REPORT .ON, DEE PER See We Acie 
GASTROPOD MOLLUSCS OF LOWER 
MES OP OT AMTA: 
PART I. ‘THE GENUS LIMNAEA. 
By N. ANNANDALE, D.Sc., F.A.S.B., Director, Zoological 
Survey of India, and BAtnt PrasHap, D.Sc., Offg. Director of 
Fisheries, Bengal, Bihar and Orissa. 
(With Plates XIII, XIV.) 
In the report of which the first part is now published we pro- 
pose to discuss the freshwater Gastropod molluscs of the delta of 
the Tigris and Euphrates and of the lower reaches of the two rivers. 
Stress of other work and official duties have already greatly delayed 
its preparation, and as the medical authorities are anxious for any 
information about the freshwater molluscs as soon as possible, we 
have decided to issue it in parts dealing with separate genera or 
larger groups. It will be convenient to include this report in the 
same volume as that on the molluscs of Seistan, as the two faunas 
are reiated. 
The material from Mesopotamia that we now have in our 
hands consists of three collections, ail presented by the generosity 
of their collectors to the Zoological Survey of India. Two of these 
have already been discussed! They were made by Lt. Col. W. H. 
Lane and Bombadier R. Hodgart and consist of empty shells, most 
of which were probably subfossil. The third collection, made by 
Capt. C. L. Boulenger, adds greatly to our knowledge as it includes 
specimens preserved in spirit. It has been possible with its aid to 
correct and expand the results based on shells previously examined. 
We have, so far as possible, consulted the literature on the 
Persian, Central and Western Asiatic molluscs, as well as that on 
those of India and Europe, but it is possible that some Russian 
works, or memoirs published in Europe during the war, may have 
escaped our notice. The only paper dealing specifically with 
Lower Mesopotamia that we have found is Mousson’s, ‘‘ Coquilles 
ters. et fluv. rec. Dr. A. Schlefli en Orient” in the Journ. de 
Conchyl. XXII (1874). The descriptions in this paper are fairly 
full and it has not been difficult with specimens before us to dis- 
criminate the species. The paper, however, is not illustrated, and 
without figures or specimens verbal descriptions of freshwater 
molluscs have little value. We are strongly of the opinion that 
t Annandale, Rec. Ind. Mus. XV, pp. 159-170, pl. xx (1918). 
