OF WASHINGTON. 203 



Psocus slossonse Banks. 



One from Falls Church, Va., izth July ; one from Glencarlyn, 

 Va., July, and one from Plummer's Island, Md., i6th July. 



Psocus bisignatus, n. sp. 



Head black, nasus with eight pale lines, two prominent pale spots on 

 vertex, and oblique pale marks downwards from the ocelli ; clypeus wholly 

 black; antennae pale brown, basal joints darker. Mesothorax black, a 

 median spot behind, and two dots on each side behind, yellowish ; meta- 

 thorax black, with a median pale spot; abdomen black, the segments nar 

 rowly margined with yellowish; legs yellowish brown, darker on tips of 

 femora and tibiae. Wings hyaline, an incomplete black band just before 

 cell, a small black spot at base of the pterostigma, and a larger spot in 

 apex, extending outward ; venation mostly dark, base of the fork of sector, 

 most of vein closing cell below, part of that on apical side, and the vein 

 around pterostigma (except near angle) pale yellowish; hind wings hya 

 line, venation brown. Vertex convex; antennae shorter than wings, and 

 with very short fine hair; discal cell very plainly 5-sided, the apical side 

 curved inward ; pterostigma with prominent angle, which is prolonged 

 into a distinct spur. Length, 3.2 mm. (Genitalia, Plate II, Fig. 10.; 



Two specimens from Falls Church, Va., 25th June, 

 Psocus elegans, n. sp. 



Head pale, almost white, nasus wholly dark brown, with a brown exten 

 sion to each eye; clypeus brown; a few dark dots behind each eye; an 

 tennae pale, basal joints white. Mesothorax dark brown, margined with 

 pale behind; metathorax paler brown ; abdomen pale; legs pale. Fore 

 wings whitish-hyaline, a more or less complete black band starting from 

 base of pterostigma and extending obliquely backward; a black spot in 

 apex of pterostigma extending outside, base of pterostigma faintly clouded, 

 and black spots in the bases of the four posterior cells; sometimes one or 

 two other small black spots in apical part of wing; hind wings hyaline; 

 venation pale, except where touched by the black marks. Head narrow 

 below; vertex deeply emarginate; eyes very prominent; antennae shorter 

 than wings, sparsely clothed with rather long hairs; nasus hairy; discal 

 cell 4-sided or almost so, lower side fully two-thirds length of upper, outer 

 side but little longer than upper; pterostigma rounded behind. Length 

 3 mm. 



Three specimens from Falls Church, Va., i2th and ryth July, 

 and 5th August; one from bark of whitewood, and two from 

 bark of chestnut trees. 

 Cerastipsocus nervosus Burmeister. , 



In colonies on trunks of trees, Falls Church, Va., August and 

 September. 

 Polypsocus corruptus Hagen. 



Abundant on the leaves of trees from July to September, 



