2432 



TORTOISES, TURTLES, AND PLESIOSAURS 



The three remaining genera, Callagur, Batagur, and Hardclla, differ from the pre- 

 ceding in that the fourth vertebral shield of the carapace is not longer than the 

 third; but it will be unnecessary to point out the features by which they are severally 

 distinguished. The largest of all is the true batagur (Batagur basca) in which 

 the carapace measures upwards of twenty inches in length. 



All the batagurs are exclusively vegetable feeders, and the larger species are 

 thoroughly aquatic in their ha*bits, spending by far the greater portion of their time 

 in the water. They abound in the larger rivers of India and Burma, where their 

 huge shells form conspicuous objects as they rise to the surface to breathe. De- 

 scribing the habits of a captive specimen, Dr. John Anderson states that when it 

 rose to breathe " its nostrils were simply protruded above the surface of the water, 

 and retained in that position for about half a minute, during which it made a long 

 expiration, followed by a deep inspiration, the creature then slowly subsiding, tail 

 backward, to the bottom. The animals, unless they were much irritated, never at- 

 tempted to bite, but, when so treated, they sluggishly seized any object put in their 

 way, holding it between their jaws with considerable tenacity, at the same time 

 withdrawing the head into the shell. They moved about on the ground with con- 

 siderable agility, supporting their heavy bodies erect on their legs like a land tor- 

 toise." Another species will occasionally snap, when, owing to the friction of its 

 serrated jaws against each other, a peculiar kind of barking sound is produced. Bat- 

 agurs are eaten in Lower Bengal by some of the inferior castes of Hindus, and are 

 kept for this purpose in tanks. 



THE BIG-HEADED TORTOISE 

 Family PL A TTS TERN ID. /; 



This extraordinary creature (Platy sternum meg aceph alum} , which is an in- 

 habitant of the south of China, Siam, and Burma, is the sole representative, not 



only of a very remarkable genus, but 

 likewise of a distinct family, which 

 appears to be to a great extent inter- 

 mediate between that of the tortoises 

 and that of the snappers. The most 

 peculiar feature about this tortoise is 

 the disproportionately large size of its 

 head, in which the beak is much 

 hooked; and an examination of the 

 skeleton will show that the temporal 

 fossae of the skull differ from those of 

 all the members of the preceding 

 family in being roofed over with 

 bone, as in the following family of 



the snappers. Moreover, the tail resembles that of the latter in its great length, 

 and also in the circumstance that the articular surfaces of most of its vertebrae have 



SIDE VIEW OF SKUI.I, OF BIG-HEADED TORTOISE. 

 (From Boulenger.) 



