On Fresh-water Entomostraca. 63 



dorsal margin in female almost straight, with an indication 

 of angle both anteriorly and posteriorly, in male evenly 

 arched throughout: — seen from above, narrow oblong, 

 more pointed in front than behind. Valves equal, smooth, 

 semi-pellucid, of whitish colour, hairy at both extremities. 

 Caudal rami very narrow, almost straight, and terminating 

 with 2 somewhat unequal claws, each having beyond the 

 middle a distinct secondary denticle, dorsal bristle wanting. 

 Length of female 0.90 mm., of male 1.00 mm. 



Remarks. — This, I believe, is the form briefly 

 described and figured by Prof. Brady as Candona tenuis. 

 It certainly belongs to the genus Candonopsis, as recently 

 characterised by Mr. Vävra in his Monograph of the 

 Ostracoda of Bohemia, and is nearly allied to the typi- 

 cal form C. Khigsleyi, though differing somewhat in the 

 form of the shell, and apparently also in the structure of 

 the caudal rami. 



Description. — The length of the shell in adult female 

 specimens scarcely exceeds 0.90 mm.; that of male specimens 

 is somewhat greater, measuring 1.00 mm. 



The shell in both sexes is highly compressed and, seen 

 laterally (fig. 6 a, 6 b), of an oblong reniform shape, the 

 greatest height scarcely exceeding half the length, and occur- 

 ring behind the middle. Both extremities are rounded, and 

 the anterior one is considerably narrower than the posterior, 

 which appears somewhat compressed in its inferior part. 

 The dorsal margin in the female (fig. 6 a) is nearly straight 

 in the middle, with an indication of an angle both in front and 

 behind, whereas in the male (fig. 6 b) this margin appears 

 quite evenly arcuate. The ventral margin is in both sexes 

 distinctly sinuated, but the sinus occurs in the male (fig. 6 b) 

 somewhat in front of the middle, whereas in the female 



5 — Archiv for Math, og Naturv. B. XVIII No. 3. 

 Trykt den 16de Juli 189G. 



