REPORT ON THE FRESHWATER GASTROPOD MOLLUSCS OF LOWER MESOPOTAMIA. Part III. — The Families Neritidae, Hydrobiidae AND Melaniidae. By B. Prashad, D.Sc, Assistant Sitperintendent, Zoological Survey of India. Since the publication of the first two parts of this series, the Indian Museum has received a valuable collection of Mesopota-mian molluscs from Dr. E. W. Bowell, made b}^ him at Basra during iVugust 19 17— February 1919, ^md placed with great generosity at our disposal. This collection, together with the collections mentioned in the previous parts of this report has rendered the working out of the Mesopotamian molluscs much easier and more satisfactory. Specimens of the families reported en in the first two parts of the report are also represented in this collection, but these do not offer any specially interesting points for further discussion. They belong to the following species : — Limnaea tenera enphratica. Gyraulus convexiusculus.^ Limnaea peregra canalijera. Gyraulus eitphraticus. BuUinus contortus. Gyraulus intermixtus. The only point to be noted in reference to these is that the large series of L. peregra canalifera exhibits much greater indivi-dual variabiHty than the specimens previously examined. Family NERITIDAE. Genus Neritina, Lamarck. Subgenus Dostia, Gray. 1919. Dosfia, Annandale and Prashad, Rec. Ind. Mas., X\'I, pp. 242, 243 In the paper cited above Dr. Annandale and I considered Dostia, Gray, as distinct from Neritina, Lamarck, but asa result of further examination of the rich collections in the Indian Museum I am inclined to consider it as worthy of subgeneric rank only. ^ We would invite attention to the fact that there has been an unfortunate transposition of lettering-in reference to Gyraulus euplwaticus and Segmentina calathus in fig. 5 on page 40 of this volume. The figure D refers to the Seg-mentina and the figure F to the Gyraulus. {N. A. and B. P.'\.
BioStor
