1921.] N. Annandale & R. B. S. Sewei<Iv ; Vivipara. 275 



Type-series. No. MiigGo/a Z.S.I, (from the Keligiri reservoir 

 Nellore district, Madras). 



Geographical Range. — This is the race commouly found in the 

 large reservoirs of the Madras Presidency and the central parts of 

 India. It occurs in abundance as far north as Sambalpur in the 

 interior of Orissa and has been collected occasionally in the south 

 central parts of the Ganges valley. Specimens from the northern 

 parts of its range are nearer the forma typica than those from the 

 eastern districts of Madras. Nevill states [Cat. Moll. Ind. Mus. 

 p. 27) that the spiral bands are sometimes absent in specimens from 

 near Calcutta, but such specimens are mere albinistic aberra- 

 tions and do not resemble eburnea in other respects. 



The race is usually found in perennial bodies of still water. 

 It reaches its maximum development among algae growing on 

 stones. 



I include provisionally in this race a small series of specimens 

 from a large pond in the town of Godaveri in the eastern part of 

 Madras. The shells are similar in shape but have the suture more 

 impressed. In one specimen, indeed, it is canaliculate, and so 

 deep that it forms an actual break in the shell at certain points, 

 where the soft parts are exposed ; but this shell was evidently 

 diseased. The pigmentation of the shell is very dense, the outer 

 surface being blackish brown with onty traces of the spiral bands, 

 while the interior is deep blue. The animal was also very 

 dark. 



These specimens were found amongst dense masses of the 

 Water Hyacinth and Pistia siratiotes, so congested that many of 

 the plants were rotting. Their peculiarities mav be due to this 

 fact. 



Race colaircnsis, nov. 



(Plate I, figs. 5-6.) 



This race is one of the most distinct with which I am 

 acquainted. It is remarkable for the elongate form of the shell and 

 its relatively small aperture, which is almost circular. These 

 features are noteworthy both in the normal and the elongate 

 type, which occurs rarely with the former. The shell is of very 

 large size, but thin and somewhat translucent. The pigmenta- 

 tion is rather deep, but dull. The alternating broad and narrow 

 bands are distinct. The sculpture resembles that of the forma 

 typica. 

 Type-series. No. MrigGi/^ Z.S.I. 



Geographical Range. — I know this race only from a single pond 

 at the village of Sriparptipada on the edge of the swamps that 

 skirt the Colair I,ake in the Kistna district of Madras. Specimens 

 from the lake itself belong to the race eburnea. 



Habits. — The pond in which my type-series was obtained was 

 deep and contained abundant water although the district was 



