FRE'^H- WATER CRUSTACEA. 843 



triangular spine at its base. The appendage of the left side is shorter and 

 stouter, with two conspicuous knobs along its lower margin and with a slightly 

 curved, somewhat lamellar, hook. 



The first leg, in immature specimens, has a large protuberance at the angle 

 of the penultimate joint, and a trace of this protuberance remains in the 

 adult. The furcal rami of one male examined are similar to those of N. 

 monacha, having a much curved shaft and three subequal setae at the end, 

 but in all other specimens, male or female, they are shorter and stouter, and 

 remarkable for the presence on the dorsal margin of a double tubercle about 

 the middle of its length. Probably, this, as also the form of the first leg, is 

 a mark of immaturity. 



Length of shell '75 mm. 



Height ,, '38 mm. 



The description given above is, owing to the nature of the material, very 

 incomplete ; but the species appears to me to be clearly distinct. It resem- 

 bles N. entzi, Daday, in some respects, but differs strikingly in the form of 

 the prehensile appendages of the male and the form of the furcal rami. 



Cyprinotus dentatomarginatus , Baird-Sars. 



Amara — Fort Farm moat. 



Cyprinotus incongruens, Ramd. 



Kharabah Marsh near Amara. 



The specimens examined differ from the type in having rather more con- 

 spicuous tubercles on the shell margin, but agree so closely in other respects 

 that I consider they should be referred to this species. 



Eiicypris virens, Jurine-G. W. Muller. 



Resht, N. W. Persia. 



The identiiication of this species is rather doubtful, since the specimens were 

 so damaged that only a single shell valve was found intact. 



Cypris pubera, G. W. Muller. 



Amara and Ezra's Tomb, Mesopotamia. Enzeli, N. W. Persia. 



Herpetocypris reptans (Baird). 



Enzeh, N. W. Persia. 



Potamocypris variegata (Brady & Norman). 



Enzeli, N. W. Persia. 



Ilyocypris hradyi. G. 0. Sars. 



Amara. 



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