CROCODILES. 61 



fish. It is interesting to note in this connection,, 

 that the Gangetic dolphin (one of the mammalia), 

 which lives in the same rivers, has a similarly 

 elongated snout and teeth of the same slender 

 type. As this creature is also a fish-eater, the 

 elongated beak is probably also the result of 

 adaptation to the same end. A full grown 

 Gharial may attain a length of twenty feet or 

 even more, though this length is far exceeded 

 by a closely allied species Rhamphosuchius cros- 

 sidem long since extinct, which attained a length 

 of fifty feet. The tip of the snout in the Gharial 

 is greatly expanded, and in the male this ex- 

 panded portion is surmounted by a hollow hump 

 on the top of which the nostrils are placed 

 Apparently this hump comes within the category 

 of sexual ornaments, for when the nostrils are 

 closed it can be inflated like a bag. Feeding 

 only on fish, this species rarely attacks man, 

 and it is probably on this account that it is. 

 held sacred by the Hindus in many parts of 

 India. Cases are on record, however, which 

 show that large individuals, at least, will occasion 

 ally select human victims ; but such instances, 

 appear to be rare. 



Crocodiles may be distinguished from Alligators- 

 by the fact that, in the former the fourth tooth 

 of the lower jaw fits into a notch in the upper 

 jaw ; whilst in the Alligators this tooth fits into- 

 a pit instead. In very old Alligators this tooth 

 often perforates the bone and is visible on the 

 surface of the upper jaw. 



The geographical range of the true Crocodiles, 

 is extremely wide, since they are found in Africa, 



