510 



joint of fore tarsi slightly less than half as long as fore tibiae ( 12 : 25) ; 

 mid and hind legs with moderately long hairs; empodium about as 

 long as claws, distinctly fringed. Venation as in Figure 9, Plate 

 XXXV. 



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

 have a slight yellowish reflection and the veins are more distinct. 

 Apical segments of abdomen as in Figure 17, Plate XXXVIII. 



Joints of flagellum of antenna about as broad as long, with broad 

 leaf like sensory organs (PI. XXXVIII, Fig. 11), basal and second 

 joints distinctly separated. Wings differ from those of the male 

 in having the third and costal veins very closely approximated for 

 some distance before the apex of latter and continued beyond begin- 

 ning of apical curve of wing. 



Length, 1.5-2.5 mm. 



Illinois localities : Muncie, Urbana, St. Joseph, Rock Island, Ha- 

 vana, Grand Tower, Normal, on dates ranging from April 24 to Octo- 

 ber 21. 



Although this species has been reared by other workers from dung, 

 no description of the larva has been published. 



Originally described from Europe and recorded from Greenland, 

 Alaska, Washington State, New Jersey, and New York. 



Females labeled as aterrinms in the collection of the U. S. Bureau 

 of Biological Survey from Washington, D. C, are hyssimis. 



4. CamptocIvAdius aterrimus Meigen ? 



Chironomus aterrimus Meigen, Syst. Beschr. Eur. Zweifl. Ins., Vol. 1, 1818, 



p. 59. 

 Camptocladius aterrimus (Meigen) Van der Wulp, Ti.idsehr. v. Eut., Vol. 17, 



1874, p. 133. 



Male. — Closely resembles suhaterrimiis, n. sp., described on later 

 page, in color and structure, but differs in the structure of the hypo- 

 pygium (PI. XL, Fig. 9) and in the comparative lengths of the basal 

 joint of fore tarsi and fore tibiae (21 : 34). Wing as in Figure 8, 

 Plate XXXIX. 



Female. — Unrecognized. 



Length, 2.5-3 mm. 



Illinois localities: Carmi, April 15, 1914, on bank of little Wa- 

 bash River, and Rattlesnake Ferry — Big Muddy River — near Grand 

 Tower, April 22, 1914 (C. A. Hart and J. R. Malloch). 



I have provisionally considered this species as aterrimus, since it 

 agrees with Johannsen's description of that species and is probably 



