510 



three, which have rather broad, pale posterior bands. In other re- 

 spects very similar to the male. 



The legs are less distinctly haired than those of the male, the cross 

 vein is nearer to the base of the wing, and the apical portion of first 

 and third veins are distinctly dilated. 



Length, 1.75-2 mm. 



Type locality, Havana, 111., taken in numbers at rest upon trees 

 and buildings at Chautautiua Park on the bank of the Illinois River 

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



Early stages unknown. 



Var. basalis, n. van 



Male. — This variety differs from the type in being slightly smaller, 

 1. 25-1. 5 mm., and in having the bases of all the femora blackened. 

 In some specimens the black covers the greater part of the femora, 

 this being most noticeable on the fore pair. The pale margins of the 

 fifth and sixth abdominal segments are either indistinct or absent. 



Female. — Differs from the male in the same manner as the type. 

 The vittae are occasionally but little darker than the ground color of 

 the thorax. 



Type locality, Havana, April 28-30, 1914, along the shore of 

 the Illinois River. Paratypes from the following Illinois localities, 

 all taken during 19 14: Big Muddy River near Grand Tower, April 

 22 ; Peoria, October 22 ; Rock Island, October 21 ; Muncie, May 24, on 

 Stony Creek; St. Joseph, May 31, — (C. A. Hart and J. R. Malloch). 



Early stages unknown. 



Var. bicolor, n. var. 



Two specimens which agree with variety basalis in size and color 

 of legs differ in the color of the abdomen, the basal half being white 

 and the pale margins of fifth and sixth segments very broad. The 

 hypopygium is slightly different also (PI. XXXVII, Fig. 6). 



Type locaHty, St. Joseph, 111., May 3, 1914 (J. R. Malloch). 



It is possible that this is a distinct species, but more specimens are 

 requisite to render an opinion advisable. 



PSECTROCIvADIUS Kieffcf 



The species in this division, as far as my present material indi- 

 cates, are generally much paler than those of Orthocladius, and in this 

 respect resemble most of those of Triclwcladius, differing from the 



