23 



(1) The carapace is broader and not quite so deep ; 



(2) the epigastric crests are not so much in advance of the post-orbital 

 crests ; 



(3) the cervical groove is not so well graven in all its course. 



2. PoTAMON (Potamon) fluviatile (LatreiUe), var. Gedrosianum, nov. 

 (or PoTAMON iBERicuM, var. Gedrosianum). (Fig. 1.) 



This variety agrees with the variety ibericum in all but the following 

 characters : — 



(1) The carapace is broader, its length in large adults seldom exceeding 

 Mths of its greatest breadth, the broadening being due to the more marked 

 convexity of the autero-lateral borders ; 



(2) The cervical groove is deep-cut in its entire course, and there is distinct 

 though faint areolation of the epibranchial regions ; 



(3) The epigastric crests are more tumid and are more in advance of the 

 post-orbital crests. 



The distinctness of the cervical groove is more marked even than in the 

 variety edule. 



In a large male tlie carapace is 2s inches long by 21 inches broad. 



The following specimens are included in the collection : — ■ 

 6416 



3 ■ 

 6996 



3 ■ 

 3167 



,7 " 

 1208-12 



10 ■ 



5015 



10 ■ 



5504 



10 



5527 



10 ■ 



5547 



To" 



Salt Range, Punjab. 



Near Hallur Haliav. 



Loc. not recorded. 



Baluchistan. 



Seistan. 



Quetta. 



Peshawur. 



5550 / Barshor R., Peshin Valley, 1 



10 ' 1 Baluchistan. j 



^£i^. Seistan. Seistan Commission of 1904-5. IcJ, !?• 



10 



3. PoTAMON (Potamon) fluviatile, var. monticola, Wood-Mason (name only), 

 or, Potamon ibericum var. monticola. 

 This small variety differs from ibericum in the following particulars : — 

 The carapace is broader, its length being only iiths its greatest breadth, 



and the epibranchial tooth is less distinct. 



