148 Records of the Indian Museum. [VoL. XVIII, 
convexiusculus, which is the more abundant of the two, at the 
edge of the lower Euphrates at all points at which deposits are 
formed by floods. Probably Mousson included both species under 
the name Planorbis (Gyraulus) devians vat. euphratica. ‘There 
are no fresh specimens in the collections examined. 
Gyraulus convexiusculus (Hutton). 
1919. Gyvaulus convexiusculus, idem, op. cit., pp. 40, 53, figs. 5e, 70, 
8d. 
This is by far the most abundant species of the family in all 
the flood-deposits from Lower Mesopotamia from which I have 
examined shells. Capt. Boulenger obtained living specimens on 
mud-flats of the River Euphrates at Gurmut Ali, N. of Basra. As 
usual, the shell exhibits great individual variability and some 
examples come much nearer G. euphraticus than others. I can, 
however, detect no constant difference from series from India, 
Burma and China. 
Gyraulus intermixtus (Mousson). 
1874. Planorbis (Gyraulus) intermixtus, Mousson, Fourn. de Conchyl. 
(3) XIV, p. 45. 
This species is scarcer in the river-deposits of Lower Meso- 
potamia than either of the other two and I have only seen empty 
bleached shells. It is, however, widely distributed in this area. 
pod 
Gyraulus intermixtus (Mousson). 
It is closely related, as Mousson points out, to G. euphraticus, 
though that author did not recognize the identity of the latter 
species with the P. compressus of Benson and Hutton; but it 
differs in that the spiral is more transverse and deviates less 
below and in that the keel is situated_at the base of the last whorl 
instead of round its middle. ‘This is a very characteristic feature. 
Mousson trefers to the sculpture as ‘‘ transverse tenurter striata.” 
In the specimens before me I can detect no transverse striae, but 
they are perhaps slightly water-worn. ‘They agree well in other 
respects with the original description. 
Subfamily BULLININAE. 
Genus Bullinus, Adanson. 
1918. Bullinus, Annandale, Rec. Jnd. Mus., XV, p. 167. 
Mousson recognizes two species of this genus from flood- 
deposits in Lower Mesopotamia. He calls them Physa (Iszdora) 
