J35 



within this group; but their right definition is by no means in every case 

 quite clear. In the Fauna of Norway 3 of these genera are represented. 



Gen. 26. Pionocypris, Brady & Norman, 1896. 



Syn: Cypridopsis, auctorum (part). 



Generic Characters. Shell tumid and more generally short and high, with 

 the ventral face more or less flattened. Valves only slightly unequal, the left 

 one being a little larger than the right, with the shelf-like expansion of the 

 ventral edge strongly marked; inner duplicatures moderately broad in front 

 and continued along the ventrale side to the hind extremity. Antennae power- 

 fully developed and well adapted for swimming. Maxillae with both the palps 

 and the masticatory lobes narrowly produced. Maxillipeds with the vibratory 

 plate more or less reduced. Anterior legs strongly built, with the apical claw 

 very long and slender. Caudal rami quite rudimentary, and apparently immo- 

 bile, forming 2 small justaposed lappets, each terminating in a slender seti- 

 form flagellum. 



Remarks. This genus was proposed in the year 1896 by Brady and 

 Norman, to comprise some of the species previously referred to the genus 

 Cypridopsis, the type of the genus being Cypris vidua of O. Fr. Muller. The 

 above-named authors included in this genus also the Australian species, Cy- 

 pridopsis globiilns G. O. Sars. But this form has turned out to be referable 

 to an other genus, viz., Cypretta Vavra, differing essentially in the structur eof 

 the caudal rami. Several species of the present genus have been recorded, 

 both from Europe and from other continents. To the Fauna of Norway belong 

 6 species, to be described in the succeeding pages. 



55. Pionocypris vidua (O. Fr. Muller). 



(PI. LXIII). 



Cypris vidua. O. Fr. Muller, Entomostraca, p. 55, PI. IV, figs. 79. 



Syn : Cypris sella, Baird. 



Monoculns vidua, Jurine. 



,, Cypridopsis vidua. Brady. 



Specific Characters. Female. Shell very tumid, seen laterally, short ovoid 

 in shape, greatest height in the middle and almost attaining 2 /s of the length, 

 dorsal margin boldly arched in the middle, ventral margin very slightly sinuated 

 and somewhat bowed in the oral region, anterior extremity well rounded off, 

 posterior a little narrower and obtuse at the end; seen dorsally, broadly ovate, 



