ON BRITISH FOSSIL REPTILES. 79 



ing Crocodiles ; the anterior one appears not to have been so much expanded 

 in the antero-posterior direction. The iliac bone seems to have been shorter 

 in the antero-posterior diameter, but longer, as measured transversely to the 

 axis of the trunk, and thus to have made a slight approach to its character- 

 istic form in the Enaliosaurs. 



Both the ischium and pubis are relatively more expanded than in the 

 Gavial. The pelvic extremities are preserved in the Whitby specimen in 

 nearly their true relative positions ; but the right is thrown directly over the 

 left. The femur presents the usual Crocodilian form., but is relatively more 

 slender than in the existing Crocodilians ; it is slightly twisted, and bent in 

 two directions. Its proximal end is expanded, compressed with a regular 

 convex curve, describing a semicircle ; the trochanter is represented by a ridge 

 which gradually subsides, and is lost upon the surface of the shaft. This is 

 nearly cylindrical at the upper part, but is produced at the anterior or convex 

 side along the distal half in the form of an obtuse ridge. The condyles are 

 very feebly indicated. In the Whitby specimen of 1824, 



Feet. In. Lines. 



The length of the femur is 1 3 3 



The breadth of proximal end of ditto . . 2 10 

 The diameter of middle of shaft .... 1 4 

 Both the tibia and fibula are subcompressed towards their distal end : the 

 length of each bone is 8 inches. The shaft of the fibula is nearly as thick 

 as that of the tibia. The bones of the leg of the Teleosauriis resemble 

 those of the Aelodon in their relative shortness as compared with the femur. 

 In these, and probably in other ancient Crocodiles with biconcave vertebrae 

 and marine habits, the tibia is little more than half the length of the femur ; 

 while in recent Gavials it is two-thirds that length. There are five tarsal 

 bones, two in the proximal and three in the distal row, as in the Gavial ; but 

 they are of more equal size ; the two proximal bones being by no means so 

 disproportionately large. All the long bones have distinct medullary cavities, 

 and these are even present in the metatarsals. In the Whitby specimen, 

 The length of the middle metatarsal is ... . 6 inches. 



The breadth of its proximal end 10 lines. 



The breadth of its distal end 6 lines. 



The ungual phalanges are depressed, smooth and convex above, rounded at 

 the end. 



Dermal armour. — The bony dermal scutes of the Teleosaur were regularly 

 disposed like those of existing Crocodiles, in both longitudinal and transverse 

 series ; the posterior margin of one scute covered the base of the succeed- 

 ing scute *, and they slightly overlapped each other laterally. 



Cuvier states that one of the fossils of the Teleosauriis Cadomensis presents 

 all those of one side in their natural situation, exhibiting, in the part of the 

 body included between the first dorsal and the beginning of the tail, fifteen 

 or sixteen transverse rows, containing five scutes on each side ; so that there 

 were at least ten longitudinal rows of these dermal bones. 



The scutes are arranged in the same manner and number, at least as regards 

 the transverse rows, in the Whitby Teleosaur ; these rows being indicated by 

 the large dorsal scutes still occupying their natural position in an uninter- 

 rupted line along the back ; they are twenty in number, and sixteen cover 

 the vertebrae included between the last cervical and first caudal. 



The scutes of the Teleosaurus Chapmanni differ as much from those of the 

 existing Gavials and Crocodiles, as do those of the Teleosaurus Cadomensis, 



* Cuv., /. c. p. 279. 



