52 
CHARLES ROBERTSON. 
A, 9 . — Black; clypeus rather strongly punctured, with a median im- 
punctate elevated line; hasal process of labruin very large, semicircular, truncate 
at tip; thorax with close shallow punctures anteriorly, scutellum sparsely punc- 
tured, postscutellum sw’ollen, enclosure of metathorax rather coarsely reticulated, 
thorax with short, thin, pale fulvous pubescence ; wings ful vo-hyaliue, apical 
margin broadly clouded, nervures and stigma honey-yellow, tegulfe reddish tes- 
taceous; legs dull ferruginous; abdomen shining, finely and sparsely punctured, 
apical margins of segments faintly depressed, the abdomen clothed with pale 
pubescence, which often forms thin apical fascise, anal fimbria fulvous. Length 
13 — 15 mm. 
"J, . — Eesembles the female; head suhquadrate, wider than thorax; the pubes- 
cence somewhat longer, thicker, more fulvous; wings often paler. Length 9 — 
12 mm. 
Twelve females, twenty-three males, taken from April 8th to May 
7th, on flowers of Dentaria laeiniata, Stellaria media, Claytonia vir- 
ginica, Staphylea trifolia, Cercis canadensis, Prunus serotina, Amelan- 
chier canadensis, Rihes gracile, Erigenia bidbosa, Antennaria plania- 
gmifolia, Salix cordata and Erythronivm albidiim. The sexes were 
taken in copula on flowers of Salix, April 28th. 
This may be the A. valida of Say, or the A. obscuripeyinis of Smith. 
A. erigenia* 9- — Black; clothed with long whitish pubescence; head as 
broad as thorax ; clypeus strongly punctured ; basal process of labrum very short 
and broad, sometimes slightly emarginate anteriorly; flagellum ferruginous be- 
neath towards tip; thorax with large, shallow, sparse punctures, the surface not 
concealed by pubescence; enclosure of metathorax longitudinally striate at base, 
finely roughened beyond; wings yellowish hyaline, nervures and tegulfe dull 
honey-yellow ; legs slender, scopa white, inclining to fuscous at base above, hind 
tarsi with yellowish hairs; abdomen clothed with thin pubescence, which is lon- 
ger and whiter towards the apex of the segments, where it forms thin fasciae, 
the anal fimbria inclining to fuscous, the segments finely roughened and rather 
strongly punctured at base, smoother beyond, apical margins testaceous. Length 
8—9 mm. 
.—Resembles the female; face subquadrate, the eyes somewhat wider apart 
below than above, the clypeal region densely clothed with a long beard of white 
pubescence; mandibles long, tip of one nearly reaching to base of the other, 
toothed remotely from the apex and rufous from below the tooth to the tip; an- 
tenufe longer, flagellum dull testaceous beneath ; wings more hyaline, nervures 
pale testaceous, second submarginal cell very variable in form and size, some- 
times receiving the recurrent nervure beyond the middle, sometimes far before 
it; middle tibiae with a slender spine at tip exteriorly. Length 7 — 8 mm. 
Seven females, ten males, taken from March 26th to May 14th, on 
flowers of Claytonia virginica, Erigenia bulbosa and Hydrophyllum 
appendiculahim. . This species is sometimes infested by Stylops. It 
is closely allied to A. iexana Cress. 
