1919. ] N. ANNANDALE & B. PrasHaD: Mollusca. 19 
Limnaea bactriana. Limnaea truncatula. 
Limnaea gedrostana. Gyraulus convextusculus. 
Limnaea gedrostana vat. rectilab- Gyraulus euphraticus. 
yum. Corbicula fluminalis. 
2? Pisidium paludosum. 
MoLLuUscA OF THE AFGHAN-BALUCH DESERT. ‘The following 
forms have been found in this desert :-— 
Melanoides pyramis var. flavida. Gyraulus euphraticus. 
Vivipara hilmandensis. Corbicula fluminalts. 
Limnaea persica. Lamellidens marginalis subsp. 
rhadinaeus. 
MoLLusca OF SEISTAN. In the alluvial plain of Seistan the 
following forms occur :— 
Amntcola (Alocinma) ststanica. Gyraulus convexiusculus. 
Vivipara hilmandensis. Gyraulus euphraticus. 
Limnaea bactriana. Segmentina calathus. 
Limnaea gedrosiana. Corbicula fuminalis. 
Limnaea gedrosiana vat. rectilab- Lamellidens marginalis subsp. 
yum. - vhadinaeus. 
Limnaea hordeum. 
Mortiusca OF PERSIAN BALUCHISTAN. Most of the molluscs 
known from this district were obtained by the late Dr. W. T. 
Blanford, but Mr. W. J. Good has recently added an interesting 
species. The following is a list of the known forms :— 
Melanordes pyramis var. flavida. Melanoides scabra. 
Melanoides pyramis var. luteo- - Melanopsis deserticola. 
marginata. Limnaea tranica. 
Of the lists, those of the species of the hill-country of Balu- 
chistan and of Seistan are probably the most complete. Moreover, 
these two are very similar and the discrepancies between them are 
probably more apparent than real. In the Seistan list five (out of 
eleven) specific names are, indeed, present that are absent from 
the other, viz. Amnicola sistanica, Vivipara lilmandensis, Limnaea 
hordeum, Segmentina calathus and Lamellidens marginalis. The 
Vivipara, however, seems to be essentially a fluviatile species, 
probably unable to live in any but pure fresh water, and rivers 
with pure fresh water (or water of auy kind) are proverbially 
scarce in Baluchistan; the Limnaea, which is also known from 
Mesopotamia, is exceedingly rare; Segmentina calathus, which is 
not uncommon at some places in the plains of North-western India, 
is local in its distribution, and the bivalve, though not yet found 
in Baluchistan, is common (in a distinct racial form) in the 
neighbouring country of Afghanistan. Of the species probably 
common to the two countries this bivalve is the only one in which 
even subspecific distinction is possible, but several others (e.g. 
Limnaea gedrosiana) exhibit slight local dfferences. Ammicola 
sistanica is the only species probably peculiar to Seistan, and 
