1918.] N. Annandale: Shells from Mesojjotamia. 169 



in the collection of the Indian Museum. These are perhaps more like 

 the typical cor. Germain {Inc. cil.) treats ('. crassuUi as a variety of 

 C fluminalis. 



Family UNIONIDAE. 



The Western Asiatic species of this family are described and figured 

 piecemeal by Kobelt in the new edition of Rossmassler's " Iconographie," 

 on which I have relied mainly in the following identifications. 

 Volumes XVIII and XIX (1912-1913) contain most of the descriptions. 

 There seems to be much confusion among the named shells from Meso- 

 potamia in the Indian Museum. 



Unio calliopsis (Bourg.), Kobelt, 



1913. Unio calliopfiis, Kobelt in Rossmassler's Iron. Land-n. Sussw. MoU in f ) 

 XIX, p. 15, pi. dxix, fig. 2703. 



There are a number of fresh shells in Mr. Hodgart's collection from the 

 banks of the Euphrates at Nasariyeh. Most of them are rather smaller 

 than Kobelt's figure, but a single worn valve which has the character- 

 istic hinge is larger : 62 mm. x 31 mm. The shell is thinner than 

 the other Unionid shells in the collection and its epidermis is paler than 

 that of other fresh specimens. 



The species was described from Baghdad. 



Unio tigridis, Bourguignat. 



1912. Unio tigridis, Kobelt, oji. cit., XVIII, p. 62, pi. dx, figs. 268.'}, 2684. 



Fresh shells from the same collection as the last species show consider- 

 able variation in outline and have the epidermis darker than it is shown 

 in Kobelt's figures. 



The species occurs in both the Tigris and the Euphrates. 



Unio dignatus var. semiramidis, Kobelt. 



1913. Unio dignnlus semiramidis, Kobelt, op. cit., XIX, p. 11, pi. dviii. fio-. 2698. 



Dead shells from Samara agree with Kobelt's figures. The variety 

 was described from " the Euphrates near Baghdad." 



Unio ciconius (Bourg.), Kobelt. 



1913. Unio ciconius, Kobelt, lorn, cit., p. 11, [)1. dvii, fig. 2607. 



Shells were found, with those of the last species at Samara by Colonel 

 Lane. The type-specimens were collected near Mossul. 



Gabillotia euphratica (Bourguignat). 



1886. Margariliina ciiphraticd, Kobelt, op. cit., II, j). 26, pi. xlv, fig. 266. 



A single fresh valve from the Euphrates at Nasariyeh agrees well 

 with Kobelt's figure. The species has been found in the Tigris as well 

 as the Euphrates. 



