93 



greater part of our country. In spite of its small size, it may easily be detected 

 by the bright chestnut brown colour of the shell. 



Distribution. Sweden (Lilljeborg), British Isles (Brady), Germany (G. W. 

 Muller), Switzerland (Kaufmann), Siberia (G. O. Sars), North America (Turner). 



28. Cyclocypris lasvis (O. Fr. Muller). 



(PI. XLIII, tig. 2). 

 Cypris Icevis, O. Fr. Muller, Entomostraca, p. 52, PI. Ill, figs. 79. 



Syn: Cypris minuta, G. O. Sars (not Baird). 

 pantherina, Fischer. 



, Cyclocypris serena, G. O. Sars (not Koch). 



Specific Caracters. Female. Shell very short and high, seen laterally, 

 rounded trigonal in shape, greatest height in the middle and almost attaining 

 3 /4 of the length, dorsal margin gibbously arched in the middle, ventral margin 

 straight, both extremities rounded off, the posterior blunter than the anterior; 

 seen dorsally, broadly ovate in outline, greatest width behind the middle and 

 about equal to the height, anterior extremity somewhat narrowed, posterior 

 broadly rounded. Valves more densely hairy than in the preceding species, 

 and exhibiting a peculiar tessellated pattern of the surface. Posterior legs with 

 the terminal joint about half the length of the penultimate one, middle apical 

 seta comparatively longer than in C. ovum and distinctly sigmoid. Caudal 

 rami of about same shape as in that species, but distinguished by a rather 

 peculiar armature of the dorsal edge at the base, consisting of a knob-like 

 prominence exerted into 3 sharp points and followed proximally by a row of 

 4 well marked denticles. 



Male scarcely differing from the female, except by the usual sexual 

 characters. 



Colour dark brownish grey, with a more or less distinct olivaceous tinge. 



Length of adult female 0.50 mm. 



Remarks. Though the identity of the above-described form with Cypris 

 Icevis of O. Fr. Muller appears to me to be very questionable, it is here 

 recorded under that specific name, as it has been so named by most recent 

 authors. It is of about the same small size as C. ovum, with which it indeed 

 seems often to have been confounded. On a closer examination, it may however 

 easily be distinguished from that species by the comparatively higher and more 

 tumid shell, and in the fresh condition also by its rather different colour. The 

 peculiar armature of the caudal rami at the base, described above, seems to 



