134 DR. J. E. GEAY'S SYNOPSIS OF THE SPECIES 



1. ToMiSTOMA SCHLEGELII. (Bomean Gavial.) 



Crocodilus gavialis schlegelii, Miiller, Naturgesch. Ost. Ind. t. 123. f. 1-5. 



Crocodilus schleyeln, Blainv. Osteog. Crocod. t. 2. f. 3 ; t. 5. f. 4. Briihl, Skelet. Krok. t. 8. f. 6. 



Owen, Fossils of the London Clay, p. 15. 

 BJiynchosuchus schlegelii, Huxley, Proc. Linn. Soc. iv. (1859) p. 17; Ann. & Mag. Nat. Hist. 1859. 

 Mecistopsjournei, Gray, Cat. Tortoises &c. B. M. 38, not synonyma. 



Ilah. Australasia, Borneo (Miiller, Brit. Mus.). 



The two figures of the skull in Midler and Schlegel, t. 3. f. 1 and 2, show the diiference 

 that occurs in the form of the skull of the same species. 



In the British Museum there is a young specimen in spirits, and an adult skull 

 received from the Leyden Collection, and a very fine adult skull from Borneo, obtained 

 from Mr. Mitten. 



Family II. CROCODILID^. 



The cervical plates forming a distinct shield, separate from the do;-sal shield. Teeth 

 strong, very unequal in size, hinder larger. The 9th upper and the 11th lower teeth 

 larger, like canines, the large teeth of the lower fitting into pits or perforations, and 

 the canines fitting into notches on the edge of the upper jaws. Nose of both sexes 

 simple. 



The upperside of the intermaxillary is slightly expanded behind, and its hinder end 

 is divided, and separated into two parts by the front end of the nasal bone. 



Crocodilida §**, Gray, Cat. Tortoises &c. B. M. 36, 1844. 

 Crocodilida, Huxley, Proc. Linn. Soc. Zool. iv. 5. 

 Crocodilus, Cu\'ier ; Gray, Ann. Phil. 1825, x. 195. 

 Champse, Merrem, Tent. 



Professor Huxley divides this family into two genera, Crocodilus and Mecistops. See 

 Journ. Proc. Linn. Soc. Zool. iv. 6. 



The Crocodiles when they are first hatched have a very short beak to the head. This 

 is even the case with the long-beaked Mecistops cataplir actus, which in its very young 

 state is hardly to be distinguished in the form of its beak from the young of the com- 

 mon Crocodile, Crocodilus vulgaris. 



As the young obtain strength the beak developes itself more or less rapidly according 

 to the species, until its normal character is attained. 



The head seems to continue of nearly the same form, merely increasing in size, for 

 some time, perhaps years ; for we know little of the duration of the life of the Crocodiles ; 

 and they are probably long-lived animals. As they reach maturity, and as old age creeps 

 on, the skull thickens considerably, and the jaws dilate and thicken on the sides. The 

 growth of the teeth, which are produced in succession, and greatly enlarge in diameter, 

 and the enlargement of the jaws ^YOceeA pari passu : the latter is also influenced by the 

 development of these teeth and the larger alveoli required to support them. 



