2458 



TORTOISES, TURTLES, AND PLESIOSAURS 



Granulated 

 Soft Tor- 

 toises 



tives of the genus occur in the Miocene and Eocene strata of Europe, as well as 

 in the Tertiary rocks of India and the United States. Two other members of 



the first subfamily, confined to Asia, 

 represent as many genera. Of these 

 Cantor's soft tortoise (Pelochelys can- 

 tori) from India, Burma, and Mala- 

 yana has the sockets of the eyes placed 

 more anteriorly than in the type genus. 

 This forward position of the eye sockets 

 is still more marked in the much elon- 

 gated skull of the great Indian chitra 

 (Chitra indica), where they are placed 

 close up to the nose. 



The three remaining 

 genera of the family are 

 characterized by the 

 sculpture of the shell 

 generally taking the form of small pus- 

 tules, and thus resembling shagreen; 

 the hyoplastral and hypoplastral bones 

 of the lower shell are united, and there is 

 a flap of skin on each side of the under 

 surface, beneath which the hind-limbs 

 can be concealed. All the forms are 



confined to the Old World; and while one of the three genera is Indian, the other 

 two are African. The Indian genus Emyda is readily characterized by the presence 

 of a complete series of neural bones in the carapace, coupled with a semicircle of 

 marginal bones at its hinder extremity. In neither of the three living species does 

 the length of the shell and its soft disc exceed ten inches, but much larger fossil 

 forms are found in the Pliocene rocks of India. Both the African genera lack 

 marginal bones, but whereas in one (Cycloderma) there is a full series of neural 

 bones to the carapace, in the other (Cyclanorbis) these form an incomplete and in- 

 terrupted series. 



All the soft tortoises are thoroughly aquatic, most of them but 

 rarely leaving the water except for the purpose of laying their eggs, 

 and in consequence of these habits very little is known as to their mode of life. 

 Although confined as a rule to rivers, a few of the species frequent estuaries, and 

 Cantor's soft tortoise has been found some distance out at sea. Occasionally, 

 again, specimens of the Indian granulated soft tortoises have been met with 

 wandering on land far from the neighborhood of water. Fiercer and more spiteful 

 than any other members of the Chelonian order, these tortoises, owing to a pecul- 

 iarity in the structure and mode of articulation of some of the vertebrae of the 

 neck, have the power of darting out the head with inconceivable rapidity, the great 

 Indian chitra being facile princeps in this respect. Owing to this habit the larger 

 species are dangerous creatures to approach incautiously, as their bite is very 



CANTOR'S SOFT TORTOISE. 



Habits 



