TUATERA. O 



now been almost exterminated 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 [Oases 

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

 exception of one species which occurs in the Yang-tse-kiang [Alli- 

 gator sinensis), 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 Alligators [A. niger and sclerops) are 

 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 or Sphenodon of naturalists. Case 11 contains examples 

 of this interesting 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 found in several parts 

 of the northern island and in the Chatham Islands ; but at present 

 it is restricted to a few small islands in the Bay of Plenty and Cook's 

 Straits, where it lives in holes, feeding on insects, worms, and 

 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 



