26 Myron Harmon Swenk . 
antennae. Vertex shiny, with many very fine punctures and a few large 
ones, clothed with a few long, erect hairs, almost all of them black, the 
occiput with a rather dense fringe of short, pale hairs. Cheeks shiny, 
closely and regularly punctured, their pubescence long and grayish white. 
Malar space short, one-third as long as broad, dull and minutely striate. 
Antennae wholly black, joint 3 decidedly longer than 4 or following joints, 
which are as long as- wide. Prothoracic spine obsolete. Pubescence of 
thorax gray and black intermixed, the latter usually predominating, short 
and sparse centrally, longer and denser on the margins and forming a 
long, erect, black fringe on scutellum, followed by a pale one on postscut- 
ellum. Mesothorax with strong, crowded, .often semi-striate punctures 
which become coarser and well-separated on a small shiny disk. Anterior 
half of scutellum polished and impunctate, posterior half with scattered, 
coarse punctures and the margin abruptly dull and finely roughened, as is 
also the postscutellum. Metathorax rounded and lacking the usual pitted 
superior face, the enclosure broadly subtriangular, somewhat shiny, rough- 
ened by coarse transverse plications over all except the apex. Lateral 
faces of posterior plate dull and finely roughened. Mesopleura shiny, with 
coarse, round, well-separated punctures and sparse, gray pubescence. Teg- 
ulae blackish. Wings slightly darkened, nervures blackish, stigma dusky. 
Legs black, the inner surface of the femora shining, clothed with a pale 
pubescence, the apices of tarsal joints with golden tufts within. Anterior 
coxae simple. Tibial spurs pale, the outer hind ones minutely pectinate. 
Posterior tarsi slender, basal joint one-third as wide as long, middle joints 
one and two-thirds as wide as long. Abdomen stout, elongate conical, 
shiny, the first segment with the basal truncation polished and impunctate, 
elsewhere with small, close, deep punctures and larger ones scattered about 
between. Second segment punctured like the first but with the two sizes 
less distinct, the third and following segments weakly and indistinctly 
punctured, and with short, scattered, blackish hairs. Ventral valve of apex 
bicarinate. Apical margins of segments 1-3 depressed, especially on seg- 
ment 1, and a narrow, loose fascia of white pubescence on apical margins 
of segments 1-5 as well as one on base of segment 2, which connects the 
interrupted fascia on apex of 1. The apical fasciae are continued narrowly 
on venter. Segment 1 with sparse, pale, erect hairs, denser down its sides 
and on sides of segment 2. 
S. Length 9-10 mm. Differs from the 2 as follows: More slender, 
pubescence longer, denser, and less intermixed with black (the black hairs 
wanting in Colorado and Arizona specimens), that on face extending down 
on clypeus, that on vertex mostly pale, that on thorax above largely pale; 
eyes strongly converging below; clypeus shining and bearing but a few 
scattered, coarse punctures, the median depression narrow and deep; malar 
space much longer, five-sixths as long as broad, rather coarsely striate; 
antennae longer, joint 3 shorter than 4 but longer than 2, the proportion 
being 5:7:8, median antennal joint five-eighths as wide as long; punctures 
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