wiirtt. Jahresh. vol. xi. p. 100. — 1862. Gyrodus titanius, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. p. 331. [Founded on the type specimen of G. circularis, Ag. | 1862. Gyrodus giganteus, T. C. Winkler, Descript. Poiss. Foss. Solen- hofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv.), p. 80, figs. 13-15. [Nearly complete fish; Teyler Museum, Haarlem. | 1867. Gyrodus titans, F. A. Quenstedt, Handb. Petrefakt. ed. 2, p. 254. 1881. Gyrodus titanius, B. Vetter, Mittheil. k. mineral.-geol. Mus. | Dresden, pt. iv. p. 21. 1887. Gyrodus titanius, K. A. von Zittel, Handb. Paleeont. vol. iii, pp. 242, 248, figs. 253, 255-257. Type. Nearly complete fish ; Paleontological Museum, Munich. | A large species, attaining a length of about 1:0. Maximum PYCNODONTID. 239 depth of trunk somewhat less than its length from the scapular arch to the base of the caudal fin, and head with opercular apparatus occupying less than one-third of the total length ex- clusive of the caudal fin. External head-bones ornamented with tuberculations. Dentition closely arranged, with comparatively feeble ornament, soon worn smooth. Vomer with prominent flat- topped median teeth, higher than either of the flanking series, and equalling or exceeding these two series together in width; the inner flanking series somewhat smaller than the outer, of which the teeth are not much elevated. Splenial with principal teeth broader than long, about equalling in width the two flanking series, of which the outermost is much the largest ; inner flanking teeth equalling in size those of the innermost series. Dorsal fin occupying the hinder half of the back, and its maximum elevation equalling at least one third of the depth of the trunk at its insertion. Scales towards the dorsal margin ornamented with distant tubercles, the others marked with a delicate reticulation, partly also tuberculated. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria and Wurtemberg. 49146. Plaster cast of type specimen, the head figured by Wagner, loc. cit. 1851, pl. i. fig. 1; Solenhofen, Bavaria. Purchased, 1878. 37039. A fine specimen 0°68 in length, with imperfect head and paired fins ; Solenhofen. Haberlein Coil. 37792. Head with imperfect trunk and dorsal fin of a still larger fish ; Solenhofen. The mouth is open, and the worn vomerine and splenial dentition has been well extricated from the matrix. Two of the anterior prehensile teeth of the lower jaw and one in the upper jaw are also shown. Some of the small, coarsely tuberculated scales are shown below the hinder part of the mandible. §Hiéiberlein Coll. P. 1622. Fragment of squamation ; Solenhofen. Egerton Coil. P. 3775. Smaller fragment ; Daiting, Bavaria. Enniskillen Coll. 35532. Plaster cast of vomerine dentition probably of this species, described and figured by Count von Mandelslohe, Joc. cit. 1845 ; Wippingen, near Blaubeuren, Wirtemberg. Purchased, 1859. It is not improbable that to Gyrodus circularis must also be assigned the portions of dentition named G'yrodus umbilicus (L. 240 ACTINOPTERYGII. Agassiz, Poiss. Foss. vol. ii. pt. i. 1833, p. 16, pt. ii. 1844, p. 227, pl. lxix. a. figs. 27, 28; F. A. Quenstedt, Handb. Petrefakt. 1852, p. 212, pl. xvi. fig. 3; ? H. E. Sauvage, Catal. Poiss. Form. Second. Boulonnais, 1867, p. 41, pl. ii. fig. 12, and Bull. Soc. Géol. France, [3] vol. viii. 1880, p. 526) from the Corallian of Durrheim, Baden, and Schnaitheim, Wurtemberg (possibly also Kimmeridgian and Portlandian of N. France), and Glyrodus jurassicus (L. Agassiz, Poiss. Foss. vol. ii. pt. 1. 1833, p. 16, pt. ii. 1844, p. 229, pl. Ixix. a. figs. 25, 26; F. A. Quenstedt, Hanae Petrefakt. 1852, p. 212, pl. xvi. fig.5 ; K. Fricke, Palzontogr. vol. xxii. 1875, p. 374, pl. xx. figs. 17, 18) from the Kimmeridgian of Soleure, Switzerland, the Corallian and Kimmeridgian of Hanover, and the Corallian of Schnaitheim, Wirtemberg. Of the latter the type specimen is in the Museum of Soleure, and the two species are represented in the Collection by the following examples :-— 22493*, 22658. Two unworn detached teeth of G. wmbilicus; Coral- lian, Schnaitheim. Purchased, 1848. 42884. Plaster cast of the type specimen of G. jurassicus, being the two associated splenial bones ; Kimmeridgian, Soleure. Van Breda Coll. P. 3778. Portion of left splenial dentition, probably the specimen referred to G. jurassicus by Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 230; Soleure. Enniskillen Coll. P. 5952. Left splenial dentition of the form referred to G. jurassicus by Fricke, Joc. cit.; Kimmeridgian, Holzen, near Eschers- hausen, Hanover. Purchased, 1889. P. 3751. Portion of abraded splenial dentition, labelled ** Pycnodus spherodus” by Agassiz; Portlandian, Neuchatel, Switzer- land. Enniskillen Coll. Gyrodus cuvieri, Agassiz. 1833-44, Gyrodus cuviert, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 16, pt. ii. p. 280, pl. lxix. a. figs. 21-23. 1867. Gyrodus cuviert, H. E. Sauvage, Catal. Poiss. Form. Second. Boulonnais (Mém. Soc. Acad. Boulogne-sur-Mer, vol. ii.), p. 48, pl. ii. fig. 13. 1875. Gyrodus ornatissimus, J. F. Blake, Quart. Journ. Geol. Soe. vol. xxxi. p. 223. [Dentition; British Museum. | 1880. Gyrodus ornatissimus, R. Damon, Geol. Weymouth, ed. 2, pl. xi. figs. 1-4, 7-9 (non fig. 6). 1880. Gants cuviert, H. EK. Sauvage, Bull. Soe. Géol. France, [3] vol. vili. p. 526. ee PYCNODONTIDZA. 241 Type. Mandibular dentition. A large species known only by the dentition, of which the splenial is indistinguishable from that of G. circularis. omer with pro- minent mammillated median teeth, usually not quite equalling the two flanking series in width, and scarcely more elevated than the outermost of the latter, which comprises triangular teeth rising to a conical apex; inner flanking teeth relatively small, low, rounded, and highly ornamented. The form and degree of ornamentation of the principal teeth on the splenial in this species vary considerably. The immature and smaller specimens are named G. ornatissumus by Blake. . Form. & Loc. Lower Kimmeridgian: Dorsetshire, Wiltshire, and Cambridgeshire ; N. France. | P. 7456. Fine example of the vomerine dentition, 0°035 in maximum width ; Kimmeridge Clay, Poulshot, Wiltshire. 41868, 43026, 43561, 43563, 44085. Five small vomers, the two first comparatively narrow and with very prominent median teeth; Kimmeridge Clay, Weymouth. Purchased, 1869, —71, —72, -73. _ P. 1615, P. 3785. Three similar specimens ; Weymouth. Egerton and Enniskillen Colls. P. 6151, P. 6166. Four similar specimens, one being figured by Damon, op. cit. pl. xi. fig. 4; Weymouth. These and the splenials numbered P. 6168 may be regarded as the type specimens of the so-called Gyrodus ornatissimus. Damon Coll. P. 1618. Plaster cast of large right splenial; Kimmeridge Clay, Boulogne. gerton Coll. 32746. Somewhat smaller left splenial; Kimmeridge Clay, Ely. Purchased, 1857. 38553. Imperfect smaller specimen, probably from Ely. Purchased, 1864 — 43025. Fine left splenial of moderate size; Kimmeridge Clay, Weymouth. Purchased, 1871. 41227, 41963. Portions of right and left splenials, with remarkably smooth principal teeth, and the first specimen exhibiting a supplementary row of small teeth within the outermost series; Weymouth. Purchased, 1868, -70. PART III. R 949 ACTINOPTERYGII, P. 6168. Two fine right splenials figured by Damon, op. cit. pl. xi. figs. 1, 7, and also a left splenial ; Weymouth. Damon Coll. P. 6164. Imperfect right splenial, figured 2bid. pl. xvii. fig. 9; said to have been obtained from the Coral Rag, near Sandsfoot, Weymouth, but probably from the Kimmeridge Clay. Damon Coll. 43559. Small elongated left splenial ; Weymouth. Purchased, 1872. 40638-39, 41176, 44087. Four small right splenials ; Weymouth. Purchased, 1867-68, 1873. P, 1614. Small right and left splenials, the latter exhibiting an irregular supplementary row of small teeth within the innermost series ; Weymouth. Egerton Coll. P, 3786,-a. Small right and left splenials, and a very diminutive specimen of the left side; Weymouth. Enniskillen Coll. P. 346. Very small left splenial, with supplementary inner teeth ; Weymouth. Purchased, 1881. P. 6151 a. Pair of very small splenials; Weymouth. Damon Coll. P. 3786 b. Abnormal right splenial, doubtfully of this species, with relatively small principal teeth and two large inner series; Weymouth. Enniskillen Coll. The following specimens do not differ much from the dentition of Gyrodus cuviert :— 40468, 40471-72. Portion of a large vomer, and a large and small splenial, much abraded; Neocomian (derived fossils), Potton, Bedfordshire. Purchased, 1867. 40467. Two anterior prehensile teeth; Potton. Purchased, 1867. Gyrodus minor, Agassiz. 1829. “ Jaw-bone and teeth of a Reptile,” J. Phillips, Geol. Yorkshire, p- 124, pl. ii. fig. 55. 1833-44, Gyrodus minor, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 16 pt. ii. p. 234, pl. Ixix. a. fig. 14, (?) 1844. Pyenodus minor, L. Agassiz, ibid. pt. ii. p. 200 (name only). I Type. Imperfect splenial dentition. A species known only by the splenial dentition, which closely resembles that of G. cuviert, but appears to have the teeth more PYCNODONTIDA. 243 strongly ornamented, while the outer end of the larger teeth is raised into a pointed eminence. Form. & Loc. Neocomian (Speeton Clay) : Yorkshire. P. 1624. Imperfect left splenial; Speeton. Egerton Coll. Gyrodus coccoderma, Egerton. (?) 1867. Pycnodus subcontiguidens, H. EK. Sauvage, Catal. Poiss. Form. Second. Boulonnais (Mém. Soc. Acad. Boulogne-sur-Mer, vol. 11.), p- 36, pl. ii. figs. 10, 11. 1869. ean coccoderma, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. xxv. p. 383, figs. 3, 4. 1880. Gyrodus apne ve, R. Damon, Geol. Weymouth, ed. 2, Suppl. pl. xi. fig. 5. (?) 1880. Mesodon subcontiguidens, H. EK. Sauvage, Bull. Soc. Géol France, [3] vol. viii. p. 528. Type. Vomer; Museum of Practical Geology, London. A species of large or moderate size, known only by the dentition. Teeth closely arranged and all with a feeble ornamentation, rapidly obliterated by wearing. Vomer with a prominent median series of teeth, at least equalling the two flanking series in width ; the outer of the latter obtusely conical, not much elevated and exceeding in size the inner series of flanking teeth, which are round or antero- posteriorly elongated. Splenial differing from that of G. corcularis: and G'. cuviert merely in the comparative smoothness of the teeth. Though the name G*. coccoderma was originally proposed for some specifically indeterminable scales, it has gradually become applied to the dentition above described, and the vomer provisionally assigned to this species by Egerton may thus be regarded as the type specimen. Form. & Loc. Kimmeridgian: Dorsetshire and Cambridgeshire ; N. France. P. 6747. Fine large vomer 0°028 in maximum width, with little- worn dentition ; Kimmeridge Clay, Weymouth. Purchased, 1892. P. 6167. Two somewhat smaller specimens, one figured by Damon, op. cit. pl. xi. fig. 5; Weymouth. Damon Coll. 43560, 43562. Portion of similar vomer, and a smaller specimen ; Weymouth. Purchased, 1372. 40637, 41175, P. 3785 a. Three fine much-worn vomers; Wey- mouth. Purchased, 1867-68 and Enniskillen Coll. RQ 244 ACTINOPTERYGII. 41392, 41870—73. Four fragments and one small much-worn vomer ; Weymouth. Purchased, 1869. P. 3787. Portion of large vomer with much-worn teeth; Kim- meridge Clay, Ely. Enniskillen Coll. 32549. Dentition of large left splenial ; Kimmeridge Clay, Havre. Lesson Coll. 41391, 44088. Two examples of the left splenial ; Weymouth. Purchased, 1869, 1878. P. 1614a. Two right splenials ; Weymouth. Egerton Coll. P. 3786 c. Right and left splenials with very irregular principal teeth, and the former showing a supplementary inner series of minute teeth; Weymouth. Enniskillen Coll. Gyrodus planidens, sp. nov. 1880. Gyrodus ornatissimus, R. Damon, Geol. Weymouth, ed. 2, Suppl. pl. x1. fig. 6 (errore). Type. Vomer; British Museum. A species of moderate or small size, known only by the vomer, which bears highly ornamented and widely spaced teeth. Teeth of median series on the vomer much less in width than the two flanking series, neither the median nor the outermost teeth much more elevated than those of the inner flanking series, which are, however, the smallest. The splenial dentition of this species is either unknown or indis- tinguishable from that of G. cwvieri. Form. & Loc. Kimmeridgian: Dorsetshire. P. 6166 a. Type specimen figured by Damon, loc. cit.; Kimmeridge Clay, Weymouth. Damon Coll. 44086. Vomer ; Weymouth. Purchased, 1873. P, 3785 b. Another fine vomer ; Weymouth. Enniskillen Coll. FP. 1615 a. Imperfect vomer; Weymouth. Lgerton Coll. 41393. Two small specimens ; Weymouth. Purchased, 1869. Gyrodus murchisoni, Mantell. 1844, Gyrodus murchisoni, G. A. Mantell, Medals of Creation, p. 6438, fig. 134. Type. Portion of vomer; British Museum. A large species known only by the vomerine dentition. Teeth of PYCNODONTID A. 945 vomer depressed and flattened, conspicuously rugose, those of the median series not very prominent and at least equalling in width the two flanking series. Form. & Loc. Jurassic: Russia. P. 3782. Type specimen described and figured by Mantell, loc. cit. ; from Rjeff, on the Volga. The crowns of the outermost series of teeth are all broken away, and only one of the median series remains. Enniskillen Coll. Gyrodus (?) cretaceus, Agassiz. 1833-39. Spherodus mammillaris, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p- 15 (in part), pl. Ixxiii. figs. 1,2. [Teeth. ] 1839-44, Gyrodus cretaceus, L. Agassiz, ibid. vol. ii. pt. ll. p. 233, pl. lxix. a. fig. 13. 1840. Gyrodus cretaceus, R. Owen, Odontography, p. 72. 1844. Gyrodus mammillaris, L. Agassiz, tbid. vol. ii. pt. il. p. 236. 1844. Pycnodus marginalis, L. Agassiz, ibid. vol. ii. pt. ii. p. 199. [ Tooth. ] 1850. Gyrodus cretaceus, F. Dixon, Geol. Sussex, p. 370, pl. xxx. fig. 15. 1850. Gyrodus conicus, F. Dixon, 2bid. p. 370, pl. xxxii. fig. 8. 1888. Gyrodus cretaceus, A. S. Woodward, Proc. Geol. Assoc. vol. x. p. 308. Type. Portion of vomerine dentition. A large species of uncertain genus, probably not Gyrodus, but known only by fragmentary dentition. Dental crowns much elevated, obtusely acuminate, and coarsely rugose ; those of the median and outer paired series on the vomer longer than broad, about equal in size ; teeth of inner paired series on this bone relativelv small and irregularly subdivided. Form. & Loc. Senonian: Sussex and Surrey. 39048. Vomerine dentition figured in Dixon’s Geol. Sussex, pl. xxx. fig. 15; Chalk, Lewes. Bowerbank Coll. 49802. Portion of vomerine dentition ; Upper Chalk, St. Catherine’s Hill Pit, near Guildford. Capron Coll. P. 6852. Portion apparently of splenial dentition, showing principal series of teeth ; Chalk, Upper Warlingham, near Croydon. Presented by G. E. Dibley, Esq., 1893. The following specimen seems to belong to Gyrodus, but is not specifically determined :— 43285. Portion of relatively broad vomer, with well-spaced teeth remarkably uniform in size (Pl. XVII. fig. 5) ; Kimmeridge 246 ACTINOPTERYGII. Clay, Weymouth. The teeth of the median and inner lateral series only are preserved, and each is slightly broader than long, with a cingulum at the base of the crown which is raised into a comparatively trenchant edge. Purchased, 1871. The following species have also been imperfectly defined, chiefly upon the evidence of the dentition, but are not represented in the Collection :— Gyrodus contiguidens: Pycnodus (Typodus) contiguidens, F. J. Pictet, Rept. et Poiss. Foss. Jura Neuchatel (1860), p. 69, pl. xvi. fig. 1; (?)J. Cornuel, Bull. Soc. Géol. France, [3] vol. x1. (1883), p. 23, pl. i. figs. 4, 5.—Kimmeridgian ; Neuchatel. (?) Neocomian; Haute Marne. [Vomer; Neuchatel Museum. | Gyrodus fabrer, H. EK, Sauvage, Bull. Soc. Géol. France, [3] vol. vi. (1878), p. 629, pl. xi. fig. 2.—Lias; Nancy, France. [Left splenial. | Gyrodus fortisi, G. G. Gemmellaro, Studi Paleont. Fauna Cale. Terebratula jantor N. Sicilia, pt. 1. (1868), p. 6, pl. i. figs. 15-31.—Tithonian ; Favara, Villabate, N. Sicily. [Detached teeth; Geological Museum, University of Palermo. | Gyrodus goweri, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. xxv. (1869), p. 379, figs. 1, 2.—Middle Jurassic; Culgower, Sutherland. [Trunk.] Gyrodus imitator: Pycnodus wmitator, J. Cornuel, Bull. Soc. Géol. France, [3] vol. v. (1877), p. 612, pl. xi. fig. 11, and ibid. vol. viii. (1880), p. 157, pl. ii. figs. 18,19. Cosmodus imitator, H. HK. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxill. (1879), pt. 11. p. 49.—Neocomian; Wassy, Haute Marne, and Ville-sur-Saulx, Meuse, France. [Im- perfect splenial. | Gyrodus (?) levior, L. Agassiz, Poiss. Foss. vol. i. pt. il. (1844), p- 233, pl. lxix.a. fig. 12.—Form. & loc. unknown’. [Right splenial ; Paris Museum Nat. Hist. ] Gyrodus larteti: Pycnodus larteti, H. E. Sauvage, Catal. Poiss. Form. Second. Boulonnais (Mém. Soc. Acad. Boulogne- sur-Mer, vol. ii. 1867), p. 33, pl. 11. fig. 1, and Bull. Soe. Géol. France, [3] vol. viii. (1880), p. 527.—Portlandian ; N. France. [Imperfect splenials; Boulogne Museum. | 1 An isolated tooth in the Enniskillen Collection (P. 3783), said to have been obtained from the London Clay of Sheppey, is labelled “ Gyrodus levior, Agass.” by Agassiz. PYCNODONTID®. 247 Gyrodus platurus, L. Agassiz, op. cit. Feuill. (1834), p. 16 (name only); A. Wagner, Abh. k. bay. Akad, Wiss., math.-phys. Cl. vol. ix. (1862), p. 336. Microdon platurus, L. Agassiz, op. cit. vol. 11. pt. 1. (1833), p. 16. Gyrodus truncatus, A. Wagner, loc. cit. vol. vi. (1851), p. 46.:—Lower Kimmeridgian (Lithographic Stone); Bavaria. [Nearly complete fish ; Palzontological Museum, Munich. | Gyrodus punctatus, L, Agassiz, op. cit. vol. ii. pt. 11. (1844), p. 231, pl. lxix. a. fig. 24; A.S. Woodward, Ann. Mag. Nat. Hist. [6] vol. xii. (1893), p. 400, pl. xviii. figs. 2-4. (?) Pye- nodus umbonatus, L. Agassiz, loc. cit. pt. 1. (1833), p. 16, pt. 11. (1844), p. 194, pl. lxxu., a. figs. 1, 3, 4 (non fig. 2).— Corallian ; Malton, Yorkshire. [Vomer; York Museum. | Gyrodus sculptus: Pycnodus sculptus, J. Cornuel, Bull. Soc. Géol. France, [3] vol. v. (1877), p. 611, pl. xi. figs. 8-10, and ibed. vol. vill. (1880), p. 157, pl. ii. figs. 20, 21. Cos- modus sculpius, H. EK, Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiil. pt. 1. (1879), p. 49.—Neocomian; Wassy, Haute Marne, and Soulaines, Aube, France. [Imperfect splenials. | Gyrodus (?)schusteri, F. A. Roemer, Verstein. Norddeutsch. Oolithengeb., Nachtr. (1839), p. 54.—Purbeckian ; Salz- burg, Osterwald. An imperfect vomer, with widely-spaced smooth teeth, appa- rently referable to a large species of Gyrodus, is described by Egerton from the Kimmeridge Clay of Kimmeridge, Dorsetshire, and wrongly named Spherodus gigas (Quart. Journ. Geol. Soc. vol. xxv. 1869, p. 385, woode. fig. 5). Some prehensile front teeth from the Kimmeridgian of Berne, Switzerland, apparently also of Gyrodus, are erroneously referred to Capitodus under the name of C. gresslyi by J. Thurmann, Nouv. Mém. Soc. Helv. Sci. Nat. vol. xviii. (1864), p. 481, pi. ixi. fig. 21. The following names have also been given to indeterminable detached teeth :— Gyrodus dixon, W. A. Ooster, Protozoe Helvetica, vol. ii. (1570), p. 46, pl. ix. fig. 7. Figure by F. Dixon, Geol. Sussex (1850), pl. xxxii.* fig.6.—Chalk; Sussex and Bernese Alps. Gyrodus ellapticus, E. von Kichwald, Leth. Rossica, vol. ii. (1868), p. 1211, pl. xxxviii. fig. 11.—Neocomian; Biassala, Crimea. Gyrodus muenstert, L. Agassiz, Poiss. Foss. vol. ii. pt. 11. (1844), p. 238, pl. lxix.a. fig. 17; A. E. Reuss, Verstein. bohm. Kreideform. pt. i. (1845), p. 9, pl. iv. figs. 57-60.—Ceno- manian; Bavaria and Bohemia. 248 ACTINOPTERYGII. Gyrodus navicularis, T. C. Winkler, Archiv. Musée Teyler, vol. iv. (1874), p. 30, pl. ii. figs. 19-21.—Middle Eocene (Bruxellian) ; Uccle, Brussels. [Not Pycenodont. ] Gyrodus quadratus, A. K. Reuss, Verstein. bohm. Kreideform. pt. 1. (1845), p. 9, pl. iv. figs. 56-61.—Cenomanian ; Bohemia. Gyrodus rugulosus, L. Agassiz, Poiss. Foss. vol. i. pt. 11. (1844), p. 235, pl. lxix.a. fig. 16—Cenomanian ; Regensburg, Bavaria. [Royal Bohemian Museum, Prague. |] Gyrodus runcinatus, L. Agassiz, zbid. pt. 1. (1833), p. 16, pt. 11. (1844), p. 236, pl. Ixix. a. fig. 19.—Form. and loc. un- known. [Stuttgart Museum. | Gyrodus wannerius, A. Dollfuss, Faune Kimm. Cap De la Heve, (1863), p. 35, pl. i. figs. 17, 18 (name said to have been originally given by Lesueur to a jaw much resembling G. jurassicus, figured on a rare plate “ Vues et coupes de la Heve,” 1843).— Kimmeridgian ; Normandy. Genus STEMMATODUS, Heckel. [Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. 1856, p. 202.1] Trunk deeply fusiform, not produced at the caudal pedicle. Head and opercular bones tuberculated; teeth with an apical indent surrounded by a crenulated margin; vomerine teeth in five longi- tudinal series, and splenial teeth in three series. Neural and hemal arches of axial skeleton of trunk not expanding sufficiently to encircle the notochord. Fin-rays delicate, spaced, and articulated in the dorsal and anal fins; stouter, more closely articulated, and divided distally in the caudal fin. Pelvic fins present; dorsal and anal fins low, acuminate in front, fringe-like behind, the former occupying at least the hinder half of the back, and the latter somewhat shorter, arising more posteriorly ; caudal fin with straight or slightly ex- cavated hinder margin. Scales covering only the anterior half of the trunk in advance of the median fins. Stemmatodus rhombus (Agassiz). 1839-44, Pycnodus rhombus, L. Agassiz, Poiss. Foss. vol. i. pt. il. p. 188, pl. lxxil. figs. 5-7. 1856. Stemmatodus rhombus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 202. 1856. Stemmatodus rhomboides, J. J. Heckel, bid. p. 205, pl. ii. figs. 9-11. [Nearly complete fish; Royal Bohemian Museum, Prague. | PYCNODONTID &. 249 Type. Nearly complete fish. The type species, attaining a length of about 0°08. Maximum depth of trunk about equal to its length from the scapular arch to the base of the caudal fin, and head with opercular apparatus occupying somewhat less than one-third of the total length of the fish ; arched dorsal contour sharply bent just in advance of the fin. External bones closely but coarsely tuberculated, in part reticulated ; all the teeth finely crenulated round the margin of the coronal indentation. Dorsal fin comprising about 36 rays, and its maximum elevation not equalling more than one-fourth of the depth of the trunk at its insertion ; anal fin with about 30 rays. Ridge-scales finely serrated. Form. & Loc. Upper Jurassic: 8. Italy. 18600. Slab with two typical specimens; Torre d’Orlando, near Naples. Purchased, 1844. 23152. Slab with three specimens, in counterpart ; Torre d’Orlando. Presented by Major Macdonald, 1849. 43451. Slab with two specimens, showing part of the dentition ; Torre d’Orlando. Presented by Kenneth Murchison, Esq., 1872. 39775. Small fish showing part of the dentition ; Torre d’Orlando. Purchased, 1862. P. 1670-73. Four specimens; Torre d’Orlando. Egerton Coil. P. 7457. A comparatively elongated fish; Torre d’Orlando. Genus CQGLODUS, Heckel’. [Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. 1856, p. 202.] Syn. Glossodus, O. G. Costa, Atti Aecad. Pontan. vol. vii. 1853, p. 26. Cosmodus, H. EK. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiii. pt. ii. 1879, p. 48. Trunk very deeply fusiform, with slender abbreviated caudal pedicle. Head and opercular bones externally rugose and punctate ; most of the teeth exhibiting an apical indent with crenulated border ; oral surface of vomer strongly convex from side to side, with teeth in five longitudinal series; splenial dentition comprising three series of teeth with long axes directly transverse, sometimes * This name having gained universal acceptance, we adopt it, notwithstanding its preoccupation among Mammalia by Celodon, Lund, 1839. 250 ACTINOPTERYGII. supplemented within by a small row, and all the outer teeth showing frequent tendency to irregular subdivision. Neural and heemal arches of axial skeleton of trunk not expanding sufficiently to encircle the notochord. Fin-rays robust, closely articulated, and much divided distally. Pelvic fins present; dorsal and anal fins high and acuminate in front, low and fringe-like behind, the former occupying at least the hinder half of the back and the latter some- what shorter, arising more posteriorly ; caudal fin deeply forked, with a convexity in the middle. Scales ornamented with reticulating ruge and punctations, and occupying only the anterior half of the trunk in advance of the median fins. Ceelodus saturnus, Heckel. 1856. Celodus saturnus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 207, pls. ili., iv. 1863. Celodus saturnus, R. Kner, Sitzungsb. k. Akad. Wiss., math.- naturw. Cl. vol. xlviil. pt. 1. p. 138. 1867. Celodus saturnus, R. Kner, zbcd. vol. lvi. pt. i. p. 198. Type. Nearly complete fish. The type species, attaining a length of about 0°5. Maximum depth of the trunk equalling about one-half, and length of head with opercular apparatus one-quarter of the total length of the fish. Vertebral axis at origin of dorsal fin midway between the dorsal and ventral borders of the fish. Teeth of median series on the vomer about twice as broad as long, those of the first lateral series little elongated and obliquely set, those of the outer series smaller and round or antero-posteriorly elongated. Teeth of the principal (inner) series on the splenial bone attaining a breadth about five times as great as their length, all nearly destitute of apical indent ; those of the next outer series half as large, and about three times as broad as long; those of the outermost series comparatively small and round. Dorsal fin with 65 rays, occupying more than half of the back; anal fin with 48 rays arising more posteriorly. 14-15 vertical series of scales. Form. & Loc. Cretaceous: Goriansk, Istria. Not represented in the Collection. Ccelodus suillus, Heckel. 1856. Celodus suillus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl. vol. xi. p. 217, pls. vi., vii. 1882. Calodus suillus, F. Bassani, 267d. vol. xlv. p. 201. Type. Fish, wanting caudal fin; Museum of Gymnasium, Zara. PYCNODONTIDZ. ya | | _ An imperfectly defined species, somewhat smaller than the type, of nearly similar proportions, but apparently differing in its rela- tively smaller head. Vertebral axis at origin of dorsal fin slightly above the middle point between the dorsal and ventral. borders of the fish. 11 vertical series of scales, each completed at the ventral margin with a coarsely serrated ridge-scale. Form. & Loc. Upper Cretaceous: Island of Lesina, Dalmatia *. P. 5947. Small specimen 0-115 in length, the hinder portion obscured by a thin film of matrix. Purchased, 1889. Ceelodus rosthorni, Heckel. 1856. Ceelodus rosthornu, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 218, pl. v. Type. Hinder two-thirds of fish ; Rosthorn Collection, Klagenfurt. An imperfectly defined species, attaining a length of at least 0°5, remarkable for its much elongated trunk and the great inter- digitating expansion of its neural and hemal arches. Vertebral axis at origin of dorsal fin slightly above the middle point between the dorsal and ventral borders of the fish. Dorsal fin with 51, and anal with 41 rays. ~ Form. & Loc. Upper Cretaceous : Comen, Istria. Not represented in the Collection. Coelodus grandis (Costa). 1853. Pycnodus grandis, O. G. Costa, Atti Accad. Pontan. vol. vii. p- 20, pl. i. figs. 1-3, 5. (2) 18538. Pycnodus achillis, O. G. Costa, zbid. p. 23, pl. ii. figs. 7-10. [Splenial dentition. | ~ 1856. Celodus grandis, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl. vol. xi. p. 203. 1882. Celodus grandis, F. Bassani, zb2d. vol. xlv. p. 232. Type. Nearly complete fish. A small, imperfectly-known, deep-bodied species, the maximum depth of the trunk considerably exceeding its length from the pectoral arch to the base of the caudal fin; head with opercular apparatus occupying about one-quarter of the total length of the fish. Vertebral axis at origin of dorsal fin very slightly above the 1 A fish from the Cretaceous of Mt. S. Agata, near Gradisca, Istria, is also described as closely related to this species by F. Bassani, Jahrb. k. k. geol. Reichsanst. vol. xxxiv. (1884), p. 405, pl. ix. fig. 3. D2 ACTINOPTERYGII. middle point between the dorsal and ventral borders of the fish. 11 vertical series of scales, The splenial dentition named Pycnodus achillis is characterized thus :—Teeth of principal series at least twice as broad as long, exceeding in width the two outer series and irregularly bordered within by one row of small round teeth; those of the inner flanking series also at least twice as broad as long, sometimes subdivided ; those of the outermost series small and round. Form. & Loc. Cretaceous: Pietraroja, Naples. Not represented in the Collection. Coelodus costz, Heckel. 1850. Pycnodus rhombus, O. G. Costa (errore), Atti Accad. Pontan. vol. v. p. 382, pl. iv. fig. 8 (non pl. v. fig. 1). 1856. Celodus coste, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl. vol. xi. p. 203. Type. Nearly complete fish. A small species attaining a length of about 0°105. Maximum depth of the trunk much exceeding one-half, and length of head with opercular apparatus equalling one-third of the total length of the fish. Teeth of principal (inner) series on splenial about three times as broad as long, indented on the apex and with crenulated margin. Dorsal fin with about 46 rays, occupying more than half of the back; anal fin with about 35 rays, arising more posteriorly. 10-12 vertical series of scales. Form. & Loc. Upper Jurassic: S. Italy. P. 1671 a. Small specimen displaying median fins and a few of the splenial teeth; Torre d’Orlando, near Naples. Egerton Coll, P. 4394. More imperfectly preserved fish, 0°105 in length, also showing some of the teeth; Torre d’Orlando. Enniskillen Coll. Ceelodus mantelli (Agassiz). 1827. “ Palates of an unknown fish,’ G. A. Mantell, Foss. Tilgate Forest, p. 58, pl. xvii. figs. 26, 27. 1833. Pycnodus microdon, L. Agassiz, Poiss. Foss. vol. il. pt. 1. p. 17. 1839-44. Pyenodus mantel, L. Agassiz, ibid. pt. il. p. 196, pl. Ixxii. a. figs. 6-14. 1839-44. Gyrodus mantelli, L. Agassiz, ibid. pt. ii. p. 284, pl. lxix. a. fig. 18. [Splenial; British Museum. ] | PYCNODONTIDZA. 253 1853. Glossodus mantellu, O. G. Costa, Atti Accad. Pontan. vol. vii. p- 28. 1856. Celodus mantel, J. J. Heckel, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xi. p. 203. Type. Jaws; British Museum. A species of small or moderate size, known only by the dentition. Teeth of median series on vomer somewhat more than twice as broad as long, with a concave posterior margin, sometimes mesially constricted ; teeth of two lateral series nearly equal in size, slightly elongated antero-posteriorly, and their width together not equalling that of the median series. Teeth of principal series on the splenial bone not more than twice as broad as long, scarcely equalling in width the two outer series, of which the innermost is nearly twice as wide as the outermost ; a row within the principal series very rarely represented even by scattered small teeth. All the teeth, when unworn, with a deep apical pit, not crenulated on the margin. Form. & Loc. Wealden: Sussex. Variety in Purbeckian: Dorset- shire and N. Germany '. 2690, 2698, 2709, 28415, 28417. Series of eight type specimens described and figured by Agassiz, tom. cit. pl. Ixxii. a. figs. 6-9, 11-14, wanting the original of fig. 10; Wealden, Tilgate Forest, Sussex. Mantell Coll. 2700, 2707, 28416. Three specimens of the vomerine dentition, the first large and imperfect; Tilgate Forest. Mantell Coll. P. 4392. Vomerine dentition, wanting outermost series of teeth; Tilgate Forest. Enniskillen Coll. 49115. Two imperfect abraded specimens; Wealden, Tunbridge Wells. Mrs. Smith’s Coll. 1 A form of dentition very closely resembling that of Celodus mantelli, from the Portlandian of Dept. Meuse, France, is also described by J. Cornuel, Bull. Soc. Géol. France, [3] vol. viii. (1880), p. 151, pl. iii. figs. 1-15. He names two varieties of the vomerine dentition, ‘‘ Pycnodus mantelli, var. brevis,” and “var. stricta.” Other doubtful portions of vomers from the Neocomian of Haute Marne, France, are described by the same author, zbid. vol. v. (1877), p. 616, pl. x1. figs. 23-25, and F. J. Pictet, Mém. Soc. Linn. Normandie, vol. xvi. (1872), no. i. p. 18, pl. i. fig. 4. The species has also been recorded from the Wealden and Purbeck of North Germany on the evidence of splenials and vomers with widely spaced dentition and with the principal teeth much more transversely extended than in the typical English jaw (W. Dunker, Nord- deutsch. Wealdenbild. 1846, p. 65, pl. xv. figs. 19, 20, and C. Struckmann, Wealdenbild. Hannover, 1880, p. 89, pl. iii. figs. 6, 7). 254 ACTINOPTERYGII. 28415 a.. Left splenial, the type specimen of the so-called Gyrodus mantelli, Agassiz, loc. cit.; Tilgate Forest. Mantell Coll. 28415 b. Two left splenials ; Tilgate Forest. Mantell Coll. 39215. Imperfect small right splenial dentition; Wealden, Battle, Sussex. Bowerbank Coll. P. 1629. Right splenial dentition showing irregular subdivision of outermost series of teeth ; Tilgate Forest. Hyerton Coll. P. 3763. Right splenial with well-preserved teeth, showing the base of a single minute tooth within the principal series ; Wealden, near Hastings. Enniskillen Coll. P. 3755. Left splenial dentition, probably of this species; Purbeck Beds, Swanage. The principal teeth and a single minute inner tooth are exhibited only by their bases; the outer- most teeth are more robust than is usual in the species. Enniskillen Coll. 21349. Two more imperfect examples of similar dentition ; Swanage. Purchased, 1847. P. 7445. Similar right splenial; Purbeckian (Serpulit), Thiister- berg, Hanover. Purchased, 1895. Ccelodus gyrodoides, Egerton. 1877. Celodus gyrodoides, Sir P. Egerton, Geol. Mag. [2] vol. iv. p- 52, pl. iv. fig. 3. Type. Vomerine dentition ; British Museum. A large species, known only by the vomerine dentition, which measures 0:04 in maximum width. Teeth of median series about twice as broad as long, with deeply concave posterior margin ; teeth of the two lateral series nearly equal in size, slightly elongated | transversely, and their width together exceeding that of the median series. All unworn teeth with apical indent, slightly crimped. Form. & Loc. Upper Cretaceous: Dorsetshire. P. 3762. Type specimen, shown of three-quarters the natural size in the accompanying fig. 31; Upper Greensand, Pinney Bay, near Lyme Regis. Enniskillen Coll. Cceelodus ellipticus, Egerton. 1877. Celodus ellipticus, Sir P. Egerton, Geol. Mag. [2] vol. iv. p. 49, pl. iii. fig. 1. Type. Right splenial dentition ; British Museum. A large species known only by the splenial dentition. Teeth of PYCNODONTIDZ. 5S principal series scarcely more than twice as broad as long, and about equalling in width the two flanking series, of which the teeth are much elongated transversely, some of the outer ones being even subdivided into two, and the inner ones much constricted; no row of small teeth within the principal series. Form. & Loc. Gault: Kent. Celodus gyrodoides ; vomerine dentition, oral aspect, three-quarters natural size. [No. P. 3762.] P. 609. Type specimen ; Folkestone. Egerton Coll. Ceelodus inzquidens, A. 8. Woodward. 1893. Celodus inequidens, A. 8. Woodward, Geol. Mag. [8] vol. x. p. 491, pl. xvii. fig. 5. Type. Left splenial, with dentition ; British Museum. A species of moderate size, known only by the splenial dentition. Teeth of principal series attaining a breadth somewhat more than twice as great as their length, and exceeding in width the two flanking series, of which the inner slightly exceed the outer teeth in size, all being about as broad as long ; a row within the principal series represented by few minute round teeth; all the teeth smooth. Form. g Loc. Cenomanian: Cambridge. 36157. Type specimen ; Cambridge Greensand, Cambridge. Purchased, 1861. 2 i oa en 256 ACTINOPTERYGII. 35383, 36158. Two fragmentary portions of splenial bone, probably of this species; Cambridge. Purchased, 1860, 1861. Ceelodus cantabrigiensis, A. 8. Woodward. 1895. Calodus cantabrigiensis, A. S. Woodward, Geol. Mag. [4] vol. ii. p- 208, pl. viii. fig. 2. Type. Right splenial, with dentition; British Museum. A large species, known only by the splenial dentition. Teeth on the splenial bone smooth; those of the principal series scarcely more than twice as broad as long, and nearly equal in width to the two flanking series; inner flanking teeth twice as broad as long, and twice as broad as the teeth of the outer series, which are scarcely broader than long; a row within the principal series represented by few small teeth. Form. & Loc. Cenomanian : Cambridge. P. 7236. The type specimen described and figured, loc. cit.; Cam- bridge Greensand. Jesson Coll, Cecelodus fimbriatus, A. 8. Woodward. 1898. Celodus fimbriatus, A. S. Woodward, Geol. Mag. [8] vol. x. p- 491, pl. xvii. fig. 6. Type. Right splenial dentition ; British Museum. A large species, known only by the splenial dentition. Teeth of principal series on the splenial bone smooth or feebly crimped round the margin, somewhat less than three times as broad as long, about equalling in width the two outer series, which are nearly similar in size, irregular in form, slightly broader than long, and having a deep coronal pit with rugose or crimped margin. Form. & Loc. Turonian: Kent. 43090. Type specimen ; Lower Chalk, Halling, Kent. Wetherell Coll. Ceelodus parallelus (Dixon). 1850. Pycnodus parallelus, ¥. Dixon, Geol. Sussex, p. 369, pl. xxxiii. fig. 3. 1888. Celodus parallelus, A.S. Woodward, Proc. Geol. Assoc. vol. x. p- 308. Type. Imperfect splenial dentition ; Brighton Museum. A large species known only by the splenial dentition. Teeth of PYCNODONTID®. 257 principal series on the splenial bone smooth, somewhat more than three times as broad as long; those of the inner flanking series considerably more than half as broad as the latter. Form. & Loc. Senonian: Sussex. _ Not represented in the Collection. The following species have also been defined from fragmentary specimens and are not represented in the Collection :— Celodus angustatus, J. J. Heckel, Denkschr. k. Akad. Wiss., math.- naturw. Cl. vol. xi. (1856), p. 203. Glossodus angustatus, O. G. Costa, Atti Accad. Pontan. vol. vii. (1853), p. 27, pl. iii. figs. 12-15.—L. Cretaceous ; Pietraroja, Naples. [Imperfect dentition. | Celodus asperulus: Pycnodus asperulus, J. Cornuel, Bull. Soc. Géol. France, [3] vol. xi. (1883), p. 24, pl. i. figs. 6, 7.— Neocomian; Haute Marne. [Splenial; Communal Museum, Doulevant-le-Chateau. | Celodus browni, E. D. Cope, Journ. Acad. Nat. Sci. Philad. [2] vol, ix. (1894), p. 447, pl. xx. fig. 10.—Lower Cretaceous ; Oklaboma. [Left splenial. ] Celodus carentonensis: Gyrodus carentonensis, H. Coquand, Descript. Géol. etc. Départ. Charente, vol. 11. (1860), p- 97. Cosmodus carentonensis, H. E. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiil. pt. il. (1879), p. 49, and Bull. Soc. Géol. France, [3] vol. viii. (1880), p. 459, pl. xiv. fig. 1.—Cenomanian ; Charente, France. [Portion of vomerine dentition, type of Cosmodus, Sauvage. | Celodus discus, J. J. Heckel, loc. cit. vol. xi. (1856), p. 203. Pycnodus rhombus, O. G. Costa (errore), loc. cit. vol. v. (1850), p. 332, pl. v. fig. 1.—Upper Jurassic; Torre d’Orlando, Naples. Celodus fabarius: Pycnodus fabarius, E. Sismonda, Mem. R. Accad. Sci. Torino, [2] vol. xix. (1861), p. 457, pl. 1. fig. 12.—Neocomian ; Piedmont. [Splenial.] Calodus major: Cosmodus grandis, H. HE. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxili. pt. 1. (1879), p. 49, pl. ii. fig. 29.—Cenomanian ; Seignelay, Yonne, France. [Splenial. ] Celodus mesorachis, J. J. Heckel, loc. cet. vol. xi. (1856), p. 220, pl. vi. fig. 1; F. Bassani, zbid. vol. xlv. (1882), p. 202.— Upper Cretaceous ; Island of Lesina, Dalmatia. [Imperfect trunk; Court Museum, Vienna. | Celodus muralti, J.J. Heckel, Bericht. Mittheil. Freund. Naturw. Wien, vol. iv. (1848), p. 184, woode., and loc. cit. vol. xi. PART III. S 258 ACTINOPTERYGII. (1856), p. 225, pl. vill. fig. 2. Picnodus muraltii, A. von Morlot, Haidinger’s Naturw. Abhandl. vol. ii, (1848), p-. 275, woode.—Cretaceous ; near Pola, Istria. [Splenial dentition. | Celodus oblongus, J. J. Heckel, Denkschr. k. Akad. Wiss., math - naturw. Cl. vol. xi. (1856), p. 222, pl. ix. figs. 1-3; F. Bassani, ibid. vol. xlv. (1882), p. 202.—Upper Cre- taceous; Island of Lesina. [Upper portion of head and trunk ; Heckel Collection. ] Celodus pyrrhurus, J. J. Heckel, loc. cit. vol. xi. (1856), p. 223, pl. ix. figs. 4-6.—Cretaceous ; Island of Meleda, Dalmatia. [Portion of caudal region; Imperial Geological Survey Museum, Vienna. | Calodus subsimilis: Pycnodus subsemilis, J. Cornuel, Bull. Soe. Géol. France, [3] vol. viii. (1880), p. 156, pl. iti. figs. 16, 17.—Portlandian ; Dépt. Meuse, France. [Vomerine and splenial dentition ; Daval Collection. | An undescribed species of Calodus is represented by portions both of the upper and lower dentition from the Cretaceous near Beyrout, now in the Museum of the Syrian Protestant College, Beyrout. Imperfect skeletons of an undetermined species probably of Celodus, from the Cretaceous of the neighbourhood of Naples, are described under the name of Anomiophthalmus vetustus by O. G. Costa, Ittiol. Foss. Ital. (1856), p. 30, pl. ii. figs. 4, 5, and Atti Accad. Pontan. vol. vill. (1864), p. 116, pl. xi. figs. 4,5. Here may also probably be placed the imperfectly known Pycnodus rotundatus (O. G. Costa, ibid. 1864, p. 82), as suggested by F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. (1882), p. 233. The so-called Glossodus heckeli, O. G. Costa (Atti Accad. Pontan. vol. viii. 1864, p. 109, pl. ix. figs. 12, 13), from the Cretaceous of Pietraroja, is too imperfect for determination (F. Bassani, loc. cit. 1882, p. 238). Genus ANOMCEODUS, Forir. (Ann. Soe. Géol. Belgique, vol. xiv. 1887, Mémoires, p. 25.] An imperfectly known genus. Head-bones ornamerted with reticulating rugee ; the smaller teeth usually with an apical indent, the principal teeth quite smooth or with a very feeble linear indent. Oral surface of vomer nearly flat, with teeth of irregular sizes in from three to five longitudinal series; splenial dentition restricted ——— PYCNODONTID. 259 to a space considerably separated throughout its extent from the thin oral border of the bone, comprising one principal series of teeth, flanked within by at least one small series and outside by two or more small series. Scales ornamented with reticulating ruge. This amended definition is given on the assumption that the so- called Gyrodus angustus, Agassiz, belongs to the same genus as Pycnodus subclavatus, Agassiz. The splenial bone in the first- named species differs from that of all other known Pycnodonts in its wide, toothless margin; but neither in the so-called Pycnodus subclavatus nor in any of the associated species has the imperfect nature of the specimens yet permitted the observation of this feature. Future discoveries must determine whether or not the arrangement here adopted is justifiable. The splenial dentition of Anomeodus is arranged as in Mesodon, but the form of the splenial bone itself is quite different from that of the last-named genus, being similar to that of Pycnodus. Anomeodus subclavatus (Agassiz). 1799. Figures by Faujas St. Fond, Hist. Nat. Mont. St. Pierre, Maes- tricht, pl. xvii. fig. 8, pl. xix. fig. 4. 1833-44. Pycnodus ecienatics, L. Agassiz, Poiss. Foss. vol. ii. pt. 1: p- 17, pt. ii. p. 198, pl. lxxil. a. fig. 59. 1848-52. Pyenodus, P. Gervais, Zool. et Pal. Frang. pl. ae . 23. Fe sus cretaceus, H. E, Sauvage (errore), Bibl. Ecole Hautes Etudes, vol. v. art. 9, p. 18, pl. i. figs. 3-6. 1887. Ceelodus cliuntns, K. A. von Zittel, Handb. Paleont. vol. iii. p. 249. 1887. Anomeodus subclavatus, H. Forir, Ann, Soc. Géol. ae vol. xiv. Mém. p. 25, pl. 1. fig. 1. Type. Principal splenial teeth ; Paris Museum of Natural History. The type species, known only by the splenial dentition. Teeth of the principal series on the splenial bone slightly arcuated, tapering and turned forwards at the inner extremity, attaining a breadth more than three times as great as their length; those of the single inner series very small and rounded, irregularly arranged ; flanking teeth in four irregular series, these mostly smooth and together not -equalling in width the principal series, the innermost teeth slightly broader than long, the next nearly similar, and the two outermost series insignificant. A good figure of this form of dentition is published by Forir, loc. cit., but there seems to be much variation even in the specimens S23 260 ACTINOPTERYGII. from a single locality (Maastricht). The teeth of the two inner- most flanking series are frequently crowded and almost triangular in form, and more nearly equal in size than shown in the figure quoted. . Form. & Loc. Upper Cretaceous (Danian and Senonian): Holland, Belgium, and France *. 42991-93. Portion of right splenial dentition and fragments; Danian, Maastricht, Holland. Van Breda Ooll. 28717, 30752. Detached teeth, probably of this species; Upper Senonian, Ciply, near Mons, Belgium. Purchased, 1853. Anomeceodus distans (Coquand). 1860. Pycnodus distans, H. Coquand, Descript. Géol. etc., Départ. Charente, vol. ii. p. 97. 1880. Pycnodus distans= Pycnodus cretaceus, H. EH. Sauvage, Bull. Soc. Géol. France, [3] vol. viii. p. 460, pl. xiv. fig. 4. Type. Imperfect splenial dentition. A species of moderate size, known only by part of the splenial dentition. Teeth of the principal series on the splenial bone much arcuated and tapering in the inner half, about three times as broad as long; teeth of the innermost row of the flanking series round and deeply pitted, smaller than those of the next adjoining row, which are almost or quite smooth. Form. & Loc. Senonian: Charente, France. Not represented in the Collection. Anomeeodus angustus (Agassiz). 1837-44. Gyrodus angustus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. pp. 235, 246, pl. Ixvi.a. figs. 14, 15. (?) 1839-44. Pycnodus cretaceus, L. Agassiz, wid. p. 198, pl. xxii. a. fig. 60. [Splenial teeth ; Manchester Museum. | 1833-44, Pycnodus angustus, L. Agassiz, abid. pt. i. p. 17, pt. i. p. 199 (name only). 1844. Pycnodus elongatus, L. Agassiz, 2bed. p. 199. 1845. Gyrodus angustus, A. Ki. Reuss, Verstein. bohm, Kreideform. pt. i. p- 9, pl. iv. fig. 55. 1845. Pycnodus rhomboidalis, A. EK. Reuss, cid. pt. i. p. 10, pl. iv. figs. 46-54. [Detached teeth. ] 1 Fragments of dentition from the Upper Senonian and Danian of Scandi- navia are also ascribed to this species by J. W. Davis, Trans. Roy. Dublin Soc. [2] vol. iv. (1890), p. 416, pl. xlil. figs. 16-18. PYCNODONTIDE. 261 1845, Pycnodus subdeltoideus, A. E. Reuss, zbzd. pt. i. p. 10, pl. iv. figs. 38-42. [Detached teeth.] 1850. Gyrodus angustus, F. Dixon, Geol. Sussex, p. 370, pl. xxx. fig. 14, pl. xxxiil. fig. 1. 1855. Pycnodus cretaceus, EK. Hébert, Mém. Soc. Géol. France, | 2] vol. v. p. 353, pl. xxvii. fig. 7. 1856. Pycnodus rhomboidalis, C. E. Fischer, Allg. deutsche Nat. Zeit., n.s., vol. i. p. 137, figs. 2, 3. 1875. Pyenodus cretaceus, H. B. Geinitz, Paleeontogr. vol. xx. pt. 1. p. 300, pl. lxv. tigs. 12-14, and pt. ii. p. 217, pl. xl. figs. 30-32. 1878. Pyenodus cretaceus, A. Fritsch, Rept. u. Fische bohm. Kreide- form. p. 22, pl. i. figs. 1-4, woodce. 48, 1878. Gyrodus angustus, A. Fritsch, zbid. p. 25, woode. 58. 1887. Colodus angustus, K. A. von Zittel, Handb. Palezont. vol. iii. p. 249. (?) 1887. Ceelodus cretaceus, K. A. von Zittel, ibid. p. 249. 1888. Celodus angustus, A.S. Woodward, Proc. Geol. Assoc. vol. x. p- 307. (?) 1888. Calodus cretaceus, A. S. Woodward, zbid. p. 308. Type. Series of teeth ; British Museum (in part). A small species, known by the dentition and part of the head and trunk. Teeth of the principal series on the splenial bone very obliquely set, truncated at their outer extremity, rapidly tapering to a blunt point at the inner extremity, and when young and unworn marked with a slight transverse coronal furrow ; inner teeth in two irregular series, those of the first elongated, those of the innermost much smaller and round, both deeply pitted; teeth of the flanking series in about three or four very irregular rows, all deeply pitted, the innermost transversely elongated and much larger than any of the others, which arerounded. Scales marked with coarse reticulations, and serrations of the ventral ridge-scales conspicuous, long, and slender. The fragment of dentition named Pycnodus cretaceus seems to differ only from the typical corresponding teeth of this species in its relatively large size. There are intermediate specimens in the Collection. Form. & Loc. Senonian: §.E. England, and Meudon, France. Cenomanian: Saxony and Bohemia}. 25731, 25780. Portion of axial skeleton of trunk, with another portion of fish displaying scales and the two splenial 1 Specimens are also recorded from Switzerland by W. A. Ooster, Protozoe Helvetica, 1870, vol. ii. p. 45. A right splenial from the Danian of Maastricht, apparently not of this species, is named Anomaodus cretaceus (Ag.) by H. Forir, Ann. Soc. Géol. Belgique, vol. xvi. (1889), Mém. p. 450, pl. xiv. fig. 2. 262 ACTINOPIERYGII. bones, noticed and figured by Dixon, op. cit. p. 370, pl. xxxiii. fig. 1; Chalk, Houghton, Sussex. In his brief notes Dixon erroneously refers to the ventral border of the fish as “the nape of the neck;” and the vacuities shown in the splenial bone may certainly be regarded as accidental. They are not observable in the right splenial, and if the drawing be not “ restored” the last-named bone must have been broken since it left the artist. There is, however, apparently much “ restoration” in the figure of the left splenial, and it is thus probable that no accident has happened since the specimen was originally studied. Dixon Coll. P. 5733. Plaster cast of portion of fish figured by Fritsch, loc. cit. figs. 1, 2, woode. 48; Planerkalk, near Schlan, Bohemia. Presented by Dr. Anton Fritsch, 1888. P. 1616. Series of five principal teeth of splenial bone, being one of the type specimens described and figured by Agassiz, tom. cit. p. 235, pl. lxvi. a. fig. 15; Sussex. Egerton Coll. P. 5408. Portion of left splenial bone and dentition, showing the broad toothless margin; Lewes, Sussex. Presented by P. E. Coombe, Esq., 1888. 39049. Fine portion of large left splenial dentition, figured by Dixon, op. cit. pl. xxx. fig. 14; Houghton. Bowerbank Coll. P. 7458. Fragment of similar dentition, probably the specimen named Pycnodus angustus, Agassiz, tom. cit. p. 199 ; Kent. History unknown. 49097. Portion of small left splenial; English Chalk. Mrs. Smith’s Coll. 49805. Portion of small left splenial, showing principal and two series of outer teeth; Newtimber, Sussex. Capron Coll. P. 3784. Imperfect small right and left splenial dentition ; Sussex. Enniskillen Coll. 39081. Portion of principal and two outer series of splenial teeth ; English Chalk. Bowerbank Coll. P. 3784 a. Fragment probably of vomer of this species ; Sussex. Enniskillen Coll. PYCNODONTID&. 263 Anomeeodus willetti, A. 8. Woodward. 1893. Anomeodus willetti, A. S. Woodward, Geol. Mag. [8] vol. x. p- 489, pl. xvii. fig. 1. Type. Imperfect skull, with dentition ; Brighton Museum. A small species, with teeth very irregularly arranged. Teeth of the principal series on the splenial bone obliquely set, very irregular in size and shape, wide mesially, tapering at each extremity, and not much broader than long; inner teeth relatively large, in one series, usually broader than long, with axis oblique; outer teeth in about three very irregular series, mostly smaller than the teeth of the inner series. Vomerine dentition anteriorly in three series, posteriorly in five, but extremely irregular; the largest teeth much antero-posteriorly elongated and comprised in the outermost series. Nearly all the teeth indented, the smaller ones having the pit especially conspicuous and surrounded with a crenulated margin. Form. & Loc. Turonian: Sussex. Not represented in the Collection. The type and only known specimen, from the Lower Chalk of Glynde, is preserved in the Willett Collection, Brighton Museum, and is important as exhibiting some features in the cranial osteology of the fish. The vomer is single ; the mandibular suspensorium is strongly inclined forwards ; the pterygo-palatine arcade is delicate, toothless, and fused through- out the greater part of its length with the base of the skull; the parasphenoid has a deep inferior lamellar keel; the articulation of the mandible is very deep and narrow; and there is a large super- ficial bone apparently to be identified with the preoperculum. Anomeeodus fraiponti, Forir. 1889. Anomeodus fraipontt, H. Forir, Ann. Soc. Géol. Belgique, vol. xvi. Mém. p. 445, pl. xiv. fig. 1. Type. Splenial dentition ; Ubaghs Collection, Maastricht. A species somewhat smaller than the type, known only by the splenial dentition. Teeth of the principal series on the splenial bone scarcely arcuated, blunt at each extremity, attaining a breadth more than three times as great as their length, and usually sub- divided into small teeth in the anterior part of the bone; inner teeth very small, in two irregular series; outer teeth equally small, in three or four irregular series. Form. & Loc. Upper Cretaceous (Danian): Holland. 42994. Part of principal series of splenial teeth of right side; Maastricht. Van Breda Coll. 264 ACTINOPTERYGII. Anomeceodus muensteri (Agassiz). 1883-44, Pyenodus depressus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p- 17, pt. ii. p. 199 (name only), 1889-44, Pycnodus munsteri, L. Agassiz, ibid. vol. ii. pt. ii. p. 197, pl. Ixxii. a. figs. 26-39. 1839-44, Pycnodus complanatus, L. Agassiz, ibid. p. 197, pl. Ixxii. a. figs. 40-48. [Detached teeth ; Royal Bohemian Museum, Prague. | * (?) 1879. Pycnodus munsteri, H. E. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiii. pt. ii. p. 42, pl. ii. fig. 4 (non pl. i. fig. 4). 1887. Celodus miinstert, K. A. von Zittel, Handb. Paleeont. vol. iii. p. 249, fig. 262. Type. Detached teeth; Paleontological Museum, Munich. A species of moderate size, known only by the dentition. Teeth of the principal series on the splenial bone slightly arcuated, taper- ing and sharply turned forwards at the inner extremity, attaining a breadth about three times as great as their length; [inner teeth unknown]; teeth of the two flanking series very irregular, relatively small, not pitted, and mostly broader than long | perhaps succeeded without by other series]. Vomerine dentition very narrow, convex from side to side, with teeth closely arranged and not pitted: median teeth ovoid, the hindermost twice as broad as long; teeth of the inner lateral series broader than long, almost pear-shaped, and their long axis oblique; outermost teeth insignificant and irregularly rounded. | Form. & Loc. Cenomanian: Bavaria.2 (?) Upper Neocomian : Yonne, France. * Indeterminable fragments are also described under this name by A. E. Reuss, Verstein. bohm. Kreideform. pt. i. (1845), p. 9, pl. iv. figs. 27-36 (Bohemian Planerkalk) ; Pictet & Renevier, Foss. Terrain Aptien Perte du Rhone (1854), p. 10, pl. 1. fig. 4 (Switzerland); Pictet & Campiche, Foss. Terrain Crétacé St. Croix (1858), p. 65, pl. viii. figs. 24, 25 (Switzerland); H. H. Sauvage, Bibl. Ecole Hautes Etudes, vol. y. art. 9 (1872), p. 8, figs. 11, 12 (a Sarthe); and H. B. Geinitz, Palzontogr. vol. xx. pt. i. (1875), p. 301, pl. Ixv. figs. 15- 21 (Saxon Planerkalk), pt. ii. p. 217, pl. xl. fig. 83. The imperfect splenial dentition of a species of Celodus from the Planerkalk of Bohemia is also named Pycnodus complanatus by A. Fritsch, Rept. u. Fische bohm. Kreideform. 1878, p. 21, pl. ii. fig. 5, woode. 47. Another splenial, perhaps of Anommodus, is similarly recorded from the Upper Neocomian of Monéteau, Yonne, France, by H. H. Sauvage, Bull. Soc. Sci. Nat. Yonne, vol. xxxiii. pt. ii. (1879), p. 41, pl. i. fig. 5. * The fragments from the Neocomian and Aptian of Switzerland ascribed to this species by Pictet and others (Pictet & Renevier, Foss. Terrain Aptien Perte du Rhone, 1854, p. 9, pl. i. figs. 2, 3; Pictet & Campiche, Foss. Terrain Crétacé St. Croix, 1858, p. 61, pl. viii. figs. 21-23) are incorrectly determined. ~ ae EUGNATHIDA. 287 more than one series over the whole of the splenial ; preoperculum smooth and narrow; suboperculum of moderate size, about half as large as the nearly rectangular operculum, and with a snort ascending process at its antero-superior angle. Ossifications in the sheath of the notochord observed only in the largest species ; ossified ribs slender. Fulcra biserial, well-developed on all the fins except the pectorals, on which they are feeble. « Pectoral much exceeding the pelvic fins in size, but the latter well-developed ; dorsal and anal fins triangular in shape, the former arising opposite or immediately behind the pelvic fins; caudal fin forked. Scales thick, with a narrow overlapped border, an inner rib, and a feeble peg-and-socket articulation; superficial ganoine smooth on the anterior half of each scale, passing on part of the body into trans- verse ruge and crenulations posteriorly; principal flank-scales rarely, and then only in part, deeper than broad, several series of ventral scales much broader than deep; postclavicular scales large ; no enlarged scales on the dorsal ridge or in the region of the anus. Lateral line inconspicuous. A description of the skeleton of Hugnathus will equally apply to Heterolepidotus (see p. 304), which differs only in minor particulars. The chondrocranium is well ossified, and the basicranial axis is straight. The basioccipital exhibits on its posterior face a deep conical fossa for the notochord; and the inferior aspect of the bone is marked by a slight longitudinal groove, though there is apparently no basicranial canal. A robust ossification is conspicuous both in the postfrontal and in the prefrontal region. Nearly the whole of the base of the skull is sheathed by a large parasphenoid, which appears to terminate in advance of the occiput and exhibits a pair of long basipterygoid processes. In front of the latter the para- sphenoid bears a long, lenticular patch of minute granular teeth. The vomers are unsatisfactorily known, but a cluster of larger short and conical teeth appears to belong to them: they are certainly paired in Heterolepidotus. The membrane bones of the cranial roof form a continuous shield, which is nearly flat. The parietals are small and short, meeting in a remarkably wavy suture which makes them an unsymmetrical pair. These are flanked by the squamosals, which are somewhat longer and form the postero- lateral angles of the cranial roof. The frontals are very large, broad behind but attenuated in front; and the median suture between them is more or less wavy in its hinder portion. The postfrontal is exposed at the anterior end of the squamosal, and between it and the prefrontal there extends a series of about three supraorbital plates. The cheek is completely covered with thin 288 "MOT} 210489, Ser * snwojsoyp4o sny qoubny A r CLTINOPTERYGITI Zh Ze ee eH ite a i wth si Wi He my git wi i i —\ = ete = == = SS seceeeaee EUGNATHID A. 289 plates. There are two very large suborbitals (or postorbitals) immediately in front of the preoperculum, and there is a circum- orbital ring of small plates of irregular size. At least one large preorbital plate may also be noticed. The maxilla is comparatively robust, long and narrow, somewhat deepened behind and with a stout inwardly directed process near its anterior extremity. Its hinder margin is excavated by a sharp re-entering angle, and the oral margin is straight or slightly concave. Above the posterior half of the bone is a long narrow supramaxilla, which is pointed in front but truncated behind. The premaxilla is antero-posteriorly extended, not deepened, but with a short narrow process rising upwards near the middle of its superior border. The hyomandi- bular is elongated, much laterally compressed, and with a large process for the support of the operculum. Its long axis is only slightly arcuated, and its expanded lower extremity meets both the quadrate and the symplectic. The latter is an elongated triangular bone, its narrow base turned upwards in contact with the hyoman- dibular, its thickened apex apparently extending to the articular condyle of the quadrate. The entopterygoid is a large laminar bone covered on the oral face by minute granulations resembling those ~ of the parasphenoid. The ectopterygoid and palatine are not certainly known. The mandible is much deepened in the coronoid region, but the limits of the coronoid bone are rarely observed; it is shown in the original of fig. 34, p. 293. The angular element is of moderate size, meeting the dentary in a wavy suture in the coronoid region. The dentary itself also rises in the front part of this elevation, but rapidly tapers and becomes very narrow at the symphysis ; it bears a single series of large conical teeth. ‘The splenial, also partly extended into the coronoid elevation, is a thin laminar bone behind, but much thickened in front, where it enters and strengthens the mandibular symphysis. Its teeth are all minute, those in its hinder portion being mere granulations. The ceratohyal is very large, deep and laterally compressed behind, but apparently depressed in front so that its inferior border exhibits a narrow flattened horizontal expansion. The triangular epihyal is small and thin; the hypohyal on each side is a still smaller, but square and much thicker bone. The branchial arches are delicate and exhibit the channel specially characteristic of modern bony fishes. They bear a much~ spaced series of large slender gill-rakers, which are straight and acutely pointed. The basibranchials are slender. The opercular apparatus is complete: the branchiostegal rays are laminar; and PART III. U 290 ACTINOPTERYGII. there is a large gular plate covering the whole of the space between the mandibular rami in front of them. The notochord is persistent, but there are usually some traces of hypocentra and pleurocentra, and these are often robust in the larger individuals. In the abdominal region there are slender ribs loosely articulated with short prominences on the hypocentra ; and there is the series of large free neural spines, so well known in Caturus, extending as far as the anterior portion of the dorsal fin. In the caudal region the neural and hemal arches are stout, and the heemal spines at the base of the caudal fin are somewhat expanded. A single pair of transversely extended supratemporal plates over- laps the occiput, and immediately behind is observed the exposed portion of a pair of large triangular post-temporals, which support the pectoral arch. The supraclavicle is long and narrow, and the arched clavicle is relatively very large. The latter element is contracted and thickened above, with a considerable outer lamina mesially, and tapering to a delicate point below where it meets its fellow of the opposite side. On its antero-superior angulation there are several longitudinal ruge. The scapula, coracoids, and basals are not satisfactorily known ; but it is clear that the immediate supports of the pectoral fin-rays were much like those of Ophiopsis _ (p. 167, Pl. III. fig. 3), the hindermost basal being the largest. — The pelvic fin-supports are irregularly hourglass-shaped, much more expanded proximally than distally, as shown in Caturus (Pl. IX. fig. 3). Conspicuous biserial fulcra appear on all the fins. Thick rhombic ganoid scales cover the whole of the trunk, and are arranged in regular oblique series except immediately at the base of the caudal fin, where the last row is directly related to covering the base of the rays. Each scale is strengthened on its inner face with a vertical median rib; and the principal flank-scales are also united by a peg-and-socket articulation. A series of four large postclavicular scales 1s connected with the clavicle. None of the ordinary scales, however, are enlarged either along the dorsal margin or in the region of the anus. The position of the latter close to the origin of the anal fin is indicated by coprolitic matter in no. 48006. Some of the ventral scales in the region of the pectoral fins are much subdivided. EUGNATHID®. 291 Eugnathus orthostomus, Agassiz. [Plate LV. fig. 1; Pl. V. fig. 1.] 1825. Lepidosteus? dentosus, C. Koenig, Icon. Foss. Sect. pl. xii. fig. 140. 1842-44. Eugnathus orthostomus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 98, pl. lvii a. 1839-44. Eugnathus speciosus, L. Agassiz, zbid. p. 100, pl. lv. [Head and scales ; Oxford Museum. | 1844. Eugnathus scabriusculus, L. Agassiz, 2b¢d. p. 105 (name only). (Jaws, etc.; British Museum. } Type. Nearly complete fish ; British Museum. The type species, attaining a length of about 0°6. Length of head with opercular apparatus equalling about one-quarter, and maximum depth of trunk about one-fifth of the total length of the fish ; minimum width of caudal pedicle equalling half the maximum depth of the trunk. Head elongated, the roof of the skull being about three times as long as its width at the occiput, and all the external bones smooth or with few small tuberculations ; hinder two-thirds of maxilla bearing comparatively small and slender elongated teeth, with stouter conical teeth in front and on the premaxilla; supramaxilla much more than half as long as maxilla ; dentary bone with few widely spaced, large, stout teeth; splenial teeth small; operculum almost as broad as deep. Dorsal fin as deep as long, with about 16 rays, arising in advance of the middle point of the back ; origin of pelvic fins exactly opposite to that of the dorsal, and the relatively small anal fin, with about 9 rays, arising at the posterior termination of the latter. Scales richly ornamented in the abdominal region, smooth on the caudal pedicle ; a few anterior flank-scales slightly deeper than broad. Form. & Loc. Lower Lias: Dorsetshire. All the following specimens were obtained from the neighbour- hood of Lyme Regis :— P. 465. Type specimen described and figured by Agassiz, loc. cit. The small teeth in front of the mandible noted in the original description are evidently those of the splenial bone, and other specimens prove that the enlargement of the teeth does not take place in the middle of that bone, but at its anterior extremity. In the crushed ventral region there are remains of the squamation of a small fish, apparently swallowed. Egerton Coll. v2 292 ACTINOPTERYGII. P. 3639. A slightly larger fish, with more imperfect anal and caudal fins. The crushed cranium is exposed from below, and the maxilla is complete, only broken across at one point ; the large teeth are conspicuous on the premaxille, as also on the left dentary ; and below the mandible the great extent of the gular plate is displayed. There are indications of slender ribs in the abdominal region, and the fish seems to have swallowed a Pholidophorus. The squamation is well preserved, and the dorsal fin almost complete. Enniskillen Coll. P. 3642. A smaller fish, more fractured, showing much of the abdominal squamation from the inner aspect and display- ing the robust peg-and-socket articulation of the flank- scales. Enniskillen Coll. 38120. Fish about 0°42 in length, shown from the ventral aspect. The marginal dentition, branchiostegal apparatus, and paired fins are well shown. Both the pectoral and pelvic fins exhibit fulcra, and these on the latter are distinctly shown to be biserial. Each pelvic basipterygium seems to have been much expanded proximally, and contracted to a very narrow distal end. Purchased, 1864. 38119. A similar specimen with more displaced squamation and with few teeth, but showing the anal fin. The fulera on the pectoral fins are relatively small, those on the pelvic fins and anal fin well developed and biserial. Some scales in the abdominal! region exhibit the peg-and-socket articu- lation. Purchased, 1864. 47043. Equally large fish, much fractured, showing the head from the dorsal aspect, the trunk in side view, and wanting the caudal fin. Purchased, 1875. P. 2027, P. 2034. Two imperfect specimens about as large as the last ; one displaying several head-bones in side view, part of the paired fins with fulcra, and some well-preserved scales ; the other vertically crushed, much fractured, and wanting all the fins except the caudal. Egerton Coll. 38735. Another imperfect specimen, showing displaced bones of head and wanting median fins. Purchased, 1865. P. 3633 a. Two imperfect specimens, the first showing the robust hemal spines at the end of the caudal pedicle, the second exhibiting the jaws and branchiostegal apparatus. Enniskillen Coll. (oy ae EUGNATHID 2. 293 P. 3633 b. Head, pectoral fin, and anterior squamation of a large fish, exhibited from the left side and shown of the natural size in Pl. IV. fig. 1. Many of the bones are well displayed, and are indicated in the figure by the lettering. There are very few traces of a tubercular ornament, apparently confined to the supratemporal, post-temporal, and operculum, though a few isolated tubercles also occur on the cranial roof. The postclavicular scales are con- spicuous, and some of the anterior flank-scales are deeper than broad. Enniskillen Coll. P. 3633 c,d. A small fish about 0°32 in length, very fragmentary, and another more imperfect small specimen. Enniskillen Coll. P. 3634f. Small head apparently referable to young of this species, but not so much elongated as in the typical adult fishes. Enniskillen Coll. P. 509. Imperfect right mandibular ramus and maxilla, with re- mains of surrounding bones and scales; the undescribed type specimen of the so-called Hugnathus scabriusculus, Agassiz, loc. ct. The specimen is shown of the natural size in Pl. V. fig. 1. Egerton Coll. P. 865. Fragment of head showing jaws, labelled Hugnathus spe- crosus by Agassiz. Lgerton Coll. Fig. 34. Eugnathus orthostomus ; left mandibular ramus, inner aspect. [No. P. 870.] ag., angular; art., articular; cor., coronoid; d., dentary; spi., splenial. P. 870. Left mandibular ramus, inner aspect, probably of this species. As shown by the accompanying illustration (fig. 34), the angular (ag.), articular (art.), coronoid (cor.), dentary (d.), and splenial elements (spl.) can be distinguished. Egerton Coll. 294 ; ACTINOPTERYGII. Eugnathus philpotz, Agassiz. [Plate V. fig. 2.] 1839-44. Eugnathus philpotie, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. pe LON spl avai: 1839-44. Hugnathus polyodon, L. Agassiz, wid. p. 104, pl. lviii a. fig. 2. [Imperfect head ; Oxford Museum. | , 1844. Eugnathus opercularis, L. Agassiz, zbid. p. 104. [Fish; un- known. | 1868. EHulepidotus sauroides, Sir P. Egerton, Quart. Journ. Geol. Soc. vol, xxiv. p. 503. [Nearly complete fish; British Museum. | 1872. Heterolepidotus sauroides, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Surv.), no. 3, pl. iii. 1887. Ophiopsis sauroides, K. A. von Zittel, Handb. Paleont. vol. iii. D2 1890. Eugnathus philpote, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 79. Type. Fish, wanting jaws ; Oxford Museum. A larger species than the type, attaining a length of about 0°7, and with a relatively deeper, dorsally-arched abdominal region. Length of head with opercular apparatus not exceeding the maximum depth of the trunk, and contained nearly five times in the total length of the fish. Head short and broad, the roof of the skull being less than twice as long as its width at the occiput, and all the external bones smooth or with few small tuberculations ; maxillary teeth numerous and slender, those of the premaxilla and dentary much larger, fewer, and more robust, but attenuated to a slender, more or less curved point; splenial teeth small; operculum as broad as deep. Fins as in the type species, but the anal apparently somewhat more remote. Scales relatively larger than in the type species, usually less conspicuously ornamented, otherwise similar. | Some specimens (e.g. no. P. 2021) prove that in this species there are ossifications in the sheath of the notochord. Form. & Loc. Lower Lias: Dorsetshire. All the following specimens were obtained from the neighbour- hood of Lyme Regis :— P. 3577. A fine specimen, nearly complete, about 0-7 in length. The long slender mandibular teeth are conspicuous. - Enniskillen Coll. P. 3576, An equally large fish, more fractured and somewhat EUGNATHIDZ. ; 295 deepened by distortion ; noticed by Egerton, loc. cit. 1872, under the name of Heterolepidotus sauroides. Enniskillen Coll. P. 559. Another large fish with fractured tail and imperfect ventrally, the type specimen of Heterolepidotus sauroides, Egerton. Egerton Coll. 40350. A more imperfect large specimen displaying the maxilla and mandible with dentition, and also the paired fins with fulera. Purchased, 1867. P. 2019. Imperfect remains of head and trunk of another large fish. Egerton Coll. P. 3634h, P. 3640. More imperfect remains of head and trunk of two large specimens, the first displaying upper and lower teeth. Enniskillen Coll. P. 2021. Hinder portion of head and remains of anterior portion of abdominal region, displaying the pectoral fins and well- developed hypocentral ossifications in the axial skeleton. Egerton Coll. P. 7522. Much-fractured specimen displaying hinder half of head, remains of dorsal and pectoral fins, squamation, and some of the abdominal hypocentra. Harford Coll. P. 3578. Fish about 0°56 in length, with partly displaced squama- tion and crushed head. The dorsal and caudal fins are especially well shown. Enniskillen Coll. 40349. An equally large fish, more fragmentary, crushed from above, displaying the roof of the skull and the right pectoral fin. Purchased, 1867. P. 1543. Crushed head and part of abdominal squamation of a similar fish. Egerton Coll. P. 3629. Head of similar specimen, vertically crushed. The bran- chiostegal rays and the left maxilla and mandibular ramus are well shown, with the characteristic teeth. Enniskillen Coll. 38104. Equally Jarge head with opercular apparatus in side view. The form and proportions of the opercular bones are well shown (PI. V. fig. 2), and part of the dentition is preserved, but the rostral region is destroyed. Purchased, 1864. 296 ACTINOPTERYGII. P, 4233. Vertically crushed head, pectoral fins, and some anterior scales, seen from above. The supratemporals are finely tuberculated. Enniskillen Coll. 19483. Imperfect fish about 0°47 in length, vertically crushed, displaying some of the slender neural spines and ribs of the axial skeleton, and the biserial fulcra on the dorsal fin. Purchased, 1845. P. 3634 a, b, P. 3641. Two equally large imperfect specimens, and one smaller individual showing head from the infero- lateral aspect. Enniskillen Coll. P, 3634c¢,d. Imperfect fish about 0°43 in length, and a smaller distorted specimen. Enniskillen Colt. 38122. Small specimen about 0°32 in length, much crushed and imperfect. Purchased, 1864. P. 2035, P. 3638 a. Two small specimens vertically crushed and shown from the ventral aspect. Egerton & Enniskillen Colls. P. 3634 g. Remains of small head, pectoral fin, and scales, probably of this species. Enniskillen Coll. Eugnathus minor, Agassiz. [Plate IV. fig. 3; Plate V. fig. 3; Plate VI. fig. 1.] 1889. Eugnathus minor, L. Agassiz, Neues Jahrb, p. 118. 1889-44. Eugnathus minor, L. Agassiz, Poiss. Foss. vol. ii. pt. il. p. 103, pl. Iviiia. fig. 1. Type. Portion of head and trunk ; Oxford Museum. A species of moderate size, attaiing a length of about 0°35. Length of head with opercular apparatus not much exceeding the maximum depth of the trunk, and contained somewhat less than four times in the total length of the fish. Head comparatively broad, the width of the roof of the skull at the occiput equalling about one-half of its length; external bones smooth or with few small tuberculations; maxillary teeth small, slender behind and stouter in front; premaxillary teeth larger and robust; dentary teeth stout and well-spaced, relatively smaller and more numerous than in the type species, and splenial teeth small; operculum considerably deeper than broad. Fins and squamation as in the type species. Form. & Loc. Lower Lias: Dorsetshire. EUGNATHIDZ&. 297 The following specimens were all obtained from the neighbour- hood of Lyme Regis :— P. 2030. Nearly complete fish, with crushed head, shown of two- thirds the natural size in Pl. VI. fig. 1. The head is obliquely distorted, but its proportions are indicated and part of the dentition is well shown. The maxilla (mz.) bears small and slender teeth increasing in stoutness forwards, and the horizontally extended premaxilla (pmz.) shows a close series of eight or nine robust teeth; the dentary bone also exhibits its sparse series of compara- tively large and stout teeth. The cheek-plates and opercular bones are crushed beyond recognition, and the squamation behind is much displaced. Portions of all the fins are shown, but only the caudal fin is well pre- served. Egerton Coll. P. 2031-33. Two specimens somewhat smaller, and a third fish, still smaller, wanting the caudal fin. The first specimen is nearly complete, distorted a little in the caudal region, and with good squamation ; the second wants the greater part of the skull and jaws; the third displays the opercular bones and the dentition of maxilla and dentary. A Egerton Coll. P. 3630, P. 3636-38, P. 4234. Five specimens more or less imperfect, varying in length from 0°33 to 0°23, and all exhibiting part of the dentition. Enniskillen Coll. P. 3634 e. A distorted and disturbed specimen, showing some scattered bones of the head. The hyomandibular is shown to be a laterally-compressed, expanded bone; and the leit mandibular ramus (PI. IV. fig. 3), with its elevated coronoid region, is well exposed. Some of the scales exhibit a robust peg-and-socket articulation. Enniskillen Coll, 38526. Asmall distorted fish, the trunk chiefly shown in impression. Part of the roof of the skull, the left maxillary and dentary bones are exhibited; and there is a displaced portion of vertebral column, probably of the same fish, which seems to comprise ossifications in the notochordal sheath. Purchased, 1864. 48006. Imperfect fish, ventral aspect, displaying branchial arches, the very small anterior ventral scales, and a coprolite at the origin of the anal fin. Purchased, 1877. 298 ACTINOPTERYGII. 35055. A much-fractured small fish. Purchased, 1860. P. 871. Greater part of fish, about 0°15 in length. Egerton Coll. P. 3628. Imperfect head and opercular apparatus with part of the anterior squamation, shown of the natural size in Pl. Y. fig. 3. The operculum (op.) exhibits the form charac- teristic of the species; the cranial roof and portions of the jaws are also well shown. Enniskillen Coll. P. 864. Head and anterior portion of a typical fish. Hgerton Coll. P. 6062. Small head and anterior portion of trunk. Presented by F. Harford, Ksq., 1889. P. 868, P. 3627, P. 3634k. Three small specimens exhibiting the head in an imperfect state. Hgerton & Enniskillen Colls. P. 3631. Imperfect head with relatively large teeth, and other fragmentary remains. Enniskillen Coll. P. 363841. Remains of head, opercular apparatus, postclavicular scales, and pectoral fin, perhaps of an unusually large individual of this species. Enniskillen Coll. P. 3638 b. Fish with imperfect head, wanting jaws and caudal fin, doubtfully ascribed to this species. The scales are unusually finely ornamented. Enmaskillen Coll. Eugnathus serratus (Davis). 1884. Lissolepis serratus, J. W. Davis, Ann. Mag. Nat. Hist. [5] vol. xiii. p. 449, pl. xvi. 1890. Eugnathus serratus, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 79. Type. Fish wanting dorsal fin; James W. Davis Collection, Chevinedge, Halifax. A species of moderate size, apparently differing only from Eugnathus minor in its relatively smaller, more numerous mandi- bular teeth, in the comparatively deeper abdominal region and more slender caudal pedicle. This is the type species of the so-called Lissolepis. Form. & Loc. Lower Lias: Dorsetshire. P. 2028. A somewhat elongated specimen, crushed and fractured, and probably of this species; Lyme Regis. The specimen bears the MS. name, Hugnathus fusiformis, in Egerton’s handwriting. Egerton Ooll.. EUGNATHID Hi. 299 Eugnathus altus, sp. nov. [Plate VI. fig. 2.] Type. Imperfect fish ; British Museum. A species of moderate size, similar in proportions to £. serratus. All the marginal teeth slender and in close series, but those of the dentary much exceeding those of the maxilla in size. Scales relatively smaller than in any of the foregoing species. Form. & Loc. Lower Lias: Dorsetshire. P. 2029. The type specimen shown of two-thirds the natural size in Pl. VI. fig. 2; Lyme Regis. The bones of the head are displaced and scattered, but some are well shown. The dentary (d.), maxilla (mw#.), and premaxilla (pmz.) exhibit long, slender teeth; while portions of the inner bones of the mouth are covered with granular teeth. The form of the hyomandibular (Am.) is also well shown, and the suboperculum (s.op.) is seen to bear an ascending process at its antero-superior angle. Behind the opercular apparatus the clavicle (cl.) is displayed, showing vertical ribbing on the outer face; but only fragments of the pectoral, pelvic, dorsal, and caudal fins are preserved, while the anal fin is wanting. Some of the anterior flank- scales are deeper than broad, and the ornament does not entirely disappear until the series at the hinder end of the dorsal fin. Egerton Coll. Eugnathus hastingsize (Agassiz). [Plate VII. fig. 1.] 1843-44, Phohdophorus hastingsie, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 284, pl. xliia. fig. 1. Type. Imperfect fish ; British Museum. A very small species, attaining a length of about 0-1. Length of head with opercular apparatus equalling about one-quarter, and maximum depth of trunk scarcely more than one-sixth of the total length of the fish; maximum width of caudal pedicle equalling half the maximum depth of the trunk. Head elongated, and the external bones almost or quite smooth; mandibular teeth few and stout, maxillary teeth closely arranged and slender ; operculum very slightly broader than deep. Fins as in the type species. Scales. very feebly ornamented in the anterior abdominal region, smooth and not serrated in the caudal region. Form. & Loc. Lower Lias ; Leicestershire and Warwickshire. 300 ACTINOPTERYGII. P. 3594. Type specimen, wanting the head and dorsal margin, and not exhibiting the “lateral line” so conspicuously as indicated in the drawing published by Agassiz; Barrow- on-Soar. Enniskillen Coll. P. 887 a. Another less imperfect specimen, shown of the natural size in Pl. VII. fig. 1; locality unknown, but probably from Barrow-on-Soar. The definition of the species given above is based upon this specimen. The teeth are very imperfectly displayed. Impressions of the neural arches above the notochord are distinct, and there are also traces of ribs besides the robust hemal arches at the base of the caudal fin. Egerton Coll. P. 888. Another larger specimen about 0-1 in length ; Barrow-on- Soar. The opercular and branchiostegal apparatus is especially well shown, and all the fins are preserved. Egerton Coll. P. 6096. Remains of head, opercular apparatus, and pectoral arch, probably of this species: Lower Lias, Wilmcote, near Stratford-on- Avon. Presented by the Rev. H. EH. Lowe, 1889. Eugnathus microlepidotus, Agassiz. 1833. Ureus microlepidotus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 12. 1839. Eugnathus microlepidotus, L. Agassiz, Neues Jahrb. p. 118. 1844, Eugnathus microlepidotus, L. Agassiz; Poiss. Foss. vol. ii. pt. ii. p- 104. 1863. Eugnathus microlepidotus, A. Wagner, Sitzungsb. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 673. Type. Imperfect fish ; Paleontological Museum, Munich. A species of moderate size, attaining a length of about 0:4. Length of head with opercular apparatus much exceeding the maximum depth of the trunk, and contained about four times in the total length of the fish. Head elongated and the external bones conspicuously ornamented with tubercles and delicate rug; teeth on the dentary bone large and very robust. Fins apparently as in the type species. Principal scales completely covered on their exposed face with a delicate striate ornament. A fish from the Lithographic Stone of Cirin, Ain, France, not readily distinguished from this species, is named Hugnathus pre- ‘longus by VY. Thiolliere, Ann. Sci. Phys. & Nat. Lyon, [2] vol. ii. EUGNATHIDZ. 301 (1850), p. 150, and Poiss. Foss. Bugey, pt. ii. (1873), p. 19. The type specimen is preserved in the Lyons Museum. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. 49138. Plaster cast of nearly complete fish, the original in the Paleontological Museum, Munich, noticed by Wagner, loc. cit. p. 673; Hichstadt. Purchased, 1878. P. 511, P. 3646. Remains of a large specimen in counterpart, displaying the scale-ornament and the stout mandibular teeth ; Solenhofen. Egerton & Enniskillen Colls. P. 3717. Imperfect head and anterior abdominal region; Solenhofen. Enniskillen Coll. P. 3646 a. Scattered remains of small head and trunk, including ring-vertebre and comparatively thick scales; Solenhofen. The sparse tuberculation is shown on some of the external bones. Enniskillen Coll. Eugnathus longiserratus (Agassiz). 1843-44. Pholidophorus longiserratus, L. Agassiz (ex Minster MS.), Poiss. Foss. vol. 1. pt. 1. p. 277, pl. xxxviil. fig. 2. 1863. Pholidophorus longiserratus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 664. 1863. Pholidophorus brevivelis, A. Wagner, ibid. p. 664. [Nearly complete fish; Paleontological Museum, Munich. | 1887. Isophols longiserratus, K. A. von Zittel, Handb. Paleeont. vol. iii. . p. 216. 1887. Isopholis brevivelis, K. A. von Zittel, zbzd. p. 216. Type. Nearly complete fish ; Paleontological Museum, Munich. A small species attaining a length of about 0-2. Length of head with opercular apparatus somewhat exceeding the maximum depth of the trunk, and equalling nearly one-quarter of the total length of the fish. Head elongated, and external bones with a rugose ornament. Fins as in the type species. Scales with relatively few, deep serrations on the hinder border. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. 37081, 37100, 37804. Two specimens in counterpart, and a larger crushed and distorted fish; Solenhofen. Hiiberlein Coll. 49128. Plaster cast of type specimen of so-called Pholidophorus brevivelis ; EKichstidt. Purchased, 1878. P. 1082. Four fragments, probably of this species ; Solenhofen. Egerton Coll. — 302 ACTINOPTERYGII. Eugnathus latimanus (Agassiz). 1838-44, Pholidophorus latumanus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p- 280, pl. xlin. 1863. Pholidophorus latumanus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 665. 1881. Pholidophorus latimanus, B. Vetter, Mittheil. k. mineyral.-geol. Mus. Dresden, pt. iv. p. 58. 1887. Isopholis tatimanus, K. A. von Zittel, Handb. Paleeont. vol. iii. p. 216. Type. Nearly complete fish; Paleontological Museum, Munich. A species closely similar to H. longiserratus, but apparently attaining only a smaller size, and with a relatively smaller head. The flank-scales are also deeper in proportion to their length. Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. 37098. Fish 0-1 in length, wanting the anal fin ; Solenhofen. Haberlein Coll. P. 1086. Slightly smaller specimen, wanting the greater part of the caudal fin; Solenhofen. Egerton Coll. 37093. Contorted specimen ; Solenhofen. Hiberlein Coll. The following specimens are specifically indeterminable and may pertain either to Hugnathus or to Heterolepidotus :— P. 3525. Fragment of head with abraded anterior portion of trunk, described as the type specimen of Lepidotus pecti- natus by Egerton, Proc. Geol. Soc. vol. iv. (1843), p. 183, and Figs. & Descript. Brit. Organic Remains, dec. vi. (Mem. Geol. Surv. 1852), no. 3, pl. i1i1.; Upper Lias, Whitby, Yorkshire. Enmskillen Coll. P. 450. Abraded mandibular ramus shown of the natural size in Pl. VIII. fig. 2, regarded by Agassiz as the type specimen of an undescribed species of Aspidorhynchus (Aspido- rhynchus anglicus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. 1844, p. 1389, name only) ; Upper Lias, Whitby. Egerton Coll. 39143. Portion of squamation ascribed to Lepidotus rugosus by Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 246, pl. xxxilia. fig. 4; Upper Lias, Whitby. Bowerbank Coll. ‘Ta ae EUGNATHIDA. 303 P. 508. Imperfect squamation and other fragments, specifically indeterminable, but marked as the type specimen of Eugnathus fasciculatus, Agassiz, Poiss. Foss. vol. ii. pt. ii. 1844, p. 105 (name only); Upper Lias, Whitby. Ligerton Coll. P. 873, P. 4468. Small fish in counterpart, wanting the head, and labelled Hugnathus fasciculatus by Agassiz. The pectoral fin is relatively large, with about 15 rays; the dorsal fin arises opposite a point midway between the pectoral and anal fins; the latter is only about half as large as the dorsal. Egerton & Enniskillen Colls. 28855 a. Fragmentary small trunk in counterpart; Upper Lias, Cheltenham. Purchased, 1854. 32450. Head and greater portion of trunk of a small fish, with highly ornamented scales which are serrated even in the hinder portion of the caudal region; Upper Lias, Caen, Normandy. The mandibular teeth are only moderately robust, and the operculum is considerably deeper than broad. Tesson Coll. P. 7563. Portion of abdominal region displaying some of the anterior flank-scales ; Lower Lias, Lyme Regis. Presented by Edward Charlesworth, Esq. P. 510. Imperfect left maxilla, shown from the outer aspect of the natural size in Pl. IV. fig. 2, intended by Agassiz to be the type specimen of his undescribed species Hugnathus tenuidens (Poiss. Foss. vol. 11. pt. ii. 1844, p. 105); Lower Lias, Street, Somersetshire. Egerton Coll. P. 517. Imperfect fish about 0°15 in total length, intended by Agassiz to be the type specimen of his undescribed species Pholidophorus leptocephalus (Poiss. Foss. vol. i. pt. 1 1844, p. 288); Lower Lias, Street. The cranium is wanting, but the right opercular and facial bones are exhibited in impression. ‘The characteristic maxilla and its dentition are distinctly observable; while the oper- culum is shown to be about as deep as broad. The fins are represented only by insignificant fragments, but the dorsal is proved to have been relatively large. The principal flank-scales are very delicately crimped and serrated on their hinder margin in the abdominal region, 304 ACTINOPTERYGII. but smooth in the caudal region. The squamation is too much disturbed both dorsally and ventrally to exhibit the precise form and proportions of the trunk. Egerton Coll. P. 867. Small slab of Lias with imperfect clavicle and specifically indeterminable scales, labelled Hugnathus ornatus by Agassiz, and perhaps intended to be the type specimen of this undefined species (Poiss. Foss. vol. ii. pt. 1. 1844, p- 105); Lower Lias, Lyme Regis. Egerton Coll. P. 866. Fragmentary remains of small head and trunk, showing ceratohyals and vertebral axis ; Lower Lias, Lyme Regis. Egerton Coll. P. 1048. Abraded and imperfect small head and abdominal region ; Lower Lias, Watchet, Somersetshire. Egerton Coll. The specific names leptodus and mandzbularis were also proposed by Agassiz for forms of Hugnathus to which there is now no clue (Poiss. Foss. vol. ii. pt. ii. 1844, p. 105, names only), from the Lower Lias of Lyme Regis. The so-called Pholidophorus elongatus (A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1863, p. 664) from the Litho- graphic Stone of Solenhofen, is also probably a species of Hugnathus. The type specimen is in the Paleontological Museum, Munich. Genus HETEROLEPIDOTUS, Egerton. (Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Surv. 1872), no. 2.] Syn. Brachyichthys, T. C. Winkler, Descript. Poiss. Foss. Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv. 1861), p. 47. Eulepidotus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. xxiv. 1868, p. 505°. A genus scarcely distinguishable from Hugnathus, but having the trunk more deeply fusiform, the marginal teeth relatively smaller, and ossified hemivertebre present in all but the smallest species. Principal flank-scales serrated, usually not pectinated. Fieterolepidotus latus, Egerton. 1834-85. Dapedius jimbriatus, L. Agassiz, Poiss. Foss., Feuill. p. 9, and vol. i. pt. 1. p. 196. 1 Withdrawn in 1872, loc. cit., Sauvage having named typical species of Leptdotus “ Eulepidote” in 1867 (Catal. Poiss. Form. Second. Boulonnais, p. 20). BUGNATHID 2%. 305 1837-89. Lepidotus fimbriatus, L. Agassiz, thid. p. 247, pl. xxxiii.-d (in part). [Scales; Oxford Museum. } 1837. Semionotus rhombifer, L. Agassiz, ibid. p. 228, pl. xxvi a. [Im- perfect fish ; British Museum. ] 1849. Lepidotus fimbriatus, W. C. Williamson, Phil. Trans. p. 444. 1849. Semionotus rhombifer, W. C. Williamson, zb2d. p. 444, pl. xli. fig. 9. 1868. Eulepidotus fimbriatus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. xxiv. p. 505. 1872. Heterolepidotus latus, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Surv.), no. 2, pl. i. 1887. Heterolepidotus fimbriatus, K. A. von Zittel, Handb. Paleont. vol. iu. p. 204. 1890. Eugnathus latus, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 78. Type. Nearly complete fish ; British Museum. A large species, attaining a length of about 0-7. Length of head with opercular apparatus not quite equalling the maximum depth of the trunk and occupying about one-quarter of the total length of the fish; the depth of the caudal pedicle contained two-and-a- half times in the maximum depth. Cranium, facial bones, opercular bones, and the well-developed postclavicular scales ornamented with coarse and sparse tuberculations ; operculum about two-thirds as broad as deep, tapering above, and its maximum breadth equalling nearly one-third the length of the cranium; marginal teeth robust and acuminate, and the teeth on the splenial bone rela- tively large anteriorly. Dorsal fin as long as deep, much larger than the anal.fin, and arising opposite the origin of the pelvic pair. Principal scales of the anterior series on the flank slightly deeper than broad, and marked with fine ridges terminating in the serra- tions of the posterior border; most of the flank scales and ventral scales as far as the origin of the dorsal and pelvic fins serrated, the others smooth. Though not clearly indicated by Egerton, this may be regarded as the type species of the genus Heterolepzdotus. Form. & Loc. Lower Lias: Dorsetshire. All the following specimens were obtained from the neighbour- hood of Lyme Regis :— 38118. The type specimen figured and described by Egerton, Joc. cit. 1872. Purchased, 1864. P. 2008. Large head with anterior abdominal squamation, displaying the-opercular apparatus and post-claviculer plates, noticed by Egerton, wid. p. 3. Egerton Coll. PART III. x 306 ACTINOPTERYGII. P. 2020. Posterior abdominal and caudal region of an equally large P. 7564. P. 3579. P. 6395. individual, the scales somewhat scattered dorsally and ventrally, and the fins imperfect. os Egerton Coll. Crushed specimen as large as the type, with scattered head- bones. Several of the elements are displayed, notably the hyomandibular and symplectic of both sides. The hyo- mandibular is relatively broad, expanded below, and not much constricted mesially; the symplectic is elongated, triangular in form, the apex being inferior and much thickened. History unknown. A slightly smaller specimen, also with displaced head- bones and exhibiting some of the incomplete anterior vertebral rings. The base of the skull is imperfectly shown, and the left quadrato-pterygopalatine arch is exposed from the inner side. On the parasphenoid and the oral face of the pterygoids, as also on the hinder part of the splenial, the dentition is reduced to a fine granu- lation ; but at the antero-inferior border of the ectoptery- goid, either on that bone itself or on the palatine, the teeth are of moderate size and arranged in a dense cluster. Enniskillen Coll. Hinder portion of head and greater part of the squamation of a fish as large as the type, in indurated Lias. The postorbital and opercular bones are shown, and the ornament of the anterior scales is conspicuous. Beckles Coll. P. 3579 a. Remains of the trunk of a similar fish, showing the P. 2009. axial skeleton. The hypocentra in the abdominal region are broad and robust, flattened below, each with a pair of lateral processes bearing nearly straight slender ribs. The neural and hemal arches in the caudal region are robust, and appear to be anchylosed with their respective pleurocentra and hypocentra. Enniskillen Coll. Well-preserved smaller fish, wanting the region behind the dorsal fin. The supratemporal and post-temporal plates are shown behind the cranium and above the operculum, ornamented with tuberculations; the robust maxilla is smooth. ‘The perforations of the scales in the lateral line are distinguishable, though inconspicuous vertical slits ; ‘ » = ——— 1 EUGNATHID A. 307 - and there are indications of a similar series of perforated scales on the dorsal portion of the flank, extending as far P. 6423. P. 1538. P. 2011. P. 2010. P. 1542. P. 3620. backwards as the dorsal fin. One of the pelvic basal bones is exposed. . Egerton Coll. Distorted and partly imperfect specimen about 0°5 in length. The teeth of the dentary bone are very closely arranged. Beckles Coll. Imperfect remains of head and greater portion of trunk of a similar fish. The biserial fulcra are well shown on the right pelvic fin. Egerton Coll. Trunk with median fins. Egerton Coll. Small specimen about 0°36 in length, The head is much crushed, and parts of the fins are wanting. Egerton Coll. Remains of small specimen originally about 0°3 in length. The head-bones are much displaced, so that several internal elements are shown. The paired fins are preserved, and the greater part of the flank-squamation is exposed from within. Egerton Coll. The type specimen of the so-called Sem2onotus rhombefer described by Agassiz, loc. cit., being a fish somewhat smaller than the preceding and almost certainly the young of Heterolepidotus latus. The comparative smoothness of the head-bones and post-clavicular plates .is apparently due to imperfect preservation. Enniskillen Coll. P. 1538 b. Middle portion of trunk of a similar fish. Egerton Coll. P. 1538 a. Caudal region of another small specimen. Egerton Coll. Heterolepidotus serrulatus (Agassiz). 1843-44. Lepedotus serrulatus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 305, pl. xxxi. 1868. Eulepidotus serrulutus, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. xxiv. p. 505. 1872. Heterolepidotus serrulutus, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Sury.), no. 2, p. 2. 1890. Eugnathus serrulatus, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 79. Type. Fish wanting caudal extremity ; British Museum. A species nearly equalling H. latus in size, but differing in its relatively larger and smoother scales, and in the robustness of the x. 2 308 ACTINOPTERYGII. caudal pedicle, the depth of which equals at least half the maximum depth of the trunk. Form. & Loc. Lower Lias: Leicestershire. The following specimens are preserved in nodules from Barrow- on-Soar :— P. 3580. The type specimen, in counterpart. The figure and description of the operculum are misleading, this bone attaining its maximum width inferiorly and tapering above, as proved by the next specimen. Hnniskillen Coll. P. 2007, P. 3580 a. Hinder part of head and the abdominal region of a large specimen in counterpart. The operculum is well shown, and the pectoral fin nearly complete. Egerton & Enniskillen Colls. P. 2007 a. Specimen much like the type, but wanting the anterior half of the head. The fulcra of the dorsal fin are dis- played, and appear to be relatively larger than in H, latus. Egerton Coll. P. 7565. Trunk wanting head, and the squamation only preserved in impression. Fulcra are conspicuous on the anterior margin of the dorsal and pelvic fins; and the greater part of the caudal fin is shown. 19488. Posterior abdominal and caudal region of a typical specimen, _ showing the greater part of the dorsal, caudal, and pelvic fins. The last-mentioned fins seem to arise just in advance of the dorsal, though there may bea displacement. There is evidence of robust vertebral elements. Presented by the Earl of Aylesford, 1845. 19488 a. Fragment of trunk, showing pleurocentrum and hypo- centrum in transverse section. Presented by the Earl of Aylesford, 1845. Heterolepidotus typicus (Winkler). 1861. Brachyichthys typicus, T. C. Winkler, Descript. Poiss. Foss. Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv.), p- 53, fig. 9. Type. Imperfect fish ; British Museum. The type species of the so-called genus Brachyichthys, attaining a length of about 0°5. Length of head with opercular apparatus about equalling the maximum depth of the trunk, and contained four times in the total length of the fish. Operculum nearly as EUGNATHIDZ. 309 broad as deep, and its maximum breadth exceeding one-third the length of the cranium; maxillary teeth very slender, those of the premaxilla and dentary much stouter and closely arranged. Principal flank-scales about as deep as broad; all the scales of the abdominal region very finely serrated, and many also equally finely pectinated. Form. § Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. 43003. The type specimen, in counterpart; Solenhofen. Winkler’s original description and figure are very inadequate and in part incorrect. Some further details may therefore be given, illustrated by the accompaning outline-sketch (fig. 35). The cranial roof is displaced forwards, exhibit- ing the thick parietals ( pa.) and frontals (fr.), with the Heterolepidotus typicus ; head-hones of type specimen, less than one half natural size. br., branchiostegal rays; ¢.k., ceratohyal ; ¢.o., circumorbitals ; ep.h., epihyal ; fr., frontal; hm., hyomandibular ; z.op., interoperculum ; md., mandible ; mx., maxilla; op., operculum ; p.cl., postclavicle; p.op., preoperculum ; pa., parietal ; pas., parasphenoid ; pmz., premaxilla ; s.mx.,supramaxilla ; s.0., suborbitals ; s.op., suboperculum ; sg., squamosal; s¢., supratemporal ; sym., symplectic; v., vomer. squamosals (sq.), from the inner aspect; while the base of the skull occurs still further forwards, apparently com- prising the long and narrow parasphenoid ( pas.) with the pair of vomerine bones (v.) in front. The two premaxille 310 ACTINOPTERYGII. (pme.) are preserved, one at the rostral end of the cranial roof, the other just to the right of the right frontal ; each with an extended oral margin and exhibiting a broad ascending process at the middle of its upper edge. The left maxilla (mwx.) occurs in position, much deepened behind and bearing very slender teeth; above it is a relatively large supramaxilla(s.m«.). The right mandibular ramus (md.), imperfectly preserved and wanting its hinder end, is displaced beneath the head, and shows traces of small, stout conical teeth. The hyomandibular (hm.) is partly exposed in position, but the remainder of the suspensorium is very fragmentary, the metapterygoid only being dis- played on the counterpart, and two isolated bones (sym.) being perhaps the symplectics; the large posterior sub- orbitals (s.o.) are obscurely indicated, and there are remains also of a smaller circumorbital ring (c.o.). The epihyal (ep.h.) and ceratohyal (c.h.) elements are shown, the former triangular and equilateral, the latter much contracted in front. All the opercular bones of the right side are shown from the inner aspect, the operculum (op.) being about as broad as deep with truncated postero- superior angle, the suboperculum (s.op.) with a large anterior ascending process, the interoperculum (7.o0p.) elongate-triangular, and the preoperculum ( p.op.) narrow and arched. There are branchiostegal rays below (6r.). Nothing can be ascertained as to the ornamentation of the external bones. The right supratemporal (st.) is exposed from the inner aspect, and there are traces of the enlarged postclavicular scales (p.cl.). One of the clavicles and both the pelvic fin-supports are displaced beneath the trunk; and, as shown by Winkler’s figure, both the fins and squamation are much disturbed. The anterior margin of the dorsal fin displays conspicuous fulcra, as also does that of the lower lobe of the caudal fin, but it is not clear whether they are uniserial; one of these elements displayed below the caudal fin is distinctly so, but it may have been basal. The scales are not so much deepened on the flank as is suggested by Winkler’s figure, and a large group of the much narrowed ventral scales is displaced beneath the head. All are thick, and whenever well displayed in the abdominal region they exhibit delicate serrations on the posterior margin; many are also finely pectinated. Van Breda Coll. EUGNATHID A. 311 Heterolepidotus striatus (Agassiz). [Plate VIII. fig. 3.] 1837-44. Semionotus striatus, L. Agassiz, Poiss. Foss. vol. i. pt. 1. p- 231, pl. xxvii a. figs. 6, 7. Type. Fish wanting head and tail; British Museum. A small imperfectly known species of robust proportions. Head and opercular bones ornamented with closely arranged coarse ruge. Scales remarkably smooth, those on the anterior part of the body with few serrations. Form. & Loc. Upper Trias: Tyrol. P. 3621. The type specimen, described and figured by Agassiz, loc. cit.; Seefeld. The original drawing of the scales is very inaccurate, and a new figure is thus given in Pl. VIII. fig. 3. The narrow ventral scales are well shown, and quite distinct in form from those of the specimens described by Kner as referable to this species (see p. 316). The position of the pelvic fins is not indicated, but they would probably arise immediately in advance of the dorsal fin. Enniskillen Coll. P. 3621 a. A more imperfect specimen, apparently of this species ; Seefeld. Enniskillen Coll. Heterolepidotus cephalus (Kner). 1866. Pholidophorus cephalus, R. Kner, Sitzungsb. k. Akad. Wiss., math.-naturw. Cl. vol. liv. pt. i. p. 326, pl. iv. fig. 2. 1889. Pholidophorus cephalus, W. Deecke, Paleontogr. vol. xxxv. p. 135, pl. vii. fig. 4. 1892. Pholidophorus cephalus, F. Bassani, Mem. Soe. Ital. Sci. [3] vol. ix. no. 3, pp. 8, 23. Type. Nearly complete fish. A very small species. Length of head with opercular apparatus equalling the maximum depth of the trunk, and contained about three-and-a-half times in the total length of the fish. Opercular apparatus [probably also head] ornamented with closely arranged, coarse ruge; operculum much deeper than broad. Dorsal and anal fins deeper than long, and the pelvic fins arising in advance of the origin of the former. Anterior scales coarsely serrated. Form. & Loc. Upper Trias: Tyrol, Lombardy, and Salerno. 21383. Specimen agreeing almost precisely with the figure given by Kner; Seefeld. Purchased, 1847. oN ACTINOPTERYGII. Heterolepidotus pectoralis (Bellotti). 1857. Lepidotus pectorals, C. Bellotti, in A. Stoppani, Studii Geol. e Paleont. Lombardia, p. 420. | 1889. Heterolepidotus pectoralis, W. Deecke, Paleeontogr. vol. xxxv. p- 114, pl. vi. fig. 8, pl. vii. fig. 10. Type. Imperfect fish ; Milan Museum. A species attaining a length of about 0°16. Length of head with opercular apparatus exceeding the maximum depth of the trunk and occupying one-third of the total length of the fish ; width of caudal pedicle contained about two-and-a-quarter times in the maximum depth of the trunk. External bones conspicuously ornamented with granulations, which are sometimes fused into ruge; scales smooth, those of the anterior part of the trunk finely serrated; principal flank-scales about as deep as broad. (Deccke.) Form. & Loc. Upper Trias: Perledo, Como. Not represented in the Collection. Heterolepidotus serratus (Bellotti). 1857. Lepidotus serratus, C. Bellotti, in A. Stoppani, Studii Geol. e Paleont. Lombardia, p. 419. 1889. Heterolepidotus serratus, W. Deecke, Paleontogr. vol. xxxv. p, L1G, pl. vai. fig. 2. Type. Nearly complete fish ; Milan Museum. A species closely related to the preceding but somewhat more elongated, and the ornament of the external bones entirely tuber- cular, not rugose. Head with opercular apparatus occupying some- what more than one-quarter of the total length of the fish ; width of caudal pedicle contained about two-and-a-half times in the maximum depth of the trunk. (Deecke.) Form. 5 Loc. Upper Trias: Perledo, Come. Not: represented in the Collection. Heterolepidotus (?) radiato-punctatus (Agassiz). 1844. Pholidophorus radiato-punctatus, L. Agassiz, Poiss. Foss. vol. ii. pt. 3. p. 287. 1844, Pholidophorus maximus, L. Agassiz, ibid. p. 287. Type. Remains of head and trunk; British Museum. A large species characterized by comparatively robust scales, whieh are not much deeper than broad on the flank, and are ail ‘ornamented with small tubercles of ganoine, usually more or less elongated and closely arranged in lines radiating from the anterior EUGNATHIDZ. ole border or from the antero-superior angle. The external bones and some of the fin-rays with a similarly fine and close tubercular ornament. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. P. 2060. Type specimen, labelled by Agassiz and Egerton, com- P. 3583. prising the imperfect head and scattered remains of the anterior portion of the trunk; Solenhofen. Part of the highly ornamented cranial roof is shown in impression, while the imperfect facial and opercular bones of the right side are exposed from within. The two left lower suborbitals are also shown from within where displaced above the head; and neither on these nor on those of the opposite side can the course of the sensory canal be traced. The outlines of the mandible and maxilla are not clear, but a displaced premaxilla exhibits a broad ascending process at one end, the height of this equalling the length of the dentigerous border of the bone. One imperfect element, which seems to be maxilla, has a slightly concave oral margin, with very small, closely- arranged teeth. The left operculum, though imperfect, is shown to have been deeper than broad; while the suture between this and the suboperculum is evidently oblique. A few very slender bones, which seem to be short ribs, are scattered among the remains of the trunk, but there are no traces of vertebree. Numerous stout fin- rays occur, and two apparently from the front of the pectoral fin are covered with the tubercular ornament, while some others exhibit the same ornament on one border. The pelvic bones are shown to be no broader distally than proximally, a wing of bone extending inwards on each side from the proximal two-thirds of the normal triangular element. The scales are remarkably scattered and shown in all positions, displaying the stout inner rib and peg-and-socket articulation; but narrowed scales are few. Among the remains are the jaws of two small Pycnodonts, perhaps the relics of food. Lgerton Coll. Imperfect caudal region with caudal fin, possibly of the same individual as the preceding, labelled “* Caturus maai- mus or new?” by Agassiz. All the scales are ornamented, and at the base of the upper caudal lobe one ridge-scale is 314 ACTINOPTERYGII. enlarged. As the series are traced backwards the peg- and-socket articulation gradually disappears, while the inner rib widens and is finally indistinguishable. Enniskillen Coll. The following species have also been imperfectly defined, but do not appear to be represented in the Collection :— fleterolepidotus angulati, W. Deecke, Mittheil. Comm. geol. Landes-Untersuch. Elsass-Lothr. vol. i. (1888), p. 207.— Lower Lias; Buchsweiler, Alsace. [Nearly complete trunk with hinder portion of head; Geological Survey Museum, Strassburg. | Heterolepidotus (?) leptocephalus: Semionotus leptocephalus, L. Agassiz, Neues Jahrb. 1832, p. 145, and Poiss. Foss. vol. i. pt. i. pp. 8, 222 (1833-44), pl. xxvi. fig. 1; F. A. Quenstedt, Flozgeb. Wirttemb. (1843), p. 243; O. Fraas, Wiirtt. Jahresh. 1861, p. 83.—Upper Lias; Boll, Wirtemberg. {Nearly complete fish; unknown. | Heterolepidotus minor, J. W. Davis, Proc. Yorksh. Geol. & Polyt. Soe. n. s. vol. viii. (1883), p. 403, pl. xxi1.—Lower Lias ; Lyme Regis. [Fish too imperfect for specific definition ; J. W. Davis Collection, Halifax. | A fish closely resembling Heterolepidotus but differing in not having the tail forked, is known from the Lower Oolite of Brora, Sutherland. It is believed to have been obtained from the carbon- aceous shale underlying the main seam of lignite in Strath Brora, and the original specimens are now in the Duke of Sutherland’s Museum at Dunrobin Castle. The fish has been described under the name of Semionotus joassi (A. S. Woodward, Ann. Mag. Nat. Hist. [5] vol. xx. 1887, p. 179, pl. viil.), but its generic position must still be regarded as undetermined (W. Deecke, Paleeontogr. vol. xxxv. p. 103). The detached maxilla ascribed to it (loc. cit. pl. viii. fig. 3) is probably named erroneously, and seems to belong to a Palzeoniscid. A generically indeterminable portion of squamation which may belong either to the Paleoniscide or to a fish resembling Hugnathus and Heterolepidotus is described as follows :— Crenilepis sandbergeri, W. Dames, Paleeont. Abhandl. vol. iv. (1888), p. 170, pl. xv. fig. 3.—Muschelkalk ; Krainberg, near Wurzburg. [Abdominal flank-squamation ; Univer- sity of Wtrzburg. } EUGNATHIDZ. ale Genus ALLOLEPIDOTUS, Deecke. [ Paleontographica, vol. xxxv. 1889, p. 114. | Body robust and fusiform, and the atrophied upper caudal lobe conspicuous. External head- and opercular bones delicate, more or less ornamented with ruge and tuberculations; snout obtusely pointed [maxilla straight?]. Ossifications in the notochordal sheath absent or very feeble. Fulcra biserial, relatively large. Pelvic fins small; dorsal and anal fins triangular in shape, the former arising opposite or immediately behind the pelvic fins; caudal fin moderately forked. Scales thick, mostly smooth, sometimes with serrations of the posterior border; principal flank-scales in part deeper than broad, and none of the ventral scales much broader than deep; no enlarged series of dorsal ridge- scales. Lateral line inconspicuous. Allolepidotus rueppelli (Bellotti). 1857. Pholidophorus ruppelii, C. Bellotti, in A. Stoppani, Geol. e Paleont. Lombardia, p. 428. 1889. Allolepidotus riuppelli, W. Deecke, Paleontogr. vol. xxxv. p. 117, pl. vi. fig. 5. Type. Plaster cast of imperfect fish ; Milan Museum. The type species, of small size, attaining a length of about 0-1. Length of head with opercular apparatus much less than the maximum depth of the trunk, and contained more than four times in the total length. External bones nearly smooth. Dorsal and anal fins deeper than long, the former larger than the latter and arising behind the pelvic fins. Some of the principal scales of the anterior series on the flank nearly twice as deep as broad, and those of other series also more or less deepened ; most of the scales of the abdominal region conspicuously serrated. Form. & Loc. Upper Trias: North Italy. The only known examples of this species were obtained from the black shales of Perledo, on the shore of the Lake of Como, between Vareuna and Regoledo. ‘There are no specimens in the Collection. Allolepidotus nothosomoides, Deecke. 1889. Allolepidotus nothosomoides, W. Deecke, Paleeontogr. vol. xxxv. De LS epleevie ite. 0) Type. Nearly complete fish. A more robust and somewhat larger species than the type. Length of head with opercular apparatus nearly equalling the maximum depth of the trunk and contained less than four times in Bo ACTINOPTERYGII. the total length of the fish. External head- and opercular bones and postclavicular scales ornamented with conspicuous coarse rug and tuberculations. Some of the principal scales of the anterior series on the flank nearly twice as deep as broad, and those of other series also more or less deepened; most of the scales of the abdominal region conspicuously serrated, some of those of the caudal region with a few widely-separated posterior denticles. Form. § Loc. Upper Trias: North Italy. P. 1548. Fish wanting head and having part of the ventral squama- tion displaced ; Perledo, Lake of Como. Egerton Coll. Allolepidotus dorsalis (Kner). (?) 1883-44. Pholidophorus dorsalis, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. pp. 9, 287 (inadequately defined). 1866. Pholidophorus dorsalis, R. Kner, Sitzungsh. k. Akad. Wiss., math.-naturw. Cl. vol. liv. pt. i. p. 324, pl. vi. fig. 1. 1866. Semionotus striatus, R. Kner (errore), ibid. p. 322, pl. v. fig. 1. 1867. Semronotus striatus, R. Kner (errore), loc. cit. vol. lvi. pt. i. p. 898, plaice; al. 1867. Pholidophorus dorsalis, R. Kner, ibid. p. 903, pl. 11. fig. 2. Type. Imperfect trunk. A robust species, attaining a length of about 0:14. Length of head. with opercular apparatus nearly equalling the maximum depth of the trunk and contained less than four times in the total length of the fish. External head- and opercular bones feebly ornamented with coarse ruge and tuberculations. None of the scales much deeper than broad; few of those of the abdominal region serrated, nearly all non-serrated and smooth. Form. & Loc. Upper Trias: Tyrol. 21380. Fish wanting head and extremity of caudal fin, but with well-preserved squamation ; Seefeld. Purchased, 1847. P. 1544. A more imperfectly preserved specimen, showing the caudal fin; Seefeld. Egerton Coll. 16655. A smaller imperfect fish, with some well-preserved scales ; Seefeld. Purchased. Genus PTYCHOLEPIS, Agassiz. [Neues Jahrb. 1832, p. 142. ] Trunk elegantly fusiform. Snout acutely pointed and prominent ; external head-bones and opercular bones ornamented with prominent ridges of ganoine; marginal teeth comparatively small and stout, EUGNATHID 2. 317 arranged in close series ; preoperculum almost or completely covered by the cheek-plates; operculum quadrangular, broader above than below; suboperculum large, trapezoidal, deeper behind than in front, and without an ascending process at its antero-superior angle ; branchiostegal rays few and broad, and a very large gular plate present, these being comparatively smooth. [Annular ossifications in the sheath of the notochord known only at the base of the tail in one specimen.| Fulcra biserial, conspicuous on all the fins except the dorsal; fin-rays more or less ornamented with ridges of ganoine. Pectoral much exceeding the pelvic fins in size, but the latter well-developed ; dorsal and anal fins triangular in shape, the former opposed to the pelvic pair, the latter small and remote ; caudal fin deeply forked. Scales thick and deeply overlapping, destitute of an inner rib, but those of the flank with a peg-and- socket articulation; the external layer of ganoine marked with deep longitudinal grooves; all the scales much longer than deep, but especially elongated in the ventral region ; no enlarged series of ridge-scales, but some enlarged on the inner side of the pectoral and pelvic fins, three large scales surrounding the anus in advance of the anal fin, and some large postclaviculars conspicuous. Lateral line obscurely marked, opening on the scales by widely-separated vertical slits. The character of the external ornament renders it difficult to observe the sutures between the head-bones in Ptycholepis; and the dense squamation obscures the endoskeleton of the trunk in all known specimens. The inner bones of the head and the inner dentition also remain unknown. Ptycholepis bollensis, Agassiz. 1832. Ptycholepis bollensis, L. Agassiz, Neues Jahrb. p. 142 (name only). 1833-44. Ptycholepis bollensis, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 11, pt. il. p. 108, pl. viii. d. 1849. Ptycholepis bollensis, W. C. Williamson, Phil. Trans. 1849, p. 444. 1852. Ptycholepis bollensis, F. A. Quenstedt, Handb. Petrefakt. p. 203, pl. xv. fig. 5. 1858. Ptycholepis bollensis, F. A. Quenstedt, Der Jura, p. 281, pl. xxx. figs. 1-7, pl. xxxi. fig. 8. 1865. Ptycholepis bollensis, G. Cotteau, Bull. Soe. Sci. Yonne, vol. xix. pt. 11. p. 337. 1875. Ptycholepis barrati, H. E. Sauvage, Bibl. Ecole Hautes Etudes, vol. xiv. no. 1, p. 8, pl. il. fig. 2. [Distorted fish.] 1891. Ptycholepis barrati, H. HE. Sayvage, Bull. Soe. Sci. Yonne, vol. xlv. pt. 11. p. 33, pl. i. 318 ACTINOPTERYGII. Type. Imperfectly preserved fish; British Museum. The type species, attaining a length of about 0°35. Length of head with opercular apparatus equalling the maximum depth of the trunk and nearly one-quarter of the total length of the fish. The ridged ornament of the head coarse, very rarely mingled with few tubercles, and covering all the external bones except the gular plate and branchiostegal rays, which are nearly smooth ; the supra- clavicle also ornamented with finer transverse ridges. Most of the ridges on the cranium, cheeks, and opercular bones longitudinal ; the ridges on the upper portion of the dentary and hinder half of maxilla oblique. The stouter fin-rays ornamented with few fine longitudinal ridges of ganoine; pelvic fins arising midway between the pectorals and the caudal; dorsal fin with slightly more than 20 rays, arising well in advance of the pelvic pair. Scales marked with from one to four or five delicate, irregular, longitudinal furrows, sometimes discontinuous, sometimes branching, rarely reaching the hinder border except on the middle of the abdominal flank, and producing an ornament of large, incomplete, rounded ridges; the hinder border deeply and coarsely denticulated. Form. & Loc. Upper Lias: Yorkshire, Wiirtemberg, and Yonne, France. P. 3688. A much crushed and distorted fish described and figured by Agassiz, op. cit. 1844, to be regarded as the type specimen ; Whitby, Yorkshire. One of the pelvic fins is mistaken in the original description for the anal; and the obscure caudal extremity, with traces of the caudal fin, is very inaccurately drawn. ‘The appearance of teeth in the mandible is deceptive. Enniskillen Coll. P. 858-a. Two imperfect specimens displaying some of the head- bones and the greater part of the squamation; Whitby. The first specimen exhibits the gaping mouth, but no teeth ; and portions of all the fins except the anal are preserved. The second specimen is more imperfect, but shows remains of the smooth branchiostegals and gular plate. Egerton Coll. P. 3691. Remains of the hinder portion of the head and the imperfectly preserved trunk of a large fish, labelled by Agassiz; Whitby. Enmskillen Coll. P. 5222. Imperfect head and ventral aspect of the abdominal region of a fish preserved in a nodule; Whitby. ‘The bases of a single regular series of small teeth are exhibited on the . Ges i - EUGNATHID.®. 319 edge of the maxilla; and there are impressions of a ceratohyal and the large gular plate between the rami of the mandible. Twoor three enlarged scales in the region between the pelvic fins are also imperfectly preserved. Presented by Sir Richard Owen, K.C.B., 1878. 35580-82. Part of the abdominal region with dorsal fin, another specimen showing part of the head and abdominal region, and an imperfect detached caudal fin; Whitby. The number of rays in the dorsal fin is difficult to ascertain, but there appear to be slightly more than 20. The form of the suboperculum is well shown in the second specimen. Purchased, 1859. 20579. A large fish much broken and partly deepened by distortion ; Boll, Wiirtemberg. The maxilla displays its obliquely ridged ornament; and a few of the abdominal scales exposed from within show the peg-and-socket articulation. Purchased, 1846, 36015. Fine large specimen wanting the dorsal and anal fins and in part much fractured; Ohmden, near Boll. A large upper postclavicular scale 1s conspicuous, and the smooth- ness of the upper branchiostegals is shown. A few of the anterior flank-scales exhibit feeble traces of elongated tubercles replacing delicate vertical folds at the anterior border. Purchased, 1861. P. 3689. Another large specimen wanting the fins, much distorted ; Ohmden, near Boll. The smooth extremity of the rostrum is shown, and most of the external ornament is well- preserved, extending both over the opercular and supra- temporal plates. Between the rami of the mandible some of. the broad branchiostegals and remains of the gular plate are conspicuous, all quite smooth. Snniskillen Coll. 20659. Part of the head and abdominal region of a smaller fish, with paired fins; Boll. Biserial fulcra are seen on the pectoral fin, and some of the broad smooth branchiostegal rays are exposed. Purchased, 1846. P. 7175. A fine specimen 0°28 in length, exposed from the lateral and partly ventral aspect, imperfect in the dorsal region; Holzmaden, Wurtemberg. The opercular plates, with the smooth branchiostegals and gular below, are displayed ; and all the fins are shown except the dorsal. Purchased, 1894. 320 ACTINOPTERYGII. P. 860-1, P. 2023. A fine portion of the abdominal squamation, from Boll; and two imperfect heads with remains of the trunk and fins, from Ohmden, near Boll. Egerton Coll. 22534. Imperfect head, pectoral fin, and anterior abdominal scales ; Boll. Purchased, 1848. 19655-56. Greater portion of trunk in impression, and imperfect remains of another specimen preserved from the origin of the dorsal fin backwards; Boll. here are no distinct traces of vertebral rings in the caudal region, although circumstances are favourable to the exposure of these if they were present in the second specimen. Purchased, 1845. P. 3690. Very imperfect but typical large specimen; locality doubtful, but labelled ‘‘ Lower Lias, Lyme Regis.” Enniskillen Coll. Ptycholepis gracilis, Davis. 1884. Ptycholepis gracilis, J. W. Davis, Ann. Mag. Nat. Hist. [5] vol. xili. p. 535, pl. x. . Type. Nearly complete fish ; J. W. Davis Collection, Halifax. A comparatively slender species of moderate size, the length of the head equalling the maximum depth of the trunk and contained nearly five times in the total length of the fish. Scales differing from those of the type species in the presence of a few feeble but conspicuous vertical folds of ganoine at the anterior overlapped border. Form. & Loc. Lower Lias: Dorsetshire. 39864. Remains of a much abraded small head and trunk with pectoral fins ; Lyme Regis. Purchased, 1866. P. 4242. Much crushed remains of a large trunk with paired fins: Lyme Regis. Two of the enlarged pelvic scales are shown. Enniskillen Coll. P. 859. Imperfect remains of a large specimen doubtfully of this species, probably referred to by Egerton, Figs. & Descript. Brit. Organic Remains, dec. vill. (Mem. Geol. Surv.), no. 8, p. 3; Lyme Regis. The detached left suboperculum, exposed from the inner aspect, exhibits no ascending anterior process. Egerton Coll. EUGNATHID®. oct Ptycholepis curta, Egerton. [Plate X. fig. 1.] 1854-55. Ptycholepis curtus, Sir P. Egerton, Ann. Mag. Nat. Hist. [2] vol. xiii. p. 435, and Figs. & Descript. Brit. Organic Remains, dec. viii. (Mem. Geol. Surv.), no. 8, pl. viii. Suppl. p. 1. Type. Crushed fish ; British Museum. A stout species of moderate size, the length of the head equalling the maximum depth of the trunk and contained about three-and-a- half times in the total length. Pelvic fins opposed to the hinder portion of the dorsal; anal fin very small and remote. External bones and fin-rays ornamented as in the type species; the scales differing in the presence of a few conspicuous vertical folds of ganoine at the anterior overlapped border. Form. & Loc. Lower Lias: Dorsetshire. P. 6334. The type specimen, apparently somewhat shortened by crushing; Lyme Regis. A few ossified vertebral rings, with their robust hzemal arches, are seen at the base of the tail. Beckles Coll. 39493. A more satisfactorily preserved fish, shown of the natural size in Pl. X. fig. 1; Lyme Regis. The caudal pedicle is accidentally elongated and the hinder portion of the dorsal fin is wanting, but the specimen is otherwise nearly complete. The maxilla distinctly shows a series of minute conical teeth, while the characteristic form of the operculum and suboperculum may be observed. The uppermost branchiostegal ray is conspicuously ornamented. Purchased, 1865. P. 3692. Imperfect example of a similar fish, evidently the second specimen described by Egerton, loc. cit. Suppl. p. 1; Lyme Regis. Portions of the smooth branchiostegals and gular plate are shown; and there is evidence of biserial fulcra on the pectoral fin. Ennisiillen Coll. P. 3692 a. A small, much-abraded specimen; Lyme Regis. Enniskillen Coll. P. 859 a. Imperfect remains of head and squamation; Lyme Regis. Many of the scales are exposed from within, and demonstrate the absence of an internal rib. Egerton Coll. PART III. Bd aoe ACTINOPTERYGII. P. 3693. A vertically crushed fish, probably of this species, ex- hibiting the small teeth in the maxilla; Lyme Regis. Enniskillen Coll. Ptycholepis monilifer, sp. nov. [Plate X. figs. 2-4. ] Type. Portions of fish; British Museum, The largest known species, probably attaining a length of not less than 0°6. The ridged ornament of the head fine and closely arranged, vermiculating, the ridges often interrupted and in part passing into tubercles. The stouter fin-rays ornamented with few oblique ridges of ganoine. Scales marked with numerous sharp, delicate ridges, sometimes branching, sometimes intercalated, the majority directed obliquely downwards and backwards and termi- nating in the serrations of the hinder border; the ridges in all the scales, except those of the caudal pedicle, passing forwards into a small sparsely tuberculated area at the anterior margin. Form. & Loc. Lower lias: Dorsetshire. 39868. Type specimen, comprising the right mandibular ramus, part of the branchiostegal apparatus, the dorsal and caudal fins, numerous scales, and other fragments ; Lyme Regis. The right mandibular ramus is shown of the natural size in Pl. X. fig. 2, but is imperfect posteriorly. A few small robust conical teeth in single series occur sparsely arranged at irregular intervals within the alveolar border, which exhibits a slightly sigmoidal curvature. The anterior extremity of the ramus is stout, though tapering to a blunt point; and this part is much more coarsely ridged than the remainder of the external surface. The superficial ridges are very irregular, frequently interrupted, branching, or intercalated, having a generally backward and downward direction; and for a considerable space bordering the alveolar margin they are replaced by fine tubercles. Part of the course of a sensory canal is conspicuous postero-inferiorly; and a branch seems to extend from this upwards and forwards to the anterior extremity of the bone. The remains of the opercular bones are very fragmentary, but one highly- ornamented plate is evidently the suboperculum, and this is accidentally overlain by the large gular, which is quite smooth except in a small mesial tuberculated area; but several of the long and narrow branchiostegal rays are EUGNATHIDA. 325 exhibited, and distinctly marked with the finely ridged, partly tuberculated ornament. A few slender rays gradually increasing in length occur in front of the dorsal fin, but there are no fulcra; the stouter rays are much ornamented, as shown in the enlarged figure, Pl. X. fig. 4. The caudal fin is large and much forked, with stout rays anteriorly but very delicate rays behind; the superior fulera are well developed, much elongated, and ornamented with short transverse ruge of ganoine; and the upper caudal lobe was evidently somewhat produced as usual in the genus, though the specimen is crushed and difficult of precise interpretation. Three scales from the region of the dorsal fin are shown enlarged in Pl. X. fig. 3, and the lowermost exhibits the feeble rudiment of a peg-and-socket articulation. Purchased, 1866. Ptycholepis minor, Egerton. 1852. Ptycholepis ninor, Sir P. Egerton, Figs. & Descript. Brit. Or- ganic Remains, dec. vi. (Mem. Geol. Surv.), no. 7, pl. vil. Type. Imperfect fish ; British Museum. A small elongated species, the length of the head with opercular apparatus somewhat exceeding the maximum depth of the trunk and occupying about one-quarter of the total length of the fish. The ornament of the external bones consisting of comparatively delicate, well-spaced ridges; the scales with few longitudinal furrows, sometimes partly convergent behind, and with some con- spicuous vertical folds at the anterior border. The feeble nature of the external ornament seems to be charac- teristic of this species, but it may be partly a deceptive appearance due to the state of fossilization. Form. & Loc. Lower Lias: Leicestershire. P. 574, P. 3694. Type specimen, about 0°095 in length, in counter- part ; Barrow-on-Soar. Egerton § Enniskillen Colls. P. 862. Part of the head, abdominal region, and pectoral fin of a much larger fish; Barrow-on-Soar. Egerton Coll. Ptycholepis avus, Kner. 1866. Ptycholepis avus, R. Kner, Sitzungsb. k. Akad. Wiss., math.- naturw. Cl. vol. lin. pt. 1. p. 167, pl. u. fig. 2. Type. Distorted fish ; Geological Survey Museum, Vienna. A very small species, attaining a length of about 0-09. Length of the head with opercular apparatus somewhat exceeding the maximum Y 2 324 ACTINOPTERYGII. depth of the trunk, and occupying about one-quarter of the total length of the fish. The ornament of the external bones consisting of closely arranged prominent ridges; the scales with strongly marked longitudinal ridges and furrows terminating in posterior denticulations, and with some conspicuous vertical folds at the anterior border. Form. & Loc. Upper Trias: Raibl, Carinthia. P. 5958. A typical specimen wanting all the fins except the dorsal and caudal, but displaying the squamation. Purchased, 1889. Ptycholepis marshi, Newberry. 1878, Ptycholepis marshii, J. 8. Newberry, Ann. New York Acad. Sci. VOL Meda i es 1888. Ptycholepis marshi, J. S. Newberry, Foss. Fishes Trias, N. Jersey & Connecticut (Mon. U.S. Geol. Surv. no. xiv.), p. 66, pl. xix. figs, 1, 2. Type. Nearly complete fish. A species of slender proportions, attaining a length of about 0°2. Head with opercular apparatus occupying somewhat less than one- quarter of the total length of the fish. Ornamental ruge on cranial roof slightly radiating; those of the facial and opercular bones more or less parallel and forked. Dorsal fin far forwards, and pelvic fins arising opposite its hinder extremity. Scales exhibiting only longitudinal ridges and furrows, and the hinder border often deeply serrated. (Newberry.) Form. & Loc. Trias: Durham, Connecticut, U.S.A. Not represented in the Collection. Some detached scales from the Upper Trias of Besano, Lombardy, are also named Ptycholepis barboi by F. Bassani, Atti Soc. Ital. Sci. Nat. vol. xxix. (1886), p. 38. The so-called Ptycholepis tenmsquamata (R. Kner, Sitzungsb. k. Akad. Wiss., math.-naturw. Cl. vol. lvi. pt. 1. 1867, p. 913, pl. iv.) from the Upper Trias of Raibl, Carinthia, apparently does not belong to this genus. Genus OSTEORACHIS, Egerton. [Quart. Journ. Geol. Soe. vol. xxiv. 1868, p. 500.] Syn. Isocolum, Sir P. Egerton, zed. 1868, p. 501. Harpactes, Sir P. Egerton (non Templeton, 1834), Geol. Mag. [2] vol. ili. 1876, p. 441. Harpactira, Sir P. Egerton, zbed. 1876, p. 576. Trunk elongate. External bones ornamented with tuberculations or ruge; marginal teeth relatively large and well-spaced; splenial BUGNATHID A, B yA, and ectopterygoid teeth smaller, very long and slender, and forming a dense cluster throughout the length of these elements; sub- operculum of moderate size, about half as large as the nearly rectangular operculum. Ossifications in the sheath of the noto- chord in the form of distinct hypocentra and pleurocentra. Fulcra present on all the fins; distal articulations of fin-rays very close. Pectoral much exceeding the pelvic fins in size, but the latter large ; dorsal and anal fins triangular in shape, the former opposite the pelvic fins, the latter immediately behind it; caudal fin forked. Scales thin, moderately overlapping, and with a large peg-and- socket articulation ; their exposed face ornamented with tubercula- tions and striz ; principal flank-scales about as deep as broad, several on the ventral aspect much broader than deep. Lateral lines inconspicuous. Osteorachis macrocephalus, Egerton. (?) 1839-44. Pachycormus? macrurus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 113, pl. lviil. a, fig. 3. [Imperfect tail ; Oxford Museum. | 1868. Osteorachis macrocephalus, Sir P, Egerton, Quart. Journ. Geol. Soc. vol. xxiv. p. 500. 1872. Osteorachis macrocephalus, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Surv.), no. 5, pl. v. 1876. Harpactira-(Harpactes) velov, Sir P. Egerton, Geol. Mag. [2] vol. i. pp. 441, 576. [Fish; British Museum. | 1885. Heterolepidotus grandis, J. W. Davis, Journ. Linn. Soc., Zool. vol. xviii. p. 293, pl. vii. [Fish; J. W. Davis Collection, Halifax. | 1890. Harpactira velor, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 92. 1890. Osteorhachis macrocephala, Wocdward & Sherborn, zbzd. p. 186. 1890. Platysiagum grandis, Woodward & Sherborn, zé7d. p. 151. 1895. Osteorachts macrocephalus, A. 8. Woodward, Geol. Mag. [4] vol. ii. p. 204, pl. vii. fig. 10. . Type. Imperfect head and abdominal region ; British Museum. The type species, attaining a length of about 1 metre. Form and proportions imperfectly known, but the length of the head with opercular apparatus probably contained about four times, and the maximum depth of the trunk seven times in the total length of the fish. Most of the external bones ornamented with a very fine and close granulation; jaws smooth. Operculum considerably deeper than broad. The suboperculum is more than twice as broad as deep in specimen no. P. 3648, and the gular plate in the same individual is about two-thirds as broad as long. Dorsal fin with not less than 18 rays, arising in advance of the middle point of the 326 ACTINOPTERYGII. back; anal fin much smaller than the dorsal. Scales finely and closely tuberculated; the tubercles only rarely fusing into trans- verse strive on the hinder half of the scale. Form. & Loc. Lower Lias: Dorsetshire. P. 3654. P. 876 x. The type specimen, being the head and greater portion of trunk, vertically crushed, described and figured by Egerton, loc. cit. 1872; Lyme Regis. Both description and figure are unsatisfactory. ‘The head is crushed obliquely and exposed from below. Remains of a large gular plate appear between the fragments of the smooth mandibular rami, and there are clusters of the small slender teeth. The premaxilla cannot be identified with certainty, and there is no evidence as to how the teeth were disposed ; one narrow fragment of bone shows the bases of three series of teeth. On one large expanded bone, which may be entopterygoid, the teeth cover an extensive area and are in part merely fine granulations. The hyomandibular is well shown on one side, but in the published drawing it is not distinguished from an adjoin- ing element which appears to be the displaced meta- pterygoid. The process of the hyomandibular for the support of the operculum is long, but its hinder end is connected with the upper and lower extremities of the element by a thin lamina of bone. Behind the hyoman- dibular, parts of the operculum and suboperculum are seen from within. The vertebral centra are not ‘ com- pletely ossified,’ but are represented merely by distinct hypocentra and pleurocentra; their arches are obscurely indicated through the displaced squamation. The tubercles on the scales are occasionally elongated, and on the hinder portion of some of the flank-scales they are observed to pass into transverse strize which terminate in feeble denticulations. The fins are too fragmentary for detailed description. Enniskillen Coll. Fragmentary remains of head, pectoral fins, and anterior scales; Lyme Regis. Part of the smooth outer face of the left dentary, with its coronoid elevation, is shown ; and there are scattered examples of the characteristic slender teeth. The cranial roof is imperfectly exposed from within, and there are remains of the hyomandibular, supposed entopterygoid, aud numerous other elements. The operculum, though fragmentary, is clearly deeper P. 3655. P. 3648. EUGNATHID®. S2E than broad, and much broader below than above, while its external face is finely and closely tuberculated. The basals of the pectoral fins are long and slender, constricted mesially, and more than six in number. Appearances are not quite clear, but the largest basal seems to be the hindermost. Some of the scales exhibit the very large peg-and-socket articulation; and others are finely orna- mented, showing the tubercles passing into strie poste- riorly. Egerton Coll. Imperfect trunk noticed by Egerton, loc. cit.; Lyme Regis. The specimen is much disturbed by crushing, and so probably does not afford a correct idea of the form of the fish, the caudal pedicle being deepened and the fins somewhat displaced and fragmentary. There are separate hypocentra and pleurocentra, as in the type specimen, none fused together. Each hypocentrum in the abdominal region is semicircular, flattened and indented with two longitudinally-elongated pits on its inferior face, bearing a pair of short lateral processes for the support of the ribs. Ihe pleurocentra are too imperfectly shown for description. There are remains of the much-elongated basals of the pectoral fin, and one of the robust, hour- glass-shaped pelvic bones is preserved. The median fins are in great part destroyed. The scales are shown in undisturbed order dorsally for some distance in advance of the dorsal fin; and many narrow scales of the ventral aspect are exhibited. The scale-ornament is well pre- served, and the tubercles rarely pass into striz on the hinder half of the scale. Enniskillen Coll. Type specimen of the so-called Harpactira (Harpactes) velox, described by Egerton, loc. cit.; Lyme Regis. This is a curiously preserved specimen about one metre in length, with remains of all the fins except the anal nearly in position, but wanting the whole of the axial skeleton of the trunk, and showing only a few traces of the squamation. The head is very imperfect and obliquely crushed. ‘The greater part of the right mandibular ramus is exhibited from the inner aspect. The dentary is much fractured in front, though showing the coronoid elevation behind ; while the splenial is displaced, but sufficiently complete to exhibit its clustered small slender teeth and the excayation of its hinder margin. Some of the charac- 328 P. 3649. ACTINOPTERYGII. teristic teeth are also scattered below the jaw. ‘The right hypohyal occurs, both large and robust. ‘The large gular plate is completely preserved, two-thirds as broad as long, obtusely rounded in front, truncated behind. There are no other recognizable elements worthy of note, and the amount of disturbance to which the fossil has been sub- jected is indicated by the fact, that the left suboperculum is displaced to the hinder part of the caudal region. The exposed portion of this plate is slightly more than twice as broad as deep, ornamented with a very fine and close tuberculation ; and there is a small ascending process at its antero-superior angle. Remains of the pelvic fins opposed to the dorsal appear to comprise some slender fulcra. The caudal fin is best preserved, exhibiting its bifurcation and the very close articulation of its stout rays; fulcra are displayed on both lobes, those on the upper lobe being especially large and distinctly uniserial at the base. Scales occur sparsely in the region of the pelvic, dorsal, anal, and caudal fins, all exhibiting the characteristic tubercular ornamentation. On the few principal flank-scales which are preserved, the tubercles have a tendency to elongation and pass in the hinder half into conspicuous strize. The peg and socket for articula- tion are very large, as usual. ‘The ventral scales are shown to have been narrowed, as also are those immedi- ately covering the base of the caudal fin-rays. Enniskillen Ooll, Fragments of mandible, apparently of this species, labelled Eugnathus polyodon by Agassiz and noticed by Egerton, loc. cit. 1868, p. 500; Lyme Regis. Enniskillen Coll. P. 3648 a. Imperfect and abraded large cranium, doubtfully of this species ; Lyme Regis. Finmaskillen Coll. P. 875. Roof of a similar but much smaller skull, with a pair of otic bones displaced behind; Lyme Regis. Egerton Coll. Osteorachis granulatus (Hgerton). 1868. Isocolum granulatum, Sir P. Hgerton, Quart. Journ. Geol. Soc. vol. xxiv. p. 501. 1872. Isocolum granulatum, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. xiii. (Mem. Geol. Surv.), no. 4, pl. iv. Type. Trunk wanting head and tail; British Museum. ‘A fish known only by a single specimen about half as large as —- —-. EUGNATHID&. 329 the preceding species, but very doubtfully distinct from the latter although made the type of another genus (lsocolum) by Egerton. The specimen is not much smaller than no. P. 3655 recorded above, but its vertebral elements and scales are both less robust. The suboperculum is deeper in proportion to its width ; and the striated character of the hinder half of the scales appears to be more general. Form. & Loc. Lower Lias: Dorsetshire. P. 3653. The type specimen described and figured by Egerton, Joc. cit.; Lyme Regis. The operculum is somewhat deeper than broad and completely covered with granulations, which are coarsest near the superior margin. The ossifi- cations in the notochordal sheath are confined to separate pleurocentra and hypocentra; and the thick, sigmoidally- bent neural spines in the abdominal region are not fused with their comparatively delicate supporting arches. The ribs are short and delicate, while the neural and hemal arches in the caudal region are especially robust. The slender fulera on the dorsal and pelvic fins appear to be biserial. The squamation is very little disturbed, and the narrowing of the scales on the ventral aspect is well shown; many of the principal flank-scales are finely denticulated. Enniskillen Coll. Genus CATURUS, Agassiz. [Neues Jahrb. 1834, p. 387. ] Syn. Ureus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 1888, p. 12 (non Ureus, Wager, 1830). Conodus, L. Agassiz, zbid. vol. ii. pt. ii. 1844, p, 105 (name only). Strobilodus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. 1851, p. 75. Eindactis, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. ix. (Mem. Geol. Surv. 1858), no. 4. Thiattodus, R. Owen, Geol. Mag. vol. iii. 1866, p. 55. Ditaxicdus, R. Owen, zbid. p. 107. Trunk elongate-fusiform. External head-bones and opercular bones feebly ornamented with ruge and tuberculations, all except the cheek-plates robust; snout obtusely pointed, and maxilla straight or with a slightly concavely-arched dentigerous border ; teeth relatively large and arranged in a sparse series on the margin 330 ACTINOPTERYGII. of the jaws, smaller on the palatine and on the splenial, where they are in single series anteriorly, minute and almost granular on the other inner bones ; preoperculum nearly smooth and narrow ; oper- culum deep, much broader below than above, and suboperculum of moderate size. Ossifications in the sheath of the notochord imsigni- ficant or absent in the smaller species, consisting only of separate hypocentra and pleurocentra in the largest species; ossified ribs slender, not reaching the ventral border of the abdomen. Fulcra biserial, well-developed on all the. fins, those of the pectoral being especially elongated and sometimes in part fused together. Pectoral much exceeding the pelvic fins in size, but the latter well-developed ; dorsal and anal fins triangular in shape, the former arising opposite or immediately behind the pelvic fins; caudal fin deeply forked. Scales delicate, smooth, feebly crimped or in part tuberculated, deeply overlapping, and none much deeper than broad ; a few series anteriorly quadrangular and possibly sometimes united with peg-and- socket, the others more or less cycloidal, and very few narrowed on the ventral aspect of the fish. Lateral line inconspicuous. The osteology of Caturus as exhibited partly in specimens from the French and German Lithographic Stone, but especially in those from the English Oxford Clay, is proved to be essentially similar to that of Hugnathus already described (p. 287). The state of pre- servation of the Oxfordian fossils in the Leeds Collection, however, permits the determination of a few additional features. In advance of the basipterygoid process of the parasphenoid there is a very large alisphenoidal ossification, much exceeding in size either of the otics behind. The prooticis equally well ossified, and the opisthotic is still more robust ; but no undoubted traces of pterotic and epiotic ossifications have hitherto been observed. As in Hugnathus, the mesethmoid appears to have been little ossified, and it was probably small. In front of the parasphenoid there is a pair of large vomers, bearing a few teeth only at their anterior end. The nasals are proved to resemble those of Amza. The supraorbitals are irregular and much subdivided at their outer margin, the tessere extending somewhat upon the cheek. The symplectic in Caturus still remains unknown ; but the palatine has been well observed in this genus, forming a small laterally compressed plate of bone with a row of teeth on its oral margin. The ceratohyal does not exhibit so much evidence of twisting as in Hugnathus. The gill-tilaments have calcified supports, and there are small tooth-like gill-rakers, some arranged on the edge of little triangular flakes of bone like those observed in Ama. EUGNATHIDA. 351 LIE SE A CSE BA i} e LBZ CLL LE Jk Cheeses & i YEE LZ JMESTEZ QO5se. esr sezes {} ¥5 5 ~ =" NS . EES SST ie) Ag) A cy ~~ Caturus furcatus ; restoration, scales omitted. Ze WW DS < Z By - ACTINOPTERYGII. Caturus furcatus, Agassiz. 1883. Pachycormus furcatus, L. Agassiz, Neues Jahrb. p. 476, and Poiss. Foss, vol. i. pt.i. p. 11. 1833. Ureus nuchalis, L. Agassiz, Neues Jahrb. p. 477, and Poiss. : Foss, vol. ii. pt, 1. p. 12. 1884. Caturus latus, G. von Munster, Neues Jahrb. p. 539. [Nearly complete fish ; Palzeontological Museum, Munich. | 1834. Ureus furcatus, L. Agassiz, Verhandl. Ges. Vaterland. Mus. Bohmen, p. 70. 1889. Caturus maximus, L. Agassiz, Neues Jahrb. p. 118. 1889. Catwrus macrodus, L. Agassiz, wed. p. 118. [Fragmentary fish ; Paleontological Museum, Munich. ] 1889-44. Caturus latus, L. iver. Poiss. Foss. vol. ii. pt. 11. p. LT, pl. lvi. 1842-44, Caturus furcatus, L. Agassiz, wid. pt. i. p. 116, pl. lvi. a. 1844. Caturus maximus, L. Agassiz, ibid. pt. 41, pp. 118, 294. 1844, Caturus macrodus, L. Agassiz, cbid. pt. 11. pp. 118, 294. 1844, Caturus nuchalis, L. Agassiz, ibid. pt. ii. p. 298. 1863. Caturus marinus, &. Wane, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. p. 700. 18638. Caturus furcatus, A. Wagner, bcd. p. 701. 1863. Caturus latus, A. Wagner, wbid. p. 702. 1863. Caturus cyprinoides, A. Wagner, bid. p. 702. [Nearly complete fish ; Paleontological Museum, Munich. | (?) 1873. Caturus furcatus, V. Thiolliére, Poiss. Foss. Bugey, pt. ii. Dpdlish Tl oxettp ules I (?) 1873. Caturus latus, V. Thiolliére, zbcd. p. 18, pl. xiit. fig. 3. 1881. Caturus fureatus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 109. 1887. Caturus maximus, K. A. von Zittel, Handb. Paleeont. vol. iii. p- 228, fig. 241 a. 1887. Caturus furcatus, K. A. von Zittel, ibed. p. 228, figs. 241 b-g. 1887. Caturus elongatus, K. A. von Zittel, ied. p. 227, fig. 240 (errore). The small fishes described under the following names also appear to be immature examples of this species :— 1833. Ureus macrurus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 12. , 1839. Caturus microchirus, L. Agassiz, Neues Jahrb. p. 118. [Skull and pectoral fin ; Paleontological Museum, Munich. | 1842. Caturus Soontos G. von Minster, Nowes Jahrb. p. 44. [Small distorted fish ; Paleontological Museum, Munich. | 1844, Caturus Peers L. egreive Poiss. F oss. vol. ii. pt. i. p. 118. 1844. Caturus microchirus, L. Agassiz, ibid. pp. 118, 294. 1861. Caturus ferox, T. ©. Winkler, Descript. Poiss. Foss, Solenhofen (Natuurk. Verhandl, Holland. Maatsch. [2] vol. xiv.), p. 56, fig. 10. [Teyler Museum, Haarlem. ] EUGNATHIDE. Hoe 1863. Caturus microchirus, A. Wagner, Abh. k. bay. Akad. Wiss. math.-phys. Cl. vol. ix. p. 703. 1863, Caturus macrurus, A. Wagner, zbid. p. 706. 1863. Caturus obovatus, A. Wagner, ebid. p. 707. 1863. Caturus gracilis, A. Wagner, wid. p. 707. [Variety in Paleon- tological Museum, Munich. | 1871. Caturus ferox,T.C. Winkler, Archiv. Mus. Teyler, vol. ili. p. 176 pl. v. figs. 2, 3. Type. Nearly complete fish ; Royal Bohemian Museum, Prague. The type species, attaining a length of about 1 metre. Length of head with opercular apparatus about equal to the maximum depth of the trunk, and usually less than one-quarter of the tctal length of the fish. Caudal region tapering to a comparatively slender pedicle, its depth little, if at all, exceeding one-third the maximum depth of the abdominal region. Teeth large, with very slender apex, and about 40 in total number in the dentary; depth of operculum somewhat exceeding its maximum breadth ; branchio- stegal rays about 24. Dorsal fin with about 20 rays, deeper than long, its depth equalling about one-half that of the trunk at its origin ; this fin arising in advance of the middle of the back, the — distance from the occiput to its origin being equal to that from its hinder border to the base of the caudal fin. Pelvic fins arising opposite the front half of the dorsal fin; anal fin, smaller than the dorsal, with from 12 to 14 rays. Scales smooth, or in part marked with a few feeble, short, transverse striz. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria, _and (?) Ain, France. 37024, 37026. Two fine specimens nearly 0:5 in length, in counter- part; Solenhofen. The vertebral pleurocentra and hypo- centra are well developed, and the first specimen exhibits the large gular plate with about 21 branchiostegal rays. Hiberlein Coll, P. 3726. Similar specimen ; Solenhofen. Enniskillen Coll. 49141. Plaster cast of large specimen (Paleontological Museum, Munich) apparently elongated by crushing; Kelheim. Purchased, 1878. 37028, 37034, 37038. Three specimens from 0-36 to 0-42 in length; Solenhofen. The last specimen shows the atrophied upper caudal lobe. Haberlein Coll. 37027. Imperfect fish 0°32 in length, in counterpart, with indica- tions of ossified pleurocentra and hypocentra ; Solenhofen. 334 ACTINOPTERYGII, The small teeth of the splenial bone are displayed within the remains of the large series on the dentary. Hiberlein Coll. 37035. A much-fractured specimen 0-28 in length, showing ossified pleurocentra and hypocentra and a relatively large dorsal fin; Solenhofen. Hiberlein Coll. P. 908. A finely preserved, though partly fractured specimen, 0°28 in length, not exhibiting either pleurocentra or hypocentra; Solenhofen. The series of large postclavicular scales is preserved ; and some of the scales in the dorsal part of the caudal region show the striation and crimping at their hinder margin. Egerton Coll. P. 5544. Fragmentary and distorted remains of a large fish; Eich- stadt. By exchange, 1888. P. 6941. Imperfect fish about 0-4 in length, displaying the left pectoral fin and the very stout hemal arches of the caudal region ; Eichstiidt. By exchange, 1893. P. 7180. Imperfect large specimen; Eichstidt. By eachange, 1894. P. 909. Portion of trunk, displaying pelvic bones ; Kelheim. Lgerton Coll. 37035 a. Imperfect head and abdominal region; Solenhofen. Haberlein Coll. P. 519. Imperfect head and other remains, in counterpart, with well-displayed dentition, labelled “ Caturus macrodus, Agass.” in Agassiz’s handwriting, and apparently intended to be the type specimen of that supposed distinct species ; Solenhofen. Egerton Coll. P. 904, P. 907. Two specimens showing more fragmentary remains of the head, the second also with the clavicles and pectoral fins; Solenhofen. Egerton Coll, 37906. Fine skull, with scattered bones; Solenhofen. Haberlein Coll. P. 904 a, P. 3722 a. Imperfect skull, in counterpart ; Solenhcfen. Egerton &§ Enniskillen Colls. 8038. Fragmentary remains of head ; Solenhofen. Mantell Coll. . 37929. Mandible with gular plate ; Solenhofen. Haberlein Coll. EUGNATHID 2. aoe P. 3722 a. Slab with scattered fragmentary remains, including the head ; Solenhofen. Enniskillen Coll. 20560. Large caudal fin ; Solenhofen. Purchased. 20577-78. Two large slabs with scattered fragmentary remains ; Solenhofen. Purchased, 1846. P. 4378-9. Two slabs with scattered fragmentary remains; Solen- hofen. Enniskillen Coll. The following specimens are probably immature examples of this species :— P. 7566. Fine specimen, 0°23 in length ; Pappenheim. History unknown. 37095, 37097, 37812. Three fine specimens, in counterpart, from 0-145 to 0°165 in length; Solenhofen. The depth of the dorsal fin seems to be relatively greater than in the typical large specimens. Haberlein Coll. 37083, 37808—09. Four fine smaller specimens ; Solenhofen. Haberlen Coll. P. 4380. Fish about 0°16 in length, with caudal fin broadened by crushing; Kelheim. Enniskillen Coll. 42844. Impression of fish 0-135 in length; Solenhofen. Van Breda Coll. P. 906. Impression of a similar fish and two smalJler specimens ; Solenhofen. Egerton Coll. P. 3721, P. 3724, P. 3729. Three imperfect small fishes, and another fine specimen 0-125 in length; Solenhofen. Enniskillen Coll. P. 906 a, P. 3725. Fine specimen 0-095 in length, in counterpart ; Solenhofen. Egerton § Enniskillen Colls. 37658. Imperfect fish, ventral and partly lateral aspect, in counter- part, probably of this species ; Solenhofen. Hdberlein Coll. 37067. Small head and pectoral fins, ventral aspect, in counterpart ; ‘\ Solenhofen. Haberlein Coll. The follwing fragmentary specimens indicate a species closely related to C, furcatus, but apparently distinguished by the form of the mandible... The depth of the dentary at the hindermost tooth equals one-quarter of the length of its dentigerous border, while 336 ACTINOPLERYGII. in C. furcatus the first measurement is only one-fifth of the second. The specimens are important as exhibiting many features in the osteology of the genus. P. 6902. Vertically depressed head, exhibiting the nasal bones, tesseree of supraorbitals, and more than 20 branchiostegal rays; Oxford Clay, Peterborough. Leeds Coll. P. 6903. Remains of head and anterior squamation in nodule; Oxford Clay, Peterborough. Leeds Coll. P. 6904. Vertically depressed head exhibiting the characteristic supraorbitals ; Oxford Clay, Peterborough. Leeds Coll. _P. 6905-7. Three fragmentary heads, the first displaying the pre- operculum, the second the alisphenoid, prootic, and para- sphenoid bones, with remains of the branchial arches ; Oxford Clay, Peterborough. Leeds Coll. P. 6908, a—c. Four examples of the hinder portion of the skull and adjoining parts; Oxford Clay, Peterborough. Leeds Coll. P. 6910. Associated maxille and palatine; Oxford Clay, Peter- borough. Leeds Coll. P. 6909. Miscellaneous fragments of trunk and fins; Oxford Clay, Peterborough. Leeds Coll, 46348. Two fragments of head; Christian Malford, Wiltshire. Cunnington Coll. 29049. Fine large depressed head, with part of the abdominal region and the bases of the pectoral fins; Oxford Clay, Christian Malford. Purchased, 1854. -39156-57. Imperfect jaws; Christian Malford. Bowerbank Coll. 36174. Maxilla; Christian Malford. Purchased, 1861. P. 967. Imperfect maxilla, and maxilla associated with the man- dible; Christian Malford. Egerton Coll 24676. Imperfect remains of head and trunk; Christian Malfor,, Purchased, 1850, Caturus pachyurus, Agassiz. 1832-33, Ureus pachyurus, L. Agassiz, Neues Jahrb. p. 142, and Poiss. Foss. vol. 11. pt. 1. p. 12. 1839. Caturus pachyurus, L. Agassiz, Neues Jahrb. p. 118. 1844. Caturus pachyurus, L. Agassiz, Poiss. Foss. vol. ii. pt: ip. We: 1844. Caturus elengatus, L. Agassiz, zbid. pp. 118, 293. [Nearly com- plete fish ; Palzeontological Museum, Munich. ] led EUGNATHIDZ. 337 1868. Caturus elongatus, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. p. 703. 1863. Caturus fusiformis, A. Wagner, wid. p. 704. [Small fish; Palee- ontological Museum, Munich. | 1863. Caturus pachyurus, A. Wagner, ibid. p. 704. 1868. Caturus contractus, A. Wagner, ibid. p. 705. [Nearly complete fish; Paleeontological Museum, Munich. | f 1871. Caturus elongatus, T. C. Winkler, Archiv. Mus. Teyler, vol. ii. p. 178, pl. v. figs. 4-10. (?) 1873. Caturus elongatus, V. Thiolliére, Poiss. Foss. Bugey, pt. 11. Pes, pl, xii. fe. 2. Type. Nearly complete fish; Paleontological Museum, Munich. A small species attaining a length of about 0°3. Length of head with opercular apparatus considerably exceeding the maximum depth of the trunk, and somewhat less than one-quarter of the total length of the fish. Caudal region little tapering, the depth of the caudal pedicle equalling about one-half the maximum depth of the trunk. Teeth large, with slender apex, and irregularly spaced. Dorsal fin with about 18 rays, deeper than long, its depth equalling at least three-quarters that of the trunk at its origin; all the fins situated as in the type species. Scales smooth. According to Wagner (loc. cit. p. 706), the imperfectly described Caturus granulatus, Munster (Neues Jahrb. 1842, p. 44), is closely related to this species. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria, and (?) Ain, France. 37076. Well-preserved large trunk, with fins and the branchial region; Solenhofen. Haberlein Coll, 37810. Fish 0°235 in length, much fractured, but with nearly complete fins and displaying relatively large, stout teeth in the dentary bone; Solenhofen. Haberlein Coll. 22518. Imperfect specimen 0°195 in length, apparently with smaller dentary teeth than the last ; Solenhofen. Purchased, 1848. P. 903. Similar specimen, wanting the caudal fin; Eichstadt. Egerton Coll. 49127. Plaster cast of type specimen of Catwrus contractus, Wagner, the trunk somewhat deepened by crushing ; Solenhofen. Purchased, 1878. Caturus driani, Thiolliére. 1850. Caturus driani, V. Thiolliére, Ann. Sci. Phys. & Nat. Lyon, [2] vol. ii. p. 145. 1873. Caturus segusianus, P. Gervais, in V. Thiolliére, Poiss. Foss. PART III. Z 538 ACTINOPTERYGII. Bugey, pt. ii. p. 17, pl. xii. fig. 1. [Nearly complete fish ; Lyons Museum. | 1881. “ Caturus” segusianus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 110. Type. Nearly complete fish ; Lyons Museum. A large species, attaining a length of about 0°5. Length of head with opercular apparatus about equal to the maximum depth of the trunk, and less than one-quarter of the total length of the fish. Caudal region tapering to a comparatively slender pedicle, its depth equalling about one-third the maximum depth of the abdominal region. Teeth smaller than in the type species. Dorsal fin deeper than long, and its depth nearly or quite equalling that of the trunk at its origin; this fin arising well in advance of the middle of the back, the distance from the occiput to its origin being considerably less than that from its hinder border to the base of the caudal fin. Pelvic fius arising opposite the hinder half of the dorsal fin; anal fin much smaller than the dorsal ; lobes of the caudal fin especially slender. Scales larger than in the type species, smooth. The peg-and-socket articulation of the scales indicated in Thiolliere’s figure, is not shown in the specimens enumerated below. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. P. 905. Fine large specimen ; Cirin. Egerton Coll. P. 4700. Smaller and more imperfect specimen, the trunk shown chiefly in impression ; Cirin. Purchased, 1884. P. 4697-8. Two imperfect large specimens about 0-54 in length, for the most part shown only in impression, probably of this species; Cirin. Purchased, 1884. Caturus velifer, Thiolliére. 1850. Caturus velifer, V. Thiolliére, Ann. Sci. Phys. & Nat. Lyon, [2] vol. ii. p. 143. 1873. Caturus velifer, V. Thiolliére, Poiss. Foss. Bugey, pt. ii. p. 17, pl. xu. fig. 2. 1881. “ Caturus” velifer, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 110. Type. Nearly complete fish ; Lyons Museum. A large species, closely related to C. drianz, but distinguished by its more elongated trunk, the length of the head with opercular apparatus exceeding the maximum depth of the trunk, and the EUGNATHIDZ. 339 dorsal fin being relatively large. Scales in part ornamented with radiating series of very fine granulations. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. Not represented in the Collection. Caturus angustus, Agassiz. 1844. Caturus angustus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 118. 1893. Caturus angustus, A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol. xii. p. 398, pl. xviii. fig. 1. Type. Fish, wanting head; Worcester Museum. An imperfectly defined species, known only by the type specimen, which measures 0°16 from the origin of the dorsal to the fork of the caudal fin. Trunk much elongated, the width of the caudal pedicle scarcely equalling half the depth of the trunk between the dorsal and pelvic fins. The origins of these two fins directly opposed, and the dorsal with about 20 rays; anal fin about as large as the pelvic fins, with not less than 12 rays. Form. & Loc. Portlandian: Garsington, Oxford. Not represented in the Collection. Caturus heterurus (Agassiz). [Plate IX.] 1839-44. Pachycormus (?) heterurus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p- 118, pl. lviil. a. figs. 4, 5. Type. Tail; Oxford Museum. A robust species of medium size, attaining a length of about 0:45. Length of head with opercular apparatus exceeding the maximum depth of the trunk and contained about four times in the total length of the fish ; depth of caudal pedicle equalling about half the maximum depth of the trunk. External head-bones, supratemporals, and opercular bones ornamented only in part with feeble rugze and tuberculations ; maxillary teeth small, slender, and in close series, premaxillary teeth larger, and those of the dentary bone largest and stoutest, well-spaced; operculum about three- quarters as broad as deep. Hypocentra and pleurocentra large, well-ossified. Dorsal fin comprising 18 rays, arising in advance of the middle of the back, about as deep as long, and its maximum depth not much exceeding half that of the trunk at its origin; pectoral fins with loose fulcra; pelvic fins arising opposite the front half of the dorsal; anal fin comprising only 9 or 10 rays, arising immediately behind termination of dorsal. Scales relatively large, some exhibiting a very feeble radiating crimping. (34 z2 340 ACTINOPTERYGII. It is not improbable that the undefined name Caturus bucklands (L. Agassiz, Poiss. Foss. vol. ii. pt. ii. 1844, p. 119) pertains to this species. It was originally applied to a specimen from Lyme Regis exhibiting the head and anterior portion of trunk, but the present writer has not been able to discover this fossil. Form. & Loc. Lower lias: Dorsetshire. All the following specimens were obtained from the neighbourhood of Lyme Regis :— 38121. Head with abdominal region exposed from the left side, shown of one-half the natural size in Pl. IX. fig. 1. The cranium is too much crushed for examination, and the facial bones are mostly imperfect and fractured. The short and deep premaxille (pmw.) bear a few large slender teeth; the maxilla (mx.) exhibits a close series of small slender teeth, and there is a supramaxillary bone (s.mw.). The mandible exhibits very large, widely-spaced teeth in the dentary bone (d.), and there are indications of the ascending plate of bone behind the tooth-bearing margin. The form and proportions of the opercular bones (op., S.op., 1.0p., p.op.) are shown, while the large size of the upper branchiostegal ray (6r.1) and of the gular plate (q.) is noteworthy. The left post-temporal (p.t.), clavicle, and supraclavicle are partly exhibited, and there are remains of the postclavicular plates. The pectoral fin is nearly complete ; its anterior rays are remarkably straight, and it appears to have been fringed with slender fulera; only four rays of the left pelvic fin remain, but the large slender fulcra are well preserved. Of the dorsal fin, only some of the supports are shown. The position of the notochord is marked by a confused line of hypocentra and pleurocentra; the ribs are long and the neural arches short, but both remarkably slender. Above the neural arches is a series of very robust, slightly bent, long bones, inclined backwards, commencing shortly behind the head and extending even beneath the supports of the dorsal fin; and these appear to be the separate neural spines. All the scales are smooth, and their rhombic form is well shown in the dorsal region. Purchased, 1864. P. 897. Head and fragment of abdominal region shown from the right side. The dentition is indicated as in the last specimen. Egerton Coll. P. 4377. Remains of head and opercular apparatus in indurated Lias. Enniskillen Coll. hg bg - 2036. BUGNATHID&. 341 Nearly complete skeleton, with imperfect head, and dis- playing part of the squamation. The thick scales on the atrophied upper caudal lobe are conspicuous, and shown in Pl. IX. fig. 2, s. One of the pelvic fin-supports is repre- sented in fig. 5, while a few of the scales of the caudal region are shown enlarged twice in fig. 4. Hgerton Coll. . 8696 b. More imperfect skeleton with obscure remains of the . 3696. . 3702. head. ‘The indurated contents of the intestine seem to preserve impressions of the folds of the spiral valve. Enniskillen Coll. The greater portion of a large fish, wanting the tail and the anterior end of the head, and with much-displaced squamation. Large slender fulcra are shown in front of each of the paired fins; and the stout median scales are preserved at the base of the lower lobe of the caudal fin. Enniskillen Coll. Similar specimen, infero-lateral aspect, showing less of the head, but with more satisfactorily preserved squama- tion. Enmskillen Coll. . 3696 a. Skeleton of the trunk of a smaller fish, with a few fragmentary head-bones. The squamation is almost destroyed, only a few rhombic scales beingishown on the flank of the abdominal region... The hypocentra in the abdominal region are broad and flattened below; those in the caudal region are smaller and firmly united with the robust pedicles of the hemal arches. The free neural spines are imperfectly exhibited; the supports of the anal fin are remarkably long, and the pelvic basipterygia are well-ossified and robust. Enmskilen Coll. . 3696 c-e. Three imperfect specimens. Enniskillen Coll. . 120. Imperfect head and abdominal region, the scales well preserved and displaying the superficial ornament. Purchased, 1880. P. 898 a. Imperfect trunk with well-preserved dorsal fin. Egerton Coll. . 898 c. Imperfect axial skeleton, with remains of partially . 3633. digested fish. Egerton Coll. Inferior aspect of head and part of abdominal region of a small fish, probably of this species. Enniskillen Coll. 342 ACTINOPTERYGII. Caturus latipennis (Hgerton). 1844. Pachycormus latipennis, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 114 (undefined). 1858. Pachycormus latipennis, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. ix. (Mem. Geol. Surv.), no. 3, pl. iii. Type. Head, with pectoral fin and scales; British Museum. An imperfectly definable species closely similar to C. heterurus. External head-bones and opercular bones ornamented only in part with feeble rugs and tuberculations, the supratemporals and post- temporals closely tuberculated ; maxillary teeth small, slender, and in close series, and those of the dentary bone large, stout, well- spaced. Hypocentra and pleurocentra distinct, robust. Scales of moderate size, smooth, The anterior pectoral fin-rays of this species seem to be some- what broader and more arcuated than in C. heterurus. Form. & Loc. Lower Lias: Dorsetshire. P. 568. The type specimen, described and figured by Kgerton, loc. cit.; Lyme Regis. Enniskillen Coll. 38527. Similar specimen exposed from the left side; Lyme Regis. The pectoral fin is well-preserved, but there are only slight traces of slender fulera. Purchased, 1864. Caturus agassizi (Egerton). 1858. Endactis agassizi, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. ix. (Mem. Geol. Surv.), no. 4, pl. iv. Type. Fragmentary head and trunk; British Museum. The type species of the so-called genus Hndactis, attaining a length of about 0:3. The proportions being apparently similar to those of C. heterurus, it remains doubtful whether the fish is not merely the young of the latter species ; but in the specimens mentioned below the scales seem to be relatively smaller and more conspicuously erimped, while ossifications in the notochordal sheath are very feeble or absent. The crimpings on the scales sometimes radiate more or less. Form. & Loc. Lower Lias: Dorsetshire. P. 567. The type specimen, very fragmentary, showing the greater part of the squamation of the right side from within ; Lyme Regis. There are distinct indications of large EUGNATHID&. 343 fulera in front of the dorsal fin; and the form of the trunk is evidently somewhat deepened by crushing. Egerton Coll. 41856. A small fish, 0:24 in length, showing the characteristic ornamentation of the scales, with imperfect head and wanting the greater part of the caudal fin; Lyme Regis. Relatively large teeth are shown in the upper jaw. ‘The neural and hemal arches of the axial skeleton of the truuk are well calcified, but there are no distinct indica- tions of skeletal elements in the notochordal sheath. Large fulcra are shown on the upper lobe of the caudal, but the other tins are too imperfectly preserved to show whether similar fulcra were present or absent. The ornamentation of the scales is very conspicuous in the abdominal region: there are stouter rhombic scales on the atrophied upper caudal lobe, and two stout median scales occur at the base of the lower lobe of the caudal fin. Purchased, 1870. Caturus insignis (Kner). 1866. Eugnathus ensignis, R. Kner, Sitzungsb. k. Akad. Wiss., math.- naturw. Cl. vol. liv. pt. i. p. 806, pl. 1. Type. Nearly complete fish; Innsbruck Museum. A species attaining a length of about 0-4. Length of head with opercular apparatus about equal to the maximum depth of the trunk and contained nearly four-and-a-half times in the total length of the fish; depth of caudal pedicle equalling about half the maximum depth of the trunk. External bones ornamented with fine granulations and ruge; mandibular teeth robust and in part striated ; operculum twice as deep as broad. Pelvic fins arising immediately in advance of the dorsal, which arises at about the middle point of the back and comprises 17 rays; anal fin with 11 rays, smaller than the dorsal, and arising opposite the hinder extremity of the latter. Form. & Loc. Upper Trias: Seefeld, Tyrol. Not represented in the Collection. The following species, known only from imperfect specimens, are remarkable for the large size and robust proportions of their teeth. They are commonly described as Conodus, Strobilodus, Thlat- todus, and Ditaxiodus, but have as yet exhibited no characters by which they can be distinguished from Caturus. 344 ACTINOPTERYGII, Caturus (Conodus) chirotes (Agassiz). [Plate VII. figs. 2, 3.] 1889. Eugnathus cheirotes, L. Agassiz, Neues Jahrb. p. 118. 1842-44. Hugnathus chirotes, L. Agassiz, Poiss. Foss. vol. i. pt. ii. p. 102, pl. lvii. 0. 1844, Conodus ferox, L. Agassiz, zbid. p. 105 (name only). [Portion of jaws ; British Museum. | 1890. Eugnathus (?) chirotes, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 77. Type. Imperfect fish; British Museum. The type species of the undefined genus Conodus, attaining a length of about 0°75. Length of head with opercular apparatus apparently exceeding the maximum depth of the trunk and con- tained about four times in the total length of the fish. -External bones ornamented in part with sparse tuberculations; maxilla thick but not much deepened, the hinder two-thirds of its dentigerous margin concavely arched, and the height of the middle teeth not equalling the depth of the bone at their point of insertion ; supra- maxilla sparsely tuberculated, half as long as the maxilla; pre- maxillary teeth very large, apparently equalling in size those of the middle of the dentary, which are somewhat tumid at the base ; splenial teeth relatively very small and numerous, stout and not much curved; enamel restricted to the apex in all the teeth. Seales for the most part smooth, but some of those of the flank exhibiting longitudinal crenulations. Form. & Loc. Lower Lias: Dorsetshire. P. 3543. The type specimen described and figured by Agassiz, Joc. cit.; Lyme Regis. The head seems to have been somewhat deepened in the fossil by the upturning and fracture of the cranium, while the jaws are displaced downwards. The otic elements are well-ossified and the thin dermal cheek-plates are conspicuous. The maxilla is much fractured and imperfect, but some of the slender teeth in its hindermost portion are well shown; one very large tooth on the premaxilla is also preserved. The mandible is obscured, and only one of its moderately large anterior teeth can be seen. The middle portion of the preoper- culum is coarsely rugose, and the same ornament appears slightly on other fragments of the external plates. The ossifications in the sheath of the notochord are much crushed, but evidently consist of separate pleurocentra P. 3645. EUGNATHID &. 345 and hypocentra, the latter with a pair of short processes for the support of the delicate ribs. In the abdominal region the series of curved robust neural spit.es, separate from the supporting arches, is well exhibited. The imperfect left clavicle is displaced upwards, and the comparatively thin and laminar supraclavicle lies above it. In the remains of the pectoral fin, the stout foremost ray is conspicuous ; and the very fine distal subdivision of most of the rays is well shown. One of the pelvic fins. occurs almost in its natural position, comprising seven or eight rays, with a series of large fulcra on its anterior margin. About sixteen rays are preserved in the frag- mentary dorsal fin, with a few displaced fulcra and thirteen of its basal bones. The caudal fin is too im- perfect for description, and the anal is wanting. The squamation is also very imperfect, and the only ornament is observable on some of the scales of the flank, which are crimped much like the scales of Eugnathus. Enniskillen Coll. An imperfect head, exposed from the right side; Lyme Regis. A fragment of the occipital portion of the cranium occurs behind, and the syuamosal is shown to be ornamented with a few sparse tubercles. The cheek- plates are mostly smooth, but sometimes feebly tuber- culated and frequently rugose towards the margin. The maxilla (m#.) and supramaa:'la (s.mx.) are shown of the natural size in Pl. VII. fig. 3. The bases of two very large premaxillary teeth are seen, and there is evidence also of equally large teeth in the mandible, which is unfortunately much obscured. The preoperculum is rugose near its hinder margin; while the crushed remains of the operculum and suboperculum exhibit a few small sparse tuberculations. Enniskillen Coll. P. 514. Crushed fragment of jaws, the dentary shown of the natural size in Pl. VII. fig. 2, and intended by Agassiz to be described as the type specimen of Conodus ferox ; Lyme Regis. Three large dentary teeth are preserved, though somewhat broadened at the base by accidental crushing; and there are the bases of smaller teeth in fragments of the maxilla. The very small and stout splenial teeth are also seen. Egerton Coll. 346 ACTINOPTERYGII. Caturus (Strobilodus) giganteus (Wagner). 1851. Strobilodus giganteus, A. Wagner, Abh. k. bay. Akad. Wiss. math.-phys. Cl. vol. vi. p. 75, pl. ii. 1863. Strobilodus giganteus, A. Wagner, ibid. vol. ix. p. 674. Type. Imperfect fish ; Paleontological Museum, Munich. The type species of the so-called genus Strobilodus, attaining a length of nearly 1 metre. Maxilla apparently more robust than in the preceding species, with concave dentigerous border and its middle teeth remarkably large and tumid, their height nearly equalling the depth of the bone at their insertion. Opercular bones finely punctate, wanting tubercular and rugose ornamenta- tion. Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. Not represented in the Collection. Caturus (Thlattodus) suchoides (Owen). 1866. Thilattodus suchoides, R. Owen, Geol. Mae, vol. 111. p. 55, pl. i. 1887. Strobilodus suchoides, K. A. von Zittel, Handb. Palzeont. vol. iii. p- 230. 1890. Strobilodus suchoides, Woodward & Sherborn, Catal. Brit. Foss. Vertebrata, p. 190. Type. Jaws; British Museum. The type species of the so-called genus T’hlattodus, known only by the jaws, which indicate a fish perhaps more than 1 metre in length. Maxilla and its dentition apparently almost similar in form and proportions to that of C. giganteus, but less deepened behind. Dentary attenuated and scarcely if at all deflexed at the symphysis. The indent at the base of the external face of the teeth very conspicuous. Form. & Loc. Kimmeridgian: Norfolk. 41386. Type specimen; Kimmeridge Clay, Downham, Norfolk. The robust prefrontal articulating with the maxilla is well shown on each side. Presented by C. B. Rose, Esq., 1869. Caturus cliftoni, sp. nov. [Plate VII. figs. 4, 5. ] Type. Imperfect right maxilla; British Museum. Maxilla similar in form to that of C. suchoides, and at least as large, but the teeth much larger, the height of those at its middle EUGNATHID &. 347 greater than the depth of the bone at their insertion ; all the teeth, both upper and lower, very slender at the apex and often incurved. Symphysial end of the only known dentary bone considerably curved downwards. Form. & Loc. Portlandian: Isle of Portland. Kimmeridgian : Dorsetshire. P. 6035. Type specimen, shown of one-half the natural size in Pl. VII. fig. 4; Portland Stone, Isle of Portland. Both bone and teeth are much fractured, but the general form of the maxilla is distinct except at its hinder extremity. The very slender small teeth are indicated posteriorly, and the attenuated incurved apex is also shown on the principal teeth, some of which are fractured to expose the inner cavity. Presented by George Clifton, Hsq., 1890. P. 6034 a. Middle portion of a similar maxilla, with teeth showing the smooth solid apex ; Portland Stone, Isle of Portland. Presented by George Clifton, Esq., 1890. 42381. Anterior portion of left maxilla and other fragments ; Portland Stone, Isle of Portland. Purchased, 1870. 40719. Right maxilla, inner aspect, wanting the hinder portion but with well-preserved remains of teeth showing their characteristic form ; Kimmeridge Clay, Dorsetshire. Purchased, 1867. P. 6034. Imperfect right dentary, shown from the outer aspect of one-half the natural size in Pl. VII. fig. 5, remarkable for the crowding of the anterior teeth and the downward curvature of the bone towards the symphysis (s.); Port- land Stone, Isle of Portland. Presented by George Clifton, Esq., 1890. Caturus (Ditaxiodus) impar (Owen). 1866. Ditaxiodus impar, R. Owen, Geol. Mag. vol. iii. p. 107, a iv. & v. Type. Jaws; British Museum. The type species of the so-called genus Ditawiodus, known only by the jaws, which indicate a fish perhaps about 1 metre in length. Maxilla thick but less deepened than in any of the preceding species, much arched throughout the greater part of its length, and the height of the middle teeth considerably exceeding the depth of the bone at their insertion. All the teeth, both upper and lower, 348 ACTINOPTERYGII. with a very slender incurved apex. Splenial teeth for the most part strongly incurved, and the largest not more than half the size of the principal teeth on the dentary. Form. g Loc. Kimmeridgian: Oxfordshire. 46318. Type specimen comprising the right maxilla with the imperfect right mandibular ramus and other fragments ; Kimmeridge Clay, Culham, Oxfordshire. The small inner row of curved mandibular teeth described by Owen is evidently borne by the splenial bone, which enters and strengthens the mandibular symphysis. Cunnington Coll. 46337. Abraded fragment of the anterior end of the right maxilla, doubtfully ascribed to this species; Kimmeridge Clay, Devizes. Cunnington Colt. Caturus (Strobilodus) purbeckensis (A. 8. Woodward). 1890. Strobilodus purbeckensis, A. S. Woodward, Proc. Zool. Soc. p- 350, pl. xxix. fig. 4. Type. Head; British Museum. Head with opercular apparatus ordinarily measuring about 0-1 in length ; external bones without ornament. Maxilla comparatively slender, the oral border slightly convex in its anterior two-thirds, then a little concave, finally turned downwards behind where the teeth are remarkably slender and closely arranged ; teeth of middle of maxilla about twice as deep as the bone at their insertion, with much produced slender apical portion. Mandible very slender, pointed but not curved downwards in front; height of middle ' dentary teeth about equal to depth cf bone at their insertion. All the teeth indented at the base on the outer face. Form. & Loc. Purbeckian: Dorsetshire. 46911. Type specimen deseribed and figured, loc. cit.; Swanage. Purchased, 1875. P. 4273. Imperfect right dentary with well-preserved teeth; Swanage. Enniskillen Coll. The following specimens may also be referred to Caturus but are not specifically determined : — P. 3578. Fragmentary remains of a large fish ; Lower Lias, Lyme Regis. Enniskillen Coll. P. 530. Imperfect skeleton nearly a metre in length; Upper Lias, Boll, Wurtemberg. Egerton Coll. EUGNATHID &. 349 P. 902, P. 3730. Three mandibular rami of the form named Caturus plewodus by Agassiz, Poiss. Foss. vol. i. pt. il. (1844), p. 118, the first described and figured in Proc. GeolsjAssoe.- vol. xi. @ls90); ps 294, pl..im. fig. 10 ; Stonesfield Slate, Stonesfield. Egerton & Enmskillen Colls. P. 4701. Remains of head and abdominal region of a fish resembling C. furcatus, but differing from this species in its relatively larger scales; Lower Kimmeridgian (Lithographic Stone), Cirin, Ain, France. . Purchased, 1884. P. 4699. Small immature fish; in counterpart; Cirin. Purchased, 1884. 38519. ees remains of fish; Kimmeridge Clay, Kimmeridge. Purchased, 1864. P. 901. Very fragmentary and fragile head and abdominal region ; Kimmeridge Clay, Studley, near Trowbridge. Egerton Coll. P. 6389. Fragmentary fish; English Kimmeridge Clay. Beckles Coll. 40648. Imperfect left maxilla and mandibular ramus of a large fish ; Kimmeridge Clay, Chapman’s Pool Bay, Dorsetshire. Purchased, 1867. P. 6901. Imperfect head of a large fish, displaying the cranium, right mandibular ramus, and some of tlie laminar toothed gill-rakers ; Oxford Clay, Peterborough. The dentary exhibits the bases of 24 teeth, and the anterior half of the splenial bears only a single series of small teeth. Leeds Coll. 29049 a. More imperfect head of a similar fish; Oxford Clay, Christian Malford, Wiltshire. About 20 branchiostegal rays are shown. Purchased, 1854. 29049 b. Imperfect fish about 0°46 in length, with remains of the pectoral, dorsal, and caudal fins: Oxford Clay, Christian Malford. From the characters of the mandible and dentition, this seems to belong to the same species as the last two specimens. Purchased, 1854. P. 4793. Left maxilla of large fish ; Jurassic, Helmsdale, Sutherland. Presented by Sir Richard Owen, K.C.B., 1884. 350 ACTINOPTERYGII. P. 442 a. Maxilla described and figured under the provisional name of C. tenwidens by the present writer, Geol. Mag. [4] vol, ii. (1895), p. 15], pl. vii. fig. 8; Middle Purbeck, Swanage. ; Purchased, 1882. P. 6584. More imperfect maxilla; Swanage. Purchased, 1891. 36175. Right dentary provisionally named C. tenwidens ; Swanage. Purchased, 1861. 40656-57. Two right dentaries of the same form, the second described and figured loc. cit. 1895, p. 151, pl. vii. fig. 7 ; Swanage. Purchased, 1867. P, 442. Similar left dentary ; Swanage. Purchased, 1882. P. 969. Similar right dentary ; Swanage. Egerton Coll. P. 6360. Imperfect abraded head, exhibiting relatively large teeth and an especially large gular plate; Wealden, Hastings. Beckles Coll. An imperfect head and pectoral fins of Caturus from the Kim- meridge Clay of Cap de la Héve, Havre, have also been described under the name of Pachycormus insignis, by H. EH. Sauvage, Bull. Soc. Géol. Normandie, vol. xiv. (1892), p. 29, pl. ii. Another im- perfect head, apparently of Caturus, from the Oxford Clay of Vaches Noires, Normandy (Prevost Collection), is named Pachycormus macro- pomus by Agassiz, Poiss. Foss. vol. i. pt. 11. (1844) p. 114. A well-preserved trunk of Caturus from the Lias of Walgau, Bavarian Alps, is described under the name of Lepidotus (Semio- notus) macropterus by K. EK. Schafhautl, Geogn. Untersuch. sudbiy. Alpengeb. (1851), p. 98, pl. xx. fig. 27. A specifically indeterminable jaw from the [Lithographic Stone of Bavaria is named Caturus branchiostegus by Agassiz, Poiss. Foss. vol. 11. pt. 11. (1844) p. 118. Nothing appears to be known of the so-called Caturus ovatus (Minster, Neues Jahrb. 1839, p. 679) and C. brevicostatus (Minster, ibid. 1842, p. 44) from Kelheim. The portion of dentary from the Chalk of Lewes named Caturus similis (L. Agassiz, Poiss. Foss. vol. ii. pt. 11. 1844, p. 118, pl. Ixvi. a. fig. 9) does not belong to this genus, but probably to a Teleostean fish. The original specimen is numbered 4842 and was obtained from the Mantell Coll. | Nothing is known of the so-called Amblysemius gracilis (UL. Agassiz, Poiss. Foss. vol. ii. pt. 11. 1844, p. 165) from the Oolite of Northampton, said to be closely related to Caturus (loc. cit. p. 119). Another species, A. bellovacinus or bellicianus (V. Thiol- EUGNATHIDR. 301 liére, Ann. Sci. Phys. & Nat. Lyon, [2] vol. iii. 1850, p. 146, and Poiss. Foss. Bugey, pt. ii. 1873, p. 19), from the Lithographic Stone (Lower Kimmeridgian) of Ain, France, is also too imperfectly described for recognition. Genus CALLOPTERUS, Thiollicre. [Bull. Soc. Géol. France, [2] vol. xv. 1858, p. 784, and Poiss. Foss. Bugey, pt. ii. 1873, p. 15.] A genus apparently differing only from Catwrus in the more remote situation of the dorsal fin, which is almost completely opposed to the anal. The caudal fin also appears to be less deeply forked. Callopterus agassizi, Thiolliére. 1846. Lepidotus armatus, A. Wagner, Gelehrte Anzeig. k. bay. Akad. vol. xxii. p. 303 (inadequate definition). 1858. Callopterus agassizi, V. Thiolliére, Bull. Soc. Géol. France, [2] vol. xv. p. 784. 1863. Lepidotus armatus, A. Wagner, Abh. k. bay. Akad., math.-phys. Cl. vol. ix. p. 620. [Fish ; Palzeontological Museum, Munich. ] 1878. Callopterus agassizi, V. Thiolliére, Poiss. Foss. Bugey, pt. ii. p. 15, pl. x. 1887. Callopterus agassiz, K. A. von Zittel, Handb. Paleont. vol. iii. p. 231, fig. 248. Type. Fish; Lyons Museum. The type species, attaining a length of about 0°45. Length of head with opercular apparatus somewhat exceeding the maximum depth of the trunk and contained about four-and-a-half times in the total length of the fish; depth of caudal pedicle about two- thirds as great as the maximum depth of the trunk. Mandibular teeth especially stout and closely arranged. Pelvic fins twice as distant from the pectorals as from the anal; dorsal fin, with 16 rays, about half in advance of the anal, which has 10 rays. Ridge-scales of upper caudal lobe much enlarged, extending half- way towards the dorsal fin. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Ain, France. Not represented in the Collection. A stouter small fish 0-115 in length, from the Lower Kim- meridgian bituminous limestone of Orbagnoux, Ain, France, has also been referred to this genus under the name of Callopterus obesus (H. E. Sauvage, Bull. Soc. Hist. Nat. Autun, vol. vi. 1893, p. 433, pl. ix. fig. 1). oor ACTINOPTERYGII. Genus BURYCORMUS, Wagner. [Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1863, p. 707. | Syn. Eurypoma, T. H. Huxley, Figs. & Descript. Brit. Organic Remains, dec. xii. (Mem. Geol. Surv. 1866), p. 32. Trunk elongate-fusiform. External head-bones and opercular bones very feebly ornamented with rugeze and tuberculations, all moderately robust: snout obtusely pointed, and maxilla laterally compressed, gradually deepened behind, with a convexly arched dentigerous border ; teeth small and arranged in a regular close series on the maxilla and splenial, similarly small and closely arranged on the other inner bones, comparatively large in the single series occupying the anterior half of the dentary bone. Ossifications in the sheath of the notochord well developed, the hypocentra and pleurocentra in part of the caudal region forming completed alternating rings; ossified ribs slender. Fulcra com- paratively small on the median fins [unknown on the paired fins]. Pectoral much exceeding the pelvic fins in size, but the latter well developed ; dorsal fin small and triangular, opposed to the pelvic pair; anal fin with somewhat extended base; caudal fin deeply forked. Scales delicate, smooth or very finely tuberculated, deeply overlapping, none much deeper than broad, and apparently none with peg-and-socket articulation. Lateral line inconspicuous. Eurycormus speciosus, Wagner. 1863. Eurycormus speciosus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 709, pl. iv. 1868. ‘* Pholidophorus obscurus, Minster, MS.,” A. Wagner, zed. p. 659. [Imperfect axial skeleton; Paleeontological Museum, Munich. ] 1887. Eurycormus speciosus, K. A. von Zittel, Handb. Paleeont. vol. ii. p- 230, fig. 242. Type. Nearly complete fish; Palzeontological Museum, Munich. The type species, attaining a length of about 0°35. Length of head with opercular apparatus about equal to the maximum depth of the trunk and occupying somewhat less than one-quarter of the total length of the fish ; caudal pedicle less than half as deep as the abdominal region. External bones smooth. Pelvic fins arising far behind the middle point between the pectorals and the anal, opposite the origin of the dorsal, which occupies the middle of the back and comprises about 16 rays; anal fin with about 17 rays, arising immediately behind the termination of the dorsal; length of each lobe of the caudal fin equalling three times the depth of the pedicle at its origin. EUGNATHID &. Joe A small fish from the Bavarian Lithographic Stone, now in the Dresden Museum, may possibly be an immature example of this species, but is not certainly determinable. It exhibits no ossifications in the notochordal sheath, and is provisionally named Eurycormus dubius by B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. (1881), p. 113, pl. ii. fig. 7. Fulcra are observable on the paired fins. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. 37934. Scattered remains of a fish displaying the typical vertebral axis ; Solenhofen. Haberlein Coll. P. 911. A more satisfactorily preserved trunk, labelled Caturus latissemus by Minster, apparently showing traces of the ovaries ; Kelheim. Egerton Coll. Eurycormus egertoni (Kgerton). 1844. Macropoma egertoni, L. Agassiz, Poiss. Foss. vol. 11. pt. ii. pp. 174, 180 (name only). 1858. Macropoma egertoni, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. ix. (Mem. Geol. Surv.), no. 10, pl. x. 1859. Paleoniscus egertoni, J. Leckenby, Geologist, vol. 1. p. 9. 1866. Eurypoma egertoni, T. H. Huxley, Figs. & Descript. Brit. Organic Remains, dec. xii. (Mem. Geol. Surv.), p. 32. 1894. Eurycormus egertoni, A. S. Woodward, Geol. Mag. [4] vol. 1. p- 214. Type. Anterior portion of fish ; British Museum. A large species, the head with opercular apparatus in the two only known specimens about 0°18 in length. Cranial roof-bones and parts of the facial bones coarsely rugose, with few tubercula- tions; maxilla smooth, more than twice as deep behind as in front ; opercular bones very feebly rugose and sparsely tuberculated. Scales finely ornamented with minute tubercles and short ruge, which are closely arranged in antero-posterior series. Form. & Loc. Kimmeridgian: Speeton, Yorkshire. Oxfordian : Northamptonshire. P. 569. The type specimen described and figured by Egerton, Joc. cit., and further noticed by Huxley and the present writer ; in waterworn indurated matrix, described as obtained from “ Gault, Speeton,” but stated by Leckenby to have been found in the stratum immediately above the clay with Ammonites biplex. Much of the fossil is very obscure, and it is only necessary to add to Kgerton’s description in three particulars. Firstly, it may be PART III. 2 A Sys ACTINOPTERYGII. remarked that there is distinct evidence of vertebral ossifications supporting the robust ribs; secondly, the apparently steep frontal profile in advance of the orbit is due partly to fracture and partly to crushing, while distortion is the cause of the great elevation immediately behind the occiput and of the comparatively forward position of the dorsal fin; thirdly, there are conspicuous branchiostegal rays behind the gular plate. Hgerton Coll. P. 6912. Imperfect obliquely-crushed head, with some anterior scales, noticed Joc. cit. 1894; Oxford Clay, Peterborough. Neither ribs nor vertebre are displayed, though certain feeble indications may denote that some are buried within the specimen ; but all the parts exhibited are identical in form, characters, and even in size with the corresponding elements shown in the type specimen. Leeds Coll. Eurycormus grandis, A. 8. Woodward. 1889, Eurycormus grandis, A. 8. Woodward, Geol. Mag. [3] vol. vi. 449, 1890. Eurycormus grandis, A.S. Woodward, 27d. vol. vii. p. 289, Re a figs. 1-8. Type. Imperfect head; Woodwardian Museum, Cambridge. A large species known only by the head and vertebra, equalling E. egertoni in size. All the external bones smooth or very feebly rugose, those of the cranial roof and some of those of the face ornamented with fine, sparse tuberculations. The squamosal bones appear to be relatively narrower than in L. egertoni. Form. & Loc. Kimmeridgian ; Cambridgeshire. Not represented in the Collection. The following ring-vertebre are not certainly determinable, but (as suggested in the Geol. Mag. [4] vol. i. 1894, p- 216) may ina pertain to Hurycormus :— P. 6176. Specimen figured in Damon’s ‘ Geol. Weymouth,’ ed. 2 (1880), Suppl. pl. xii. fig. 9; Kimmeridge Clay, Weymouth. Damon Coll. 41181, 41231, 45926. Nine specimens; Kimmeridge Clay, Wey- mouth. Purchased, 1868, 1874. 41231 a. Imperfect hypocentrum; Kimmeridge Clay, Weymouth. Purchased, 1868. EUGNATHID®. S00 Genus NEORHOMBOLEPIS, A. 8. Woodward. [ Proc. Geol. Assoc. vol. x. 1888, p. 304. ] Trunk elongate-fusiform, and head relatively large. External head-bones and the opercular bones robust, more or less ornamented with tubercles and rugee of enamel; maxilla with a straight denti- gerous border, and a long supramaxillary bone; teeth in regular series, large and hollow, nearly as large on some of the inner bones as on the margin of the jaw, but short and tubercular on the entopterygoid ; suboperculum at least half as large as the nearly rectangular operculum, and separated from the latter by an almost horizontally-extended suture. Vertebral centra completely ossified, much shorter than deep in the abdominal, more elongated in the caudal region. Pectoral fins relatively large, with an especially robust preaxial ray ; [other fins unknown]. Scales thick, with a narrow overlapped border not produced at the angles, and the peg-and-socket articulation feeble or wanting; superficial ganoine nearly smooth ; few principal flank-scales as deep as broad, the majority broader than deep, and those of numerous ventral series at least twice as broad as deep. Neorhombolepis excelsus, A. 8. Woodward. [Plate VIII. fig. 4.] 1888. Neorhombolepis excelsus, A. 5. Woodward, Proc. Geol. Assoc. vol. x. p. 304, pl. i. fig. 1. Type. Imperfect anterior portion of fish; British Museum. The type species, with head attaining a length of about 0-085. External bones ornamented with closely-arranged elongated tubercles and short ruge of ganoine ; marginal teeth slender, with incurved apex, in a close regular series, and those of the maxilla almost as large as those of the dentary. Preaxial pectoral fin-ray ornamented with elongated tubercles and ruge of ganoine. Large postclavicular scales ornamented as the head-bones, other scales smooth ; scales of the ventral abdominal region very much elon- gated, often nearly three times as broad as deep, and some with two or three coarse denticulations on the hinder margin. Form. & Loc. Turonian: Kent. 43077. The type specimen, comprising the imperfect head, abdo- minal region, and right pectoral fin, shown of the natural size in Pl. VIII. fig. 4; Lower Chalk, Upper Halling, Kent. In the original description of the fossil, only the portion behind the cranium is noticed, the imperfect head 242 306 ACTINOPTERYGII. having been subsequently met with in the Collection. Of the cranium, only the highly-ornamented posterior portion of the roof is exposed (fig. 4a), and the parietals ( pa.) are shown to be very small, the squamosals (sq.) extending about twice as far forwards, and the frontals ( fr.) uniting in a Wavy median suture. The smooth hinder margin of the cranial roof must have been deeply overlapped by the large supratemporal plates, of which the outermost is preserved on the left side. The rostral half of the skull is shown in irregular transverse section, and the pterygo- palatine arcade exhibits a large laminar bone, apparently the entopterygoid, covered with closely-arranged tubercular teeth, which become elongated towards the inferior margin and are nearly as large on the ectopterygoid (? or palatine) ason the maxilla. Onthe right side the greater part of the maxilla (mw.), with an elongated supramaxilla (s.ma.) on its hinder half, is preserved, showing some traces of ornament and the nearly straight dentigerous border ; the mandible is also preserved, but more imperfectly, and tall conical teeth seem to occur on the splenial as viewed in transverse section. Beneath the mandible is part of a large, thin, ornamented plate, evidently the gular. One large cheek-plate (s.o.), with sparse radiating ornament, is also shown on the right side. The post-temporal plates are long and narrow, and ornamented in their exposed portion. Two fragments of the operculum (op.) on the left side are ornamented, and the suboperculum (s.op.) on the right side is more than half as deep as the operculum. The last-named and remaining characters are indicated in the published figure and description. Purchased, 1871. NWeorhombolepis valdensis, sp. nov. [Plate VIII. fig. 5.] - Type. Imperfect fish; British Museum. A species about as large as the type, similarly known only from an imperfect specimen. Principal flank-scales and many of the narrow ventral scales extremely finely pectinated on their hinder margin; vertebral centra in the posterior abdominal region rela- tively longer than in WV. eacelsus. Other characters, so far as known, as in the latter species. Form, & Lov. Wealden: Sussex. EUGNATHID®. 357 P. 6364. The type specimen, a waterworn piece of sandstone with imperfect coiled-up fish; Wealden, Hastings. The fish is partly exposed on both sides of the slab, and portions of its pectoral fin, squamation, and vertebral centra are shown of the natural size in Pl. VIII. figs. 5, 5a, b. The head and opercular apparatus are too imperfect for description, but traces of the characteristic external orna- ment are preserved both on the cranial roof and on the cheek-plates. The middle of the parasphenoid exhibits a cluster of small teeth; and its lateral ascending portion is forked, the anterior limb rising as usual to meet the post- frontal, the posterior limb reaching one of the hinder otic elements. A horizontal (not median) section across one of the short abdominal vertebre is shown in fig. 5a; and one of the three elongated centra, as exposed in. the anterior part of the caudal region, is shown in side view in fig. 5 6. The latter are followed by other centra not so much elongated, but still longer than deep. The clavicle and pectoral fin are preserved on the left side, the latter comprising not less than 24 rays, of which each is undivided in its proximal two-thirds but becomes very finely branched and articulated distally. A portion of the largest postclavicular plate on the same side (p.cl.) displays the characteristic external ornamentation. The scales are all remarkably smooth, exhibiting no markings beyond feeble, scattered pits ; and the serration of their hinder border is extremely fine and inconspicuous. Even the principal flank-scales are broader than deep, while the ventral scales are not only extremely narrowed but also become in part subdivided. Beckles Coll. Neorhombolepis (?) punctatus (A. 8. Woodward). 1844. Lepidotus punctatus, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. p. 306 (name only). 1844, Lepidotus punctulatus, L. Agassiz, ied. pt. 1. p. 287 (name only). 1888. Genus non det., A. S. Woodward, Proc. Geol. Assoc. vol. x. p- 304, pl. i. tig. 2. Type. Detached scales ; British Museum. A species known only from detached scales, and doubtfully placed in Neorhombolepis. ‘The largest known scale measures 0°015 in breadth, and none are so deep as broad; all specimens exhibit a smooth external layer of ganoine, marked with a few punctations, 308 ACTINOPTERYGII. and the hinder margin is not serrated. ‘That the scales do not pertain to Leprdotus is shown not only by their form, but also by the non-production of the angles of the overlapped anterior border. Form. & Loc. Turonian: Kent and Surrey. P. 4705. Group of associated scales, to be regarded as the type specimen ; Lower Chalk, Burham, Kent. Enniskillen Coll, -P. 1106. Two smaller groups of imperfect scales, one labelled by Agassiz; Burham. Egerton Coll. P. 6526. Group of six associated scales, three figured in Proc. Geol. Assoc. vol. x. pl. i. fig. 2; Blue Bell Hill, Burham. Presented by S. J. Hawkins, Esq., 1891. P. 7567. Abraded scale ; Lower Chalk, Dorking, Surrey. Purchased, An imperfect fish much resembling Neorhombolepis, but differing in its more powerful dentition and the subdivision of the gular plate into four pieces, is described as follows :— Otomitla speciosa, J. Felix, Paleontogr. vol. xxxvui. (1891), p. 189, pl. xxix. fig. 3, pl. xxx. figs. 3-5.—Neocomian ; Cerro de la Virgen, Tlaxiaco, Oaxaca, Mexico. [Head with scattered scales and vertebre; J. Felix Collection, Leipzig. | Genus LOPHIOSTOMUS, Kgerton. | Figs. & Deseript. Brit. Organic Remains, dec. vi. (Mem. Geol. Surv. 1852), no. 10.] An imperfectly known genus with relatively large head, which appears to have heen much depressed. External head-bones and the opercular bones robust, more or less ornamented with tubercles and rugee of enamel; the roof of the cranium raised into a promi- nent boss on each side immediately behind the orbit; jaws relatively very large, the maxilla with a straight or slightly concave dentigerous border, and the premaxille fused with the ethmoid ; teeth in regular series, large and hollow on the margin of the jaw, minute on the inner bones, and those of the dentary larger than those of the maxilla; suboperculum nearly half as large as the operculum, which is quadrangular but truncated at the postero-superior angle; gular plate very large. [Axial skeleton of trunk not certainly known.] Fin-rays robust, externally ornamented ; paired fins without fulcra, the pelvic pair relatively small; [median EUGNATHID.®. 309 fins unknown]. Scales thick, with a narrow overlapped border not produced at the angles, and the peg-and-socket articulation feeble or wanting; superficial ganoine more or less striated or pitted ; numerous series of narrow ventral scales. One group of remains mentioned below, and another similarly fragmentary group in the Brighton Museum, exhibit ring-vertebree which probably belong to this fish. Lophiostomus dixoni, Egerton. 1852. Lophiostomus dixon, Sir P. Egerton, loc. cit. no. 10, pls. x., x*. 1888. Lophiostomus divont, A. S. Woodward, Proc. Geol. Assoc. vol. x. p- 308. Type. Head with part of abdominal region; British Museum. The type species, with head attaining a length of 0:06. External bones and fin-rays ornamented with closely-arranged short ruge and tubercles of ganoine. Maximum width of cranial roof exceed- ing two-thirds of its length; the paired frontal] prominences narrow and laterally compressed but much elevated, the height of each exceeding half the distance between them. Marginal teeth in one regular series, some exhibiting feeble vertical wrinkles in their apical portion ; mandibular ramus about three and a half times as long as its maximum depth. Branchiostegal rays about 12 in number, nearly all ornamented; gular plate as long as the denti- gerous portion of the mandible, and at least two-thirds as broad as long. Ornament of fin-rays consisting chiefly of oblique wrinkles. Hinder border of scales with coarse, long, acuminate pectinations, continued on the outer face of the principal scales as oblique wrinkles or elongated pits. Form. & Loc. Senonian: Sussex and Kent. 23023. The type specimen, described and figured by Egerton, Joc. cit.; Alfriston, Sussex. The comparatively smooth plate named ‘scapula,’ is evidently one of the postclavicular series. Presented by Capt. J. L. Beckford, RN. P. 1116. Scales and an associated bone-fragment; Alfriston. Egerton Coll. P. 5409. Portion of fin-ray and two imperfect scales ; Sussex. Presented by P. E. Coombe, Esq., 1888. 39121. Group of scales and remains of fin-rays ; Maidstone. Bowerbank Coil. P. 4263. Scales apparently with imperfect ring-vertebrie ; Lewes. Kuuiskillen Coll. 360 ACTINOPTERYGII. Lophiostomus affinis, A.8. Woodward. 1895. Lophiostomus affinis, A. S. Woodward, Geol. Mag. [4] vol. ii. p- 210, pl. viii. fig. 6. Type. Hinder portion of cranial roof; British Museum. A species as large as L. divoni, known only by the hinder portion of the skull, which is somewhat more finely ornamented than in the type species. Frontal prominences slight, not forming a slender eminence. Form. & Loc. Cenomanian (Cambridge Greensand): Cambridge. P. 7233. Type specimen described and figured loc. cit. Jesson Coll. Family AMIIDA. Trunk elongate or elongate-fusiform, more or less laterally compressed. Cranial and facial bones moderately robust, externally enamelled, and opercular apparatus complete ; mandibular suspen- sorium nearly vertical or inclined backwards, and gape of mouth wide ; snout not produced; premaxille separate and in contact mesially ; marginal teeth mostly stout and conical, inner teeth com- paratively small or even minute. Notochord persistent or more or less replaced by vertebre, which remain as disconnected pleuro- central and hypocentral dises in part of the caudal region. Fin-rays robust, the majority well-spaced, articulated and divided distally ; fulcra almost or completely wanting; dorsal and anal fins variable in length. Scales thin and deeply imbricating, more or less rounded in their exposed portion. The characters of the genus Liodesmus, mentioned below, render it difficult to compile a satisfactory diagnosis of this family, which must be regarded as a specialised branch of the Eugnathide. The principal descriptions of the osteology of the type genus, the existing Amza of North American lakes and rivers, are the following :— H. Franque, ‘‘ Afferuntur nonnulla ad Amiam calvam accuratius cognoscendam ” (Inaugural Dissertation: Berlin, 1847). T. W. Bridge, ‘“‘ The Cranial Osteology of Ama calva” (Journ. Anatomy & Physiol. vol. xi. 1877, pp. 605-622, pl. xxiii.). M. Sagemehl, “Das Cranium von Amia calva” (Morphol. Jahrb. vol. 1x. 1884, pp. 177-228, pl. x.). R. W. Shufeldt, ‘‘ The Osteology of Amia calva” (Ann. Rep. U.S. Commiss. Fisheries, 1883 [1885], pp. 747-878, pls. 1.—x.), AMIID.E. 361 L. Schmidt, “ Untersuchungen zur Kenntniss des Wirbelbaues von Amia calva” (Zeitschr. f. wiss. Zool. vol. liv. 1892, pp. 748-764, pl. xxxiv.). Synopsis of Genera. I. Vertebral elements rudimentary or absent; dorsal fin short-based. Trunk elongate, scarcely tapering; fulcra wanting; caudal fin rounded or only slither eds ie Sitar rete ness ee ay LIiodesmus (p. 361). II. Vertebral elements forming complete discs; | dorsal fin more or less extended. Dorsal fin not occupying more than the middle Ghird- Of fhe back. ce sae ae Set: ... Megalurus (p. 363). Dorsal fin occupying more than half the henesth ofthe back 2 5.) 7 eee Pak. aes Ama (p. 367). Genus LIODESMUS, Wagner. [Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1863, p. 709.] Syn. Lophiurus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. 1881, p. 116. Trunk elongate, scarcely tapering to the caudal pedicle. Head relatively large, with obtuse snout; marginal teeth all large and well-spaced. Notochord persistent, without ossifications in the sheath. Fin-fulcra wanting. Dorsal fin short-hased, opposed to the pelvic pair ; caudal fin fan-shaped or slightly bifurcated. Scales very small. Liodesmus gracilis (Agassiz). 1838-44. Pholdophorus gracilis, L. Agassiz (ea Miinster, MS.), Poiss. Foss. vol. 11. pt. 1. p. 285, pl. xlii. fig. 2. 1839-44. Megalurus parvus, 11. Agassiz (ex Minster, MS.), 2bed. vol. 11. pt. 1. p. 149, pl. li. fig. 4. [Nearly complete fish ; Paleontological Museum, Munich. ] 1851. Megalurus parvus, A.Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. vi. p. 70. 1851. Megalurus intermedius, A. Wagner (ex Minster, MS.), ced. p- 71. [Nearly complete fish; Paleontological Museum, Mu- nich. | 1863. Liodesmus gracilis, A. Wagner, 2bid. vol. ix. p. 711. Type. Vertically crushed fish ; Paleontological Museum, Munich. The type species, attaining a length of about 0:06. Head with opercular apparatus occupying somewhat less than one-quarter of 362 ACTINOPTERYGII. the total length of the fish. Dorsal fin arising at a point half as distant from the occiput as from the upper caudal lobe; caudal fin (according to Wagner) with convex hinder border. form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. if Not represented in the Collection. Liodesmus sprattiformis, Wagner. 1863. Liodesmus sprattiformis, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 713, pl. v. fig. 1. Type. Nearly complete fish; Paleeontological Museum, Munich. A species attaining a length of about 0:09, similar in proportions to the type, but the caudal fin distinctly cleft; pelvic fins arising immediately behind a point opposite to the origin of the dorsal fin. Form. &§ Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. 37931. Fine nearly complete specimen, in counterpart; Solen- hofen. ‘The large, spaced conical teeth are shown in the premaxilla, maxilla, and dentary; and beneath the mandible there are remains both of the gular plate and branchiostegal rays. ‘The neural and hemal arches are somewhat separated by crushing; but the slender ribs in the abdominal region and the thickened hemal spines at the base of the tail are distinct. The characters of the median fin-rays are especially well-displayed; and the few short rays at the origin of the dorsal fin are con- spicuous. The squamation is scarcely displaced in any part, but it is difficult to determine the precise form and proportions of the deeply overlapping scales. Hiberlen Coll. P. 912. Specimen with more imperfectly preserved scales and caudal fin, and wanting the anterior half of the head; Solenhofen. The axial skeleton of the trunk, the pelvic fin-supports, and the impression of hard coprolitic matter in the intestinal tract, are noteworthy features. Ligerton Coll. P. 3659. Imperfect fish, partly dorsal and partly lateral aspect ; Kelheim. Enniskillen Coll. An imperfect small fish in the Dresden Museum, from the Litho- graphic Stone of Bavaria, described under the name of Lophiurus AMIID-E. oGs minutus by B. Vetter (Mittheil. &. mineral.-geol. Mus. Dresden, pt. iv. 1881, p. 116, pl. ii. fig. 16), also seems to be referable to the genus Liodesmus. Genus MEGALURUS, Agassiz. = Sy wri Yt [Poiss. Foss. vol. i. pt. 1, 1833, p. ie Trunk elongate, much laterally compressed. Head large; all the marginal teeth large and conical, but those of the dentary largest; inner teeth minute; maxilla laterally compressed and much deepened behind; gular plate present. Vertebral centra completely ossified in the adult, biconcave, the hypocentra and pleurocentra forming distinct alternating discs in part of the caudal region ; ribs short and delicate. Fin-fulera wanting.’ Dorsal fin somewhat extended, but not occupying more than the middle third of the back ; anal fin small and short-based ; caudal fin with convex hinder border. Scales almost oval in shape, the long axis hori- zontal. ] Megalurus lepidotus, Agassiz. 1833-44. Megalurus lepidotus, 11. Agassiz, Poiss. Foss. vol. ii. pt. i. — p. 13; pt. ii. p. 146, pl. lia. 1839-44. Megalurus brevicostatus, L. Agassiz, ¢bid. pt. ti. p. 147, pl. h. fig. 3. [Imperfect fish ; Palatal Museum, Munich. | 1851. Megalurus lepidotus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. vi. p. 69. 1851. Megalurus brevicostatus, A. Wagner, tbid. vol. vi. p. 70. 1863. Megalurus lepidotus, A. Wagner, id. vol. ix. p. 714. 1863. Megalurus brevicostatus, A. Wagner, ibid. vol. ix. p. 719. 1881. Megalurus brevicostatus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 116. Type. Nearly complete fish ; Paleontological Museum, Munich. The type species, attaining a length of about 0-+. Head with opercular apparatus occupying nearly one-quarter of the total length of the fish, and the depth of the caudal pedicle contained much less than five times in the length from the hinder border of the oper- culum to the base of the middle caudal fin-rays. Vertebre about 45 in number, all much deeper than broad, smooth and not indented laterally. Dorsal fin comprising about 20 rays, the distance between its origin and the post-temporal bones about equal to that between 1 Wagner (Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. 1863, p. 717) describes “ feinen, borstenartigen Stacheln (fulera)” on the pelvic fins of the so-called AV. altivelis. 1 bch 364 ACTINOPTERYGII. its hinder extremity and the end of the upper caudal lobe; pelvic fins arising opposite the origin of the dorsal, and the anal fin comprising about 9 rays, opposed to the hinder portion of the latter. It is not improbable that the skull from the Lithographic Stone of Nusplingen, Wirtemberg, described under the name of Strobi- lodus suevicus (F. A. Quenstedt, Der Jura, 1858, p. 809, pl. c. fig. 10), also pertains to this species. The type specimen is pre- served in the University Museum, Tiibingen, Wiirtemberg. Form. § Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. f | 37366. Plaster cast of type specimen ; Solenhofen. Purchased, 1863. . i P. 952. Fish 0°155 in length, well preserved but chiefly as an | impression ; probably from Solenhofen. Nineteen sup- | | ports are distinctly shown in the dorsal, and nine in the anal fin. Egerton Coll. P. 953. Immature fish wanting the head and the greater part of the fins: Kelheim. Egerton Coll. Megalurus elongatus, Agassiz. 1859-44. Megalurus elongatus, L. Agassiz (ex Minster, MS.), Poiss. Foss, vol. ii. pt. ii. p. 148, pl. li. figs. 1, 2. Nt 1851. Megalurus elongatus, A. Wagner, Abh. k. bay. Akad. Wiss., . math.-phys. Cl. vol. vi. p. 70. 1851. Megalurus polyspondylus, A. Wagner (ex Minster, MS.), aid. vol. vi. p. 71. [Nearly complete fish ; Palzeontological Museum, Munich. | 1865. Megalurus grandis, A. Wagner, ibid. vol. ix. p. 714. [Ditto. | | 1863. Megalurus polyspondylus, A. Wagner, zbid. vol. ix. p. 718. i 1863. Megalurus elongatus, A. Wagner, 2bid. vol. ix. p. 719. q 1873. Megalurus polyspondylus?, V. Thiolliére, Poiss. Foss. Bugey, i pt. ii. p. 22, pl. viii. fig. 1. | 1881. Megalurus polyspondylus, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 116. 1887. Megalurus polyspondylus, K. A. von Zittel, Handb. Paleeont. i vol. iii. p. 234, fig. 247. | Type. Nearly complete fish; Paleontological Museum, Munich. I A species attaining a length of about 0°45. Head with oper- | cular apparatus occupying not more than one-fifth of the total length of the fish, and the depth of the caudal pedicle contained more than five times in the length from the hinder border of the operculum to the base of the middle caudal fin-rays. Vertebree about 60 in AMIID &. 30D number, some nearly as deep as broad, all smooth and not indented laterally. Fins as in the type species except that the dorsal, pelvic, and anal are placed slightly further forwards. Form. & Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria, and Ain, France. 49140. Plaster cast of type specimen of the so-called M. grandis ; Eichstadt, Bavaria. Purchased, 1878. P. 5545. A fine, equally large specimen; Hichstidt. The caudal vertebre exhibit a feeble longitudinal keel on the middle of each centrum; and a regular series of twelve branchi- ostegal rays is displayed on the right side of the fish. Purchased, 1888. 22510. Caudal pedicle and fin of an equally large fish ; Solenhofen, Bavaria. Purchased, 1848. P. 3658. Fish 0°23 in length, somewhat fractured but displaying all the characters of the species; Kelheim, Bavaria. The caudal vertebree scarcely show the lateral keel noted in a previous specimen. Twenty-two supports are exhibited in the dorsal, and eight in the anal fin. Hnniskillen Coll. 49133. Plaster cast of specimen of the so-called MW. polyspondylus described by Wagner, loc. cit. 1863; Eichstadt. Purchased, 1878. Megalurus elegantissimus, Wagner. 1863. Megalurus elegantissimus, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 720, pl. v. fig. 2. Type. Nearly complete fish ; Paleeontological Museum, Munich. A smal! species attaining a length of about 0°15, apparently only distinguished from JM. elongatus in the somewhat more slender pro- portions both of the head and trunk. Form. § Loc. Lower Kimmeridgian (Lithographic Stone): Bavaria. 37368. Plaster cast of type specimen ; Solenhofen. Purchased, 1863. 37102. A larger specimen 0-145 in length, showing all the fins and displaying the vertebral column in the caudal region ; Solenhofen. ‘Twenty-two supports are observable in the dorsal, and seven in the anal fin. FHlaberlein Coll. | 366 ACTINOPTERYGII. Megalurus damoni, Egerton. 1858. Megalurus damoni, Sir P. Egerton, Figs. & Descript. Brit. Organic Remains, dec. ix. (Mem. Geol. Surv.), no. 8, pl. viii. 1873. Megalurus damon, V. Thiolliére, Poiss. Foss. Bugey, pt. ii. p. 22; pli ax. Type. Imperfect fishes; British Museum. A species attaining a length of about 0°3. Head with opercular apparatus occupying about one-fifth of the total length of the fish, i and the depth of the caudal pedicle contained scarcely five times in \ the length from the hinder border of the operculum to the base of | the middle caudal fin-rays. External bones slightly rugose, other- | wise not ornamented. Vertebre not exceeding 50 in number, each || with an upper and lower deep lateral indent. fins as in the type species. Scales apparently all much broader than deep. H | Form. & Loc. Purbeckian: Dorsetshire. Lower Kimmeridgian | (Lithographic Stone): Ain, France. P. 563, P. 3660. The two type specimens ; Bincombe, near Wey- mouth. Enniskillen & Egerton Colls. 41156. Fine specimen 0°195 in length; Isle of Portland. The caudal region is fractured and thus in part somewhat obscured, but there cannot have been many alternating hypocentra and pleurocentra. Purchased, 1868. . P. 3661. Smaller, more imperfect fish apparently showing more | numerous alternating hypocentra and pleurocentra in the caudal region; near Weymouth. Enniskillen Coll. 41171. Two halves of a large fish on the alternate halves of coun- terpart slabs; Isle of Portland. Purchased, 1868. Megalurus austeni, Egerton. 1858. Megalurus austent, Sir P. Egerton, Figs. & Descript. Brit. | Organic Remains, dec. ix. (Mem. Geol. Sury.), no. 9, pl. ix. ¢ t 1858. Attakeopsis (?) austent, V. Thiolliére, Bull. Soc. Géol. France, [2] vol. xv. p. 785. | Type. Imperfect head and abdominal region; British Museum. , | An imperfectly known and indefinable species closely resembling . M. damon, having similar vertebre but apparently differing in the | relatively much greater depth of the scales in the abdominal region. Form. & Loc. Purbeckian: Dorsetshire.’ 1 The species is supposed by Thiolli¢re (/oc, cit.) to occur also in the Litho- graphic Stone of Cirin, France. AMIID&. SOF P. 564. Type specimen, evidently owing the relatively great depth of the abdominal region to distortion; Swanage. Some of the scales are well preserved in the dorsal part of the abdominal region. Egerton Coll. The following species have also been named and inadequately defined, but there are no examples in the Collection :— Megalurus altivelis, A. Wagner, Abh. k. bay. Akad. Wiss., math.- phys. Cl. vol. ix. (1863), p. 716.— Lower Kimmeridgian (Lithographic Stone); Bavaria. [Imperfect skeleton ; Paleontological Museum, Munich. | Megalurus idanicus, V. Thiolliere, Ann. Sci. Phys. & Nat. Lyon, [2] vol. i. (1850), p. 158, and Poiss. Foss. Bugey, pt. ii. (1873), p. 22.—Lower Kimmeridgian (Lithographic Stone); Cirin, Ain, France. [Imperfect fish; Lyons Museum. | Genus AMITA, Linneus. [Syst. Nat. ed. 12, 1766, p. 500. | Syn. Cyclurus, L. Agassiz, Poiss. Foss. vol. v. pt. 1. 1844, p. 12. Noteus, L. Agassiz, zbed. 1844, p. 15. Trunk elongate and laterally compressed. Head large; supra- maxillary bone relatively large; maxilla, premaxilla, palatine, and dentary with a single series of large conical teeth; the complex splenial and other inner elements with minute teeth; gular plate present. Vertebral centra completely ossified in the adult, short and biconcave, the hypocentra and pleurocentra forming distinct alternating discs in part of the caudal region; each neural arch articulating with two centra, and the abdominal vertebre with prominent transverse processes ; ribs at least as long as the neural arches in the abdominal region. Fin-fulera wanting. Dorsal fin much extended, occupying more than half the length of the back; anal fin small and short-based; caudal fin with convex hinder border. Amia valenciennesi (Agassiz). 1839-44. Cyclurus valenctennesti, L. Agassiz, Poiss. Foss. vol. v. pt. 1. p. 12; pt. ii. p. 44, pl. liii. figs. 2, 3. 1851. Amia, J. J. Heckel, Sitzungsb. k. Akad. Wiss., math.-naturw. Cl. vol. vi. p. 223. 1858. Noteus laticcudus, M. de Serres (errore), Comptes Rendus, vol. xlvi. p. 7d. tippy ; fj, QL. Z 7 LELY LITLE Ctr) LID eee YY L IS LBL: tj yyy iy DED ACTINOPTERYGII. Amia calva; skeleton of recent fish (after Franque). ee) io) A AMIID®. 369 ~ LB Wy Mire . i CAN: = nt x WWE SSSss ee 3 er SS nae — a a ~ —— ee a hinder border and a fringe of small fulcra on its anterior | margins. The scales are smooth, but the majority | probably exhibit only their inner face. | By exchange, 18938. P. 7181. An equally large fish similarly displaying the axial skeleton of the trunk and the very fine tubercular orna- ment of some of the external bones; Eichstidt. The pelvic fins are displaced but well preserved, and the remains of the dorsal fin exhibit a fringe of small fulcra on its 393 PACHYCORMID At. tj y Y), YY ‘payjiMo Moyemenhs ‘aoryesoqser { sawbaseue snwwsooosdh pT 394 ACTINOPTERYGII. anterior border. More than 40 supports of the anal fin are preserved, but the series is incomplete. Above the expanded hemal at the base of the caudal fin there are indications of a series of robust supporting spines which also are probably heemal. By exchange, 1894. P. 954. Crushed remains of head and trunk; Solenhofen. The cranium is exposed from above, displaying the obtuse rostrum in front (Pl. XIV. figs. 1, 1 @) and much spar beneath the hinder portion, The mandibular dentition is also well shown. Egerton Coll. P. 4236. Imperfect trunk with scattered squamation and displaced median fins; Solenhofen. The single expanded hemal is well shown in position; and at the base of the upper lobe of the displaced caudal fin there is the series of robust supports noted in the last specimen. 44 supports of the anal fin remain, but the series is incomplete. The scales are shown to be rhombic, narrowed towards the ventral border, and all are smooth. Enniskillen Coll. Elypsocormus macrodon (Wagner). 1858. Strobilodus giganteus, F. A. Quenstedt (errore), Der Jura, p. 808, pl. xevii. fig. 12. 1858. Eugnathus macrodon, A. Wagner, Gesch. d. Urwelt, ed. 2, vol. ii. . 471, 1863, Eugnathus macrodon, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 671. 1883. Strobilodus giganteus, F. A. Quenstedt (errore), Handb. Petrefakt. ed. 3, p. 334, woode. fig. 105. | 1887. Hypsocormus macrodon, K. A. von Zittel, Handb. Paleont. vol. iii. p. 226. Type. Nearly complete fish; Paleontological Museum, Munich. A large species, attaining a length of about 1°5. Head with opercular apparatus occupying about one-fifth of the total length to the base of the caudal fin. Snout short and obtuse, with large vomerine teeth directed almost vertically. External bones and anterior fin-rays tuberculated. Scales of the flank in part deeper than broad, those of the ventral aspect 3 or 4 times as broad as deep, all more or less finely tuberculated, many also with a few vertical striations near the anterior margin. Form. & Loc. Lower Kimmeridgian (Lithographic Stone); Bavaria and Wiurtemberg. PACHYCORMID ®. 395 P. 6011. A contorted specimen about 1°5 in length, showing the paired and caudal fins, noticed in Ann. Mag. Nat. Hist. [6] vol. xiii. 1894, p. 511; Solenhofen. The large trian- gular lower suborbital exhibits a few radiating fissures or grooves in its hinder half, and it seems to have been unornamented except at its superior and inferior borders. Eight of the characteristic posterior cireumorbital plates are preserved, each finely rugose or tuberculated in front ; while between this series and the two great suborbitals, there are three other irregular plates. The arrangement is shown in the restoration of H. insignis, fig. 40, p. 393. The two vomerine teeth are well-preserved. The ossified sclerotic is shown in section. 21 rays can be counted in the pectoral fins, all divided distally, and the anterior ones are finely tuberculated. The scales exhibit the superficial granulations most distinctly in the abdominal region, the vertical markings best in the caudal region. Purchased, 1889. Hypsocormus leedsi, A. 8. Woodward. [Plate XI. fig. 1.] 1889. Hypsocormus leedsi, A. S. Woodward, Geol. Mag. [8] vol. vi. p. 450. Type. Remains of skull; British Museum. An imperfectly known species about as large as H. macrodon. Snout obtusely pointed, the two sides meeting approximately in a right angle at its anterior termination, and the external surface finely granulated; the large pair of vomerine teeth inclined much forwards and apparently projecting out of the mouth. Form. & Loc. Oxfordian : Huntingdonshire. P. 6913. The type specimen, comprising rostrum, portion of splenial, the two post-frontals, and other fragments of cranium ;: Oxford Clay, near Peterborough. The inferior aspect of the rostrnm (2'1. “1. fig. 1) exhibits the basal portion of the r:gnt vomerine tooth (v.) and the socket for that of the left side; while both of these are shown to be much directed forwards and the posterior wall of their socket is not ossified. Flanking each tooth externally there is a triangular area covered with small conical teeth fused with the supporting bone, only the apical portion of each enamelled ; and two of the marginal teeth directly in front of the vomerine pair are much larger than the others. 396 P. 6914. P. 6915. P. 6833. ACTINOPTERYGII. The blunt anterior end of the rostrum, well shown in side-view (fig. 1a), exhibits a slight mesial vertical ridge. There are some traces of closed sutures in the cranial roof, but the fragments are too imperfect for satisfactory deter- mination. Leeds Coll. Imperfect rostrum about half as large as the type, asso- ciated with the tooth-bearing border of the dentary bone ;, near Peterborough. Only the base of the left vomerine tooth is preserved ; and instead of two enlarged marginal teeth anteriorly, there is but one. A transverse section of one of the large teeth of the dentary is prepared for microscopical examination, and exhibits the complex structure noted in Ann. Mag. Nat. Hist. [6] vol. xiii. (1894), p. 511. Leeds Coll. Abraded large right splenial with remains of anterior end of dentary, probably of this species; near Peterborough. Leeds Coll. Fragments of skull and pectoral fin probably of this species ; near Peterborough. Leeds Coll. Hypsocormus tenuirostris, A. 8. Woodward. [Plate XI. figs. 2-6.] 1889. Hypsocormus tenutrostris, A. S. Woodward, Geol. Mag. [3] vol. vi. p. 451. . Type. Remains of skull; British Museum. An imperfectly known species about as large as H. macrodon. Snout acutely pointed and produced so that its length in advance of the large vomerine teeth somewhat exceeds its breadth at their insertion ; external surface finely granulated; the large vomerine — teeth directed almost vertically. Form. & Loc. Oxfordian: Huntingdonshire. P. 6916. The type specimen, comprising rostrum, right maxilla and premaxilla, portion of left dentary, and other associated fragments ; Oxford Clay, near Peterborough. The ros- trum (Pl. XI. figs. 2, 2a) is comparatively narrow and acutely pointed, and there is a considerable extension in advance of the vomerine area (fig. 2,v.a.). The whole of the external surface is ornamented with fine tubercles. The two vomers seem to be fused into one bone, and the greater part of the large tooth of the right side is pre- served, while the socket only of that on the left is exhibited. PGS17. PACHYCORMID. 397 A few teeth of variable size are arranged in a single irregular series on the margin of the vomerine area, the largest being three teeth on the right side. The pre- maxilla (figs. 3, 3 a, pm.) is triangular in form and laterally compressed, with thickened alveolar border ; and the upper margin of its inner face exhibits a long narrow facette ( f.) for direct articulation with the cranium. The maxilla (figs. 3, 3 a, mx.) is long and slender and gently arched, and sends forwards a process (incomplete in this specimen) on the inner side of the premaxilla resting immediately above its thickened oral border (fig. 3a, p.). Posteriorly the bone is imperfect, but there remains part of the rugose facette overlapped by the supramaxilla (fig. 3, s.ma.). The outer face of the maxilla, as also the lower portion of the outer face of the premaxilla, is orna- mented with fine tuberculations like those of the rostrum ; and the extreme outer margin of the alveolar border bears very minute teeth or pointed tubercles. The teeth of the maxilla are comparatively small and uniform, all well- spaced ; while those of the premaxilla are much larger, closely arranged, and apparently largest in the middle of the bone. The dentary (fig. 4) is imperfect, only the thickened alveolar border being preserved, though this for the greater part of its length. The teeth are fused with the bone in sockets which are incomplete on the inner side; they are all well spaced, largest in the middle of the element, and considerably exceed the maxillary teeth in size. Leeds Coll. Imperfect head and portions of fins of a typical fish; near Peterborough. The extremity of the rostrum is wanting, and the head is so much fractured that several interesting features in its osteology are exhibited. All the external bones are ornamented with very fine, closely-arranged tuberculations. The cranium is too much crushed for description; but a robust ossification is shown in the prefrontal region on the right side, and the greater part of the parasphenoid is also exposed. ‘The latter element is considerably expanded in front and bears an elongate patch of minute granular teeth immediately in advance of the pair of foramina for the internal carotids. Among the remains of cheek-plates, some of the characteristic small circumorbitals are shown on the left side. The maxillx (mz.) and premaxille (pmuw.), similar to those of the last 398 ACTINOPTERYGII. specimen, are preserved on each side, though somewhat fractured, as shown in fig. 5; and part of the supra- maxillary plate (fig. 5, s.mx.) is also exhibited overlapping the hinder end of the maxilla. The anterior end of the alveolar border of the dentary bone of the mandible (fig. 5, d.) appears sinuous in side view, and the most anterior teeth, which are enlarged, are directed slightly forwards. Within the mouth remains of the pterygo- palatine arcade are observed above (fig. 5, pt.), but it is not possible to distinguish the elements; on its inner face there is a crowd of minute denticles (probably entoptery- goid) which gradually become a little enlarged below, while on the oral margin (probably ectopterygoid and palatine) there are large teeth irregularly arranged and spaced, the largest being near the anterior end. When viewed from within, the dentary exhibits the usual thickened alveolar border, this in its hinder portion roofing the space occu- pied by the meckelian cartilage. The splenial element is also conspicuous, and may consist of more than one portion. As shown in a fragment from the left side a thickened, lenticular portion of this element (fig. 5a, spl.) enters the mandibular symphysis, and bears at least one large tooth immediately behind the enlarged, forwardly pointing teeth of the anterior end of the dentary. Posteriorly on the inner face of the left mandibular ramus a thin laminar bone (fig. 5, spl.?), bearing minute granular teeth, is crushed upon the dentary in such a way as to suggest its forming the inner wall of the cavity for the meckelian cartilage. Another specimen stillin Mr. Leeds’ private collection exhibits the same plate continued forwards above in a long slender process ; it is thus probably to be identified as a hinder splenial. There is nothing worthy of remark in the remains of the pectoral arch, but one of the pectoral fins (fig. 6) is interesting. The three fore- most rays, successively increasing in length, are fused together, and their thickened proximal end (fig. 6a) exhibits a hollowed, circular, articular facette (f.). The other rays are closely adpressed and unjointed so far as preserved, while their proximal ends simply clasp the basal cartilages. A few very fine tubercles ornament the sharp anterior border of the fin, and similar tubercles are observed on parts of the other rays. Among fragments PACHYCORMID®. 399 of the caudal fin the expanded supporting hemal spine is conspicuous, and there is a slight longitudinal ridge on this bone where the rays of the upper and lower lobes diverge. A few uniserial fulcra are intercalated between the tips of the gradually lengthening rays on the anterior borders of the fin. All the scales preserved both behind the pectoral arch and at the origin of the caudal fin are ornamented with very fine tubercles. ~ Leeds Coll. P. 6920. Expanded heemal arch from base of caudal fin either of this or the preceding species; near Peterborough. Leeds Coll. The following specimens are not specifically determined :— 42368 a, 43028 a, P.347 a. Five fragments of jaws of a small species, noticed in Geol. Mag. [3] vol. vi. 1889, p. 451; Kimmeridge Clay, Weymouth. Purchased, 1870, 1871, 1881. P. 6918. Two very stout left maxille, more or less imperfect ; Oxford Clay, near Peterborough. Leeds Coll. 36308. Expanded hemal arch from base of caudal fin, associated with fragments of rays; Oxford Clay, Christian Malford, Wiltshire. Purchased, 1861. Genus PROTOSPHYRAENA, Leidy. [Trans. Amer. Phil. Soc. vol. xi. 1857, p. 95.] Syn. Erisichthe, E. D. Cope, Proc. Acad. Nat. Sci. Philad. 1872, p. 280. Pelecopterus, E. D. Cope, Vert. Cret. Form. West. (Rep. U.S. Geol. Surv. Territ. vol. ii. 1875), p. 244 c. An imperfectly definable genus known only by the head, pectoral arch, and pectoral fins, which are closely similar to the corresponding parts of Hypsocormus. Rostrum ordinarily much produced ; pre- maxilla large and triangular in shape. Dentition powerful, all the principal teeth much compressed, with sharp anterior and posterior edges, and fixed in deep, complete sockets; those of the vomer, premaxilla, and splenial especially large, and similar teeth pro- jecting forwards from the downwardly-curved anterior extremity of the oral border of the dentary ; those of the maxilla and hinder portion of dentary comparatively small and in a single close series ; 400 ACTINOPTERYGII. those of the pterygoid bones more or less granular. Gular plate present. Pectoral fins large and sickle-shaped, consisting of closely- apposed, unjointed and unbranched rays, of which the majority terminate successively at the oblique, trenchant anterior margin. The teeth of this genus from European Cretaceous formations were originally referred by Agassiz (Poiss. Foss., Feuill. 1835, p- 95) in error to Saurocephalus of Harlan (Journ. Acad. Nat. Sci. Philad. vol. iii. 1824, p. 337) ; while the pectoral fins were wrongly described as fin-rays of Ptychodus (Agassiz, ibid. vol. iii. 1837, p. 56). The mistake in the identification of the teeth was first pointed out by Leidy (loc. cit. 1857), who, however, failed to recog- nize that the elongated rostrum belonged to the same fish as these fossils. The pectoral fin-rays were first proved to be not Elasmo- branch by Cope (Joc. cit. 1875), and their identity with Protosphy- rena was subsequently determined both by Cope (in A. 8. Wood- ward, Proc. Geol. Assoc. vol. x. 1888, p. 321) and by A. R. Crook (Paleontogr. vol. xxxix. 1892, p.110). The best description of the head hitherto published is that by J. Felix (Zeitschr. deutsch. geol. Ges. vol. xli. 1890, pp. 278-302, pls. xii.-xiv.); but neither Crook nor the present writer has observed any evidence of the so-called “‘ praedentale” described by this author. The thickening of the alveolar border of the dentary bone is interpreted by Cope as an anomalous median element. Protosphyrzena ferox, Leidy. 1822. “ Undetermined,” G. A. Mantell, Foss. South Downs, p. 228, pl. xxxiii. figs. 7-9. . 1835-44. Saurocephalus lanciformis, LL. Agassiz (errore), Poiss. Foss., Feuill. p. 55, vol. v. pt. i. p. 102, pl. xxv. ¢. figs. 21-29. 1844, Saurocephalus lanceolatus, L. Agassiz, ibid. vol. v. pt. i. p. 8 (misprint). 1850. Saurocephalus lanciformis, F. Dixon, Geol. Sussex, p. 374, pl. xxx. fig. 21, pl. xxxi. fig. 12; pl. xxxii.* fig. 1, pl. xxxiv. fie, 1 1857. Protosphyrena ferox, J. Leidy, Trans. Amer. Phil. Soe. vol. x1. p. 95. 1857. Xitphias divoni, J. Leidy, tbid. p. 95. [Rostrum; British Mu- seum. | (?) 1860. Saeocephalus lanciformis, V. Kiprijanoff, Bull. Soc. Imp. Nat. Moscou, vol. xxxiii. pt. i. p. 666, pl. x. fig. 4. 1877. Erisichthe dixont, EK. D. Cope, Bull. U.S. Geol. Surv. Territ. vol, iii. p. 823. 1878. Erisichthe dixont, W. Davies, Geol. Mag. [2] vol. v. p. 260, pl. viii. fig. 3. 1878. Protosphyrena ferox, KH. T. Newton, Quart. Journ. Geol. Soc. vol. xxxiv. p. 789. PACHYCORMID &. 401 1888. Protosphyrena ferox, A. 8. Woodward, Proc. Geol. Assoc. vol. x. p. 321. 1895. Protosphyrena feror, A. S. Woodward, Geol. Mag. [4] vol. ii. p. 211, woodcut fig. 3. Type. Teeth; British Museum. The type species. Rostrum much elongated and attaining a length of about 0°3 with a transverse diameter of 0:05 at its base where the vomerine teeth are implanted; circular in transverse section throughout its whole length, except within a short distance of the vomerine teeth, where it becomes slightly flattened on the upper part of its sides and the top and passes into the gradually widening flattened cranial roof; its external surface ornamented with reticulating rugs, of which the most prominent are longitudi- nally directed. Cranial roof more finely rugose and tuberculated. Teeth sometimes smooth, but usually with slight longitudinal wrinkles, which cause splits in the enamel of the fossils ; the acute edges not serrated. Symphysial extremity of each dentary bearing three large teeth, and its oral border toothless where apposed to the dentigerous part of the splenial; splenial with two large teeth, and smaller teeth in front but none behind. Form. & Loc. Senonian, Turonian, and Cenomanian: S8.E. Eng- land. (?)Cenomanian: Kursk, Russia. P. 6529. Very fine rostrum, measuring 0°28 from the vomerine teeth to its incomplete distal extremity, showing a frag- ment of the anterior part of the cranial roof and associated with pyritised remains of the anterior half of the right mandibular ramus; Lower Chalk, Blue Bell Hill, Burham, Kent. The internal cavity of the rostrum at its base is subdivided by a median vertical septum which is shown considerably in advance of the vomerine teeth; and the outer surface of the rostrum exhibits the characteristic ornamentation. The vomerine tooth of the right side is completely preserved, but on the left there is only the apex of what seems to be a successional tooth. Two of the much larger anteriorly-projecting teeth of the dentary are also exposed; and part of the series of diminutive teeth is preserved on its oral border behind the region of the splenial. Presented by S. J. Hawkins, Esq., 1891. P. 3955-56. A much abraded, fractured, and partially crushed rostrum, associated with the mandible and other frag- ments; Chalk, Kent. Only the right vomerine tooth is preserved, and the hollow portion of rostrum above it is PART Ill. 2D ACTINOPTERYGII. laterally compressed by accidental crushing. A sclerotic ring, showing some traces of rugosity, lies in the matrix beneath the fossil. The mandible wants its hinder extremity, and only the bases of the larger teeth remain. The outer face of the anterior end of the dentary is very coarsely rugose, and the symphysis is somewhat expanded for the sockets of the three anteriorly-directed large teeth. Of the latter on the left side the uppermost socket appears to be almost obliterated. There is no suture between the symphysial end and the remainder of the dentary bone, but it exhibits its usual slight constriction where flanking the splenia], and the oral border is toothless until a point considerably behind the dentigerous portion of the inner element. The teeth of its single, moderately spaced series are small and nearly equal in size, a diminution being shown only in the foremost five or six; the hindermost teeth, however, are not preserved. The middle portion of the dentary is about one-third deeper than its symphysial end, much thinner, and with the inferior margin slightly turning inwards. The splenials evidently enter the sym- physis, but pyrites obscures their anterior end. Viewed from above each is lenticular in form, though produced in a very long and slender extension posteriorly ; and the thickest portion on the left side exhibits the bases of two large teeth besides one small anterior tooth, while the corresponding part on the right side seems to indicate a diseased state of the bone. Fragments of other elements are displaced between the mandibular rami, but it is - impossible to determine them. Enniskillen Coll. P. 5651. P. 5630. Fragments of skull in a block of chalk; Cuxton, Kent. A. portion of the flattened cranial roof is rugose on the external surface, but affords no clue to the arrangement and limits of the elements. The imperfect parasphenoid is exposed from the inner aspect, showing the very robust though narrow bar beneath the orbit, and the much- extended laminar basipterygoid processes. ‘There is also a fragment of a premaxilla with one tooth. Harford Coll. Fine rostrum, much fractured but displaying the super- ficial rugose ornament and the bases of the vomerino teeth, and apparently not distorted by crushing ; Kent. A side view of this fossil is given in outline, of one-half PACHYCORMIDZ. 403 Fig. 41. 2 oS6 So6sS sone te Outlines of Rostra of Protosphyrena in lateral aspect and transverse section, one-half natural size. No. 1. Protosphyrena tenwirostris, A. S. Woodward.—Cambridge Greensand. [Woodwardian Museum, Cambridge. | No. 2. Protosphyrena compressirostris, A. S. Woodward.—Kentish Chalk. [No. P. 5631.) No. 3. Protosphyrena ferox, Leidy.—Kentish Chalk. [No. P. 5630.] No. 4. Protosphyrena keepingi, A. S. Woodward.—Cambridge Greensand. | Woodwardian Museum, Cambridge. | 2p2 i fond ee ee SSS Ss a Pes Se Ser be yn OS SS eee SSS es SS 404 ACTINOPTERYGII. the natural size, in fig. 41, no. 3, three transverse sections being added in nos. 3 a-c. Harford Coll. 33254. Imperfect rostrum; English Chalk. Taylor Coll. P. 612. Imperfect rostrum noticed and figured by Dixon, Geol. Sussex, p. 374, pl. xxxii.* fig. 1, under the name of Saurocephalus lanciformis, and termed Xiphias dixont by Leidy, loc. cot.; Chalk, Kent. Egerton Coll. P. 1801. Another imperfect rostrum showing the forward triangular extension of the flattened cranial roof; English Chalk. Egerton Coll. 33310. Fragment of rostrum; Chalk, Burham, Kent. Purchased, 1858. 49103. Crushed base of rostrum ; English Chalk. ) Mrs. Sinith’s Coll. 49759. Fragment of rostrum; Chalk, Glynde, Lewes. Capron Coll. 35154. Imperfect rostrum, showing base of one vomerine tooth ; Cambridge Greensand, Cambridge. Purchased, 1859. P. 1802. Two fragments of distal end of rostrum; Cambridge Greensand. Egerton Coll. 35155. Imperfect base of rostrum; Cambridge Greensand. Purchased, 1859. 20709. Imperfect base of rostrum showing vomerine teeth, described and figured by W. Davies, Geol. Mag. [2] vol. v. p. 260, pl. viii. fig. 3; Chalk, Amberley, Sussex. Dixon Coll. 32747. Another fragment of base of rostrum showing vomerine tooth ; Chalk, Burham. Purchased, 1857. 49012. Portion of right premaxilla, figured by Dixon, op. cit. pl. xxxiv. fig. 11; Chalk, Burham. Mrs. Smith’s Coll. P. 3954. Larger but more imperfect portion of premaxilla, showing six large teeth and one successional tooth ; Chalk, Kent. Enniskillen Coll. 49820. Fragment of premaxilla ; Chalk, Glynde. Capron Coll. P. 5651. Right maxilla; Lower Chalk, Burham. Harford Coll. PACHYCORMID#. 405 49827. Fragment apparently of dentary, associated with an inner bone displaying a finely granular dentition; Chalk, Amberley. - Capron Coll. 39438. Anterior extremity of mandible, figured by Dixon, op. cit. pl axxi, fie. 12; ChalkWent. Bowerbank Coll. 49089. Two fragments of anterior extremity of dentary; Lower Chalk, Burham. Mrs. Snuth’s Coll. 49742. Fragment of dentigerous bone ; Chalk, Amberley. Capron Coll. P. 5633-34. Fragments of jaws; Lower Chalk, Burham. Harford Coll. 4088, 4089, 4096, 4135. Five teeth, the type specimens described and figured by Agassiz, tom. cit. p. 102, pl. xxv. c. figs. 21, 24, 27-29 ; Chalk, Lewes. Mantell Coll. 25751-52, 25754, 25834. Four teeth figured by Dixon, op. cit. pl. xxx. figs. 21 a-d; Chalk, Sussex. Dixon Coll. 25750, 25808. Two teeth; Chalk, Sussex. Dixon Coll. 49770. Four teeth ; Chalk, Amberley. Capron Coll. P. 4543. Large tooth in bone-fragment. Enniskillen Coll. 27033. Tooth; Lower Chalk, Guildford. Purchased, 1851. 38584, 47925. Two large teeth ; Lower Chalk, Burham. Purchased, 1864, and presented by Hon. Robert Marsham, 1877. P. 6530. Tooth in bone-fragment ; Lower Chalk, Blue Bell Hill, Burham. Presented by S. J. Hawkins, Esq., 1891. 33255. Two large teeth ; Chalk, Kent. Taylor Coll. 39055. Fine tooth ; English Chalk. Bowerbank Coll. Protosphyrzna compressirostris, A. 8. Woodward. 1895. Protosphyrena compressirostris, A. 8. Woodward, Geol. Mag. [4] vol. il. p. 218, woodcut fig. 2. Type. Rostrum; British Museum. Rostrum much elongated and attaining a length of at least 0°19 with a transverse diameter of 0-02 at its base where the vomerine teeth are implanted ; laterally compressed in its proximal half, the transverse section here being an oval with vertical long axis ; 406 ACTINOPTERYGII. circular in transverse section in its distal portion ; the top of the base gradually becoming flattened as it passes into the cranial roof. External ornament as in P. ferow. | Form. & Loc. Senonian: Kent. P. 5631. The type specimen, a fractured rostrum showing the bases of the pair of vomerine teeth ; Chalk, Kent. A diagram- matic outline of the left side-view of the fossil is shown of half the natural size in fig. 41, no. 2(p. 403), and trans- verse sections are given ibid. nos. 2 a—c. Harford Coll. Protosphyrzena minor (Agassiz). 1837-44. Tetrapterus nunor, L. Agassiz, Poiss. Foss. vol. v. pt. i. pp. 7, 91, pl. lx. a. figs. 9, 10 (non figs. 11-13). 1888. Protosphyrena minor, A. 8. Woodward, Proc. Geol. Assoc. vol. x. p. 821. 1890. Protosphyrena minor, J. Felix, Zeitschr. deutsch. geol. Ges. vol. xi. p. 299. Type. Fragment of rostrum; British Museum. Rostrum comparatively delicate and much elongated, attaining a length of at least 0°15; the transverse section a depressed oval throughout its length, and the internal cavity extending a con- siderable distance towards the gradually tapering end; the external surface ornamented with coarse, closely-arranged, parallel longitu- dinal ridges, and its upper aspect marked with a median longitudinal groove which does not obliterate the ornamentation. No portion of this fish except the rostrum has hitherto been identified. Form. & Loc. Turonian: Kent and Sussex. 4078. Fragment of rostrum described and figured by Agassiz, loc. cit.; Chalk, Lewes. The extremity of the fossil was missing when received by the Museum. Maniell Coll. 49758. Larger portion of a similar rostrum, much fractured ; Grey Chalk, Lewes. Capron Coll. 49100. Another crushed and broken specimen, displaying the large internal cavity and the superficial ornamentation; pro- bably from the Lower Chalk of Burham, Kent. Mrs. Smith’s Coll. 32337. Distal end of rostrum, displaying ornament and apparently worn towards the extremity; Lower Chalk, Burham. The ridged ornament is more irregular on the inferior than on the superior aspect. Purchased, 1857. PACHYCORMIDA. 407 Protosphyrzna tenuirostris, A. 8. Woodward. 1860. Saurocephalus striatus, V. Kiprijanoff (errore), Bull. Soc. Imp. Nat. Moscou, vol. xxxiii. pt. 1. p. 666, pl. x. fig. 3. 1895. Protosphyrena tenuirostris, A. S. Woodward, Geol. Mag. [4] vol. il. p. 211, woode. fig. 1. Type. Rostrum ; Woodwardian Museum, Cambridge. Rostrum much elongated and slender, somewhat flexed upwards shortly in advance of the vomerine teeth, and attaining a length of about 0-24 with a transverse diameter of 0:027 at its base where the vomerine teeth are implanted; transverse section remarkably eylindroidal throughout its length, slightly depressed in its middle portion ; external surface marked by fine longitudinal ridges. A diagrammatic outline of the left side-view of the type specimen is shown of half the natural size in fig. 41, no. 1 (p. 403), and transverse sections are given, zbid. nos. 1a-c. ‘The Russian speci- men described by Kiprijanoff is slightly more attenuated. Form. & Loc. Cenomanian (Cambridge Greensand): Cambridge- shire; Kursk, Russia. Not represented in the Collection. Protosphyrzna keepingi, A. 8. Woodward. 1895. Protosphyrena keepingi, A. 8S. Woodward, Geol. Mag. [4] vol. 11. p. 212, woodcut fig. 4. Type. Portion of rostrum ; Woodwardian Museum, Cambridge. Rostrum remarkably stout and short, circular in transverse section, only slightly flattened on the top at its base; external sur- face ornamented with reticulating ruge. A diagrammatic outline of the left side-view of the type specimen is Shown of half the natural size in fig. 41, no. 4 (p. 403), and transverse sections are given, bid. nos. 4a, b. Form. g Loc. Cenomanian (Cambridge Greensand) ; Cambridge- shire. Not represented in the Collection. Protosphyrzena ornata, A. 8. Woodward. 1895. Protosphyrena ornata, A. S. Woodward, Geol. Mag. [4] vol. ii. p. 212, pl. win. fig. 7. Type. Imperfect rostrum; Woodwardian Museum, Cambridge. Rostrum much elongated and attaining a length of about 0-2 with a transverse diameter probably of 0:02 or 0-025 at its base where the vomerine teeth are implanted ; vomerine area elongated, 408 ACTINOPTERYGII. and the rostrum much laterally compressed, except towards its attenuated distal extremity which is round in section. The rounded upper contour of the rostrum gradually becoming raised into an obtuse median longitudinal ridge at its base and ornamented with coarse ruge, which frequently subdivide into tubercles and are mainly longitudinal in direction though partly turned obliquely downwards; the lateral portions ornamented with much finer longitudinal ruge which in part tend to converge at the middle of the side, and form a slight median longitudinal ridge on the inferior aspect of the rostrum for some distance in advance of the yvomerine area. Form. & Loc. Cenomanian (Cambridge Greensand): Cambridge- shire. P. 7248. Uncrushed fragment of base of rostrum, displaying the upper contour and ornamentation, the pair of ethmoidal canals, and part of the vomerine area. Jesson Coll. P. 7246-47. Five typical fragments of rostrum. Jesson Coll. Protosphyrzena brevirostris, A. 8. Woodward. 1895. Protosphyrena brevirostris, A. 8. Woodward, Geol. Mag. [4] vol. ii. p. 212, pl. viii. fig. 9. Type. Imperfect rostrum; British Museum. Rostrum comparatively short and acute, its length apparently not exceeding 0°05 in a specimen measuring 0°025 in transverse diameter where the vomerine teeth are implanted. Upper aspect of rostrum flattened and the sides converging below in a median inferior keel, making the transverse section triangular at the end of the vomerine region ; surface nearly smooth. Form. & Loc. Cenomanian (Cambridge Greensand) : Cambridge- shire. P. 7253. Type specimen described and figured, loc. cit. Jesson Coll. P. 7252. A more abraded rostrum, with a slightly larger and longer extension, imperfect at the extremity but exhibiting a flattened triangular area immediately in front of the vomerine teeth, noticed ibid. p. 214. Jesson Coll. Protosphyrzna depressa, A. 8. Woodward. 1895. Protosphyrena depressa, A.S. Woodward, Geol. Mag. [4] vol. ii. p- 212, pl. vii. fig. 8. Type. Imperfect rostrum; Woodwardian Museum, Cambridge. Rostrum comparatively short and depressed, its length apparently PACHYCORMID &. 409 not exceeding 0°055 in a specimen measuring 0-025 in transverse diameter where the vomerine teeth are implanted. Upper aspect of rostrum flattened, almost hollowed, the sides converging below so that the transverse section appears triangular with rounded angles; surface smooth or in part slightly rugose. Form. & Loc. Cenomanian (Cambridge Greensand) ; Cambridge- shire. Not represented in the Collection. Protosphyrzena nitida (Cope). 1872. Erisichthe nitida, E. D. Cope, Proc. Acad. Nat. Sci. Philad. p- 281. 1874. Erisichthe nitida, E. D. Cope, Bull. U. S. Geol. Surv. Territ. vol. i. no. 2, p. 42. 1875. Erisichthe nitida, E. D. Cope, Vert. Cret. Form. West (Rep. US. Geol. Surv. Territ. vol. ii.), p. 217, pl. xlviii. figs. 3-8. 1877. Erisichthe nitida, EK. D. Cope, Bull. U.S. Geol. Surv. Territ. vol. iii. p. 821. 1890. Protosphyrena nitida, J. Felix, Zeitschr. deutsch. geol. Ges. vol. xli. p. 278, pls. xii., xiii., pl. xiv. figs. 2-7. 1892. Protosphyrena nitida, A. R. Crook, Paleontogr. vol. xxxix. p- 110. Type. Portions of skull. The type species of the so-called genus Erisichthe. Rostrum much elongated, slightly recurved, and attaining a length of about 0-155 with a transverse diameter of 0:025 at its base where the vomerine teeth are implanted ; flattened above in its distal half, the transverse section in this region is semicircular, a strong angle on each side limiting the superior plane, while the section at the base of the rostrum is a transverse oval; the flattened upper surface finely rugose, the remainder ornamented with closely arranged longitudinal ridges, in part reticulated. Form. & Loc. Upper Cretaceous (Niobrara Group): Kansas, U.S.A. Not represented in the Collection. Protosphyrzna penetrans (Cope). 1877. Erisichthe penetrans, E. D. Cope, Bull. U.S. Geol. Surv. Territ. vol. iii. p. 822. 1890. Protosphyrena penetrans, J. Felix, Zeitschr. deutsch. geol. Ges. vol. xl. p. 297, pl. xiv. fig. 1. 1892. Protosphyrena penetrans, A. R. Crook, Paleeontogr. vol. xxxix. p- 109. Type. Rostrum. Rostrum much elongated and attaining a length of about 0°15 410 ACTINOPTERYGII. with a transverse diameter of 0°035 at its base where the vomerine teeth are implanted, but more slender than the rostrum of P. nitida; transverse section a depressed oval throughout; surface ornamented with conspicuous longitudinal rugs, in part reticulated. Form. & Loc. Upper Cretaceous (Niobrara Group): Kansas, U.S.A. Not represented in the Collection. The following specimens of Protosphyrena are not specifically determined :— 40395. Imperfect, abraded rostrum, much elongated and either depressed or compressed ; Chalk, Burham, Kent. Purchased, 1867. 47291. Imperfect, crushed rostrum, much elongated and depressed, exhibiting remains of an external ornament of fine longi- tudinal ruge ; Grey Chalk, Dover. Gardner Coll. P. 7243-44. Nine jaw-fragments; Cambridge Greensand, Cam- bridge. Jesson Coll. P. 1796. Fragment of pe Gault, Barnwell, near Cam- bridge. Egerton Coll. 30258, 35131, 35437, 40356. Teeth ; Cambridge Greensand. Purchased, 1855, 1859, 1867. 47961. Five teeth ; Cambridge Greensand. Presented by Hon. Robert Marsham, 1877. P. 7245. Three imperfect large teeth; Cambridge Greensand. Jesson Coll. 32392. Tooth; Upper Greensand, Kilmerton, Isle of Wight. Purchased, 1857. 35675. Tooth; Red Chalk, Speeton, Yorkshire. _ Bean Coll. 47225. Ten teeth; Gault, Folkestone. Gardner Coll. 36111. Tooth ; Grey Chalk, Dover. Purchased, 1861. P. 406. Tooth; Grey Chalk, Dover. Presented by the Earl of Ducie, 1881. 47247. Three teeth ; Chalk Marl, Dover. Gardner Coll. PACHYCORMID.. 411 P. 7257. Four expanded hemal bones doubtfully ascribed to this genus ; Cambridge Greensand. Jesson Coll. P. 7258. Ten expanded hemal bones doubtfully ascribed to this genus, deeper than the preceding specimens and some exhibiting feeble vertical flutings ; Cambridge Greensand. Jesson Coll. 30259, 35160, 35394. Hight expanded hamals; Cambridge Green- sand. Purchased, 1855, 1859. P. 7256. Other still more deeply expanded hemals of the form provisionally ascribed to this genus by W. Davies, Geol. Mag. [2] vol. v. p. 256; Cambridge Greensand. Jesson Coll. 35160 a, 35351. Two similarly expanded hemals, imperfect but dis- playing slight vertical furrows ; Cambridge Greensand. Purchased, 1859. 47191, P. 38. Two small expanded hemals of similar form; Gault, Folkestone. Gardner Coll. 49102. Imperfect large example of similarly expanded haemal 0-125 in depth; Chalk, Kent, Mrs. Smith’s Coll. 38027. Smaller specimen ; Chalk, Lewes. Purchased, 1863. P, 5120. Still smaller specimen ; Neocomian, Choroskowo, Russia. Purchased, 1886. P. 1483. Small expanded hemal overlapped by caudal fin-rays ; Chalk, Sussex. Egerton Coll. 4074, 4099. Two fragments of pectoral fins showing wavy anterior border, described and figured by Agassiz (Poiss. Foss. vol. ii. 1837, p. 57, pl. x. a. figs. 1, 3) under the name of Ptychodus spectabilis; Upper Chalk, Lewes. The first specimen is also figured by Mantell (Geol. Sussex, 1822, pl. xxxix.) as ‘‘a dorsal fin, or radius, of a fish allied to the genus Balistes.” Mantell Coll. 39471. Larger portion of a similar fin; English Chalk. Bowerbank Coll. 35374, Small fragment of similar fin ; Chalk, Cambridge. Purchased, 1859. ‘ } i | { ’ } } 1 i} { 4192 ACTINOPTERYGII. 41079. Another fine specimen of the anterior border of the pectoral — fin; Chalk, Merstham, Surrey. Presented by Prof. N. S. Maskelyne, 1868. 35554. Anterior portion of similar fin; Gault, Folkestone. Purchased, 1859. i. 46961. Fragment of still larger pectoral; Lower Chalk, Burham, Kent. Purchased, 1876. P. 1480. Two fragments of similar fin ; Chalk, Lewes. Egerton Coll. 4070. Fragment with more widely spaced anterior eminences, de- scribed and figured by Agassiz (op. cit. vol. ili. p. 58, pl. x. a. fig. 2) under the name of Ptychodus arcuatus, and also figured by Mantell (op. cit. pl. xl. fig. 3); Upper Chalk, Lewes. Mantell Coll. P, 7254-55. Small fragments apparently of similar fins ; Cambridge Greensand. Jesson Coll. 4075. Anterior portion of more delicate pectoral! fin, with less pro- minently sinuous margin, described and figured by Agassiz (op. cit. p. 58, pl. x. a. fig. 4) under the name of Ptychodus gibberulus ; Chalk, Lewes. Mantell Coll. 49747-48, Two fragments of similar fins; Lower Chalk, Southeram, Lewes. Capron Coll. 41695. Fine fin showing a basal bone; Chalk, Kent. . | ; Toulmin Smith Coll. 39066. Similar but more imperfect fin; Chalk, Harisham, Kent. Bowerbank Coll. 33176. Two fragments of similar fin ; Chalk, Burham. Purchased, 1857. 36092-93, 47280. Three imperfect specimens of similar fin; Lower Chalk, Dorking, Surrey. Purchased, 1861, and Gardner Coll. 49733. Fine fin and another small specimen ; Dorking. Capron Coll. 49029-30. Two similar specimens; English Chalk. Mrs. Smith's Coll. PACHYCORMID &. 413 P. 1482 a. Another similar specimen; English Chalk, Egerton Coll. 25846. Fragment of fin; Chalk, Sussex. Dixon Coll. 49817. Another small fragment; Chalk, Amberley. Capron Coll. The following specimens are more doubtfully assigned to Proto- sphyrena :— 4077. Anterior portion of fin described and figured by Agassiz (op. cit. vol. 111. p. 59, pl. x. 6. fig. 18) under the name of Ptychodus ; Chalk, Lewes. Mantell Coll. 25846 a. Fragment figured as Ptychodus in Dixon’s Geol. Sussex, pl. xxxi. fig. 14; Chalk, Sussex. Dixon Coll. P. 7573. Very imperfect pectoral fin showing seven basals and other bones ; English Chalk. History unknown. The so-called Ptychodus articulatus, Agassiz (op. cit. vol. ili. p. 58, pl. x.a. figs. 5, 6) seems to be a fragment of the caudal fin of Portheus or an allied fish. The appearance of a wavy margin given in Agassiz’s figure is imaginary. The following specimen probably belongs to the family Pachy- cormidee, if not to the genus Protosphyrena itself :— 49531. Middle portion of caudal region noticed in Ann. Mag. Nat. Hist. [6] vol. xiii. (1894), p. 512; Upper Cretaceous, Sahel-el-Alma, Mt. Lebanon. There are no traces of vertebral centra, but the arches are very numerous and well ossified, somewhat expanded at the base. Remains of a dorsal fin occur in advance of a smaller anal. Fos- silized remains of the muscular fibres are also conspicuous. . Lewis Coll. An imperfect and abraded rostrum from the Cretaceous (Niobrara Group) of Kansas is also referred to this genus under the name of Erisichthe ziphioides by KE. D. Cope, Bull. U.S. Geol. Surv. Territ. vol. iii. (1877), p. 823. Fragments of jaws from the Cretaceous of North Carolina are provisionally placed here (Portheus angulatus, E. D. Cope, Proc. Acad. Nat. Sci. Philad. 1872, p. 281, and in Kerr’s Rep. Geol. Surv. N. Carolina, 1875, Append. B, p. 32; Erisichthe angulata, KE. D. Cope, Vert. Cret. Form. West, 1875, p- 275). Pectoral fins of undetermined species of Protosphyrwna were Ne eh states © ais |. er 414 ACTINOPTERYGII. originally regarded by Cope (loc. cit. 1875, p. 244 4) as representing a previously unknown order of Actinopterygian fishes, named Acri- wocutrI. The American specimens are described as exhibiting “ six single and one paired basilar bones supporting the pectoral fin, and all articulating with the scapula.” The following forms, not repre- sented in the Collection, are distinguished :— Pelecopterus chirurgus, E. D. Cope, Vert. Cret. Form. West (Rep. U.S. Geol. Surv. Territ. vol. ii. 1875), p. 2442, woode. fig. 10, pl. xlviii. fig. 1, pl. liv. fig. 9.—Upper Cretaceous — (Niobrara Group); Kansas. | Peélecopterus gladius, E. D. Cope, loc. cit. (1875), p. 244 8, pl. li. 4 fig. 3, pl. xliv. fig. 12: Portheus gladius, HK. D. Cope, . Q Proc. Acad. Nat. Sci. Philad. 1873, p. 338, and Bull. U.S. © Geol. Surv. Territ: vol. i. no. 2 (1874), p. 40.—Ibid. Pelecopterus perniciosus, E. D. Cope, loc. cit. (1875), p. 2440, - pl. xlviii. fig. 2, pl. lii. fig. 2, pl. xliv. fig. 13: Ichthyo-. dectes perniciosus, E.D. Cope, Bull. U.S. Geol. Surv. Territ. vol. i. no. 2 (1874), p. 41.—Ibid. [The type species of — Pelecopterus, referred to Protosphyrana nitida by A. R, Crook, Palzontogr. vol. xxxix. (1892), p. 110. | To the Pachycormide may also perhaps be referred the large problematical fish from the Oxford Clay of Peterborough named Leeda problematica (A. 8. Woodward, Geol. Mag. [3] vol. vi. 1839, p. 451 [Leedsichthys problematicus |, and abid. vol. vii. 1890, p. 292, pl. x. figs. 9, 10). The type specimens from the Leeds Collection are now preserved in the Museum, but the determination of all the bones except the gill-rakers (? or gill-supports) is still so uncertain, that it seems advisable to postpone the description of them until the final Supplement, when more satisfactory evidence of their true 4 nature may perhaps be forthcoming. The massive bones, which have been compared with branchiostegal rays, will most likely prove to be vertebral arches. The genus also occurs in the Oxford Clay of Vaches Noires, Normandy, and in the Kimmeridge Clay of Dorsetshire. ASPIDORH YNCHID®. 415 Suborder II]. AETHEOSPONDYLI. Notochord varying in persistence, but pleurocentra and hypo- centra usually fused, never forming alternating discs or rings; tail abbreviate-heterocercal or homocercal. Mandible complex, with well-developed splenial rising into a coronoid process, which is completed by a distinct coronoid bone. Infraclavicular plates wanting in the pectoral arch; pectoral fin with more than five basals. Scales ganoid. In the living forms—air-bladder connected with the cesophagus in the adult, optic nerves not decussating, but forming a chiasma, and intestine with remnants of a spiral valve. Synopsis of Families. A distinct presymphysial bone in man-. dible; vertebral centra annular or amphiccelous ; fin-fulcra minute or RISE Ga G6 Oe ae Ene ener ee cer iowene ASPIDORHYNCHID& (p. 415). No presymphysial bone; vertebral centra opisthoccelous; fin-fulcra large .... LEPIDOSTEID# (p. 440). Family ASPIDORHYNCHIDAL. Head and trunk much elongated, the snout produced, and the abdominal much longer than the caudal region; tail homocercal. Cranial and facial bones robust and opercular apparatus complete, all more or less ganoid; mandibular suspensorium vertical or inclined forwards, but gape of mouth wide; a distinct azygous pre- symphysial bone present in mandible; marginal teeth slender, conical. Branchiostegal rays numerous. Vertebral centra annular or amphiccelous. Fins small, with broad flattened rays, branched and articulated distally ; fulera minute or absent. Scales rhombic, much deepened on the flank. Synopsis of Genera. Rostrum much produced in advance of man- dibular symphysis; an intercalary cheek- plate between the suborbitals and pre- operculum ; foremost scales of lateral line not deeper than those immediately beneath Aspidorhynchus (p. 416). Rostrum scarcely if at all produced in advance of mandibular symphysis; suborbitals in contact with preoperculum ; all scales of lateral line deeper than those immediately emeath. os: < erate nt Bie tes tlie ats 3 Belonostomus (p. 428). 416 ACTINOPTERYGII. Genus ASPIDORHYNCHUS, Agassiz. [Poiss. Foss. vol. 11. pt. i. 1833, p. 14.] Rostrum slender, much produced in advance of mandibular sym- physis ; circumorbital plates very small, suborbitals large, and an intercalary plate between the latter and the preoperculum ; teeth irregular in size, largest on the premaxilla, palatine, and presym- physial bone, reduced to a fine granulation on the inner face of the ectopterygoid ; branchiostegal rays short and broad, and gular plate apparently absent. Vertebral centra annular. Fulcra wanting on paired fins, minute on median fins. Pelvic fins situated at about the middle of the trunk; dorsal and anal fins short-based, tri- angular, remote and opposed; caudal fin symmetrically forked. Scales robust, smooth or rugose; in three deepened series on the flank of the abdominal region, and the foremost scales of the series traversed by the lateral line not deeper than the series below. The chondrocranium of Aspidorhynchus must have been consider- ably ossified, but its characters are as yet unknown. ‘The cranial roof-bones form a continuous shield, and the frontals constitute much the largest portion of it; the whole of the roof is more or less rugose externally, and the median suture between the frontals is remarkably wavy. The parasphenoid is narrow and delicate, paraliel with the hinder portion of the cranial roof, and apparently destitute of teeth. The elongated though robust vomers meet in an acute angle below the mesethmoid, and are firmly fused with the latter ; they are likewise toothless, so far as the present writer has been able to observe them. ‘The rostrum appears to be simple, but is often marked with longitudinal ridges which may readily be mistaken for separate elements in crushed specimens. The hyo- mandibular is much expanded, with a large process for the support of the operculum; and immediately behind the fan-shaped quadrate element there is a small narrow symplectic, widest at its upper end. The ectopterygoid is toothless behind, where it exhibits a moderately deep expansion, but bears further forwards a closely-set series of slender teeth, which gradually increase in size to its anterior ex- tremity where it articulates with the palatine. The teeth on the latter element are largest behind and diminish forwards. The entopterygoid is long and narrow, while both this and the im- perfectly-known metapterygoid are delicate. The epihyal is small and the ceratohyal very Jarge, but the basihyal is unknown. The maxilla is much elongated and slender, bearing a series of relatively — small teeth; and there is a curious laminar expansion along its upper border immediately in advance of the orbit. There are also ms > * IT ce a ASPIDORHYNCHID &, 417 some indications of a short supramaxilla above its hinder end. The premaxilla is also much elongated, with relatively large and spaced teeth posteriorly diminishing to minute teeth forwards; it is fused with the ethmoidal region, but does not meet its fellow of the opposite side in front, the groove between this pair of bones being continued for some distance along the base of the rostrum. Two relatively large plates of the suborbital series occupy the greater portion of the cheek behind the orbit; but the upper plate, as also sometimes the superior end of the lower plate, is separated from the preoperculum by a third element which is truncated above and acuminate below. There are also small cheek-plates surrounding the narial opening immediately in advance of the orbit ; but the circum- orbitals are insignificant and apparently do not form a continuous ring. The sclerotic is ossified. The dentary is much the, largest element in the mandible and bears a single series of teeth on its oral border. It meets its fellow of the opposite side at the symphysis, and articulates in front with an azygous, bilaterally- symmetrical presymphysial bone. Posteriorly there is a small angular plate exposed on the outer face of the ramus; but the coronoid has not hitherto been observed. The splenial is a very thin lamina, excavated on its hinder border and bearing minute teeth. 7 On the branchial arches the calcified supports for the gill-filaments are always conspicuous. The opercular apparatus is complete, and there is a long series of branchiostegal rays; but a gular plate has not hitherto been observed. The vertebral centra, so far as the present writer has observed them, are always in the form of delicate rings, each bearing its own arch. The ribs are very short and thin. In the abdominal region the neural spines appear to be separate from their supporting arches, though this is not quite certain ; in the caudal region, both hemal and neural spines are fused with their arches, and the latter with their respective centra. As might be expected from the stout pro- portions of the rays, the supports of the dorsal and anal fins are especially robust ; and they are shown to be more numerous than the vertebral segments beneath them. The scales are all thick and rhombic, strengthened by a slight internal median rib, and those of the flank united by a large peg-and-socket articulation. The lateral line pierces each scale it traverses. PART ITI. 2n ‘OUITJNO PetO}sod ‘ S2ugsou2jNID snyouhysoprdsy way ey 8: LEZ ES Cot Js OQ, > &. z SOS ASPIDORHYNCHID®. 419 Aspidorhynchus acutirostris (Blainville). 1755. Figures by G. W. Knorr, Samml. Merkwiirdigk. Natur, pt. 1. P36, pis. oan xxix. fie. I. 1818. Esox acutirostris, H. D. de Blainville, Nouv. Dict. d’Hist. Nat. vol. xxvii. p. 332. 1823. Esox acutirostris, J. F. Kriiger, Geschichte der Urwelt, vol. i. p. 665. 1833. Aspidorhynchus acutirostris, L. Agassiz, Neues Jahrb. p. 478, and Poiss. Foss. vol. ii. pt. 1. p. 14. 1842. Aspidorhynchus longissimus, G. von Minster, Neues Jahrb. p. 44. [Nearly complete fish; Paleeontological Museum, Munich. | 1844. Aspidorhynchus acutirostris, L. Agassiz, Poiss. Foss. vol. i. pt. i. p. 136, pl. xlvi. 1844. Asnidorhynchus speciosus, L. Agassiz, zbid. p. 187, pl. xlv. [Imperfect trunk; Paleontological Museum, Munich. | 1842-44, Aspidorhynchus ornatissimus, Li. Agassiz, ibrd. p. 138, pl. xlvii. [Portion of fish; Paleontological Museum, Munich, and Wood- wardian Museum, Cambridge. | 1844, Aspidorhynchus mandibularis, L. Agassiz, tbid. p. 138. 1861. Belonostomus microcephalus, T. C. Winkler, Descript. Poiss. Foss. Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv.), p. 26, fig. 4. 1863. Aspidorhynchus acutirostris, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 680. 1863. Aspidorhynchus mandibularis, A. Wagner, zbid. p. 684. 1871. Aspidorhynchus ornatissimus, T.C. Winkler, Archiv. Mus. Teyler, vol, ii. p. 183, pl. v. figs. 11, 12. 1881. Aspidorhynchus acutirostris, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 83. 1887. Aspidorhynchus acutirostris, K. A. von Zittel, Handb. Paleont. vol. ii. p. 220, figs. 233, 234. 1887. Aspidorhynchus, O. Reis, Sitzungsb. k. bay. Akad. Wiss., math.- phys. Cl. vol. xvii. p. 151, pl. i. figs. 1-3, 6, 7, pl. i. figs. 1-4, 7. Type. Nearly complete fish ; Paris Museum of Natural History. The type species, of large size, attaining a length of 1 metre. Head with opercular apparatus occupying somewhat less than one- quarter of the total length; maximum depth of trunk contained between nine and ten times in the total length. Cranium rapidly tapering to the acute rostrum, which projects in advance of the mandible to an extent at least equal to one-third of the total length of the cranium; cranial bones and operculum ornamented with granulations and short longitudinal ruge, the latter especially con- spicuous on the rostrum; preoperculum with radiating ridges at the angle; mandible and branchiostegal apparatus almost smooth ; presymphysial bone rapidly tapering, twice as long as its maximum depth ; upper laniary teeth at the base of the rostrum, one or two 2E2 420 ACTINOPTERYGII. teeth at the dentary symphysis, and a single tooth at the proximal end of the presymphysial bone large, the principal mandibular teeth of the dentary bone numerous, well-spaced, regularly arranged, and of moderate size. Pelvic fins arising midway between the pectorals and the caudal; anal with about 20 rays, slightly nearer to the pelvic fins than to the caudal, and dorsal fin, with about 12 rays, directly opposed to its anterior portion. Scales almost smooth in — young individuals, coarsely though sparsely tuberculated and partly rugose in adults. The synonymy and characters of this species given above are chiefly based on the researches of Wagner and Vetter. ‘The last- named author also points out that the rostrum of the fish attains its full development at an early stage, subsequently only increasing in thickness ; it thus appears relatively longer in the young than in the adult. One fine specimen from Hichstadt in the Paleontolo- gical Museum, Munich, only differs from the typical A. acutirostris in its somewhat blunter snout and is described under the specific name of A. obtusirostris by A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. (1863), p. 637. Form. & Loc. Lower Kimmeridgian (Lithographic Stone) : Bavaria. P. 7574. Scattered remains of a large fish about one metre in length, in counterpart; Solenhofen. Some of the head-bones, ring-vertebre, and highly ornamented scales are well shown; and the paired fins are preserved. 37777. Similar fish with squamation less displaced, in counterpart ; Solenhofen. Presented by W. G. Neville, Esq., 1863. P. 3808. An equally large fish, wanting the snout but with well- preserved caudal fin and remains of the dorsal, anal, and paired fins; Solenhofen. As in the two previous speci- mens, the vertebral axis of the caudal region is curiously displaced and thrown upwards beyond the limits of the continuous squamation. Enniskillen Coll. 37791. Somewhat smaller specimen in a similar state of preserva- tion, but having the vertebral axis disjointed and wanting the greater part of the head; Solenhofen. Haberlein Coll. P. 972, P. 3807. Imperfect contorted fish at least 0°85 in length, showing some of the finely ornamented squamation, in counterpart ; Solenhofen. Egerton & Enniskillen Colls. ASPIDORHYNCHIDA. 491 P. 972 a. Part of the pectoral fins and abdominal squamation of a similar specimen, labelled “‘ Aspidorhynchus acutirostris, Agass.,” by Agassiz ; Solenhofen. Egerton Coll. P. 972 b. Scattered remains of. the head of another large fish, dis- playing among other elements the ceratohyal, epihyal, and expanded hyomandibular ; Solenhofen. Ligerton Coll. 36013-14. Similar remains of a large head with the pectoral fin, in counterpart ; Solenhofen. The cranium is shown from above, and the branched character of the pectoral fin-rays is well displayed. Purchased, 1861. P. 971. Head and anterior portion of the abdominal region exhi- biting chiefly an ornament of rug, and labelled ‘‘ Aspido- rhynchus speciosus, Agass.,” by Agassiz; Kelheim. Egerton Coll. 37790. Contorted fish 0-75 in length, with complete rostrum, several well-preserved vertebral rings and portions of squamation, and perfect caudal fin; Solenhofen. The rostrum is conspi- cuously marked with longitudinal ruge. Hdberlein Coll. 37802. Head of an equally large specimen, in counterpart, with the pectoral fin ; Solenhofen. Haberlen Coll. P. 2055. Fragmentary remains of large trunk with richly orna- mented scales, labelled ‘“ Aspidorhynchus acutirostris, Agass.,” by Agassiz; Solenhofen. Egerton Coll. - 49145. Plaster cast of nearly complete fish 0°67 in length, the specimen figured by Agassiz, tom. cit. pl. xlvi. fig. 2; Solenhofen. Purchased, 1878. P. 2056. Feeble impression of the head and imperfect trunk of a similar fish, showing vertebral rings ; Kelheim. Egerton Coll. P. 2057. Mandible, scattered head-bones, and part of the trunk of a similar fish; Solenhofen. Egerton Coll. 22657. Specimen 0:58 in length, with almost smooth scales and opercular apparatus; Solenhofen. The anal fin is espe- cially well shown, with minute fulera. Purchased, 1848. 37789. More imperfect specimen 0°55 in length, displaying the forked caudal fin; Solenhofen. In both this and the previous fish the dorsal fin is distinctly smaller than the 422 ACTINOPTERYGII. anal, The quadrate, symplectic, epihyal, and ceratohyal bones are conspicuous. The delicate ribs are shown. Haberlein Coll. P. 6940. Fine specimen, 0°56 in length ; Eichstiidt. By exchange, 1893. 37068. Head of a similar fish in lateral aspect, displaying the dentition of the maxilla, dentary, and splenial bones; Solenhofen. A small plate above the hinder end of the maxilla seems to be the supramaxilla. Haberlein Coll. P. 973. Another head with opercular apparatus, well preserved in lateral aspect, showing some of the ornament of the operculum and cranial roof. A small supramaxilla occurs above the hinder end of the maxilla ; and the apertures of the lateral line are conspicuous along the outer face of the dentary. Egerton Coll. P. 3805. Somewhat larger head, lateral aspect, with several bones crushed and displaced; Kelheim. The palato-pterygoid dentition is shown within the mouth, and part of the suture between the angular and dentary elements in the mandible can be distinguished. One of the branchial th | arches with its gill-supports is displaced below the A mandible.’ The series of branchiostegal rays is also well- We shown, about 12 in number on one side, and there are ih remains of the ossified sclerotic ring. Enniskillen Coll. P. 970, P. 3806. Head and greater portion of trunk of a fish about 0:45 in length, very imperfectly preserved in counterpart ; Solenhofen. The position of the notochord is indicated by a vacant space, the absence of calcified ring-vertebree Wa. being doubtless due to the immaturity of the specimen. The scales are smooth. Egerton &§ Enniskillen Colts. 1 37803. Head and anterior abdominal flank-scales of a very small ) Wi fish, with slender rostrum equalling nearly half of the . i total length of the cranium; Solenhofen. | i Haberlein Coll. P. 970a. A slightly larger head with much elongated rostrum ; Solenhofen. Egerton Coll. ASPIDORHYNCHIDZ. 423 Aspidorhynchus euodus, Egerton. [Plate XVII. figs. 6-10.] 1845. Aspidorhynchus euodus, Sir P. Egerton, Quart. Journ. Geol. Soe. vol. i. p. 231, with outline figs. Type. Scales, rostrum, and presymphysial bone; unknown. An imperfectly known species of moderate size. Cranium rapidly tapering to the acute rostrum, which projects in advance of the mandible to an extent scarcely exceeding one-quarter of the total length of the cranium ; cranial bones ornamented with granulations and short longitudinal ruge, mandible and opercular bones almost smooth ; presymphysial bone slender and tapering, length about three times as great as its maximum depth; upper laniary teeth at the base of the rostrum, one tooth at the dentary symphysis, and a single tooth at the proximal end of the presymphysial bone very large, the principal mandibular teeth of the dentary bone well spaced and of moderate size. Scales feebly rugose. Form. & Loc. Oxfordian ; Wiltshire. All the following specimens were obtained from Christian Malford, near Chippenham :— 40518. Imperfect head-and opercular bones, with scattered scales and ring-vertebre. The tip of the rostrum is broken away, and the whole of the mandible, except the presym- physial bone, is wanting. The pterygo-quadrate arcade, however, and the dentigerous base of the rostrum are well-preserved. The skull is shown of the natural size in Pl. XVII. fig. 6. The characteristic narrow parasphenoid (pas.) is exposed in the middle of the cranium and the nasal opening (na.) is indicated immediately in advance of the orbit. The quadrate bone (qu.) is fan-shaped, with a relatively small condyle. The ectopterygoid (ecpt.) is toothless behind, where deeply expanded, and its slender, closely-set teeth gradually increase in size from behind forwards: it meets the palatine (pl.) at an uncertain point in front, this bone bearing a single large tooth posteriorly and a regular, close series of small teeth anteriorly. The entopterygoid (enpt.) is long and narrow, but imperfectly exhibited, and the metapterygoid is of uncertain form. Overlying the operculum of the left side, which is exposed from its inner face, is a long, narrow, laminar bone (pt.), tapering above, abruptly 424 ACTINOPTERYGII. truncated below, strengthened with a ridge on its anterior margin, and evidently to be interpreted as the left post- temporal element. The presymphysial bone exhibits its characteristic tapering form, with the large unsymmetri- cally-placed tooth at its base. Most of the scales are exposed from the inner aspect, showing the large peg-and- socket articulation and broad, flattened, inner ridge; but the external face is evidently rugose. Purchased, 1867. P. 7575. Crushed remains of small head and abdominal region. The large teeth on the presymphysial bone are well displayed. History unknown. P. 967 a, b. Two fragmentary specimens of the head and abdominal region, the first showing the base of the pectoral fin and the rugose ornament of the scales, besides some tuber- culated head-bones. Egerton Coll. 46345—a. Small head, in counterpart, lateral aspect, showing the jaws but wanting the dentary bone; also a detached rostrum. Cunnington Coll. P. 5147, P. 967c. Imperfect remains of a small head, and a detached rostrum. Egerton Coll. P. 4281-2. Portions of head in side view, showing the associated rostrum, presymphysial bone, operculum, and suboper- culum, and detached splenial bones. Enniskillen Coll. re 2904244. Fine large cranium broken across the middle, the cranial i ‘i roof exposed from above and the rostrum from below ae , (Pl. XVII. fig. 7); an equally large cranium, imperfect i | behind, displayed from the infero-lateral aspect; and a nia detached rostrum with premaxillary dentition. In the | first specimen, as shown in the figure, the cranial roof is ornamented with tubercles and longitudinal ruge, and is ha produced backwards at its postero-lateral angles; the Ht frontals ( fr.) are evidently large compared with the parietals (pa.), though the intervening suture is not very clear; and the parasphenoid (pas.) is crushed outwards on the right side. At the base of the rostrum a Y-shaped | ahi eminence (v.) on its inferior face seems to represent a } Ht pair of toothless vomers united in front; and the groove ei between the long dentigerous premaxille (pma.) is con- ! tinued forwards along the lower face of the rostral prolon- | wl gation. The prefrontals (pf.) seem to have been well a ossified. Purchased, 1854. ~ ASPIDORHYNCHIDZ. 425 37319. Rostrum in side view, well displaying the premaxillary dentition. Purchased, 1863. 21430-a. Two small rostra. Purchased, 1847. 46350. Two ectopterygoid bones. Cunnington Coll. 21430 b. Another ectopterygoid. Purchased, 1847. 29045. Large maxilla and two fragments. Purchased, 1854. 29045 a. Maxilla, shown of the natural size in Pl. XVII. fig. 8. Purchased, 1854. 46349. Small maxilla. Cunninyton Coll. 40519, 41296, 42295, 46412. Six detached dentary bones, the largest shown of the natural size in Pl. XVII. fig. 9. Purchased, 1867, 1869, 1870, 1875. P. 967 d. Right dentary bone. Egerton Coll. 21430 c, 24676, 29047. Four splenial bones, one shown -of the natural size in Pl. XVII. fig. 10. Purchased, 1847, 1850, 1854. Aspidorhynchus sphekodes, Sauvage. 1893. Aspidorhynchus sphekodes, H. KE. Sauvage, Bull. Soc. Hist. Nat. Autun, vol. vi. p. 481, pl. vill. fig. 1. Type. Fish wanting paired fins. A much-elongated species attaining a length of about 0°3. Head with opercular apparatus occupying about one-quarter of the total length ; maximum depth of trunk contained considerably more than ten times in the total length. Rostrum slender, projecting in advance of the mandible for a length equalling about one-third that of the cranium; cranial roof-bones rugose and in part tuber- culated. Scales smooth. Form. & Loc. Lower Kimmeridgian: Orbagnoux, Ain, France. Not represented in the Collection. Aspidorhynchus fisheri, Egerton. 1854-55. Aspidorhynchus fishert, Sir P. Egerton, Ann. Mag. Nat. Hist. [2] vol. xii. p. 434, and Figs. & Descript. Brit. Organic Remains, dec. vili. (Mem. Geol. Surv.), no. 6, pl. vi. 1880. Aspidorhynchus fisheri, A. Giinther, Study of Fishes, p. 369, fig. 146. Type. Nearly complete fish ; Dorchester Museum. A species attaining a length of about 0°35-0°4. Head with HH i | | | i ; | 426 ACTINOPTERYGIU, opercular apparatus comprised nearly four-and-a-half times in the total length; maximum depth of trunk equalling about one-ninth of the total length of the fish. Cranium rapidly tapering to the acute rostrum, which is produced in advance of the mandible to equal one-third of the total length of the cranium; cranial bones and cheek-plates ornamented with fine granulations, which are fused into longitudinal ruge on the rostrum and sometimes on part of the cranial roof; mandible and opercular bones almost smooth; presymphysial bone very short, scarcely longer than deep; man- dibular teeth very robust. Pelvic fins situated far behind the middle point of the trunk. Scales smooth, except those of the dorsal region, which are marked with longitudinal ruge. The ‘“ single row of small close-set tubercles,” noted by Egerton on the ramus of the mandible, is an appearance due to the orifices of the sensory canal. Form. & Loc. Purbeckian : Dorsetshire. 28621. Head and abdominal region, lateral and partly superior aspect, with the base of the right pectoral fin; Swanage. In the mandible the presymphysial bone is well shown, and the head is figured in Giinther’s ‘ Introduction to the Study of Fishes,’ p. 369, fig. 146 (copied in Proc. Geol. Soc. 1884, p. 50, fig. 4). Purchased, 1853. P. 6380. Imperfect cranium and the greater portion of the trunk, much fractured; Swanage. The ornamentation of the dorsal scales is well shown, and there are slight traces of serrations on some of the deep flank-scales. Beckles Coll. Aspidorhynchus crassus, A. 8. Woodward. [Plate XVII. fig. 11.] 1844. Sauropsis mordax, L. Agassiz, Poiss. Foss. vol. 1. pt. 11. p. 122 (name only). 1871. Pholidophorus minor?, J. Phillips, Geol. Oxford, p. 180, woode. xl, figs. 5, 6. [Mandibular ramus ; Oxford Museum. |] (?) 1871. Belonostomus fleruous, J. Phillips, aid. fig. 3. [| Maxilla ?; Oxford Museum. | 1888. Aspidorhynchus sp., A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol. i. p. 355. 1890. Aspidorhynchus crassus, A. S. Woodward, Proc. Geol. Assoc. vol. xi. p. 296, pl. i. figs. 11-14. Type. Cranium; British Museum. A small species known only by cranium and jaws. Cranium low, gradually tapering to the acute rostrum, which is produced in advance of the mandible to equal one-third of the total length of ASPIDORHYNCHID®. 427 the cranium ; cranial bones ornamented with prominent ruge and granulations, mandible almost smooth ; principal mandibular teeth broad, of moderate size, and well spaced ; presymphysial bone about three times as long as its maximum depth. Form. & Loc. Bathonian; Oxfordshire. 39199, 39200. The type specimens, two skulls described and figured in Proc. Geol. Assoc. vol. xi. p. 295, pl. iii. figs. 11, 12; Stonesfield Slate, Stonesfield, near Oxford. Bowerbank Coll. P. 959. Two portions of cranial roof; Stonesfield. Egerton Coll. P. 3720 a. Right maxilla, figured loc. cit. pl. 11. fig. 13 ; Stonesfield. Enniskilien Coll. P. 877 b. Fragment probably of a maxilla of this species ; Stones- field. Egerton Coll. P. 3720b. Left dentary bone, figured loc. cit. pl. ii. fig. 14; Stonesfield. Enniskillen Coll. 41294. Left dentary ; Stonesfield. Purchased, 1869. P. 877 a, c, d. Three imperfect dentaries ; Stonesfield. Egerton Coll. P. 3720 c, d, e. Three imperfect dentaries; Stonesfield. Enniskillen Coll. P. 3720 g. Presymphysial bone with teeth, shown of the natural size in Pl. XVII. fig. 11. Enniskillen Coll. P. 3720 f. Imperfect left pterygoid arcade; Stonesfield. Enniskillen Coll. The following specimen is too imperfect for specific determina- tion :— P. 2058. Much-disturbed remains of a fish measuring about 0°36 from the pectoral arch to the base of the caudal fin; Lithographic Stone, Cirin, Ain, France. The trunk appears to be stouter than in A. acutirostris from Bavaria, and all the scales exhibited are smooth. Ring-vertebre are displayed, and the ribs shown in the abdominal region are both short and delicate. Of the anal fin 16 supports are preserved, while there is only evidence of 12 rays in the dorsal. Egerton Coll. Aspidorhynchus silesianus is an undefined name given by Hohe- negger to some fragments from the Aptian of Wernsdorf, Moravia, 428 ACTINOPTERYGII. in the Paleontological Museum, Munich (F'. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. 1882, p. 264; K. A. von Zittel, Handb. Paleont. vol. iii. 1887, p. 221). Aspidorhynchus walchnert is another undefined name applied to fragments of the skull of Belonorhynchus from the Upper Lias of Baden and Wirtemberg (L. Agassiz, Poiss. Foss. vol. i. pt. i. 1833, p. 14; F. A. Quenstedt, Flozgeb. Wiirttemb. 1843, p. 244 (ed. 2, 1851, p. 563), and Der Jura, 1858, p. 234). . An indeterminable portion of skull and anterior vertebrae from the Cretaceous of Pietraroja, Benevento, now in the Geological Museum of the University of Naples, bears the name of Aspido- rhynchus platycephalus (O. G. Costa, Atti Accad. Pontan. vol. viii. 1864, pp. 62, 193, pl. ix. fig. 8; discussed by F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. 1882, p. 231). The same specimen was previously described under the name of Dzchelo- spondylus longirostris by O. G. Costa, Ittiol. Foss. Ital. (1856), p18, pl. i fies. Genus BELONOSTOMUS, Agassiz. _Neues Jahrb. 1834, p. 388.] Syn. Ophirachis, O. G. Costa, Ittiol. Foss. Ital. 1856, p. 13. Snout very slender, scarcely, if at all, produced in front of the extremity of the much-elongated presymphysial bone; cheek- plates robust, the postorbitals extending to the anterior border of the preoperculum; the conical teeth irregular in size, largest on the hinder part of the premaxille and the median line of the pre- symphysial bone, obtuse on the splenial, and reduced to a fine granulation on the inner face of the ectopterygoid. Ossified vertebra usually pierced by a remnant of the notochord. Fin-rays distally bifurcating ; fulcra wanting on paired fins, rare on median fins. Pelvic fins situated near the middle of the trunk; dorsal and anal fins short-based, triangular, remote and opposed; caudal fin sym- metrically forked. Scales robust, smooth or rugose; in three deepened series on the flank of the abdominal region, and the series traversed by the lateral line the deepest; dorsal scales between the flank-scales and the median ridge in two series. Belonostomus sphyrznoides, Agassiz. 1837. Belanostomus sphyrenoides, L. Agassiz, Bericht. Versamml. deutsch. Naturf., Jena, 1836, p. 127 (name only). 1837. Belanostomus brachysomus, L. Agassiz, ibid. p. 127 (name only). ASPIDORHYNCHID 2. 429 (?) 1842. Belonostomus angustus,G. von Munster, Neues Jahrb. p. 45 (imperfectly defined). [Fish, wanting jaws; Paleontological Museum, Munich. | 1844, Belonostomus sphyrenoides, L. Agassiz, Poiss. Foss. vol. ii. pt. il. pp. 140, 297, pl. xlvii. a. fig. 5. 1844. Belonostomus brachysomus, L. Agassiz, 2rd. pt. i. pp. 148, 297. 1863. Belonostomus sphyrenoides, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 690. Type. Nearly complete fish; Paleontological Museum, Munich, and Woodwardian Museum, Cambridge. The type species, attaining a length of about 0°3. Head with opercular apparatus occupying about one-third of the total length ; maximum depth of trunk contained twelve times in the total length. Cranium about five times as long as its maximum depth; jaws equal in length. Vertebre in the form of robust constricted rings, scarcely longer than deep. Space between the origin of the pelvic fins and that of the anal fin less than the space between the latter and the caudal. Scales smooth or very feebly tuberculated ; those of the lateral line not much exceeding in depth the series below. Form. & Loc. Lower Kimmeridgian: Bavaria. 49129. Plaster cast of type specimen ; Lithographic Stone, Eich- stadt. ts Purchased, 1878. 37800. Large imperfectly preserved fish about 0°285 in length, contorted, of the variety named B. brachysomus by Agassiz; Solenhofen. Hldberlein Coll. P. 3800. Trunk nearly complete from the pelvic fin backwards, but disturbed in front, probably of this species; Kelheim. Enniskillen Coll. P. 7576. Extremity of tail with caudal fin, probably of this species ; Kelheim. Egerton Coll. Belonostomus muensteri, Agassiz. 1834. Aspidorhynchus miinsteri, L. Agassiz, Verhandl. Ges. vaterland. Mus. Bohmen, p. 70 (name only). 1857. Belanostomus miinsteri, L. Agassiz, Bericht. Versamml. deutsch. Naturf., Jena, 1836, p. 127 (name only). 1844. Belonostomus miinstert, LL. Agassiz, Poiss. Foss. vol. ii. pt. ii. pp. 141, 297, pl. xlvii. a. fig. 2. 1848. Belonostomus muenstert, C. G. Giebel, Fauna der Vorwelt, Fische, p. 155. 1861. Belonostomus miinsteri, T. C. Winkler, Descript. Poiss. Foss. Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. xiv.), p. 34, fig. 5. 430 ACTINOPTERYGII. 1863. Belonostomus miinstert, A. Wagner, Abh. k. bay. Akad. Wi, math.-phys. Cl. vol. ix. p. 689. 1863. Belonostomus speciosus, A. Wagner, zbid. p. 689. {| Imperfect fish. Paleontological Museum, Munich. | 1887. Belonostomus spectosus, O. Reis, Sitzungsb. k, bay. Akad. Waa 5 math.-phys. Cl. vol. xvii. p. 159, pl. i. fig. 4. Type. Head and anterior part of trunk ; British Museum. A species of moderate size attaining a length of about 0-4. Head with opercular apparatus occupying about one-quarter of the total length ; maximum depth of trunk contained fifteen times in the total length. Cranium about five times as long as its maximum depth ; jaws equal in length, the pointed anterior extremity of the dentary bones suturally united with a deep re-entering angle in the presymphysial bone; external ornament very finely rugose. Ver- tebre in the form of robust constricted rings, longer than deep. Space between the origin of the pelvic fins and that of the anal fin about equal to the space between the latter and the caudal. Scales finely tuberculated, partly rugose; those of the lateral line not much exceeding in depth the series below. Form. & Loc. Lower Kimmeridgian: Bavaria, and (?) Ain, France, P. 505, P. 3801. The type specimen described and figured by Agassiz, in counterpart; Lithographic Stone, Solenhofen. The suture at the proximal end of the presymphysial bone is well shown. Egerton & Enniskillen Colls. 37798. Large specimen in counterpart, wanting the dorsal, anal, and pelvic fins, and part of the caudal fin, with much- disturbed squamation ; Solenhofen. Haberlem Coll. 37796, 37799, 37801. Three large specimens, variously imperfect, showing several of the principal characters of the species ; Solenhofen. Haberlein Coll. P. 3802. A similar specimen, contorted, wanting all the fins except the basal half of the caudal; Solenhofen. Enniskillen Coll. 37797. Imperfect vertebral column, with remains of the head and scattered scales ; Solenhofen. Thesuture between the pre- symphysial and dentary bones is shown ; and in the caudal region the short neural and hemal arches and spines are preserved. Haberlen Coll. P, 4690. Head wanting rostrum, with trunk wanting caudal region, of the form ascribed to this species by Thiolliere, Poiss. Foss. Bugey, pt. 11. (1873), p. 24; Cirin, Ain, France. Purchased, 1884. fh 4 : D. ASPIDORHYNCHID &. 431 Belonostomus kochi, Agassiz. 1834. Aspidorhynchus lepturus, L. Agassiz, Verhandl. Ges. vaterland. Mus. Bohmen, p. 70 (name only). 1844, Aspidorhynchus lepturus, L. Agassiz, Poiss. Foss. vol. ii. pt. il. p. 189 (undefined). 1844. Belonostomus kochit, lL. Agassiz, ibid. p. 148. 1863. Belonostomus kochii, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 689. Type. Nearly complete fish ; Paleontological Museum, Munich. A species closely related to B. muensterz, but less elongated and of more delicate proportions ; head with opercular apparatus occupying one-quarter of the total length. Jaws equal in length. An immature example apparently of this species in the Palewon- tological Museum, Munich, is labelled B. longimanus by Minster. Form. & Loc. Lower Kimmeridgian: Bavaria. 49136. Plaster cast of type specimen 0°275 in length ; Lithographic Stone, Kelheim. Purchased, 1878. Belonostomus tenuirostris, Agassiz. = (elate XV ED fis. 12, | 1833. Aspidorhynchus tenuirostris, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 14. 1834. Belonostomus tenuirostris, L. Agassiz, Neues Jahrb. p. 388. 1837. Belanostomus tenuirostris, L.Agassiz, Bericht. Versamml. deutsch. Naturf., Jena, 1836, p. 127. 1837. Belanostomus tabulatus, L. Agassiz, zbid. p. 127 (name only). 1844. Belonostomus tenwirostris, L. Agassiz, Poiss. Foss. vol. 11. pt. i. pp. 148, 297. 1844. Belonostomus subulatus, L. Agassiz, 2bid. pp. 148, 297. [ Imper- fect anterior half of fish ; Paleontological Museum, Munich. } 1863. Belonostomus tenuirostris, A. Wagner, Abh. k. bay. Akad. Wiss., math.-phys. Cl. vol. ix. p. 691. 1863. Belonostomus tenutrostris, var. brevivertebralis, A. Wagner, wid. p- 691. 1881. Belonostomus tenuirostris, B. Vetter, Mittheil. k. mineral.-geol. Mus. Dresden, pt. iv. p. 85. Type. Head, &.; unknown. A species of very slender proportions attaining a length of about 0-3. Head with opercular apparatus occupying one-third of the tota] length; maximum depth of trunk contained fourteen times in the total length, Cranium about nine times as long as its maximum depth, having the snout excessively elongated, and projecting to 432 ACTINOPTERYGII. some extent in advance of the anterior extremity of the mandible ; the pointed front end of the dentary bones suturally united with a deep re-entering angle in the presymphysial bone; superficial ornament consisting of delicate ruge. Vertebre in the form of separated narrow rings, much deeper than broad. Scales smooth or feebly tuberculated and rugose; those of the lateral line not much exceeding in depth the series below. The vertebral rings in this species evidently differ from those of the preceding species merely in the circumstance that they repre- sent a lower stage of calcification than the elongated constricted rings already described. This is indicated by the considerable width of the spaces between the successive rings. Form. & Loc. Lower Kimmeridgian: Bavaria, and (?) Ain, France. 35014. Head and greater part of the trunk with paired fins, the head shown of the natural size in Pl. XVII. fig. 12; Lithographic Stone, Solenhofen, The specimen is ex- hibited in side view, displaying the shortness of the mandible, the suture separating the presymphysial bone (ps.) from the dentary (d.), and the proportions of the opercular apparatus, The fins are fragmentary, and the scales are mostly shown in obscure impressions. Purchased, 1860, 36029. Contorted fish showing the principal specific characters, including the incomplete calcification of the notochordal sheath in the form of deep and narrow separated rings ; Solenhofen. Purchased, 1861, P. 962. Imperfect specimen showing the head and greater part of the trunk with pectoral fins chiefly in impression ; Solen- hofen. Ligerton Coll. P, 962 a. Detached skull and mandible, much crushed, showing the superficial rugose ornament, some of the teeth in the lower jaw, and the suture between the dentary and pre- symphysial bone; Solenhofen, Egerton Coll. P. 2001. Two imperfect specimens chiefly in impression, probably of this species; Cirin, Ain, France. The dorsal ridge- scales in one specimen are coarsely rugose. Lgerton Coll. The following imperfect specimen appears to exhibit a snout as much attenuated as that of Belonostomus tenuirostris, but the fish is of larger dimensions than usual in this species and the squamation has more nearly the aspect of that of B. muensterr. The specimen ee ASPIDORHYNCHIDZ. 433 is labelled Belonostomus ventralis, apparently in Agassiz’ hand- writing; but this species has not been adequately defined (L. Agassiz, Bericht. Versamml, deutsch. Naturf., Jena, 1836, p. 127, and Poiss. Foss. vol. 1. pt. 11. 1844, pp. 1438, 297), and the type specimen is said by A. Wagner to be specifically inde- terminable (Abh. k. bay. Akad, Wiss., math.-phys. Cl, vol. ix. 1863, p- 692) :— P. 7577. Remains of head and greater portion of trunk of a fish in counterpart, noticed and figured as Serpens marimus in J. J. Baier’s ‘Monumenta rerum petrificatarum ’ (Nurem- burg, 1757), p. 10, pl. vi. fig. 4; Lithographic Stone, Solenhofen, Bavaria. Though not satisfactorily shown, it seems probable that the much-attenuated rostrum projected in advance of the mandible, in which the pre- symphysial bone is distinctly separated from the dentary by suture. The scales are comparatively robust, and some exhibit a tuberculated or rugose ornament. History unknown. Belonostomus dorsetensis, sp. nov. [Plate XIV. fig. 2.] Type. Imperiect skull and mandible; British Museum. A species of moderate size known only by the head, which attains a length of about 0°115. Rostrum much attenuated and projecting for some distance in advance of the anterior extremity of the mandible; the blunt anterior extremity of the dentary bones suturally united with a slight excavation in the presymphysial bone, and the median series of widely-spaced teeth on this bone relatively large ; ornament of cranium consisting of fine ruge of ganoine, that of the mandible only of structural ruge. Form. & Loc. Kimmeridge Clay: Dersetshire. P. 6175. The type specimen shown of the natural size in Pl. XIV. fig. 2, comprising the vertically crushed cranium imper- fect behind, the left ectopterygoid (ecpt.) and imperfect dentary (d.), and the presymphysial bone (ps.); Kimme- ridge Clay, Weymouth. The rostrum is shown to extend considerably in advance of the dentigerous premaxille and exhibits a longitudinal groove on its inferior aspect; the presymphysial bone is dentigerous throughout its length. The ectopterygoid is granulated on its inner face and bears a single row of closely arranged, elongated conical PART III. 25 434 ACTINOPTERYGII. teeth on its outer margin; the dentary has an irregular series of large conical teeth in its hinder two-thirds, very small closely-set teeth in front. Purchased, 1890. P. 6175 a. Laterally compressed rostrum and presymphysial bone, probably associated ; Weymouth. Purchased, 1890. 41180, 41229, 41401, 42368, 43566, 44190. Twelve fragments of cranium, variously crushed ; Weymouth. Purchased, 1868-73. 43564. Complete presymphysial bone 0-04 in length, and four times as long as its maximum depth; Weymouth. Purchased, 1872. 41229 a, 41401 a, 41879, 42365, 43027, 43565, 44189, P. 6175 b. About twenty specimens of the presymphysial bone, more or less imperfect and of various sizes; Weymouth. Purchased, 1868, 1869, to 1890. Belonostomus crassirostris, Costa. 1858. Belonostomus crassirostris, O. G. Costa, Atti Accad. Pontan. vol. vii. p. 29, pl. ii. figs. 1, 2. 1855. Belonostomus gracilis, O. G. Costa, zbzd. p. 31, pl. i. fig. 3. [Portion of rostrum; Geological Museum, University of Naples. ] Type. Fish wanting pelvic fins; Geological Museum, University of Naples. A species attaining a length of 0:6, with relatively small head occupying about one-sixth of the total length. Scales smooth, and those of the lateral line much exceeding in depth the series below. Form. & Loc. Cretaceous: Pietraroja, Province of Benevento, Italy. Not represented in the Collection. Belonostomus lesinaensis, Bassani. (?) 1867. Hemirhynchus heckeli, R. Kner, Sitzungsbh. k, Akad. Wiss., math.-naturw. Cl. vol. lvi. pt. i. p. 182. [Head; Museum of Imperial Geological Survey, Vienna. | (?) 1867. Hemirhynchus comenianus, R. Kner, ibid. p. 182. [Head; Museum of Imperial Geological Survey, Vienna. | 1879. Belonostomus crasstrostris, F. Bassani (errore), Verhandl. k.-k. geol. Reichsanst. p. 166. 1882. Belonostomus lesinaensis, F. Bassani, Denkschr. k. Akad. Wiss., math.-naturw. Cl. vol. xlv. p. 198, pl. i. fig. 10. Type. Nearly complete fish; Museum of Imperial Geological Survey, Vienna. ASPIDORHYNCHIDZ. 435 A slender species attaining a length of at least 0-3. Head with opercular apparatus contained about three-and-a-half times, and maximum depth of trunk fifteen times in the total length; jaws nearly equal in length. Anterior scales of lateral line about twice as deep as broad. Form. & Loc. Cretaceous: Island of Lesina, Dalmatia; (?) also Comen, Istria. Not represented in the Collection. Belonostomus comptoni (Agassiz). 1841. Aspidorhynchus comptoni, L. Agassiz, Edinb. New Phil. Journ. vol. xxx. p. 83. 1844. Aspidorhynchus comptont, L. Agassiz, Comptes Rendus, vol. xviii. p. 1009. 1890. Belonostomus comptoni, A. S. Woodward, Proc. Zool. Soc. p. 629, pls. liv., lv. figs. 1-10. Type. Distorted fish, imperfect anteriorly and posteriorly ; British Museum. A large species attaining a length of about 0°8. Head with opercular apparatus occupying somewhat less than one-third of the total length; maximum depth of trunk contained about ten times in the total length. Snout rapidly tapering to a very slender rostrum; external ornament of head and opercular apparatus consisting of thick, closely-arranged, rounded ruge of ganoine; [jaws unknown]. Vertebree well-ossified, smooth and constricted, about as long as deep, and pierced by a small thread of persistent notochord. Scales ornamented with a conspicuous, fine rugosity, and a vertical ridge on each of the scales in the two deepened series of the flank; the scales of the iateral line truncated inferiorly and much exceeding in depth the series below, those on the anterior portion of the abdominal region being at least five times as deep as broad. Form. & Loc. Upper Cretaceous: Province of Ceara, Brazil. 47892. Hinder portion of head and greater portion of trunk described and figured in Proc. Zool. Soc. 1890, p. 629, pl. liv.; Barra do Jardim, Serra de Araripe, North Brazil. This may be regarded as the type specimen, the few fragments noticed by Agassiz being too imperfectly described and now lost. Presented by the Hon. Robert Marsham, 1877. 15495 e, a. T'wo specimens showing the upper aspect of the cranium and remains of the anterior portion of the trunk ; 22 436 ACTINOPTERYGII. Barra do Jardim. An upper view of the rostrum of the first specimen is given Joc. cit. pl. ly. fig. 1, and a transverse section of the rostrum in the second specimen is shown, with the upper part of the operculum, pei NW ; GCA iW hl dled all le ALN R aes SS cae yt FE = a mM S) a ia = 449 ACTINOPTERYGII. between the pectorals and the anal; dorsal and anal fins short- based, remote and more or less completely opposed; caudal fin rounded. Scales robust, the majority with produced anterior angles, and those of the flank not deeper than broad. Lepidosteus (Clastes) fimbriatus, Wood. 1846. Lepidosteus fimbriatus, 8. V. Wood, Lond. Geol. Journal, pp. 6, 122, pl. ii. fig. 9. Type. Fragment of mandible and operculum ; British Museum. An imperfectly definable small species, known only by fragments. External bones ornamented with elongated tubercles of ganoine, usually arranged in more or less radiating series. Operculum slightly deeper than broad, its conspicuous ornament radiating from the antero-superior angle. Scales all smooth, none serrated or fimbriated, except a few narrow scales apparently from the anal region or from the base of the pelvic fins. The typical operculum measures 0°016 in maximum depth and 0-015 in maximum breadth. Form. & Loc. Upper Eocene : Hampshire. 25252*, 25254*. Right operculum and fragment of dentary, the type specimens figured loc. cit.; Hordwell Cliff. The fragment of jaw exhibits the bases of the large teeth in spaced series, with minute teeth on the outer side though none within. Presented by Searles V. Wood, Esq., 1850. P. 1529 a. Three opercula, one being incomplete, and one sub- operculum ; Hordwell. Egerton Ooll. P. 1700 a. Associated remains in block of sand, including operculum and portions of jaws ; Hordwell. Egerton Coll. as) . 1529 b. Numerous head-bones chiefly of this species, but some comparatively large and coarsely marked ; Hordwell. Egerton Coll. P. 1529 c. Vertebree; Hordwell.’ Egerton Coll. 30295. Vertebre and scales; Hordwell. Hastings Coll. 48041 a. Vertebre ; Hordwell. John Brown Coll. P. 1529 d. One complete and two imperfect clavicles exhibiting fine interrupted ridges of ganoine on the outer face; Hordwell. Egerton Coll. LEPIDOSTEID &. 443 P. 1700 b. Groups of scales in matrix ; Hordwell. Egerton Coll. P. 1529 e. Four fimbriated scales, two being in association with the typical smooth scales ; Hordwell. Egerton Coll. P. 1529. Various scales and other remains; Hordwell. Egerton Coll. Lepidosteus (Clastes) cuneatus, Cope. 1878. Clastes cuneatus, E. D. Cope, Proc. Amer. Phil. Soc. vol. xvii. p. 9 (name only). 1884. Clastes cuneatus, H. D. Cope, Vert. Tertiary Form. West, Book I. (Rep. U.S. Geol. Surv. Territ. vol. iii.), p. 55, pl. i. fig. 6. Type. Nearly complete fish; Museum of Salt Lake City. A small species about 0°3 in length, of rather stout proportions. External bones ornamented with radiating lines of tubercles of ganoine, fused into nearly continuous ridges on the operculum and suboperculum. (Pelvic fins with long and slender fulcra, arising nearer to the base of the caudal fin than to the end of the snout, which is not much elongated. Scales all smooth, in 18 or 19 longitudinal series. Form. § Loc. Miocene (Manti Shales); Central Utah, U.S.A. Not represented in the Collection. The following fragmentary specimens are not specifically deter- minable :— . 28540 a. Three fragments of jaws, a rugose operculum 0-032 in depth, and two other external bones; Bracklesham Beds, Bracklesham Bay, Sussex. The dentary is destitute of minute teeth on its inner border. Dixon Colt. P. 5442. Large vertebral centrum; Bracklesham Beds. Presented by P. EH. Coombe, Esq., 1888. P. 6476. More depressed vertebra; probably Bracklesham. Beckles Coll. P. 2268. Tooth; Bracklesham Beds. Egerton Coll. P. 1532 a. Left operculum ; Lower Tertiary, Isle of Wight. Ligerton Coll. 37201. Scales ; Lower Eocene, Dulwich, London. Presented by R. W. Wolston, Esq., 1863. EB ARC See ere age, ee Sen 444 ACTINOPTERYGII. P. 5504. Scales; Dulwich. Caleb Evans Ooll. 29017. Scales ; Lower Eocene, Kyson, Suffolk. Presented by Rev. J. Middleton, 1854. Numerous fragmentary remains of Lepidosteide, all too imperfect for specific, and the majority even for generic determination, have also been described under the following provisional names :— Lepidosteus atrow, J. Leidy, Proc. Acad. Nat. Sci. Philad. 1873, p. 97, and Contrib, Extinct Vert. Fauna W. Territ. (Rep. U.S. Geol. Surv. Territ: vol. 1. 1873), p. £39) pleat figs. 14, 15. Clastes atrox, EK. D. Cope, Ann. Rep, U.S. Geol. Surv. Territ. 1872 (1873), p. 634, and Vert. Tertiary Form. West, Book I. (Rep. U.S. Geol. Surv. Territ. vol. 1. 1884), p. 54, pl. i. figs. 1-24.—Kocene (Bridger Series); Wyoming. [ Vertebra. | Lepidosteus glaber, O. C. Marsh, Proc. Acad. Nat. Sci. Philad. 1871, p. 105. Clastes glaber, E. D. Cope, loc. cit. 1872 (1873), p. 634.—Kocene ; Wyoming. [Scales and vertebre ; Yale College Museum. | Lepidosteus maaimiliani, P. Gervais, Zool. et Pal. Frang. ed. 2 (1859), p. 530; G. Vasseur, Bull. Soc. Géol. France, [3] vol. iv. (1876), p. 301, pl. vi. figs. 1-21. Lepidotus maximiliant, L. Agassiz, Poiss. Foss. vol. ii. pt. 1. 1839- 44), pp. 9, 268, pl. xxixe. figs. 8-11; P. Gervais, Zool. et Pal. Frang. (1848-52), Poiss. Foss., Expl. Pl. p. 2, pl. lxvii. figs. 9-13.—Middle Eocene (Calcaire Grossier) ; Paris. [Scales. | Lepidosteus notabilis, J. Leidy, loc. cit. 1873, p. 98, and op. cit. (1873), p. 192, pl. xxx. figs. 12, 13.—Hocene (Bridger Series); Wyoming. { Vertebra. | Lepidosteus simplex, J. Leidy, loc. cit. 1873, p. 98, and op. cit. (1873), p. 191, pl. xxxii. figs. 18, 26, 31-43.—Hocene (Bridger Series); Wyoming. [ Vertebre, scales, &c. | Lepidosteus strausi, F. Kinkelin, Ber. Senckenb. nat. Ges. (1884), p. 244, pl.in. fig. 1; A. Andreae, Verhandl. Nat. Ver. Heidelberg, n. s. vol. v. (1893), p. 7, and Abhandl. Senckenb. nat. Ges. vol. xvii. (1894), p. 355, pl. 1. figs. 1—7.—Lower Miocene; Messel, Darmstadt. [Squamation ; Senckenberg Museum. | Lepidosteus (?) suessionensis, P. Gervais, Zool. et Pal. Frang. (1848-52), Rept. &c., Explic. Pl. p. 4, pl. lviil. figs. 3-5, LEPIDOSTEID 2. 445 and Comptes Rendus, vol. Ixxix. (1874), p. 846; L. Dollo, Bull. Sci. France et Belg. vol. xxv. (1893), p. 193.—Lower Eocene; France. [Portions of jaws ; Paris Museum of Natural History. | Lepidosteus whitneyi, O. C. Marsh, Proc. Acad. Nat. Sci. Philad. 1871, p. 105.—Eocene ; Wyoming. [Vertebre; Yale College Museum. | Lepidosteus sp., R. Owen, in J. Prestwich, Quart. Journ. Geol. Soc. vol. x. (1854), p. 156, pl. iti. fig. 1—Lower Eocene (Woolwich and Reading Beds); Upnor, Kent. [ Vertebra. | Lepidosteus sp.: Lepidotus francotte, A. Daimeries, Ann. Soc. Malacol. Belg. [2] vol. vii. (1893), Bull. p. xv.—Middle Kocene (Bruxellian) ; near Brussels. [Scales. | Clastes anax, HK. D. Cope, Ann. Rep. U.S. Geol. Surv. Territ. 1872 (1873), p. 633, and Vert. Tertiary Form. West, Book I. (Rep. U.S. Geol. Surv. Territ. vol. i. 1884), p- 03, pl. i. figs. 50-52.—Hocene (Bridger Series) ; Wyoming. [Cranial bones. | Olastes cycliferus, E. D. Cope, loc. cit. 1872 (1873), p. 6384, and op. cit. (1884), p. 54, pl. u. figs. 25-45.—Hocene ; Wyoming. [The type species of Olastes, founded on cranial bones and scales '. | Pneumatosieus nahunticus, E. D. Cope, Proc. Amer. Phil. Soc. vol. xi. (1869), p. 242, and in W. C. Kerr, Rep. Geol. Surv. N. Carolina, vol. i. (1875), Append. p. 31.—Miocene; North Carolina. [The type species of Pneumatosteus, founded on a vertebra; Cope Coll. ] Naisia apicals, G. von Minster, Beitr. Petrefakt. pt. vii. (1846), p. 34, pl. 11. fig. 23; W. Dames, Zeitschr. deutsch. geol. Ges. vol. xxxv. (1883), p. 669.—Upper Eocene; Oster- weddingen, Magdeburg. [The type species of Naisia, founded on a tooth. | Trichiurides sagittidens, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. (1876), p. 31, pl. ii. figs. 22,28; W. Dames, Zeitschr. deutsch. geol. Ges. vol. xxxv. (1883), p. 669.—Middle Eocene (Bruxellian); near Brussels. [The type species of Trichiurides, founded on a tooth. | * The generic characters of ‘“‘ Clastes” are stated by Cope as follows :— “Mandibular ramus without or with reduced fissure of the dental foramen, and without the groove continuous with it in Lepidostews. One series of large teeth, with small ones exterior to them in the dentary bone, the inner superior aspect of that bone without prominent dentiferous or rugose rib.” 446 ACTINOPTERYGII. Suborder IV. ISOSPONDYLI. i Notochord varying in persistence, the vertebral centra usually complete, but none coalesced ; tail homocercal, but hemal supports not much expanded or fused. Symplectic bone present; mandible simple, each ramus consisting only of two elements (dentary and articulo-angular), with rare rudiments of a splenial on the inner side. Pectoral arch suspended from the cranium ; a precoracoid arch present, infraclavicular plates wanting; pectoral fin with not more than four or five basals. Pelvic fins abdominal. Scales ganoid only in the less specialized families. In the living forms—air- bladder connected with the cesophagus in the adult, optic nerves — decussating, and intestine either wanting spiral valve or with an incomplete representative of it. Synopsis of Familes (contained in Part IL1.). I. Margin of upper jaw formed by maxilla and premaxilla; parietal bones in contact mesially. Vertebral centra not more than rings; no fused or expanded hypurals; no inter- muscular bones ; fins fringed with fulcra; scales rhombicand ganoid ............ PHOLIDOPHORID Vertebral centra complete or with minute ~ (p. 446). perforation; no fused or expanded hy- purals; intermuscular bones rare or with absent ; fins fringed with fulcra; scales Cy CloiWal > 5, 8) yu jeeneee ee caew aac te Yd OLIGOPLEURIDZ Vertebral centra nearly complete, but with | (p. 490). perforation ; no fused or expanded hyp- urals; intermuscular bones well-devel- oped; no fulcra on fins; scales cycloidal, but ganoid = Vege eee eee LEPTOLEPIDZ (p. 500). (To be continued in Part IV.) Family PHOLIDOPHORIDA. Trunk elegantly fusiform. Head with delicate membrane-bones, the suborbital and circumorbital plates completely covering the cheek, all enamelled ; snout not produced ; mandibular suspensorium nearly vertical or inclined forwards, and gape of mouth wide; -premaxilla very small; maxilla large, loosely attached and with two well-developed supramaxillary plates; teeth small and conical. Opercular apparatus complete. Vertebral centra never advanced PHOLIDOPHORID®. 447 beyond the annular stage; ribs delicate; no fused or expanded heemal arches at the base of the tail. Intermuscular bones absent. Fin-fulera present, but usually small; dorsal and anal fins small, the former above or behind the pelvic fins. Scales ganoid, more or less rhombic, but deeply overlapping, and the hinder margin often somewhat rounded. Synopsis of Genera. I. Flank-scales united by peg-and-socket, not excessively deepened. | _ Pectoral and pelvic fins small; dorsal in achvance ofanalie jel ts ih Set ee, Pholidophorus (p. 447). Pectoral fins greatly enlarged, and pelvic fins small; dorsal opposed to anal ........ Thoracopterus (p. 478). Il. Flank-scales united by peg-and-socket, one series excessively deepened. Pelvic fins absent; dorsal opposed to anal ; ventral scales broader than deep; lateral line along deepened scales ............ Pholhdopleurus (p. 479). ~~ Pelvic fins small; dorsal in advance of anal ; ventral scales as broad as deep; lateral : line along deepened scales ............ Peltopleurus (p. 481). Pelvic fins smali; dorsal opposed to anal; ventral scales about as broad as deep; lateral line deflected to upper series of emit MSCAlOsie sy ase. She als ceete aside os Pleuropholis (p. 482). II. Flank-scales not united by peg-and-socket, not excessively deepened. q Pectoral and pelvic fins of moderate size; P: dorsal and anal opposed; scales thin .. Archeomene (p. 488). 4 IV. Flank-scales unknown. Fins with long slender fulcra, and dorsal in advance of anal; large caudal ridge- SCOUCS yes. Uae tied oes aa we anaes « Ceramurus (p. 489). Genus PHOLIDOPHORUS, Agassiz. [Neues Jahrb. 1832, p. 145. ] Syn. (?) Microps, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 1888, p. 10.« Geren gu Trunk not much deepened, and head relatively large. External | bones smooth or delicately ornamented with ruge and tubercula- . _ tions; sensory canal on suborbital and preorbital plates branched ; maxilla more or less arched, the oral margin convex and provided with minute teeth; mandibular teeth larger, but still minute and arranged in a single series. Preoperculum broad mesially and marked with slight radiating furrows; suboperculum large, but a e a ay A. oN mae ata: © eae eling is $ 21h, Oe ihe Te ee ASS tes MY Te 4 f : ; Fea ey tise 448 ACTINOPTERYGII. smaller than the trapezoidal operculum, from which it is divided by an oblique suture; branchiostegal rays numerous. Pleurocentra and hypocentra in notochordal sheath fused or separate. Fin-fulera small, extending along the foremost ray of each of the fins. Pectoral not excessively large, but much exceeding the pelvic fins in size; dorsal and anal fins triangular in shape, not extended, the former opposite or arising somewhat behind the pelvic fins; caudal fin deeply forked. Scales thin, deeply overlapping, usually with an inner rib and peg-and-socket articulation, and the external layer of ganoine smooth or feebly ornamented; principal flank-scales deeper than broad, ventral scales in part broader than deep ; no enlarged series of ridge-scales, but a large scale at the base of one or both lobes of the caudal fin, and three slightly enlarged scales round the anus at the base of the anal fin. Lateral line opening by widely separated large pores. Little can be added to the osteological characters of this fish noted in the generic diagnosis. In the axial skeleton of the trunk the pleurocentra and hypocentra are delicate, always directly Fig. 44. Head, ete., of Pholidophorus macrocephalus, left lateral aspect (after Zittel). cl., clavicle; fr., frontal ; é.op., interoperculum ; md., mandible; mx., maxilla ; na., nasal; op., operculum ; pa., parietal ; pmv., premaxilla; pop., pre- operculum ; psph., parasphenoid ; pt., supratemporal ; sc/., “ supraclayicle ” (? post-temporal) ; so., suborbital ; sop., suboperculum. opposed, not alternating ; but it is difficult to determine whether or not they usually fuse into complete rings. In the abdominal region, the two halves of each neural arch appear to be separate from each other and from the spine they support; while the ribs are delicate and extend only about half-way to the ventral border. The remote situation of the anus is indicated not merely by the enlarged median and paired scales surrounding it, but also by coprolitic matter in PHOLIDOPHORIDA. 449 some specimens. The right and left halves of the rays in the dorsal and anal fins are very loosely apposed, and their frequent displace- ment in the fossils renders it difficult to count them. The characters of Pholidophorus are remarkably constant through- out the Jurassic period, but most of the later species are more elaborately ornamented than those of earlier date. Some of the distinctive features of the species described below are enumerated in the following synopsis :— I. Scales not serrated. Length of head slightly less than maximum depth of trunk and contained five times in total length ; dorsal opposite pelvic fins; scales large and smooth, scarcely convex border, four deepened SEWICG Se 2:57. sea etols ase Qeeler als lueee ett 6 bechei (p. 450). Stouter, with relatively larger scales .... pachysomus (p. 453). Smaller, differing in larger size of head which equals about one quarter of the Ova hemect ier ihra staal oes lakh ale 42 3) as latiusculus (p. 454). More slender; head occupying one-fifth ; dorsal arising behind pelvic fins ; scales thinner, with convex hinder 1S QCSTRING en Aen A Se stricklandt (p. 456). Somewhat stouter and head smaller; dorsal opposite pelvic fins; scales very thin, none much deeper than broad .. caudalis (p. 457). Head occupying one-fifth ; dorsal opposed to pelvic fins; scales coarsely but feebly rugose, and about six series BICC Gs ahora arora > weds dy Bell: Crustacea - sot, KE. J. Miers. Coleoptera - - - 4, C.O. Waterhouse. Lepidoptera - - ,, A. G. Butler. Aleyonaria and Suaeniie +9, Sa Oy. Badley. Lf, 20s: MAMMALS. _List of the Specimens of Mammalia in the Collection of the British Museum. By Dr. J. E. Gray, F.R.S. Pp. xxviii. 216. [With Systematic List of the Genera of Mammalia, Index of Donations, and Alphabetical Index.] 1843, 12mo. 2s. 6d. List of the Osteological Specimens in the Collection of the British Museum. By John Edward Gray. Pp. xxv., 147. 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Catalogue of the Fulicaria (Rallide and Heliornithide) and Alectorides* (Aramide, Eurypygida, Mesitidz, Rhinochetide, Gruide, Psophiide, and Otidide) in the Collection of the British Museum. By R- Bowdler Sharpe. Pp. xiii, 353: 9 coloured Plates. [With Syste-~ matic and Alphabetical Indexes.] 1894, 8vo. 20s. Hand-List of Genera and Species of Birds, distinguishing those oe in the British Museum. By G. R. Gray, F.R.S., &e.: Part II. Conirostres, Scansores, Columbe, and Galline. Pp. xv.,278. [Table of Genera and Subgenera: Part II. ] 1870, 8vo. 6s. Part III. Struthiones, Gralle, and Anseres, with "yates of Generic and Specific Names. Pp. xi. 350. [Table of Genera and Subgenera: Part III.] 187 L 8vo. 8s. List of the Specimens of Birds in the Collection of the British Museum. By George Robert Gray :— Part III., Section I. Ramphastide. Pp. 16. [With Index.] 18855, 12mo. 6d. Part III., Section II. Psittacide. Pp. 110. [With Index. ] 1859, 12mo. 2s. Part III., Sections III. and IV. Capitonide and Picide. Pp. 1387. . [With Index.] 1868, 12mo. ls. 6d. PartIV. Columbe. Pp. 73. [With Index.] 1856,12mo. Is. 9d. - Part V. Galline. Pp. iv., 120. [With an Alphabeticai Index.] 1867, 12mo. 1s. 6d. Catalogue of the Birds of the Tropical Islands of the Pacific Ocean in the Collection of the British Museum. By George Robert Gray, F.L.S., &c. Pp. 72. [With an Alphabetical Index.] 1859, 8vo. 1s. 6d. - 6 LIST OF PUBLICATIONS OF THE | REPTILES. Catalogue of the Tortoises, Crocodiles, and Amphisbzenians in the Collection of the British Museum. By Dr. J. EH. Gray, F.R.S., &ce. Pp. vii., 80. [With an Alphabetical Index. | 1844, 12mo. Is. Catalogue of Shield Reptiles in the Collection of the British Museum. By John Edward Gray, F.R.S., &c. :— Part I. Testudinata (Tortoises). Pp..79. 50 Plates. 1855, 4to. 21. i0s. | | Supplement. With Figures of the Skulls of 36 Genera. Pp. ix., 120. 40 Woodcuts. 1870, 4to. 10s. Appendix. Pp. 28. 1872, 4to, 2s. 6d. - Part II. Emydosaurians, Rhynchocephalia, and Amphis- beenians. Pp. vi., 41. 25 Woodcuts. 1872, 4to. 3s. 6d. Hand-List of the Specimens of Shield Reptiles in the British Museum. By Dr. J. E. Gray, F.R.S., F.L.8., &c. Pp. iv., 124. [With an Alphaketical Index.] 1873, 8vo. 4s. Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the British Museum (Natural History). New Edition. By George Albert Boulenger. Pp. x., 311. 73 Woodcuts and 6 Plates. [With Systematic and Alphabetical Indexes.|] 1889, Svo. lds. Gigantic Land Tortoises (living and extinct) in the Collection of the British Museum. By Albert C. L.G. Giinther, M.A., M.D., Ph.D., F.R.S. Pp. iv., 96. 55 Plates, and two Charts of the Aldabra group of Islands, north-west of Madagascar. [With a Systematic Synopsis of the Extinct and Living Gigantic Land Tortoises.] 1877, 4to. 14. 10s. 4 Catalozue of the Specimens of Lizards in he Callecaes of the British Museum. By Dr. J. E. Gray, F.R.S., &c., Pp. xxviii., 289. | With Geographic, Systematic, and Alphabetical Indexes. | 1845, 12mo. 3s. 6d. Catalozue of the Lizards in the British Museum (Natural His- tory). Second Edition. By George Albert Boulenger :— Vol.I. Geckonidx, Hublepnaride, Uroplatide, Pygopodide, Agamide. Pp. xii., 436. 32 Plates.. [With Systematic and Alphabetical Indexes.| 1885, 8vo. 20s. Vol. II. IRguanide, Xenosauride, Zonuride, Anguide, Anniellide, Helodermatide, Varanide, Xantusiide, Teiide, Amphisbenide. Pp: * xin., “497. 22 Plates. sa qvarm Systematic and Alphabetical if ndexes.| 1885, Svo. 20s. Vol. ILI. Lacertide, Gerrhosauride, Seincide, Anelytro- pide, Dibamide, Chameleontide. Pp. xil., 575. 40 Plates. [With a Systematic Index and an Alphabetiea! Index to the three volumes.] 1887, Svo. 12, 6s. BRITISH MUSEUM (NATURAL HISTORY). 7 Catalogue of the Snakes in the British Museum (Natural Histor y): By George Albert Boulenger, F.R.S. :— Vol. I, containing the families Typhlopide, Glauconiide, Boide, Ilysiidz, Uropeltide, Xenopeltidz, and Colubridz aglyphe, part. Pp. xiii, 445: 26 Woodcuts and 28 Plates. [With Systematic and Alphabetical Indexes. | 1893, 8vo. 12. 1s. Vol. II., containing the conclusion of the Colubride aglyphe. Pp. xi. . 382: 25 Woodcuts and 20 Plates. [With Systematic and Alphabetical Indexes.] 1894, 8vo. 17s. 6d. Catalogue of Colubrine Snakes in the Collection of the British Museum. By Dr. Albert Giinther. Pp. xvi, 281. [With Geographic, Systematic, and Alphabetical Indexes.] 1858, 12mo. 4s, BATRACHIANS. Catalogue of the Batrachia Salientia in the Collection of the British Museum. By Dr. Albert Giinther. Rp. xvi., 160., 12 Plates. [With Systematic, Geographic, and Alphabetical Indexes.| 1858, 8vo. 6s. Catalogue of the Batrachia Salientia, s. Ecaudata, in the Collection of the British Museum. Second Edition. _By George Albert Boulenger. Pp. xvi., 503. Woodcuts and 30 Plates. [With | Systematic and Alphabetical Indexes.| 1882, 8vo. 17. 10s. Catalogue of the Batrachia Gradientia, s. Caudata, and Batrachia Apoda in the Collection of the British Museum. Second Edition. By George Albert Boulenger. Pp. viii, 127. 9 Plates. [With Systematic and Alphabetical Indexes.] 1882, Svo. 9s. FISHES. - Catalogue of the Fishes in the Collection of the British deen. By Pr. Albert Giinther, F.R.S., &c. :— Vol. ITI. Acanthopterygii (Gobiider, Discoboli, Oxudercide, Batrachide, Pediculati, Blenniide, Acanthoclinide, Come- phoridz, Trachypteride, Lophotidas, Teuthidide, Acro- nuride, Hoplognathide, Malacanthide, Nandide, Polycen- tride, Labyrinthici, Luciocephalide, Atherinidz, M ugilida, Ophiocephalide, ‘Trichonotide, Cepolide, Gobiesocide, Psychrolutids, Centriscide, Fistularida, Mastacembe- lide, Notacanthi). Pp. xxv., 586. Woodcuts. [With Systematic and Alphabetical Tndexes, and a Systematic Synopsis of the families of the Acanthopterygian Fishes. ] 1861, Svo. 10s. 6d. ae / i Se LIST OF PUBLICATIONS OF THE Catalogue of Fishes, &c.—continued. Vol. IV. Acanthopterygii pharyngognathi and Annes. Pp. xxi, 534. [With Systematic and Alphabetical Indexes.] 1862, 8vo. 8s. 6d. Vol. V. Physostomi (Siluride, Characinide, Haplochitonide, Sternoptychide, Scopelide, Stomiatide). Pp. xxil., 455. Woodeurs. [| With Systematic and Alphebetiae Indexes. | 1864, 8vo. 8s. Vol. VII. Physostomi (Heterophygii, Cyprinide, Gono- rhynchide, Hyodontide, Osteoglosside, Clupeide, Chiro- centride, Alepocephalide, Notopteride, Halosauride). Pp. xx., 512. Woodcuts. [With Systematic and Alpha- betical Indexes.|] 1868, 8vo. 8s. : Vol. VIII. Physostomi (Gymnotide, Symbranchide, Mure- nide, Pegaside), Lophobranchii, Plectognathi, Dipnoi, Ganoidei, Chondropterygii, Cyclostomata, Leptocardii. Pp. xxv., 549. [With Systematic and “Ae Indexes.] 1870, 8vo. 8s. 6d. List of the Specimens of Fish in the Collection of the British Museum. Part]. Chondropterygii. By J.E. Gray. Pp. x., 160. 2 Plates. [With Systematic and Alphabetical Indexes. ] - 1851, 12mo. 3s. Catalogue of Fish collected and described by Laurence Theodore Gronow, now in the British Museum. Pp. vii., 196. [Witha Systematic Index.] 1854, 12mo. 3s. 6d. Catalogue of Lophobranchiate Fish in the Collection of the British Museum. By J.J. Kaup, Ph.D., &c. Pp. iv., 80. 4 Plates. [ With an Alphabetical Index.] 1856, 12mo. 2s. | MOLLUSCA. Guide to the Systematic Distribution of Mollusea in the British Museum. Part I. By John Edward Gray, Ph.D., F.R.S., &e. Pp. xii., 230. 121 Woodcuts. 1857, 8vo. 5s. List of the Shells of the Canaries in the Collection of the British - Museum, collected by MM. Webb and Berthelot. Described and figured by Prof. Alcide D’Orbigny in the “ Histoire Naturelle des Iles Canaries.” Pp. 32. 1854, 12mo. 1s. List of the Shells of Cuba in the Collection of the British Museum, collected by M. Ramon de la Sagra. Described by Prof. Alcide d’Orbigny in the “ eae de Ile de Cuba.” Pp. 48. 1854, 12mo. Is. List of the Shells of South America in the Collection of the British Museum. Collected and described by M. Alcide D’Orbigny n the “‘ Voyage dans Amérique Méridionale.” Pp. 89, 1854, 12mo. 2s. | BRITISH MUSEUM (NATURAL HISTORY). 9 Catalogue of the Collection of Mazatlan Shells in the British Museum, collected by Frederick Reigen. Described by Philip P. Carpenter. Pp. xvi. 552. 1857, 12mo. 8s. List of Mollusca and Shells in the Collection of the British Museum, collected and described by MM. Eydoux and Souleyet in the “ Voyage autour du Monde, exécuté pendant les années _“ 1836 et 1837, sur la Corvette ‘ La Bonite,” and ia the “ Histoire naturelle des Mollusques Ptéropodes.” Par MM. P. C. A. L. Rang et Souleyet. Pp. iv., 27. 1855, 12mo. 8d. Catalogue of the Phaneropneumona, or Parreabial Operculated Mollusca, in the Collection of the British Museum. By Dr. L. Pfeiffer. Pp. 324. [With an Alphabetical Index.] 1852, 12mo. 5s. Nomenclature of Molluscous Animals and Shells in the Collection of the British Museum. Part I. Cyclophoride. Pp. 69. [With an Index.| 1850, 12mo. Is. 6d. Catalogue of Pulmonata, or Air Breathing Mollusca, in the Col- lection of the British Museum. PartI. By Dr. Louis Pfeiffer. Pp. iv., 192. Woodcuts. 1855, 12mo. 2s. 6d. Catalogue of the Auriculide, Proserpinide, and Truncatellide in the Collection of the British Museum. By Dr. Louis Pfeiffer. Pp. iv., 150. Woodcuts. 1857, 12mo. 1s. 9d. List of the Mollusca in the Collection of the British Museum. By John Edward Gray, Ph.D., F.R.S., &e. Part I. Volutide. Pp. 23. 1855, 12mo. 6d. Part Il. Olivide. Pp. 41. 1865, 12mo. Is. Catalogue of the Conchifera, or Bivalve Shells, in the Collection of the British Museum. By M. Deshayes :— Part I. Veneride, Oyprinide, Glauconomide, and Petri- colade. Pp. iv., 216., 1853, ]2mo. 3s. Part IJ. Petricolade (coneluded); Corbiculade. Pp. 217-292. [With an Alphabetical Index to the two parts.|- 1854, 12mo. 6d. BRACHIOPODA. Catalogue of Brachiopoda Ancylopoda or Lamp Shells in the Collection of the British Museum. [Jsswed as ‘‘ Catalogue of the Mollusca, Part TV.” | Pp. iv.,128 25 Woodcuts. [ With an Alphabetical Index.] 1858, 12mo. 38. POLYZOA. Catalogue of Marine Polyzoa in the Collection of the British Museum. Part III. Cyclostomata. By George Busk, F.R.S. Pp. viii., 39. 38 Plates. [With a Systematic Index.] 1875, Svo, 5s. 10 LIST OF PUBLICATIONS OF THE : CRUSTACEA. Catalogue of ‘Crustacea in the Collection of the British Museum. Part I. Leucosiade. By Thomas Bell, V-P.R.S., Pres. L.S., &e. Pp. iv., 24. 1855, 8vo. 6d. Catalogue of the Specimens of Amphipodous Crustacea in the Collection of the British Museum. By C. Spence Bate, F.R.S., &c. Pp. iv., 399. 58 Plates. with an Alpbabetical Index. 1 1862, 8vo. its OS. cb MYRIOPODA. Catalogue of the Myriapoda in the Collection of the British Musum.. By George Newport, F.R.S., P.H.S., &c. Part I. Chilopoda. Pp. iv., 96. [With an Alphabetical Index. ] 1856, 12mo. 1s. 9d. : INSECTS. Coleopterous Insects. Nomenclature of Coleopterous Hata in the Collection of the British Museum :— Part IV. Cleride. By Adam White. Pp. 68. [With Index.] 1849, 12mo. ls. 8d. | | Part V. Cucujide, &c. By Frederick Smith. [Also issued as “ List of the Coleopterous Insects. Part 1.”] Pp. 25. 1851, 12mo. 6d. Part VI. Passalide. By Frederick Smith. Pp. iv., 23. 1 Plate [With Index.] 1852, 12mo. 8d. : Part VII. Longicornia, I. By Adam White. Pp. iv., 174. 4 Plates. 1853, 12mo. 2s. 6d. Part VIII. Longicornia, II. By Adam White.- Pp. 237. 6.Piates. 1855, 12mo. 38s. 6d. Part IX. Cassidide. By Charles H. Boheman, He Mees of Natural History, Stockholm. Pp. 225, (With Index. | 1856, 12mo. ds. Illustrations of Typical Specimens of Coleoptera i in the Collection of the British Museum. Part I. Lycide. By Charles Owen Waterhouse. Pp. x., 83. 18 coloured Plates. [With Syste- matic and Alphabetical Indexes.| 1879, 8vo. 16s. Catalogue of the Coleopterous Insects of Madeira in the Collection of the British Museum. By T. Vernon Wollaston, M.A., F.L.S. Pp. xvi., 244: 1 Plate. [With a Topographical Catalogue and an Alphabetical Index. | 1857, 8vo. 3s. BRITISH MUSEUM (NATURAL HISTORY). 11 Catalogue of the Coleopterous Insects of the Canaries in the Collec- tion of the British Museum. By T. Vernon Wollaston, M.A., F.L.S. Pp. xii., 648. {With Topographical and Alphabetical Indexes.| 1864, 8vo. 10s. 6d. Catalogue of Halticidz in the Collection of the British Museum. By the Rev. Hamlet Clark, M.A., F.L.S. Physapodes and (Kdipodes. Part I. Pp. xii., 301. Frontispiece and 9 Plates. 1860, 8vo. 7s. Catalogue of Hispide in the Collection of the British Museum. iby doseph S. Baly, M.E.S., &e... Part I... Pp. x.,. 172... 9 Plates. [With an Alphabetical Index.] 1858, 8vo. 6s. . Hymenopterous Insects. List of the Specimens of Hymenopterous Insects in the Collection of the British- Museum. By Francis Walker, F.L.S.:— Part Il. Chalcdites. Additional Species. Appendix. Pp. iv., 99-237. 1848, 12mo, 2s. Catalogue of Hymenopterous Insects in the Collection of the British Museum. By Frederick Smith. 12mo. :— Part I. Andrenide and Apide. Pp. 197. 6 Plates. 1858, 2s. 6d. Part II. Apide. Pp. 199-465. 6 Plates. [With an Alphabetical Index.] 1854, 6s. Part III. Mutillide and Pompilide. Pp. 206. 6 Plates. 18355, 6s. Part IV. Sphegide, Larride, and Crabronide. Pp. 207- 497. 6 Plates. [With an Alphabetical Index.] 1856, 6s. Part V. Vespide. Pp. 147. 6 Plates. [With an Alpha- betical Index.] 1857, 6s. Part VI. Formicide. Pp. 216. 14 Plates. [With an Alphabetical Index.] 1858, 6s. Part VII. Dorylide and Thynnide. Pp. 76. 3 Plates. [With an Alphabetical Index.] 1859, 2s. Descriptions of New Species of Hymenoptera in the Collection of the British Museum. By Frederick Smith. Pp. xxi., 240. | With Systematic and Alphabetical Indexes.] 1879, 8vo. 10s. List of Hymenoptera, with descriptions and figures of the Typical Specimens in the British Museum. Vol. I., Tenthredinide and Siricide. By W. F. Kirby. Pp. xxviii, 450. 16 Coloured Plates. [With Systematic and Alphabetical Indexes.] 1882, Svo. 17. 18s. Dipterous Insects. List of the Specimens of Dipterous Insects in the Collection of the British Museum. By Francis Walker, F.L.S. 12mo. :— Part II. Pp. 231-484. 1849. 3s. 6d. Part IV. Pp. 689-1172. [With an Index to the four parts, and an Index ot Donors.] 1549. 6s. 12 LIST OF PUBLICATIONS OF THE List of the Specimens of Dipterous Insects, &¢.—continued. Part V. Supplement I. Stratiomide, Xylophagide, and Tabanide. Pp. iv., 330. 2 Woodcuts. 1854 4s. 6d. Part VI. Supplement JI. Acroceride and part of the family Asilide. Pp. ii., 331-506. 8 Woodcuts.. 1854, 3s. Part VII. Supplement III. Asilide. Pp. ii, 507-775. 1855. 3s. 6d. Lepidopterous Insects. Illustrations of Typical Specimens of Lepidoptera Heterocera in the Collection of the British Museum :— Part I. By Arthur Gardiner Butler. Pp. xiii, 62. 20 Coloured Plates. [With a Systematic Index.] 1877, Ato. 20. Part III. By Arthur Gardiner Butler. Pp. xviii., 82. 41-60 Coloured Plates. [With a Systematic index. | 1879, 4to. 22. 10s. Part V. By Arthur Gardiner Butler. Pp. xii, 74. 78-100 Coloured Plates. [With a Systematic Index. | 1881, 4to. 22. 10s. Part VI... By Arthur Gardiner Butler. Pp. xy 969. 101-120 Coloured Plates. [With a Systematic Index. | 1886, Ato. 2/. 4s. Part VII. By Arthur Gardiner butler. Pp. iv., 124. 121-138 Coloured Plates. [With a Systematic List. ] 1889, 4to. 27. . Part VIII. The Lepidoptera Heterocera of the Nilgiri District. By George Francis Hampson. Pp. iv., 144. 139-156 Coloured Pilates. (With a Systematic List. ] 1891, 4to. 27. Part IX. The Macrolepidoptera Heterocera of Ceylon. By George Francis Hampson. Pp. -y., 182. 157-176. Coloured Plates. [With a General Systematic List of Species collected in, or recorded from, Ceylon.j] 1898, Ato. 21. 2s. Catalogue of Diurnal Lepidoptera of the family Satyride in the Collection of the British Museum. By Arthur Gardiner Butler, F.L.S., &e. Pp. vi., 211. 5 Plates. [With an Alphabetical Index.] 1868, 8vo. ds. 6d. Catalogue of Diurnal Lepidoptera described by Fabricius in the * Collection of the British Museum. By Arthur Gardiner Butler, F.L.S., &e. Pp. iv., 303. 3 Plates. 1869, 8vo. 7s. 6d. Specimen of a Catalogue of Lycanide in the British Museum. By W.C. Hewitson. Pp.15. 8 Coloured Plates. 1862, 4to. 1. 1s. List of Lepidopterous Insects in the Collection of the British Museum. Part I. Papilionide. By G. R. Gray, F.L.S. Pp. 106. [With an Alphabetical Index.] 1856, 12mo. 2s. _ BRITISH MUSEUM (NATURAL HISTORY). — ig List of the Specimens of Lepidopterous Insects in the Collection of the British Museum. By Francis Walker. 12mo. :— Part I. Lepidoptera Heterocera. Pp. iv., 278. 1854, 4s. Part IV. : Pp. 776-976. 1855, 3s. ‘Part VI. ——-—— ——_-——__ Pp. 1258-1507. 1855, 3s. 6d. Part VII.———___— Pp. 1508-1808. [With an Alphabetical Index to Parts I.-VII.] 1856, 4s. 6d. Part X. Noctuide. Pp. 258-491. 1856, 3s. 6d. Part XI. — _ Pp. 492-764. 1857, 3s. 6d. Part XIJ. ————_ Pp. 765-982. 1857, 3s. 6d. Part XIII. __—_—._ Pp. 983-1236. 1857, 3s. 6d. Part XIV. ——-—— Pp. 1287-1519. 1858, 4s. 6d. Part XV. ————— Pp. 1520-1888. [With an Alpha- betical Index to Parts IX.-XV.] 1858, 4s. 6d. Part XVI. Deltoides. Pp. 253. 1858, 3s. 6d. Part XVII. Pyralides. Pp. 254-508. 1859, 3s. 6d. Part X VIII. -—— Pp. 509-798. 18859, 4s. Part XTX. ——— Pp. 799-1036. [With an Alpha- betical Index to Parts XVI.-XIX.] 1859, 3s. 6d. Part XX. Geometrites. Pp. 1-276. 1860, 4s. Part X XI. Pp. 277-498. 1860, 3s. Part X11. ——__——-. Pp, 499-755... 1861, 3s. 6d. Part XXIII. —————_ Pp. 756-1020. 1861, 3s. 6d. Part XXIV. ——————._ Pp. 1021-1280. 1862, 2s. 6d. Part XXYV. —— Pp. 1281-1477. 1862, 3s. Part XXVI. — Pp. 1478-1796. [With an Alphabetical Index to Parts XX.-XXVI.] 1862, 4s. 6d. Part XXVIII. Crambites and Tortricites. Pp. 1-286. 1863, 4s. Part XXVIII. _ Tortricites and Tineites. Pp. 287-561. 1868, 4s. Part XXIX. Tineites. Pp. 562-835. 1864, +s. Part XXX. — Pp. 836-1096. [With an Alpha-. betical Index to Parts XXVIIL.-XXX.] 1864, 4s. Part XXXI. Supplement. Pp. 1-321. 1864, is. Part X XXII. Part 2. Pp. 3822-706. 1865, 5S. Part XXXII. ——— Part 3. Pp. 707-1120. 1865, 6s. ( Part XXXIV. —————— Part 4. Pp. 1121-1533. 1865, 5s. 6d. Part XXXV. Part 5. Pp. 1534-2040. [ With an Alphabetical Index to Parts XXXI-XXXV.] 1866, Vit. il ins _. LIST OF PUBLICATIONS OF THE | Neuropterous Insects. - Catalogue of the Specimens of Neuropterous Insects i in 1 the Colléc- tion of the British Museum. By Francis Walker. 12mo. :— Part I. Phryganides—Perlides. Pp. iv., 192. 1852, 2s, 6d. Part UH. Sialide—Nemopterides. Pp. alae 193-476, 1853, 35 OG. iam Part Hf. Termitide—Ephemeride. Pp. ii., 477-585. 1858, ls. 6d. Part IV. Odonata. Pp. ii., 587-658. 1853, bg Ls. Catalogue of the Specimens of Neuropterous Insects in the Col- lection of the British Museum. By Dr. H. oS xt i. Termitina. Pp, 34. 1858, 12mo. 6d. i - Orthopterous Insects. Catalogue of Orthopterous Insects in the Collection of the British Museum. Part I, -Phasmide. By Jobn Obadiah Westwood, F.LS., &. Pp. 195. 48 Plates. [With an Alphabetical Index. 1 1859, 4to. 37. Catalogue of the Specimens of Blattariz in the Collection wf the British Museum. By Francis Walker, F.L.8., &e. Pp. 239. [With an Alphabetical Index.] 1868, Svo0. 5s. 6d. Catalogue of the Specimens of Dermaptera Saltatoria [Part I.] and Supplement to the Blattariz in the Collection of the British Museum. Gryllide. Blattarie. Locustide: By Francis Walker, F.L.S., &c. Pp. 224. [With an Alphabetical Index. | 1869, 8vo. 5S. Catalogue of the Specimens of Dermaptera Saltatoria in the Collection of the British Museum. By Francis Walker, F.L.S., &e.— © Part IJ. Locustide (continued). Pp. 225-423. [With an Alphabeticai Index.] 1869, 8vo. 4s. 6d. Part III. Locustide (continued).—Acridide. Pp. 495-604. [With an Alphabetical Index.] 1870, 8vo. 4s. Part IV. Acridide (continued). Pp. 605- 809. [ With an Alphabetical Index.] 1870, 8vo. 6s. Part V. ‘Tettigide.—Supplement to the Catalogue of Blat- tarie.—Supplement to the Catalogue of Dermaptera Saltatoria (with remarks on the Geographical Distribution of Dermaptera). Pp. 811-850; 43;-116. [With Alpha- betical Indexes.] 1870, 8vo. Gs. ~Hemipterous Insects. List of the Specimens of Hemipterous Insects in the Collection of the British Museum. By W. S. Dallas, F.L.S. :— Part I.. Pp. 868. 11 Plates.- 1851, 12mo. 7s. Part IT. Pp. 369-590. Plates 12-15. 1852, 12mo. 4s. OE BRITISH MUSEUM (NATURAL HISTORY). 15 Catalogue of the Specimens of Heteropterous Hemiptera in the Collection of the British Museum. By Francis Walker, F.L.S., &e. 8vo.:— | Part I. Scutata. Pp. 240. 1867. ds. Part II. Scutata (continued). Pp. 241-417. 1867. As. Part III. Pp. 418-599. [With an Alphabetical Index to Parts I., IT., III, and a Summary of Geographical _ Distribution of the Species mentioned.| 1868. 4s. 6d. Part IV. Pp. 211. [Alphabetical Index.] 1871. 6s. Part. VV. Pp. 202. ~—— 1872.. 5s. Earth vi. fp. 710. ———————. 1873. is. Part VII. Pp. 2138. ——-—————-———-__ 1873. 6s. ’ Part VIII. Pp. 2 1872. 6s. 6d. Homopterous Insects. List of the Specimens of Homopterous Iusects in the Collection of the British Museum. By Francis Walker. Supplement. Pp. ii., 369. [With an Alphabetical Index.| 1858, 12mo. 4s. 6d. VERMES. Catalogue of the Species of Entozoa, or Intestinal Worms, con- tained in the Collection of the British Museum. By Dr. Baird, Pp. iv., 182. 2 Plates. [With an Index of the Animals in whieh the Entozoa mentioned in the Catalogue are found; and an Index of Genera and Species.| 1853, 12mo. 2s. ANTHOZOA. Catalogue of Sea-pens or Pennatulariide in the Collection of the British Museum. By J. E. Gray, F.R.S., &c. - Pp. iv., 40. 2 Woodeuts. 1870, 8vo. Is. 6a. Catalogue of Lithophytes or Stony Corals in the Collection of the British Museum. By J. E. Gray, F.R.S., &c. Pp. iv., 51. 14 Woodcuts. 1870, 8vo. 3s. Catalogue of the Madreporarian Corals in the British Museum (Natural History). Vol. I. The Genus Madrepora. By George Brook. Pp. xi., 212. 35 Collotype Plates. [With Systematic and Alphabetical Indexes, Explanation of Plates, and a Preface by Dr. Giinther.| 1893, 4to. 17. 4s. BRITISH ANIMALS. Catalogue of British Birds in the Collection of. the British Museum. By George Robert Gray, F.L.S., F.Z.S., &e. Pp. xil., 248. [With a List of Species.] 1863, 8vo. 3s. 6d. Catalogue of British Hymenoptera in the Collection of the British Museum. Secend edition. Part I. Andrenide and Apide. By Frederick Smith, M.E.S. New Issue. Pp. xi. 236. 11 Plates. [With Systematic and Alphabetical Indexes.] 1891, 8vo. 6s. 16 LIST OF PUBLICATIONS OF THE © Catalogue of British Fossorial Hymenoptera, Formicidae, and Vespide in the Collection of the British Museum. By Frederick Smith, V.P.E.S. Pp. 236. 6 Plates. [With an i Index. ] 1858, 12mo. 6s. A Catalogue of the British Non-parasitical Worms in the Collec. tion of the British Museum. By George Johnston, M.D., Edin., ¥F.R.C.L. Ed., Li.D. Marischal Coll. Aberdeen, &c. Pp. 365. Woodcuts and 24 Plates. [With an Alphabetical Index. | 1865, 8vo. 7s. Catalogue of the British Echinoderms in the British Museum (Natural History). By F. Jeffrey Bell, M.A. Pp. xvii., 202. Woodcuts and 16 Plates (2 coloured). [With Table of Cun- tents, Tables of Distribution, Alphabetical Index, Description of the Plates, &c.|] 1892, 8vo. 12s. 6d. List of the Specimens of British Animals in the Collection of the British Museum; with dbo ii and References to figures. 12mo. :— Part I. Centronie or Radiated Animals. By Dr. J. E. Gray. Pp. xiii, 173. 1848, 4s. Part IV. Crustacea. By A. White. Pp. iv., 141. (With an Index.) 1850, 2s. 6d. | Part V. Lepidoptera. By J. F. Stephens. 2nd Edition. By H. T. Stainton and E. Shepherd. Pp. iv., 224. 1856, 1s. 9d. Part VI. Hymenoptera. By F. Smith. Pp. 134. 1851, 2s. Part VII. Mollusca, Acephala, and Brachiopoda. By Dr. J. E. Gray. Pp. iv., 167. 1851, 3s. 6d. Part VIII. Fish. By Adam White. Pp. xxi., 164. (With Index and List of Donors.) 1851, 3s. 6d. Part IX. Eggs of British Birds. By George Robert Gray. 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