202 PELOMEDVSlD.t:. 



B. Alveolar ridges short and feeble. 



Mental barbels two -i- exj)(insci, j). 2u4. 



A single barbel 5. sextuberculata, p. 204. 



II. Forehead flat ; jugal in contact with the quadrate. 



Intergular shield very small, shorter 



than the gulars ; interparietal shield 



pointed behind 0. madwjascariensis, p. 205. 



Intergular shield longer than the 



gulars; interparietal shield widening 



behind 7. tracaxa, p. 206. 



1. Podocnemis dumeriliana. 



Emys dumeriliana, Schwpir/g . Prodr. p. 31 (1814). 



cayeuneusis, ScJnoeicjy. I. c. p. 29. 



en'throcephala, Sjnx, Test. Bras. p. 9, pi. vii. (1824). 



Hydraspis dumeriliana, Oray, Syn. Rept. p. 42 (18-31). 

 ■ — — cayeunensis, Gray, I. c. 



lata, Gray, I. c. p. 77. 



Podocnemis dumeriliana, Dum. S) Bihr. ii. p. 387 (1835); Gray, Cat. 



Tort. p. 45 (1844) ; Strauch, Chelon. Stud. p. 147 (1862) ; Gray, 



Proc. Zool. Soc. 1864, p. 134. 

 dumeriliana, part., Graxj, Cat. Sh. Rept. i. p. 62, pi. xxviii. 



(1855). 

 Clielonemys dumeriliana, part., Gray, Siippl. Cat. Sh. Rept. i. p. 83 



(1870),V/«fZ App. p. 25 (1872). 



Carapace oval, rather convex, but feebly expanded posteriorly ; 

 usually second and third vertebral shields with an obtuse keel. 

 Plastron large, front lobe broader than hind lobe ; the width of the 

 bridge at least equals the width of the hind lobe; intergular shield 

 much longer than the gulars ; the longest mcdiaii suture is formed 

 by the abdominals, the shortest by the humcrals. luterorbital 

 space concave, much narrower than the diameter of the orbit; 

 upper jaw not hooked ; a lai-ge interparietal shield, behind which 

 the parietals usually form a suture : this shield subcordiform and as 

 broad as long in the young, much elongate in the adult ; the width 

 of the mandible at the sym2;)hysis exceeds the diameter of the orbit ; 

 alveolar sui'f ace of upper jaw with two strong ridges, running along 

 the whole length of the jaw ; lower jaw with three cutting-edges, 

 the median and the inner close together. Chin with two short 

 dermal appendages. Two veiy large shields on the outer border 

 of the foot. Carapace brown or blackish above ; lower surface 

 yellowish or brownish, with blotches of blackish ; head reddish 

 brown in the adult, in the young blackish, with a yellowish band on 

 each jaw, a ytUowish spot behind the eye, and a pair of yellowish 

 round spots with black centre on the interparietal shield. 



Length of shell 38 centim. 



System of the Amazon. 



