484 CEGCODILTJS CATAPHEAUTUS 



narrow slips of bone, •which descend npon the nasals a con- 

 siderable way below the anterior margin of the pre-frontals. 

 The nasal bones are extremely narrow and attenuated, but, 

 as in the true Crocodiles, they descend between the maxil- 

 laries so as to project into a niche between the intermaxillary 

 bones. The same holds good in G. Schlegelii ; whereas in the 

 Gavial the nasals terminate a short way in front of the orbits, 

 and do not enter into the formation of the anterior portion 

 of the beak. This character is a good diagnostic mark be- 

 tween the Crocodiles proper and the Gavials ; separating C. 

 Schlegelii from the latter subgenus under which Muller has 

 ranged it. The nasal opening is smooth, oval in form, and 

 of moderate size. There are seventeen teeth in the upper 

 jaw, and fifteen in the lower ; the largest teeth in the upper 

 are the third and ninth ; in the lowei:, the first, fourth, tenth, 

 and eleventh. The dimensions are subjoined. 



II. Crocodilus marginatum ('?), Geoff. Croc. d'Egypte, 165, 

 and Gray's Catal. Brit. Mus., p. 61; C. vulgaris, var. C, Dinner. 

 et Bibr. Erpetolog., iii. p. 110; G. vulgaris, Cuv., Annal. du 

 Mus., torn. x. 40. 



The Belfast specimen is doubtfully referred to this species, 

 there not being sufficient materials in the London museums 

 to admit of a satisfactory determination. Neither the College 

 of Surgeons' collection nor the British Museum is possessed 

 of an adult cranium of the common Crocodile of the Nile, G. 

 vulgaris, or of G. marginatum, although there are numerous 

 stuffed specimens attributed to both species in the British 

 Museum collection. The comparison of the Belfast specimen 

 has in consequence been limited to the reduced figure of the 

 skull of G. vulgaris in the ' Ossemens Fossiles.' 



The cranium is 19 inches long, and must have belonged 'to 

 an adult animal. The principal distinctive character assigned 

 to G. marginatus, both by Geoffroy and by Dumeril and 

 Bibron, in addition to the form of the nuchal and dorsal 

 scutes, is that the borders of the cranial tablet are raised, 

 while in C. vulgaris the frontal area is perfectly flat. In the 

 Belfast cranium these lateral margins are also considerably 

 elevated, and the following points of difference from G. vul- 

 garis are besides observable. The facial portion of the head 

 is less elongated in proportion to the cranial, and more obtuse 

 than in G. vulgaris ; the interval between the orbits is greater ; 

 the crotaphite foramina are relatively larger ; the lachrymals 

 are narrower, and descend further upon the nasals ; the muzzle 

 is considerably blunter, and the niche for the reception of the 

 fourth tooth of the lower jaw is larger, causmg a greater 

 amount of constriction. The general outline of the muzzle, 

 instead of being acute and subcuneiform, is obtuse and oblong, 



