128 



movements of the animal are not particularly rapid, though it is often seen 

 to swimm freely about in the water in the usual manner. 



Distribution. Throughout Europe, Siberia, Sumatra (O. O. Sars). 



Gen. 24. Herpetocypris, Brady & Norman, 1889. 



Generic Characters. Shell elongate, more or less reniforme in shape, 

 with the dorsal face scarcely at all arched. Valves conspicuously unequal, the 

 left being the larger and considerably overlapping the right both in front and 

 behind, edges smooth. Antennae not adapted for swimming, the natatory setae 

 of the posterior ones being quite rudimentary. Maxillae with the masticatory 

 lobes rather produced, spines on the outermost lobe distinctly denticulated, palp 

 with the distal joint slightly widening at the end. Maxillipeds with the vibra- 

 tory plate small, but well defined, palp slender and attenuated. Both pairs 

 of legs rather elongated. Caudal rami comparatively strong, sublinear in form, 

 with the dorsal edge minutely spinulose, apical claws rather unequal in size 

 and distinctly denticulated, dorsal seta very small and attached close to the apex. 



Remarks. This genus was proposed in the year 1889 by Brady and 

 Norman, to include Cypris reptans Baird and some other species considered 

 by them to be congeneric with it, and was chiefly caracterised by the rudi- 

 mentary condition of the natatory setae on the posterior antennas, causing the 

 animal to be quite devoid of swimming power; hence the generic name proposed. 

 The genus is here taken in a much more restricted sense than done by Brady 

 and Norman, only the type ^species being left in this genus, whereas the 

 other species referred to it by the said authors have been discarded and trans- 

 ferred to the next genus. Dr. Kaufmann has also confined the limits of this 

 genus in a similar manner, though one of his species, H. peregrina must be 

 removed from the genus. Only the type species is represented in the Fauna 

 of Norway. 



50. Herpetocypris reptans (Baird). 



(PI. LXIX). 



Candona reptans, Baird, British Entomostraca, p. 160, Pi. XIX, iigs. 3, 3 a. 



Syn: Cypris reptans, Lilljeborg. 



virescens, Brady. 



Specific Characters. Female. Shell, seen laterally, oblong reniform in 

 shape, height almost equal throughout and not attaining half the length, dorsal 

 margin nearly straigt and horizontal, with a slight angular bend in the ocuh 



