J42_ 



ated in the middle, anterior extremity well rounded off, posterior somewhat 

 narrower and obtuse at the lower comer; seen dorsally, oblong ovate in 

 outline, with the greatest width behind the middle and about equalling half 

 the length, anterior extremity gradually narrowed to an obtuse point, posterior 

 rounded off. Surface of shell distinctly pitted and rough from numerous short 

 and stout spines, being moreover rather densely hairy. Natatory setae on 

 posterior antennae finely ciliated and extending somewhat beyond the tips of 

 the apical claws. Vibratory plate of maxillipeds with 4 setae. Caudal rami 

 very small, with the flagellum twice as long as the stem. 



Colour of shell dark bluish green. 



Length of adult female 0.72 mm. 



Male unknown. 



Remarks. This form was recorded as early as the year 1852 by Costa, 

 and was the following year described by Lilljeborg as new, but with the same 

 specific name as that given to it by Costa. It is easily recognised from oui 

 other fresh water Ostracoda by the very dark bluish green colour of the sheli 

 and by its spiny armature. In the latter respect it comes however very neai 

 to some of the exotic species. 



Occurrence. I have taken this form rather abundantly in several places 

 of our country, but always in more or less brackish water. The reproduction 

 seems to be exclusively parthenogenetical, as I have newer come across ever 

 a single male specimen among the many hundred examined. The animals 

 are rather activ, swimming about in the water with great dexterity. 



Distribution. Throughout Europe, Island, Central Asia, North and South 

 Africa. 



Gen. 28, Cypridopsella, Kaufmann, 1900. 



Syn: Potamocypris, Aim (not Brady). 



Generic Characters. Shell much compressed, more or les reniform ir 

 shape and densely hairy. Valves very unequal, the right overlapping the lef 

 more or less conspicuously along the dorsal face. Antennae well adapted foi 

 swimming. Maxillae with the masticatory lobes short and stout, palp rather large 

 with the distal joint spatulate in shape and armed at the end with coarse 

 spines. Vibratory plate of maxillipeds quite rudimentary. Anterior legs rathe 

 slender. Caudal rami of a structure similar to that in the 2 preceding genera 

 Genital lobes of female provided in front with a peculiar hooked process. 



