CROCODILIA. 117 



facial or maxillary portion which is requisite for its unequivocal determination to 

 either of the two species which the more perfect specimens since acquired have 

 proved to have existed at the Eocene tertiary period. The form of the mutilated 

 portion of skull, and the figure of it given in PI. 25' of the ' Bridgewater Treatise,' might 

 well appear to indicate a short and broad snouted species of true Crocodile ; but if it 

 be not distinct from the two better represented species above described, I should be 

 more inclined to refer it to tliat which has the longest and narrowest snout, from the 

 conformity of the characters'of the part of the skull which is preserved. A view of the 

 palatal surface of the specimen in question is given in PI. 2 B, fig. 2. 



Crocodilian vertebra referable to the two foregoing species of Sheppg Crocodiles. 



Not more than two species of Crocodile are indicated by the detached vertebrae 

 from Sheppy ; but the different proportions of the homologous cervical vertebrae, 

 figs. 3 and 7, PI. 3 J, and of the characteristic biconvex caudal vertebra, fig. 7, PI. 3, and 

 fig. 10, Plate 3 A, would have determined the fact of there being two distinct species, 

 had their cranial characters, which are so satisfactorily demonstrated in Plates 2 and 

 2 A, remained unknown. I refer, provisionally, the shorter and thicker vertebrae to 

 the Crocodilus toliapicus with the shorter and thicker snout, and the longer and thinner 

 vertebrae to the Croc, champsoides with the snout of similar proportions. 



VertebrcB of the Crocodilus toliapicus, Plate 3 and Plate ?> A, figs. 1, 2, 3, 5, 6. 



The vertebra, figs. 1, 2, PI. 3 A, is the fourth cervical ; it differs from that of the 

 Crocodilus acufus. Croc. Suchus, and Croc, biporcaius, in the greater breadth and squareness 

 of the base of the hj^papophysis (fig. 2 h), which extends almost to the bases of the 

 parapophyses J9 ; the vertical diameter of the parapophyses is greater in comparison with 

 their antero-posterior extent in the fossil than in tlie above-cited recent Crocodiles ; 

 the neurapophyses are thicker, and terminate in a more rounded border both before 

 and behind ; their bases extend inwards, and meet above the centrum, whilst a narrow 

 groove divides them in the recent Crocodiles above cited ; the length of the centrum 

 is greater in proportion to the height and breadth in the fossil vertebra. In other 

 respects the correspondence is very close, and the modem crocodilian characters are 

 closely repeated. Traces of the suture between the centrum and neurapophysis remain, 

 as shown at n, n, fig. 1 . The diapophysis d, and the upper portion of the neural arch, 

 with the zygapophyses and neural spine, have been broken away ; the borders of the 

 articular ends of the centrum have been worn away. 



The vertebra (fig. 3, PI. 3 A) is the sixth cervical : in this specimen the base of the 

 hyi^apophysis is contracted laterally and extended antero-posteriorly ; the side of the 

 centrum above the parapophysis {p) has become less concave ; the vertebra has increased 



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