499 



vein ending considerably in front of apex of wing (PI. XXXIX, Fig. 

 17) ; surface of wings with very distinct hairs. 



Female. — Differs from the male in being much paler in color, the 

 abdomen having only brownish markings on anterior portions of dor- 

 sal segments. 



The legs are rather stouter and somewhat shorter than in the 

 male, the proportions of the basal joint of fore tarsi and fore tibiae 

 being as 12, 18, and the surface hairs on wings are more distinct than 

 in the male. 



Length, 1-1.25 mm. 



Type locality, Muncie, 111., May 24, 1914, swept from vegetation 

 on bank of Stony Creek (C. A. Hart and J. R. Malloch). 



Allotype and paratypes from Madison, Wis., August 26, 1913, at 

 light (A. C.Burrill). 



This species differs from lundhccki in having the third vein very 

 much shorter — a character which will distinguish it also from every 

 other described North American species of Metriocncniiis. 



Chasmatonotus Loew 



The species of this genus are separable from those of any other 

 chironomid genus occurring in North America by the presence on the 

 thoracic dorso-median line of a distinct narrow furrow or fissure 

 which extends beyond the middle of the disc. The antennae in both 

 sexes are short- haired and consist of eight joints (2+6). The vena- 

 tion is somewhat similar to that of Ortlwcladius (PI. XXXV, Fig. 8). 

 Only one species has been taken in Illinois as far as I am aware. The 

 other four North American species of the genus have been collected as 

 follows: unk'ittatus Coquillett, in Alaska; iiniiuaculatits Loew, in 

 New Hampshire; fascipciiiiis Coquillett, in British Columbia; and 

 hyalinus Coquillet, in California. 



— Chasmatonotus bimaculatus Osten Sacken 



Chasmatonotus himaculatus Osten Sacken, Bull. U. S. Geol. Surv., Vol. 3, 1S77, 

 p. 191. 



This species is distinguishable from any of the others in the genus 

 by the wing-markings (PI. XXXV, Fig. 8). The hypopygium is 

 shown in Figures 7 and 10, Plate XXXVI. 



Illinois localities: Lake Forest (Johannsen) ; Urbana, May (C. A. 

 Hart) ; St. Joseph, six specimens swept from undergrowth May 17, 

 1914 (C. A. Hart and J. R. Malloch). 



Recorded from New York, New Jersey, and Quebec. 



Early stages undescribed. 



