BIG-HEADED TORTOISE. 



75 



black patches on the bright yellow plastron ; the carapace being brown. I have 

 taken specimens of this pretty little batagur, which does not exceed 8 inches in 

 length and is generally much smaller, near the fort at Calcutta. Like the under- 

 mentioned dhongoka, it occurs fossil in the Pliocene deposits of Northern 

 India. The larger species of the genus, such as the Indian dhongoka (C. dhongoka), 

 which grows to over 14 inches, has the fourth vertebral shield broad in front, 

 instead of being narrowed to a point. The three remaining genera, Callagur, 

 Batagur, and Hardella, differ from the preceding 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 20 inches in length. 



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

 thoroughly aquatic in their habits, 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. 

 Describing 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-backwards, to the bottom. The animals, unless they were much 

 irritated, never attempted 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 considerable agility, supporting their heavy bodies erect on their 

 legs, like a land-tortoise." 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. Batagurs 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 PLATYSTERNID^E. 



This extraordinary creature 

 (Platy sternum megacephalum), which 

 is an inhabitant of the south of China, 

 Siam, and Burma, is the sole repre- 

 sentative, not only of a very remark- 

 able genus, but likewise of a distinct 

 family, which appears to be to a great 

 extent intermediate 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 



SIDE VIEW OF SKULL OF BIG-HEADED TORTOISE. 



(From Boulenger). 



