168 Illinois State Laboratory of Natural Histor/i. 



Inner ramus of right fifth leg one-segmented, very narrow, 

 extending about half its length beyond the end of the first 

 segment of the outer ramus ; apex with an acute triangle, 

 hairy at the tip ; sides parallel. 



First basal segment of the left fifth leg produced on the 

 anterior aspect, near the outer margin, into a long tubercle 

 ending in a minute, sharp spine ; second basal segment with 

 delicate hair near the outer distal angle. First segment of 

 the outer ramus subquadrate, shorter than the preceding, 

 slightly longer than broad ; second segment about as long as 

 the first and about twice as long as wide ; very similar to the 

 corresponding segment of D. sicilis Forbes. 



Inner ramus of left fifth leg long and narrow, margins sin- 

 uously curved; extending about to the middle of the last 

 segment of the outer ramus ; delicately hairy at the tip. 



Second basal segment of fifth leg of female (PI. XXXII., 

 Fig. 1, 2) with the usual delicate hair at the outer margin. 

 First segment of the outer ramus about twice as long as 

 wide ; second segment somewhat longer than the first, taper- 

 ing to a rather sharp point and curving outward slightly, 

 delicately denticulate on the inner margin; third segment 

 wanting, represented by two spines, the outer about twice as 

 long as the inner. 



Inner ramus one-segmented, extending slightly beyond 

 first segment of the outer ramus, hairy, ending in acute tri- 

 angular tip ; armed at the apex with two rather long sub- 

 equal spines which are sometimes hairy. 



Length of female .97 mm. ; of male .9 mm. 



A reference to the "Distribution of American Species" (see 

 page 183), will show the wide range of this form. In the 

 collections of the U. S. Fish Commission from Lake Samma- 

 mish, Lake Union, and Lake Washington, "Wash. ; Tsiltcoos 

 Lake, Tahkenitch Lake, and Klamath Lake, Oregon ; and 

 Lake Pend d' Oreille and Gamble's Lake, Idaho, T>. ashlandi 

 was found in immense numbers, being either the only centro- 

 pagid or occurring in connection with Epischura nevadensis 

 Lilljeborg. 



