oG 
CHARLES ROBERTSON. 
. — Closely resembles the female; the clypeus whitish, sometimes there is 
also a white spot on each side of the face between the upper part of the clypeus 
and the eye. Length 5 — 6 mm. 
Twenty females, ten males, taken from May 7th to June 4th, on 
Gowers of the following Umbelliferte : Zizia aurea, Pimpinella in- 
tegerrima, Sanicula marilandica and Pastinaca saliva. The sexes 
were taken in cojjula on Zizia, May 7th. 
A. astei'is 9 . — Black ; clypeus with sparse, feeble punctures; basal process 
of labrum small, deeply notched ; thorax with sparse, feeble punctures, clothed 
(at least anteriorly) with long, close, dirty white pubescence, enclosure of meta- 
thorax finely roughened ; wings fusco-hyaline, nervres and stigma fuscous, teg- 
ulse piceous; legs black, basal joint of middle tarsi broad, scopa yellowish white, 
fuscous at base above, basal joint of posterior tarsi with fuscous pubescence; 
abdomen impunctate, or with sparse feeble punctures, apical margins of segments 
pale testaceous, segments 2-4 with thin fascise of white pubescence on their 
broadly depressed apical margins, anal fimbria fuscous. Length 10 — 11 mm. 
% . — Resembles the female; abdomen more punctate; clypeus and spot on each 
side yellowish, the former with two elongate dark spots, basal process of labrum 
bidentate. Length 9 mm. 
Two females, one male, taken October 8th and 11th, on flowers of 
Aster. 
A. riKlbeckiae 9 • — Black ; clypeus closely and strongly punctured, clothed 
with close, short, pale pubescence, basal proce.ss of labrum cleft, forming two 
sharp teeth, palpi short, flagellum dull testaceous beneath; thorax densely and 
finely punctured, densely clothed with very short, dull ochraceous pubescence, 
enclosure of metathorax finely roughened; wings ful vo-hyaline. the apical mar- 
gins clouded, uervures testaceous, stigma small, fuscous, tegulse ferruginous; 
legs dull ferruginous, clothed with short pubescence, basal joint of middle tarsi 
broad ; abdomen finely roughened, evenly punctured with large, close, shallow 
punctures, apical margins of the segments depressed, reflecting golden, with a 
narrow white line at extreme edge; the abdomen clothed with pale pubescence, 
which forms fasciae on apical margins of all of the segments, the anal fimbria 
golden-yellow. Length 13 — 14 mm. 
% . — Resembles the female ; antennae short, clypeus and a large spot on each 
side yellowish white. Length 12 mm. 
Eleven females, one male, taken on flowers of Pudbeckia hirta, 
June T2th to 23d. The depressed margins of the abdominal seg- 
ments vary considerably in color, being sometimes golden, pale 
yellowish, or reddish purple. The sexes were taken in copula. 
.A. CresKOiiii 9- — Black; clypeus closely and rather strongly punctured, 
except in median line, basal process of labrum small and very short; thorax 
clothed with thin, fulvous pubescence, rather closely and strongly punctured, 
scutellum sparsely punctured, enclosure of metathorax small, rough, commonly 
with longitudinal ridges; wings fusco-hyaline. apical margins a little clouded, 
nervures and stigma dull testaceous, teguke black, often with a dull testaceous 
