TUATERA. 5 



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

 all the freshwaters 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 Gharials (Gavialis) may be readily recognized by their 

 extremely long and slender snout. The Gharial 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 tributaries, 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 indi- 

 viduals are enabled to remain under water for a longer time than 

 females or young. 



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

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

 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- 

 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 disti aguish 

 the Tuatera from ordinary Lizards ; but important differences 

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



