113 



Gen. 19. Eucypris, Vavra, 1891. 



Generic Characters. Shell of somewhat varying shape, but as a rule of 

 less firm consistency than in the preceding genus, and not particularly flattened 

 ventrally, edges of valves smooth, inner duplicatures comparatively broader than 

 in Cypris. Antennae well adapted for swimming and, like the oral parts, of 

 a very similar structure to that in the preceding genus. Legs however, some- 

 what different, the anterior ones having the penultimate and antepenultimate 

 joints well defined, and the posterior ones terminating in a more or less 

 distinctly developed minute chela formed by a small hook-like projection of 

 the apical joint impinging against a projecting lobute of the preceding joint. 

 Caudal rami comparatively shorter than in the preceding genus. Propagation, 

 as a rule, exclusively parthenogenetical. 



Remarks. This genus was proposed in the year 1891 by Vavra, but was 

 taken by him, as also by most other authors, in a much wider sense than 

 admitted in the present account. In the restriction here adopted only 6 

 European species are referable to this genus, 3 of which will be described 

 below, the other 3 species not yet found in Norway being E. ornata (Jurine), 

 E. clavata (Baird) and E. Lilljeborgi (G. W. Miiller). In more southern lati- 

 tudes, however, the genus seems to be very abundantly represented. 



39. Eucypris virens (Jurine). 



(Pi. LH). 



Monoculas virens, Jurine, Hist, des Moncles, p. 174, PI. XVIII, figs. 15, 16. 

 Syn: Cypris tristriata, Baird. 

 ,, ,, ornata, Fischer (not Jurine). 



Specific Characters. Female. Shell moderately tumid, seen laterally, 

 suboval or slightly reniform in outline, greatest height about in the middle and 

 equal to 3 /5 of the length, dorsal margin boldly archeil, forming in the middle 

 an abrupt, almost angular bend, and sloping at a nearly equal rate to each 

 extremity, ventral margin slightly sinuated in the middle and a little bowed 

 in the oral region, both extremities rounded off and nearly equal; seen 

 dorsally, oblong ovale in outline, greatest width somewhat behind the middle 

 and about equalling half the length. Surface of valves smooth and clothed 

 with short and fine hairs more conspicuous at each extremity; inner duplica- 

 tures of moderate size, rather broader in front than behind. Anterior antennae 

 with the terminal part about the length of the basal one, joints gradually 

 diminishing in size. Posterior antennae with the penultimate joint somewhat 

 shorter than the preceding joint and about of equal width throughout, apical 



14 Crustacea. 



