74 



Records of the Indian M usciiiii. 



[Voh. IX, 



I have no doubt that recent authors arc right in regarding these 

 two species of Anderson {tricarinata and theohaldii) as specifically 

 identical. There is little if any constant difference between skulls 

 from the two districts (Chaibassa and northern Assam) in which the 

 two species were supposed to live, but the individual variation 

 between two skulls from Assam is not only considerable but also of 

 great importance in the taxonomy of the genus. I have alread}^ 

 indicated its nature (p. 65), which is clearly shown in fig. 6, pi. vi. 

 No information is available as to the soft parts of specimens from 

 Chota Nagpur. 



The following measurements include those of the type of 

 Geuemyda tricarinata, Blyth, and of two co- types of Chaibassia 

 theobaldii , Anderson : — 



No. 816. No. 1017. No. 188. No. 189. 

 (cf) (9) ( 9 ) (c^) 



Length of carapace 



(straight) 

 Breadth of carapace 



(straight) 

 lycngth of carapace along 



curve 

 Breadth of carapace along 



curve 

 Height of carapace 

 Length of plastron (notch 



to notch) 

 Length of skull 

 Breadth of skull 

 Length of orbit 

 Interorbital breadth 

 Length of snout 

 Height of nasal aperture 

 Width of nasal aperture 

 Breadth of lower jaw and 



of symphysis 



136 mm. 163 mm. 163 mm. 130 mm. 



01 



165 



lOI 



197 



97 



IQO 



159 



4*5 



The skull of No. 1017 was accidently broken some years ago 

 and that of No. 189 has not been removed from the specimen. 

 Although exact measurements of the former cannot be given, 

 sufficient of it remains to prove its close resemblance to that of 

 No. 188. 



Geoeniyda tricarinata ' has hitherto been found in the district of 

 Singhbhum (Chaibassa) in the south of Chota Nagpur and at the 

 base of the foot-hills north of the Brahmaputra. Anderson has 

 shown that the locality " Naga Hills" was given in error. The 

 species is apparently terrestrial in habits. Specimens are very 

 difficult to obtain on account of the inaccessible districts in which 

 t occurs. 



1 Since this paper went to the printer I have received a living specimen from 

 Mr. Lancelot Travers, who obtained it in the neighbourhood of the Baradighi 

 tea-estate in the Jalpaignri district of northern Bengal. 



