3o6 Records of the Indian Museum. [Voiv. VIII ^ 



I have compared specimens from the Brahmaputra system 

 with examples from Bombay determined by Prof. Bouvier as var. 

 sumatrensis and with others which appear to represent the same 

 form from Medha, Yenna Valley, Satara district, collected by 

 Mr. F. H. Gravely, and find a few differences which may ultimately 

 prove of importance. 



The rostral teeth are less numerous. Those on the dorsal 

 margin vary in number from lo to 17 (12 — 14 in 74% of the 

 specimens examined) and of these 3 to 5 (usually 4) are situated 

 on the carapace behind the orbital notch. On the ventral margin 

 there are from i to 5 teeth (2 or 3 in 78% of the specimens 

 examined). 



The fact that a number of dorsal teeth are situated on the 

 carapace behind the orbit (figs, 24, 25) shows that the Brahma- 

 putra race is more closely allied to the var. sumatrensis than to 

 the typical form. In the variety, however, the dorsal teeth are 

 decidedly more numerous (16 — 20), and comparison with specimens 

 from the Satara district seems to indicate that the Assamese 

 individuals are more stoutly built with rather shorter and less 

 slender limbs. 



In the chelae of the second peraeopods (fig. 27) the palmar 

 portion is decidedly more than half the length of the dactylus, a 

 feature noticed by Bouvier in examples of var. sumatrensis. 



C. weberi appears to be one of the commonest species of 

 Caridina in India and Burma : a large collection of specimens from 

 widely different localities awaits examination in the Museum. It 

 will probably be possible to distinguish a number of local races, 

 but to attempt to do so at the moment would be premature and 

 beyond the scope of the present paper. 



The colour of living specimens is very variable. They may be 

 uniformly dark, blotched or mottled. Frequently a broad whitish 

 mid-dorsal stripe is found running the whole length of the animal 

 and occasionally specimens are obtained which are vertically 

 barred on the sides. 



Specimens of the Brahmaputra race of C. weberi were found 

 on the Abor expedition at Kobo (Regd. no. ^) and at Dibru- 

 garh (^0 ). The form is also represented in the Museum collections 

 by numerous examples from the Darrang district on the right bank 

 of the Brahmaputra, — from the Dhansiri R. at Kowpati {—), from 

 the Deshnoi and Rowta rivers on the frontiers of Assam and Bhutan 

 {""^i'), from Mazbat (^") and Mangaldal i'}f). 



Caridina excavata, sp. nov. 



(Plate XX, figs. 32-35 ; plate xxi, figs. 36, 37.) 



The rostrum extends beyond the end of the antennular 

 peduncle and in some examples reaches just to the apex of the 

 antenr^l scale. In lateral view it is dorsally a little convex in the 



