Ig19Q. | N. ANNANDALE & B. PrasHaD: Mollusca. 47 
near the point at which the liver-duct enters the alimentary canal. 
The proximal part of the stomach is somewhat sacculated. The 
liver is large and the intestine rather stouter than in some species. 
The genitalia are very like those of L. chlamys,' but the upper 
part of the male duct above the prostate, the lower part of the 
same duct and also the svermathecal duct are all considerably 
longer. Other apparent differences (the larger size of the female 
accessory glands and the more lobate form of the hermaphrodite 
gland) are probably due to the state of sexual activity in the 
specimens examined. The ovarian part of the hermaphrodite 
gland is particularly well developed. The prostate is spindle- 
shaped, but very small. 
Habitat. This species was described from Quetta and was 
found in considerable abundance in an irrigation-channel leading 
to the garden of the British Consulate at Nasratabad (Seistan 
town) and also in pools on the parade-ground at the same place. 
In the channel the water was usually still, but it was allowed to 
flow freely every few days. It was always more or less turbid. 
The bottom was composed of stiff clay and supported a rather 
scanty growth of Characeae and of a narrow-leafed Potamogeton. 
In the pools, which had a similar bottom but contained a some- 
what more luxuriant vegetation consisting chiefly of Zannichellia 
palustris, the water was extremely foul, being frequented by 
camels, donkeys and mules. ‘The basins had been excavated in 
obtaining clay for bricks and the water had probably entered 
by percolation. Shells were also found subfossil in the banks of 
old water-channels near Nasratabad. 
Habits. It is noteworthy that these molluscs, though living 
in water the surface of which was frequently frozen at the season at 
which they were observed, were in a state of sexual activity so 
far as the female organs were concerned. Egg-masses were abun- 
dant on the water-weeds. The adults seemed to feed chiefly on 
minute algae growing on the mud. 
No difference was observed between those individuals from 
the dirty pools and those from the irrigation channel. 
Affinities. Until the anatomy of the Asiatic Limnaeidae is 
better known some doubt must remain as to the affinities of this 
species. The shell resembles those of the group L. Jagotis, but is 
more distinctly perforate. The structure of the spire somewhat 
resembles that of L. lagotis var. subdisjuncta,? Nevill, but the 
penultimate whorl is relatively large and the structure of the 
mouth is quite different. Hutton in his original description com- 
pared the shell to that of the young L. chlamys, Benson, and curi- 
ously enough, before we recognized the identity of our specimens, 
we did the same so far as the genitalia were concerned. ‘There 
can be little doubt, therefore, that a relationship with the Indian 
! Annandale and Prashad, Rec. Ind. Mus., XVI, p. 143, fig. 4 (1919). 
2 Sci. Res. Yarkand Miss. Mollusca, p. 9 (1886). For figures see Weber, 
Wiss. Ergeb. Reise. Thian-Schan, Mollusken, pl. i, figs. f- (Ab. Bayer. Ak. 
Wiss. Math.-phys. Klasse, XX VI, 1913). 
