256 Illinois State Laboratory of Natural History. 



angle of the second segment of the leg of nevadensis, will all 

 assist in determining the species. 



De Guerne and Richard (89b) make the statement that tin- 

 females always have the spermatophore — which they describe 

 as curved in a semicircle around the abdomen — attached. ( hi 

 none of the females examined by the writer was this structure 

 present. It may of course have been torn off, although 

 even then the statement that it is always present seems to 

 me too strong, since in E. lacustris and E. nevadensis the 

 female, even when mature, is very often found without a 

 spermatophore. 



Epischura nevadensis Lilljeborg. 



Epischura nevadensis , de Guerne et Richard, "89b, p. 93. PI. II., Fig. 



17.24; PJ. III., Fig. 21. 

 Epischura nevadensis columbice, Forbes/93. p. 254. PI. XLL, Fig. 19-21. 

 Epischura nevadensis, Herrick and Turner, '95. p. 84. PI. XL, Fig. 



1, 6, 8. 

 Epischura nevadensis columbice, Herrick and Turner. '95, p. 84. PJ. 



XL, Fig. 4, 10. 

 Epischura nevadensis, Schmeil, '97, p. 183. 



Of medium size and somewhat oval in form, broadest 

 before the middle. Front armed on each side with a hook- 

 like process pointing downward. Cephalothorax six-seg- 

 mented, the second segment the longest, about twice as long 

 as the first or last, which are subequal, the remaining three 

 segments subequal, each about a fourth the length of the 

 second. First two segments somewhat confluent, as are the 

 last two; last segment, seen from above, not produced and 

 entirely unarmed. Abdomen (furca included) composed of 

 five segments, the first two confluent and together almost as 

 long as the two following, which are subequal and slightly 

 longer than the furca. Furcal rami subquadrate, very short 

 and broad, and provided on the posterior part of the inner 

 margin with a few fine hairs ; armed at the outer apical angle 

 with a stout pointed spine, and at the inner apical angle with 

 a slender smooth seta, posterior margin armed with three long 

 delicately plumose setae, of which the inner is the longest, 

 the other two being about equal. In the male the abdo- 



