Gen. 2. Erythrocypris, G. W. Mtiller, 1894. 



Syn: Pontocypris, G. O. Sars (part). 



Generic Charachters. Shell of a more or less deep reddish or brownish 

 Colour and rather more elongate than the in preceding genus, almost cuneiform 

 in shape, with the posterior extremity considerably exerted and terminating in 

 an obtuse point. Valves only slightly pellucid and more or less densely hairy, 

 the right one distinctly serrated at the hind corner below. Eye wholly wanting. 

 Both pairs of antennae comparatively shorter and stouter than in Pontocypris, 

 but otherwise of a very similar structure. The other limbs likewise built on 

 the very same type as in that genus. Prehensile palps of the maxillipeds in 

 male, however, considerably more powerfully developed and conspicuously 

 unequal. Posterior legs in both sexes with the pectinate apical seta much larger 

 than the other 2, which are very thin and subequal. Caudal rami rather stronger 

 than in Pontocypris and of more equal width throughout, distal seta of the 

 dorsal edge very small. Copulatory appendages in male of rather varying shape 

 in the several species. Spermatic vessels densely coiled within the posterior 

 extremity of the valves. Ovarial tubes forming a simple bend, their extremity 

 extending forwards along the ventral edge. 



Remarks. This genus, established by G. W. Muller in 1894, is closely 

 related to Pontocypris, and indeed 2 of its species were formerly referred by 

 the present author to that genus. Yet, on a closer comparison, some well marked 

 differences, mentioned in the above diagnosis, between the 2 genera are found, 

 which would seem to corroborate the distinction of them. G. W. Muller records 

 7 species of this genus found by him in the gulf of Naples, one of them being 

 however identical with the form described below as E. mytiloides. 2 other 

 species belonging to the Fauna of Norway wiL also be treated of in the sequ( 



2. Erythrocypris mytiloides, (Norman). 



(PI. XXI & XXII) 



Cythefe mytiloides Norman, Species of Ostracoda new to Britain. Ann. Mag. Nat. Hist. Vol. IX, 



p. 50, PI. Ill, figs. 13. 



Syn : Cypris serrutata, G. O. Sars. 



Cythere avena, Norman. 



. Pontocypris serrulata G, O. Sars. 



, Erythrocypris serrata G. W. Muller. 





Specific Characters. Female. Shell much compressed, seen laterally, elong- 

 ate triangular or somewhat cuneiform in shape, highest in front and gradually 

 tapered behind, greatest height in the anterior third part and not nearly attaining 



