1919- 1 N. Annandale ; Bombay Streams Fauna. 141 



This species was found in considerable abundance at Khrin 

 dalla in pools containing an abundant aquatic vegetation but 

 largely of artificial origin and formed by the damming of small 

 hill-streams. 



The shells bear a close general resemblance to Von Marten's 

 figure of the var. patula, but vary considerably in the breadth o^ 

 the body-whorl. Most of the adult specimens are not more than 

 about 19 mm. long and about 10 mm. broad. Occasionally, how- 

 ever, very much larger and broader individuals occur in the ponds. 

 The shells of such individuals are always eroded on the surface 

 and have the apex more or less eaten away ; if complete they 

 would be about 30 mm. long and 18 mm. broad. The aperture 

 of the shell is relatively large (about 21 mm. by 11 mm.). Such 

 shells are evidently those of aged individuals which have survived 

 the vicissitudes to which most of their contemporaries have 

 succumbed. 



The Oligochaete worm Chaeiogaster was frequently observed on 

 this mollusc at Khandalla. 



The species is one of the commonest of the Indian Lininaeae, 

 and has been found in many parts of Peninsular India and the 

 Indo-Gangetic Plain. 



Limnaca acuminata var. nana, nov. 



(Plate IV, fig. i; pi. V, fig. 2). 



The shell of this form (pi. IV, fig. i) is very small, rather 

 thick, of a blackish colour and with the longitudinal striae very 

 strongly developed. In outline it somewhat resembles the var. 

 rufescens, Gray, as figured by Von Martens in the paper cited 

 above, but the spire is relatively longer, the body-whorl more 

 swollen, the columellar callus coarser and the aperture narrower 

 and somewhat curved inwards posteriorly. 



Measurements of type-specimen. 



Length . . - ■ • ■ 9 3 mm- 



Breadth . . . . • . 5'6 mm. 



Length of aperture . . 6 mm. 



Breadth of aperture • • 3 mm. 



Shells of this size are sexually mature. The radula (fig. 2, 

 pi. V) differs from that of the typical form mainly in the greater 

 irregularity of the shape of the teeth. Even in parts which are 

 quite unworn the cusp of the central tooth is irregular and often 

 asymmetrical. The cusps of the lateral teeth are shorter and the 

 inner cusp is relatively smaller. In the marginal teeth the second 

 and the innermost cusps are considerably enlarged. 



The central piece of the horny upper jaw is narrower, paler 

 in colour and apparently less convex than in the foryna typica. 



The genitalia (text-fig. 3) agree precisely with those of the 

 typical form. 



