141 



Gen. 27. Cypridopsis, Brady, 1866. 



Generic Characters. Shell of somewhat varying shape in the different 

 species, but, as a rule, far less tumid than in Pionocypris. Valves only slightly 

 unequal, the right being however a little larger than the left, and overlapping 

 it in front by a narrow pellucid border; surface more generally rough by 

 numerous densely set impressed pits, and in some cases armed with stout 

 spines. Antennas well adapted for swimming, but comparatively less strongly 

 built than in Pionocypris. Maxillae with the masticatory lobes narrowly pro- 

 duced; palp rather feeble, with the distal joint narrow and longer than broad. 

 Maxillipeds with the palp comparatively short, and in male prehensile; vibratory 

 plate more or less reduced. Anterior legs more slender than in Pionocypris. 

 Caudal rami very small and of a structure similar to that in the said genus. 

 Copulative appendages of male with the outer lappet boot-shaped. Ejaculatory 

 tubes with numerous whorls of radiating spikes, proximal extremity truncate. 

 Spermatic vessels forming in each valve dense coils both in front and behind. 



Remarks. The present genus is here taken in a more restricted sense 

 than done by Brady and most other authors. Indeed the 3 species comprised 

 by Brady, in his genus represent in my opinion as many separate genera, one 

 of them, C. vidua, being the type of the genus Pionocypris treated of in the 

 preceding pages, and another, C. villosa, that of the genus Cypridopsella Kauf- 

 mann, to be spoken of farther below. It is thus only left in the genus Cyprid- 

 opsis the 3rd species recorded by Brady, viz., C. aculeata. Although rather 

 nearly allied to Pionocyptis, the present genus is well distinguished by the far 

 less tumid shell, and by the right valve (and not the left) being the larger. 

 Moreover slight difierenses are to be found in the structure of some of the 

 appendages. The genus is represented in the Fauna of Norway by only a 

 single species, to be described below; but in other parts of the world numerous 

 species referable to this genus have been recorded. 



61. Cypridopsis aculeata. (Costa). 



(PI. LXV., fig. 3). 

 Cypris aculeata, Costa, Fauna del regno di Napoli. 



Specific Characters. Female. Shell, seen laterally, broadly oval or some- 

 what trigonal in shape, greatest height in the middle and nearely attaining 2 / 3 

 of the length, dorsal margin boldly arched and almost angular in the middle, 

 sloping rather steeply both in front and behind, ventral margin distinctly sinu- 



