441 



The early stages are unknown. 



This species has the usual comb of spinules at apex of hind tibia; 

 which characterizes Chironomus. In the Orthocladius group the hind 

 tibiae have one or two apical spurs. 



23. Chironomus basalts, n. sp. 



Male. — Black. Head entirely black, plumes of antennae fuscous. 

 Thorax opaque, entirely covered with dense grayish pruinescence ; 

 postnotum with the pruinescence more dense on apical than basal half. 

 Abdomen shining black when viewed from behind, but when viewed 

 from in front the segments are seen to be covered with pale grayish 

 pruinescence. Legs fuscous, tibiae and basal two tarsal joints of all 

 legs pale brown. Wings clear, cross vein not infuscated or indistinctly 

 so; veins brown. Halteres brown, knobs yellow. Hairs on body and 

 legs yellowish. 



Apical joint of palpi about one half longer than subapical, the latter 

 slightly longer than the antepenultimate. Pronotum linear on upper 

 half, reaching nearly to upper margin of mesonotum; hairs on meso- 

 notum confined to the median and submedian lines. Hairs on abdomen 

 rather sparse, regularly distributed ; hypopygium almost identical with 

 that of palliatus (PI. XXXHI, Fig. 16). Fore tarsi bare, basal joint 

 slightly longer than fore tibiae (50:45); scalelike protuberance at 

 apices of mid and hind femora large, mid and hind femora and tibiae 

 with long hairs. Third and fourth veins end respectively at an equal 

 distance before and behind apex of wing; cubitus forking distinctly 

 but not greatly beyond cross vein. 



Female. — Agrees in coloration with the male except that the legs 

 are generally darker, the pale color of tarsi being generally confined to 

 the base of the first joint. 



Length, 3-3.5 mm. 



Type locality, Dubois, 111., April 24, 19 14 (C. A. Hart and J. R. 

 Malloch). Swept from vegetation along bank of creek. 



24. Chironomus palliatus Coquillett 



Chironomus palliatus Coquillett, Proc. U. S Nat. Mus., Vol. 25, 1902, p. 9). 



Larva. — Length, 6—7 mm. Yellowish or yellowish green. The 

 condition of the larval exuviae is such that a description is not possible 

 beyond indicating that the labial plate (PI. XXXII, Fig. 6) has the 

 central tooth divided in the middle ; that the mandibles are as in Figure 



