170 Illinois State Lahoratorii of Natural History. 



minute spine ; second and third segments subequal ; fiircal 

 rami slightly longer than the third segment, about twice as 

 long as wide ; and delicately hairy within. In the male the 

 second abdominal segment and the furcal rami are subequal, 

 and each is longer than any of the other segments. The 

 furcal rami are considerably longer than the preceding seg- 

 ment, fully twice as long as wide, and hairy within. 



Antennfe 2 5 -segmented, reaching well beyond the tips of 

 the furcal setae. Eight male antenna not much swollen 

 anterior to the geniculate joint- antepenultimate segment 

 unarmed. 



Left fifth leg of male (PI. XXVIII., Fig. 1) short, extending 

 beyond the middle, but not reaching the end of the second 

 segment, of the outer ramus of the right leg. First basal 

 segment armed at the outer distal angle with a short, sharp 

 spine. Second basal segment aljout equal to the first, almost 

 as wide as long. First segment of the outer ramus irregularly 

 trapezoidal in form, about half as wide as the second basal 

 segment, and delicately hairy on the inner margin. Second 

 segment somewhat as in D. oregoncnsis Lilljeborg. It is pro- 

 duced into two digitiform j^rocesses, the outer of which is 

 more than twice as long as the inner and armed on the inner 

 margin at the tip, with a small cushion-like, delicately hairy 

 process. There is a distinct suture between the main part of 

 the second segment and the inner of the two processes, and the 

 process itself is minutely denticulate on the outer margin. 



Inner ramus of left fifth leg one-segmented, reaching to the 

 base of the inner digitiform process ; outer margin hairy, 

 almost straight ; inner margin somewhat sinuously curved. 



First basal segment of the right fifth foot of the male sub- 

 quadrate, slightly longer than wide, armed at the outer distal 

 angle wdth a short, sharp spine. Second segment about as 

 wide as the first and one and a half times as long ; provided 

 with the usual hair on the outer margin. First segment of the 

 outer ramus a little more than half as long as the second 

 basal segment and slightly longer than wide ; second segment 

 less than half as wide as long and more than twice as long as 

 the preceding segment. Marginal spine rather short, about 



