220 



CHELYDID^. 



olive-brown, lower surface yellow, with some black spots under tbe 

 neck ; a black streak under the car and another behuid the barbel. 



Length of shell 32 centim. 



Brazil. 



G. PLATEMYS. 



Hj'draspis, part., BcU, ZooL Joi/rn. iii. p. 51 1 (1828) ; Grai/, Si/n. 



^liept. p. an (18;51), and Cat. Tort. p. 38 (1844). 

 riateniys, Wof/ler, Si/.^t. Amph. p. 135 (1830) ; Gray, Cat. Sh. Bept. 



i. p. 53 (1855), and Siij)p/. p. 75 (1870). 

 rialeuijs, part,, Ihoii. S^- Bibr. ii. p. 404 (1835) ; Strauch, Chelon. 



Stud. p. 45 (1802). 

 Acanthocholys, Gray, Aim. 8,- May. N. II. (4) xi. p. 305 (1873). 



Fig. 01. 



Shell of Platemys platycephala. 



Neural plates absent; nuchal shield present, marginal. Plastron 

 large, with moderately strong axillary and inguinal buttresses, the 

 latter anchylosed to the fifth costal plate. Parietal bones broad, 

 expanded above, connected with the strong supraoccipital arch ; 

 jaws moderately strong, without alveolar ridges. Chin with a i)air 

 of dermal appendages, or barbels. Digits webbed. 



South America. 



