304 



Eyes contiguous; antenna about one third longer than head and 

 thorax combined, only the apical three joints distinctly elongated, as in 

 Figure 7, Plate XX. Hairs on mesonotum short. Hypopygium as in 

 Figure i6, Plate XX. Legs slender ; hind tibiae with rather long hairs ; 

 basal joint of hind tarsi as long as the next three joints combined; 

 fourth over two thirds as long as fifth ; claws simple, short, not more 

 than half as long as fifth joint. 



Female. — Agrees with male in color. Eyes narrowly separated; 

 antenna about one third longer than head and thorax combined, the 

 last five joints elongated, the apical three slightly more elongated than 

 the two preceding, sensory hairs curved, as long as the joints ; the en- 

 larged palpal joint with its thickest part at middle, rather oviform, the 

 last two joints very short and closely fused. Otherwise as the male 

 except that the wings are, as usual, much broader and more distinctly 

 spotted. 



Length, 1.5 mm. 



Type locality, Dubois, 111., April 24, 1914, male. Allotypes from 

 LTrbana, May 18-24 and October 9, the last two dates at light; and 

 from St. Joseph, May 3, 19 14. Specimens taken by Chas. A. Hart 

 and the writer. Paratypes and allotype from South Haven, Mich., 

 July 15, 19 1 4, at light (C. A. Hart). These latter specimens as com- 

 pared with the Illinois specimens, have the thoracic markings reduced 

 slightly and paler in color. A single paratype is in the collection of the 

 U. S. Bureau of Biological Survey, from Graham Mt., Arizona, 3200 

 feet, May 30, 191 4. 



Ceratopogon Meigen 



The species of Ceratopogon, in the restricted sense, are not numer- 

 ous in Illinois, but two of the species are very widely distributed and 

 common. The larva of one species only is known to me. Nothing is 

 known of the habits of the Illinois species in the adult stage. Johann- 

 sen has described eques, which either belongs to this genus or to Pseii- 

 docidicoides, and records it as attacking a bat.* The present writer has 

 usually been able to obtain adult specimens by sweeping vegetation 

 near to streams, and many have been taken on windows of houses in 

 the daytime or on store windows at night, after the lights were 

 turned on. 



Key to Illinois Species 



1. Scutellum yellow, contrasting with the much darker color of the mes- 

 onotum 2 



— Scutellum brown or black, eoneolorous with disc of mesonotum ... 3 



*Bull. 124, N. Y. State Mus., 1908, p. 266. 



