CHABACTEES OF BECENT CROCODILIA. 19 



Inches. 



Length 12 



No tooth measures transversely more than -^ 



The face is very smooth ; but a slight longitudinal groove runs 

 down on each side from the anterior margin of the orbit for about 

 two inches. Anteriorly to this point the snout retains a nearly 

 even diameter as far as the ninth tooth, in front of which it sud- 

 denly narrows a little, retaining nearly the same dimensions to the 

 fourth tooth, where it widens a very little, and then sviddenly 

 narrows to the terminal beak. The lower jaw does not expand at 

 all at its extremity. The nasals join the premaxillaries opposite 

 the ninth tooth, and the splenial bones, in the lower jaw, end op- 

 posite the tenth mandibular tooth, as the figures of Miiller and 

 Schlegel show. The vomers appear between the inner edges of the 

 palatines posteriorly, as a thin bony band If inch long by ^ inch 

 wide, which tapers at each end and is divided by a longitudinal 

 suture. The ninth tooth of the upper jaw is stronger than the rest. 



The only point in which the description of Miiller and Schlegel 

 seems to me to be incomplete* is with regard to the disposition of 

 the teeth. They say — " The teeth of C. Sclilegelii, as regards 

 their form and development, more nearly resemble those of the 

 true Crocodiles ; but in the way in which the teeth of the two 

 jaws are opposed, there is the most complete resemblance between 

 our species and the Gangetic Gavial, — both which species dififer 

 from aU other crocodiles in the circumstance that when the mouth 

 is shut, all the teeth of the under jaw project outside the lateral 

 margin of the upper jaw" (1. c. p. 22). 



What I find is this : — The anterior teeth of both the upper jaw 

 and the mandible are long, slender, sharp-edged, and slightly 

 curved. The posterior eleven, on each side, in the upper jaw, are 

 short, straight, conical, and constricted below their crowns. There 

 are deep interdental pits between the ten posterior mandibular 

 teeth, into which the opposed teeth of the maxilla are received 

 when the jaws are closed. All the mandibular teeth, except the 

 two anterior and the fourth pair, pass into like pits in the upper 

 jaw. The anterior eight teeth on each side of the upper jaw pass 

 straight down outside the lower jaw. In the Gangetic Gavial the 

 relations of the teeth of the two jaws appear to me, as I shall 

 state below, to be very different. 



* Or it is possible that the Rhynchosuchus from New Guinea, which I have 

 examined, is specifically distinct from the Bornean form. 



2* 



