413 



CoRYXONEURA Winncrtz 



This genus of very small species is distinguished in the females 

 from other genera of the Chironomincc by the absence of the anal 

 angle of the wing and the peculiar thickening of the veins and mem- 

 brane of the wing from the apex of the subcostal vein to the apex of 

 the third. The antennae of the male are 13-jointed, the flagellum 

 short-haired and consisting of 11 joints; the antennae of the female, 

 7- jointed. 



Thienemanniella Kieffer differs from Corynoneura in having the 

 eyes pubescent. 



Corynoneura celeripES Winnertz 



Corynoneura celeripes Winnertz, Stett. Ent. Zeit., Vol. 13, 1852, p. 50, sp. 3. 



Female. 

 Corynoneura atra Winnertz, ibid., sp. 4. Male. 



This species is the only member of the genus recorded from 

 North America. The sexes differ considerably in color, the male 

 being much darker than the female, the mesonotum being velvety 

 black, while the female has the thorax almost entirely yellow, with 

 three brown or blackish vittse on the mesonotum and the scutellum 

 brown. Winnertz, misled by this color difference, described the sexes 

 as different species. 



Length (of both sexes) generally slightly less than i mm. 



lUinois localities: Havana, April 29, 1914 (J. R. Malloch), and 

 Algonquin, May 12, 1896 (W. A. Nason). 



Originally described from Europe. Recorded subsequently from 

 Greenland by Lundbeck, and from Ithaca, N. Y., by Johannsen. I 

 have seen a female specimen taken at Lafayette, Ind., April 24, 1914, 

 by Professor Aldrich. 



Corynoneura similis, n. sp. 



Female. — Yellow, opaque. Mesonotum with the vittae dark 

 brown; postnotum paler brown. Dorsal surface of abdominal seg- 

 ments brown, with pale spots at the bases of the hairs. Legs yellow. 

 Wings clear, the thickened portions of the veins yellowish brown. 

 Halteres yellow, knob pale brown. 



Structurally very similar to celeripes, the most noticeable differ- 

 ence being in the wing venation. In celeripes the cubitus forks very 

 distinctly beyond the apex of the third vein, whereas in similis it forks 

 appreciably before that point. The thickening of the veins is also 

 more abrupt in celeripes than in siniilis. The wing of the latter is 



