422 Illinois State Laboratory of Natural History. 



FAMILY CYTHERIDiE. 



"Shell mostly hard, calcareous, usually with an un- 

 even surface either sparingly clothed with hairs or alto- 

 gether bare; hinge generally toothed. Eyes more or 

 less separated, sometimes wanting. Antennules sub- 

 pediform, geniculate at the base; five- to seven-segmented; 

 beset with short setse which are partly spine like. Anten- 

 nae strong, pediform, curved, four- or five-segmented, with 

 two terminal claws; basal segment bearing a long seti- 

 form biarticulate fiagellum, which conveys a duct from 

 a poison gland ; second segment destitute of a setose 

 brush. 



"Mandibles usually strong, enlarged and toothed at 

 the apex; palp well developed, directed forward, and 

 bearing on the posterior margin strong curved setse 

 and a poorly developed branchial appendage. First 

 pair of postoral appendages more or less maxilliform; 

 the three following alike, pediform, directed downwards, 

 adapted for walking. One pair of branchial laminae 

 attached to the maxillae. Caudal rami obsolete, form- 

 ing two rounded setiferous lobes. Copulatory organs of 

 the male large and complex; in addition to which there 

 is a curious bifurcate appendage between the feet of the 

 first pair; ovaria and testes not produced between the 

 valves; no mucous gland. Animal incapable of swim- 

 ming."— G. O. Sars. 



I am not aware that representatives of this family have 

 heretofore been reported for America. Of the dozen or 

 more genera belonging to this family, but one (Limni- 

 cythere) seems to be purely a fresh-water genus. 



I. LiMNICYTHERE BraDY. 



1850. Cytkere, Baird (2, p. 163). 



1868. lAmnicythere, Brady (6, p. 419). 



1878. Acanthopus, Vernet (72, p. 516). 



1888. Limnocythere, Dahl (20, p. 615). 



1889. lAmnicythere, Brady & Norman (9, p. 170). 

 1891. Limnicythere, Vdvra (68, p. 107). 



