130 BRITISH FOSSIL REPTILES. 



centrums, the primitive piscine form of vertebra under modifications, usually of a 

 more consolidating kind, still prevailing. But the Protosuchians combined there- 

 with jaws, longer and more slender than in existing Crocodiles and Alligators, 

 armed with slender, conical, sharp-pointed and equal teeth, adapted like those of 

 the existing Gavials, to the seizure and destruction of fishes. 



The Protosuchian species fall into two genera, characterised by the position 

 and aspect of the external nostril, which aperture in one — called Steneosaurus — is 

 situated a little behind and above the anterior termination of the upper jaw, in 

 the other — called Teleosaurus — the nostril is at that end, or is ' terminal,' and 

 looks more directly forward. 



Genus — Teleosaueus. 

 Species — Teleosaurus Chapmanni, Plate 15 {Crocodilia), figs. 2, 2 a. 



The extinct reptile from which the characters of the genus Teleosaurus are 

 derived, is one of the earliest of the evidences of ancient Reptilia which is recorded 

 in a scientific publication. A brief description and figures of an incomplete skeleton 

 found in the lias (alum schale) of the Yorkshire coast, about half a mile from 

 Whitby, were published by Messrs. WooUer and Chapman, in two separate commu- 

 nications, in the 50th volume of the ' Philosophical Transactions,' 1758 (Pt. 2, pi. 

 xxii and xxx). Their figures exhibit a contorted and incomplete vertebral column, 

 about 9 feet long, and a cranium, slightly displaced, 2 feet 9 inches in 

 length. About ten vertebrae of the lumbar and sacral region of the trunk, and 

 twelve vertebrae of the tail, remain in place ; the cervical, dorsal, and middle coccy- 

 geal vertebrae were indicated only by their impressions, and these are fewer in 

 number than the vertebrae in the existing Crocodiles. The skull is reversed, pre- 

 senting its basal surface to view; the single occipital condyle, the zygomatic 

 arches, terminated behind by the strong tympanic bones, and the large convex 

 articular surface in each of these, for the lower jaw, placed in the same transverse 

 line as the occipital condyle, are all recognisable. The skull appears to contract 

 gradually to a pointed muzzle, but in reality to the base of a long and slender 

 maxillary beak. In the remaining basal or posterior portions of the jaws the 

 sockets of the teeth are seen separated by intervals of about 9 Unes ; in some of 

 these there are pointed conical teeth which cross alternately those of the opposite 

 jaw. The teeth are covered with polished enamel. 



Each of the vertebrae is 3 inches in length. Near the pelvic region, a portion 

 of the shaft of the femur, including the head, was exposed, measuring between 3 

 and 4 inches in length. A few fragments of ribs were found near the dorsal 

 vertebrae. The authors of the papers just analysed perceived suflBcient resem- 



