On Stenocypris Chevreuxi. 



Stenocypris Chevreuxi, G. O. Sars. 

 (PL 1 & 2). 



Specific Characters. — Y Shell, seen laterally, oblong 

 reniform, height about equalling 2 /h of the length, anterior 

 extremity somewhat obliquely rounded, posterior obtusely 

 produced, dorsal margin perfectly straight in the middle, 

 and subangular above the eye, ventral slightly sinuated in 

 front of the middle: — seen from above, oblong fusiform, 

 greatest width about equalling V3 of the length and occurring 

 behind the middle, both extremities obtusely pointed. Valves 

 very unequal, the left one being much the larger, and over- 

 lapping the right considerably both in front and behind; 

 inner duplicatures of moderate size, and somewhat different 

 in the 2 valves. Surface of shell smooth and polished, 

 clothed at both extremities with hairs, those of the hind 

 extremity remarkably elongated and less densely crowded 

 than on the anterior. Natatory setæ of the inferior antennæ 

 extending to the tips of the terminal claws. Caudal rami 

 rather strong, though narrower than in the type species, and 

 perfectly equal, outer half of the dorsal edge divided into 

 4 — 5 slight lobes, each armed with a comb-like series of 

 teeth; terminal claw about twice as long as the other, both 

 coarsely denticulated on their concave edge, apical seta 

 rather elongated, that of the dorsal edge very small and 

 occurring close to the proximal claw. Colour light greenish, 

 clouded with darker shadows. Length of adult female 

 2.40 mm. 



Remarks. — In its general appearance, this form shows 

 some resemblance to the well-known European species, 

 Herpetocypris reptdns (Baird), exhibiting a similar elongated 

 reniform shape of the shell. It cannot, however, even be 

 referred to the same genus, as the natatory setæ of the 



