TUATERA. 5 



was once common in Egypt proper. It has now been almost exter- 

 minated in the lower parts of the Nile, but infests in great numbers 

 all the fresh waters of Tropical Africa; and it is believed that more 

 people are killed by Crocodiles than by any other of the wild beasts 

 of Africa. 



The Gaviah(Gavialis) may be readily recognized by their extremely 

 long and slender snout. The Gavial of the Ganges (G. gangeticus), 

 of which a large specimen (B) is mounted in the middle of the Gallery 

 opposite to the entrance, is abundant in that river and its tribu- 

 taries, and attains to a length of 20 feet. It feeds chiefly on fishes, 

 for the capture of which its long and slender snout and sharp teeth 

 are well adapted. Old males have a large cartilaginous hump on the 

 extremity of the snout containing a small cavity for the retention 

 of air, by which means these individuals are enabled to remain 

 under water for a longer time than females or young. 



In the Alligators {Alligator) the fourth lower tooth is received [Cases 

 in a pit in the upper jaw, when the mouth is shut. With the 'J 

 exception of one species which has been lately discovered in 

 China, they are found only in America. They do not grow to the 

 large size of the true Crocodiles. The species most generally 

 known is A. mississippiensis, which abounds in the southern parts 

 of North America. The Black Alligator {A. sclerops) is common in 

 South America as far south as 32° lat. S. 



Order II. RHYNCHOCEPHALIA. 



Of this Order, which seems in the Permian and subsequent forma- [Case 11.] 

 tions to have been represented by various genera, one species only 

 has survived to our period. It is the Tuatera of the Maoris, or 

 Hatteria of naturalists. Case 11 contains an example of this inter- 

 esting Reptile, with skeleton and skulls. It is the largest of the 

 few Reptiles inhabiting New Zealand, but scarcely attains to a 

 length of 2 feet. Formerly it was probably found in several parts 

 of the northern island ; but at present it is restricted to a few small 

 islands in the Bay of Plenty, where it lives in holes feeding on 

 other small animals. Externally there is nothing to distinguish 

 the Tuatera from ordinary Lizards; but important differences 

 obtain in the structure of its skeleton, viz. the presence of a double 



