G. cAiiiAX. 297 



Chanipsa gibbiceps, Natttrer, I. c. pi. xxviii. 



Cainuiu palpebro.-us, Gray, Cat. Tort. Sfc. p. 07 (1.'544), and Sh. 

 Jiept. ii. p. 28 (1872). 



Ijribbiceps, Gray, Cat. Tort, ^-r., p. (57. 



Alligator palpi'brosu.s, Straach, Syn. Crocod. p. 25 (18G(5j. 



19 or 20 upper and 20 lower teeth on each side ; third and fourth 

 maxillary teeth largest. Head once and three tilths to once and 

 two thirds as long as broad ; snout subacurainate, its basal width 

 contained about once and a half in its length : no cross-ridge in front 

 of the interorbital region, which is but slightly concave ; upper 

 eyelid flat and smooth^ entirely bony, the bony plate consisting of 

 four distinct jneccs ; lores very steep and high ; canthus rostralis 

 angular; su])ratemporal fossa obliterated. Two transverse scries 

 of postoccipital scutes, follow ed by four or five transverse series of 

 large, very highly and sharply keeled nuchals, the second and third 

 usually composed of three or four scutes, the others of two. Dorsal 

 scutes in 18 or 19 transverse series, the broadest of which ai-e 

 composed of six or eight scutes, which are less liighly keeled than 

 in the jjreccding species ; those between the hind limbs constantly 

 in four longitudinal scries. The caudal crest becomes single on the 

 twelfth or thirteenth verticil. Dorsal and ventral bony armour 

 much developed ; sides of body soft, with scattered small bony 

 tubercles ; gular and outer ventral scutes keeled. Fingers free, toes 

 webbed at the base. Yellowish-brown above, spotted and cross- 

 barred with black. 



Total length 1 m. 20 centim. 



Guianas and Bi'azil. 



a, h. Ad. & hgr., stffii. ? 



c, d. Yg., spir. ■ • ? 



The precise affinities of the following Crocodile are uncertain, as 

 the original description does not give the number of the mandibular 

 teeth ; and as, in the unique specimen upon which the species is 

 founded, the fourth mandibular tooth on one .side is received into a 

 notch as in true Crocodiles, and on the other into a pit, as in the 

 Alligators, it is difficult to say to which group it belongs, although 

 Cope suspects its affinities to be "rather more AlJigatorial." It 

 also appears to me doubtful whether the absence of the claw in the 

 third finger will prove a constant character. 



PEROSUCHUS. 



Cope, Proc. Ac. Phihul. 1868, p. 203, and Tr. Am. Phil. Soc. (2) 

 xiv. p. 83 (1870). 



" Toes 5 — 4, with claws two — three. No osseous nasal septum or 

 bony eyelid. Eelly protected by series of osseous plates, as well as 

 the 'back." 



