373 



face hairs very long and assuming a whorl-like arrangement on each 

 segment ; apical portion of lateral arm of hypopygium shaped some- 

 what like that of illiuooisis, but the thicker, or main branch of the 

 stem is not clubbed at apex. Legs slender; basal joint of fore tarsus 

 shorter than the next two joints together and about three fifths as 

 long as fore tibia; mid and hind legs with long surface hairs; fore 

 tarsus with short hairs ; fourth tarsal joint longer than fifth. Wings 

 rather narrow, cross vein well before middle; costa reaching to curve 

 at apex of wing; surface hairs numerous and distinct. 



Female. — Similar in coloration to the male except that the abdo- 

 men is generally almost entirely yellowish, or occasionally with the 

 dorsum grayish. 



The antennae are very slightly longer than the thorax, and as long 

 as from base of wing to cross vein ; the hairs are rather long and fine, 

 and the apical joint is not swollen. The body is stout and has short 

 surface hairs. In other respects as the male. 



Length, 1-1.5 mm. 



Illinois localities: Havana, at light, September 12-15, 1^95 5 same 

 locality, June 15, September 16 and 27; Quiver Lake, Havana, July 

 27, 1896; Ashley, Havana, Carmi, Grand Tower, and Golconda dur- 

 ing the latter part of April, 1914; Monticello, June 28; Momence, July 

 17; L^rbana, October 5 — the last two at light (C. A. Hart and J. R. 

 Malloch). 



Originally described from the District of Columbia. I have seen a 

 specimen from Lafayette, Ind. (Aldrich). 



Coquillett described pallcns from Las Vegas Hot Springs, N. M., 

 and without comparing the specimens in hand with his type of that 

 species it is impossible to decide w^iether our specimens are pallens. 

 The markings on the abdomen vary considerably in the series of speci- 

 mens before me, and may occasionally appear as described by Coquil- 

 lett. 



The descriptions that follow probably apply to the larva and pupa 

 of piloscllus, but as they have not been reared the identification is 

 only provisional. 



Larva. — Length, 3 mm. Head two and a half times as long as its 

 greatest breadth, slightly tapering anteriorly, ventral surface as shown 

 in Figure 14, Plate XXVI; a single large black eye-spot on each side 

 at middle ; antennae retracted but the basal portion apparently not over 

 twice as long as the apical portion, the whole about half as long as the 

 head ; mandible pale, apical tooth sharp, but not very slender, a trun- 

 cated tooth near middle of inner surface ; labial plate toothed as in 

 Figure II, Plate XX\\ Anterior pair of pseudopods very long and 



