103 



lappets. Ejaculatory tubes more slender than in Notodromas, but, as in that 

 genus, provided with numerous densely crowded whorls of radiating spikes, 

 ends of the tubes funnel-shaped, but less sharply marked off than in the 

 said genus. 



Remarks. This genus was proposed in the year 1854 by Zenker, to 

 include 2 species, the one of which is that described below, the other being 

 Cypris monacha O. Fr. Miiller, which now is removed as the type of a dif- 

 ferent genus, Notodromas. The differences between these 2 genera are indeed 

 very conspicuous, though in the structural details they have some characteristic 

 features in common, as pointed out in the above diagnosis. 



34. Cyprois marginata, (Strauss). 



(PI. XLVII, fig. 2, PI. XLVIII). 

 Cypris marginata, Strauss, Mem. Mus. Paris, Vol. 7, p. 59, PI. 1, figs. 20 22. 



Syn : Cypris flava, Zaddach. 

 dispar, Fischer. 



Cyprois dispar, Zenker. 

 . flava, Brady & Norm. 



Specific Characters. Female. Shell somewhat compressed, seen laterally, 

 broadly ovate or more properly subtriangular in shape, being considerably 

 higher in front than behind, greatest height about in the middle and some- 

 what exceeding 2 /a of the length, dorsal margin strongly arched in the middle 

 and sloping rather steeply behind, more slowly in front, exhibiting in the ocular 

 region a fainte concavity, ventral margin very slightly sinuated or nearly straight, 

 anterior extremity remarkably broad, almost semicircularly rounded off, posterior 

 obliquely deflexed and gradually narrowed, to form below a somewhat pro- 

 jecting obtuse corner; seen dorsally, oblong ovate in outline, greatest width 

 behind the middle and only slightly exceeding 2 /s of the length, anterior 

 extremity narrowly produced, posterior more obtuse. Valves subequal, with 

 the surface quite smooth and clothed at each extremity with scattered delicate 

 hairs, pellucid border very conspicuous in front and behind, being continued 

 also dorsally and ventrally as a narrow stripe, thus encircling the whole shell; 

 inner duplicatures rather broad in front. Eye comparatively small, but with 

 dark pigment. Anterior antennae with the terminal part considerably longer 

 than the basal one, its 1st joint about the length of the 2 succeding joints com- 

 bined. Posterior antennae with the penultimate joint very narrow and fully as 

 long as the preceding joint, apical claws rather slender and present in the 

 usual number, the outermost one however much reduced in size; natatory 



