Dr. Falconer on two Crania of Crocodiles. 363 



are separated only by a narrow interval ; while in the Garial they 

 are large and wide apart. The lachrymals form narrow slips of 

 bone which descend upon the nasals a considerable 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 maxillaries so as to project into a niche 

 between the intermaxillary bones. .The same holds good in 

 C. Schlegelii ; whereas in the Garial 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 between the Crocodiles proper and the Garials ; 

 separating C. Schlegelii from the latter subgenus under which 

 Miiller 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 lower, the first, fourth, tenth and 

 eleventh. 



The dimensions are subjoined at page 364. 



Crocodilus marginatus (?), Geoff. Croc. d'Egypt. 165 ; Gray, 

 Catal. Brit. Mus. p. 61. C. vulgaris var. C, Dumer. et Bibr. Er- 

 petolog. iii. p. 110. C. 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, C. vulgaris, 

 or of C. marginatus, although there are numerous stuffed speci- 

 mens attributed to both species in the British Museum collec- 

 tion. The comparison of the Belfast specimen has in consequence 

 been limited to the reduced figure of the skull of C. vulgaris in 

 the l Ossemens Fossiles/ 



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

 adult animal. The principal distinctive character assigned to 

 C. 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 C. vulgaris are besides observable. The facial 

 portion of the head is less elongated in proportion to the cranial, 

 and more obtuse than in C. 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, causing a greater 



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