TEIONYX. 



13 



7. Trionyx hurum. 



Trionyx hiinim, Gray, Syn. Hejjt. p. 47, pi. x ; id. III. Ind. Zool. ii, 



pi. Ixvi ; Boideny. Cat. Chel. ^-c. p. 249. 

 Trionyx ocellatus, Gray, III. Ind. Zool. i, pi. Ixxviii ; Theuh. P. A. S. 



B. 1875, p. 174, pl. iv ; id. Cat. p. 29. 

 Trionyx gangeticiis, Giinth. Rept. B. I. p. 47. 

 Trionyx buchanani, Theob. P. A. S. B. 1874, p. 78. 

 Trionyx gangeticus, part., Theob. Cat. p. 28. 



Fig. 5. — Trionyx httritm (young). 



Costal plates eigbt pairs, the last well developed and in contact 

 throughout on the median line ; two neurals bet\^eeu the fii'st 

 pair of costals ; plates coarsely pitted and vermiculate. Epiplastra 

 narrowly separated from each other in front of the entoplastron, 

 which forms an obtuse or a right angle ; plastral callosities very 

 large, hyo-hypoplastral, xiphiplastral, and in old specimens ento- 

 plastral. Dorsal skin of young \^ith longitudinal ridges of small 

 tubercles. Head moderate ; snout (on the skull) a little longer 

 than the diameter of the orbit ; interorbital region, in the adult, as 

 broad as the nasal fossa ; postorbital arch somewhat more than 

 half the diameter of the orbit in the adult ; mandible without 

 strongly raised inner edge or longitudinal sympbysial ridge ; the 

 diameter of the mandible at the symphysis exceeds the diameter of 

 the oi'bit. Olive-brown above and beneath ; head, neck, limbs, and 



