1918.] N. Annandale : Shells from Mesopotamia. 165 



occur in lower Mesopotamia. A large proportion of the shells I have 

 examined are immature or broken ; all are very small and many seem 

 to be distorted or abnormal. Some species of the genus are extra- 

 ordinarily plastic and an enormous number of forms have received 

 varietal or specific names. Indeed, it is doubtful whether a final diag- 

 nosis is possible in many cases without an examination of the radula 

 and genital system. I have not attempted, therefore, to name the 

 majority of specimens in the collection. They include representatives 

 of curious races or varieties that may belong to such species as L. lagotis 

 and L. ovata but, except in a few instances, I have not been able to 

 identify them with described forms. All are certainly different from 

 any of the forms from central Asia and from Baluchistan, Persia or 

 Palestine represented by specimens in the collection of the Zoological 

 Survey of India. In three cases I have been able to select series of 

 shells that agree tairly well with published figures of supposed species. 

 To these I give the appropriate names, but in so doing I wish it to be 

 understood that I do not intend to express an opinion as to the specific 

 validity of the forms. 



Limnaea tenera (Parreyss), Kiister. 

 (Plate XX, fig. 3.) 



1862. Limnaeus tener, Kiister, " Die Gattungen Limnaeus," etc., in Chemnitz's 



Conch.-Cab. (ed. Kiister), p. 54, pi. xii, figs. 1, 2. 

 1S65. Limnaeus tener, Tristram, Proc. Zool. Soc. London, }). 540. 

 1874. Limnara EuphnUka. Mousson, Journ. <le Conch. XXI, p. 40. 

 1894. Limnaea tenera, Dautzenberg, Rev. hiol. Nord France VI, p. .335. 



This may be no more than an Asiatic race of L. ovata, which in its turn 

 is probably no more than a phase of L. peregra. It was described from 

 Persia and according to Dautzenberg is common in swamps and lakes in 

 Syria. I have selected a series of shells from the specimens collected by 

 Colonel Lane in a swamp-deposit at Nasariyeh. The larger specimens, 

 though considerably smaller than Kiister' s figures, agree with them 

 otherwise in every respect except that the mouth is slightly narrower. 



Limnaea peregriformis, Locard. 

 (Plate XX, fig. 4.) 



1883. Limnaea peregriformis, Locard, Arch. Mas. d'' Hist. Nut. Li/on 111, p. 28(), 

 pi. xxiii, Hgs. 41-43. 



Several specimens from the lake-deposit at Nasariyeh agree fairly 

 closely with Locard's figures, except that they are much smaller (not 

 longer than 10-5 mm.) and that the body-whorl is sometimes not quite 

 so elongate. I am not at all sure that the form is specifically distinct 

 from the same author's L. lagotojjsis and L. reneana, and Kobelt^ is 

 inclined to regard the former as no more than an individual aberration 

 of L. lagotis and the latter as a young form of Locard's L. axiaca, which 

 Westerlund calls a variety of L. stagnalib. According to Kobelt, however, 



1 Kobelt in Rossmassler's Icon. Land-u. Siissw.-MoU. (new edition) XVIII, pp. 

 4,5. 



