ROE ORT? ON -<f Et Boe P_R OE SO EEW ALE EaR= GAS R OF 
POD MOLLUSCS 7OF WOW R 
MESOPOTAMIA. 
PAR? II.—THE FAmtity PLANORBIDAE. 
By N. ANNANDALE, D.Sc., F.A.S.B., Director, Zoological Survey of 
India. 
I have examined shells of four species of this family from 
Lower Mesopotamia, three belonging to the genus Gyvaulus, one to 
Bullinus. As all but one of these have recently been discussed in 
these “‘ Records’”’ and as the one species not hitherto considered 
is represented in the collections before me merely by empty shells, 
there is not much that can be profitably said here. I think, how- 
ever, that it will now be convenient to treat Bullinus as the type- 
genus of a distinct subfamily, in which Physopsis, Krauss, may be 
provisionally included. At least one recent writer has talked of 
the family Bullinidae, but in view of the close resemblance between 
the young shell of certain species of Planorbis (s.s.) and the adult 
shell of Bullinus, this course seems to me to go too far. 
Family PLANORBIDAE. 
Subfamily PLANORBINAE. 
Genus Gyraulus, Agassiz. 
Of the three species found in Lower Mesopotamia, two have 
been discussed already in this volume. I have unfortunately no 
information about the anatomy of the third. 
Key to the species of Gyraulus of Lower Mesopotamia. 
1. Shell surrounded by astrong median keel ; mouth 
of shell sharply pointed externally .. G, euphraticus. 
2. Median keel absent or poorly-developed ; mouth 
rounded or bluntly-pointed externally ... G. convexiusculus. 
3. Mouth of shell relatively small, bluntly pointed 
externally ; a fairly strong basal keel on peri- 
phery of shell see aac .. G. inteymixtus. 
Gyraulus euphraticus (Mousson). 
1919. Gyraulus euphraticus, Annandale and Prashad, Rec. Jnd. Mus., 
XVIII, pp. 40, 53, 55, figs. 5c, 7a, 8a. 
I have nothing to add to our recent observations on this 
species except to say that shells occur mixed with those of G. 
