TRIONYCHID^. V 



R. 1426. The distal extremity of a costal bone, probably belonging 

 to this species ; from the Narbada Yalley. 



Presented by C. Eraser, Esq., 1849. 



R. 1426 a. The postero- external angle of the left hypoplastral ; 

 from the Narbada Yalley. This specimen exhibits the 

 marked flatness characteristic of this species as distinct 

 from T. hurum. Presented by C. Fraser, Esq., 1849. 



R. 1426 b. The left xiphiplastral, wanting the posterior extremity ; 

 from the Narbada "Valley. 



Presented by C. Fraser, Esq., 1849. 



Crtongj: fjurum, Gray ] . 



Smaller than the preceding species. Skull with a longer and 

 more pointed muzzle, the interorbital bar as wide as the nares, and 

 a longer mandibular symphysis. Hypoplastrals much curved exter- 

 nally ; carapace with traces of longitudinal ridges. 



Var. sivalensis. 



Characterized by a median and two lateral ridges on the carapace, 

 of which there are only traces in the living form. 

 Bab. India. 



R. 601. Cast of the plastral aspect of an imperfect shell. The 

 original, which is preserved in the Indian Museum, Cal- 

 cutta, was obtained from the Pliocene of the Siwalik Hills, 

 and is described and figured by the writer in the ' Palse- 

 ontologia Indica ' (Mem. Geol. Surv. Ind.), ser. x. vol. iii. 

 p. 205, pi. xxvii. fig. 3, without specific name. The 

 plastron accords so closely with that of T. hurum, that 

 there seems little doubt that the specimen can only be 

 regarded as a variety of that species. 



Made in the Museum, 1885. 



R. 1427. The postero-external angle of a left hypoplastral agreeing 

 generally with the corresponding part of T. hurum, but 

 indicating a somewhat larger form than existing indi- 

 viduals; from the Siwaliks. If not referable to this 

 species, this specimen probably indicates an allied form, 

 since it is quite distiuct from T. gangeticus. 



Cauiley Collection. Presented, 1840 



1 ' Synopsis Reptilium,' p. 47 (1831). 



