TRANSACTIONS OF SECTION C. 585 



New York (Newberry, 'Geol. Surv. Ohio,' vol. i., pt. ii., p. 296) and the Low. Old 

 Red Sandstone Passage Beds of Ledbury, England {Onychodus amjlicus, A. S. 

 Woodw., ' Geol. Mag.' [3] vol. v., p. 600)." The new specimen thus considerably 

 extends the known range of Onycliodus in space, and, so far as can be ascertained, 

 pertains to a hitherto undetermined specific type. Four fractured teeth are pre- 

 served, scarcely more than half as large as those of the smallest described species,^ 

 O. anglicus, and differing from the latter in the very large size of the internal 

 cavity. The form may be provisionally named Onychodus arcticus. 



8. Notes cm some new and little-known British Jurassic Fishes.^ 

 By A. Smith Woodward, F.G.S., F.Z.8. 



The remains of many undescribed fossil fishes from British Jurassic formations 

 are preserved in various collections, and the author remarks upon a few of the 

 more prominent types. Some are of genera already recognised on the Continent, 

 but not hitherto discovered in England. 



1. Eurycormus yrandis, sp. nov. Founded on a well-preserved head from the 

 Kimmeridge Clay of Ely, in the Woodwardian Museum. About twice as large 

 as the typical E. spcciosiis, and differing in the granulation of the head-bones. 



2. atrohilodus suchoides, Owen sp. As suggested by Von Zittel, the so-called 

 Thlattodus siichoides, Owen, from the Kimmeridge Clay of West Norfolk, is certainly 

 generically identical with the previously described Strobilodus giganteus from the 

 Bavarian Lithographic Stone. 



3. Hypsocormus Leedst, sp. nov., and Hypsocormus tenuirostris, sp. nov. The 

 jaws of two new species of Hypsocormus have been discovered in the Oxford Clay 

 of Peterborough, by Mr. Alfred N. Leeds, of Eyebury. The tirst (Zf. Leedsi), 

 equals the Bavarian species, /i. macrodon, in size, and has a similarly obtuse snout; 

 but it differs in the marked obliquity of the two great leeth in the upper jaw. 

 The second species {H. tenuirostris) attains about half the size of the first, and is 

 distingiushed by the comparative elongation and acutely pointed form of the snout j 

 the two great upper teeth seem to have been directed almost vertically downwards, 

 as ui H. macrodon. These fossils suggest an interesting com])arison between the 

 dentition of IIyj)Socoiinus and that of the Upper Cretaceous Protosphyrcena ; two 

 large tusk-like teeth at the base of the snout in each genus being opposed to a 

 pair of similar teeth on each side of the mandible, fixed in sockets in a short, stout, 

 splenial bone. 



4. Leedsichthys problematicus, gen. et sp. nov. This, probably the largest Jurassic 

 fish hitherto discovered, is indicated by an associated series of bones from the 

 Oxford Clay of Peterborough in Mr. Leeds' collection. It can only be provisionally 

 defined, and may be appropriately named Leedsichthys problem aficus. None of the 

 bones are externally ornamented, but ail have a distinctly fibrous texture. A 

 supposed frontal bone measures 2 feet in length by 1 foot 3 inches in maximum 

 breadth ; the hyomandibidar is squamous, at least 1 foot 3 inches in length ; and 

 the bones of the branchial arches are irregularly <-shaped in transverse section, 

 bearing numerous gill-rakers. The last-named bones are elongated, laterally 

 compressed, slightly expanded at the base, and rarely straight, but irregularly bent 

 and contorted ; the surface is coarse and rugose, and one long border is rounded 

 while the other is cleft by a longitudinal median furrow ; the rounded border is 

 comparatively smooth, but the furrowed edge is coarsely serrated, a series of short 

 oblique ridges terminating in points on each side. The branchiostegal rays are very 

 large, dense, and rounded in section, in not less than six pairs. The pectoral fin- 

 rays sometimes attain a length of 5 feet, frequently dichotomouslv branching, but 

 not jointed ; each consists of fibrous bone, appearing as if compoi^ed of numerous 

 long, tapering splints incompletely fused together, and the two halves of the ray 

 remain separate. The jaws and axial skeleton of the trunk are still unknown. 



5. Thrissops. Though not hitherto recorded, remains of the genus Thrissopa 



' Printed in extento in Geol. May. [3] vol. vi. 1889, pp. 448-455. 



