24 
COLORADO EXPERIMENT STATION. 
to twice the length of the latter, and possessing a single row of rath- 
er stout, pale yellow spines along the outer margins ; color pale 
greenish yellow. [See fig. 1.] 
Described from fifteen females and five males taken by the 
writer sweeping native plants, in most cases short prairie grass, be- 
tween August 16th and October 7th, and on May 28th. The points 
from which specimens were taken are Fort Collins, Colorado Springs, 
FIG. 1. 
Deltocephalus parvulus : (a) upper surface of vertex, pronotum and scutellum; (b) female 
genitalia from beneath; (c) male genitalia from beneath . Grealty enlarged (original). 
New Windsor, and Horsetooth Gulch. This species is a rival of 
minimus 0. & B. in minuteness, which species it closely resembles. 
It is readily distinguished, however, by the broadly rounded, uni- 
colorous, entire last ventral segment of the female, and the smaller, 
more acute valve in the male. 
DELTOCEPHALUS COOKEI, n. sp. 
Color cinereous to grayish brown, vertex with dark markings, 
length 2J m. m. 
Vertex broad, flat, not distinctly depressed nor strongly pro- 
duced, rounded at the apex ; color pale yellowish, variously flecked 
with dark brown, median line nearly obsolete, length barely equal- 
ing the distance between the eyes and less than one-half the width 
of the head. Froiit pale brown, with about six incomplete trans- 
verse bars, and nearl}^ parallel sided, rather narrow, width at cly- 
peus fully one-half the width at the ocelli ; labrum sordid yellow, 
in most examples streaked with black on the middle, nearly parallel 
sided, broadest near the rounded apex ; genaB sordid yellow streaked 
with black beneath the eyes, next the antennae, and along the loral 
suture ; the inferior angle of the lorm black in some examples, in 
others entirely yellow ; genre, below the lorae, very narrow. Prono- 
tum on the anterior margin, concolorous with the vertex, darker 
posteriorly, in some examples nearly unicolorous and in others with 
a distinct longitudinal dark stripe back of the inner angle of the eye; 
still others are marked with a small black spot on the anterior 
margin against the middle of each eye and liave from one to three 
