PRI3IABY DIVISIONS OF THE CHELONIDES. 



117 



and the crocodile ; the body and limbs being those of the 

 former, while the tail is long, and sharply serrated, as in 

 the latter. A similar length of tail is found in the genus 

 Platysternon of Mr. Gray ; and there is reason to be- 

 lieve that other forms, imperfectly indicated by the old 

 writers, will be ultimately added to this group.* That 

 these singular animals are likewise connected to the soft 

 tortoises, belonging to the last division, is placed beyond 

 doubt by the structure of the Chelys fimbriata, or fim- 

 briated tortoise, — an animal which has the . lengthened 

 muzzle of the TrionicidcB, and the firm and plate 1 shell 

 of the ChelidridcB. This singular species {^fig. SQ.) in- 



' '^-^iv>'> 



habits the rivers of South America, and its shell, as in all 

 the other alligator tortoises, is much too small to receive 

 the head and feet : the nose is prolonged into a short thin 

 proboscis, the mouth opens crosswise ; while the jaws, 

 instead of being horny, like its congeners, are covered 

 with a soft skin, " much resembling," observes Cuvier, 

 " some of the frogs, particularly the Pipa, or Surinam 

 toad." The head and neck are large, thick, and more 

 than half the length of the shell ; the skin in these 

 parts is not only warty, but has several fimbriated or 

 membranaceous appendages, particularly two, which 

 stand nearly erect above the ears, and thus resemble 

 horns : other appendages are on the neck, so that the 

 whole animal has a most singidar and grotesque aspect. 

 The tail is like that of the TrioniddcB, being but an 



* Particularly the T. squamata of Linn,, which at present rests only 

 upon the short account and rude figure of Bontius, who describes it from 

 personal knowledge. He says that the whole body, as well as the neck, 

 legs, and tail (the latter much lengthened), is covered with scales re- 



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