NORTH AMERICAN HYMENOPTERA. 
51 
A. bicolor F. {= A. hirticeps Sm. % ) 
Sixteen females and eighteen males taken from March 23d to May 
5th on flowers of Isopyrum biternatmn, Dentaria laciniata, Viola pu- 
bescens, V. striata, Claytonia virginica, Cercis canadensis, Cluerophyl- 
lum procwnbens, Erigenia bullosa, Sal.ix hwnilis, Erythronmm albidum 
and Uviilaria grandiflora. I took five pairs in copula on flowers of 
Erigenia, Ajiril 7th. 
A. priliii 9 . — Black; liead as broad as thorax, clothed with pale fulvous 
pubescence; clypeus rather sparsely and strongly punctured, except a median 
raised line, which is impunctate; basal process of labrum semicircular, large, not 
truncate at tip; antennae with flagellum dull ferruginous beneath ; thorax closely, 
not strongly punctured, the surface concealed by close fulvous pubescence; wings 
yellowish hyaline, the apical margins faintly clouded, third submarginal little 
longer than second, nervures, stigma and tegulse reddish testaceous; enclosure 
of metathorax minutely roughened ; abdomen ovate, depressed, shining, with a 
thin fulvous pubescence on the sides, segments closely punctured, except a broad, 
depressed apical portion, which is rufo-piceous, apical fimbria bright fulvous; 
legs clothed with pale fulvous pubescence, the tarsi, and sometimes posterior 
tibiae, ferruginous. Length 11 — 12 mm. 
. — Blacker, the wings and pubescence paler, antennae as long as thorax, 
more ferruginous beneath. Length 10 mm. 
Ten females and one male. There is a strong contrast between the 
thorax and abdomen, the former being closely pubescent and fulvous, 
the latter being bare and black. 
I have taken it from April 23d to June 2d, on flowers Staphylea 
trifolia, Claytonia virginica. Viburnum prunifolium, Prunus serotina 
and Pastinaca sativa. The male and female were taken in copula 
on flowers of Viburnum, April 29th. 
A. I*ere*i 9- — Black, the abdomen red; clypeus flat, not very strongly 
punctured, a median line impunctate; basal process of labrum broad, semicircu- 
lar, truncate or emarginate at tip.; flagellum dull testaceous beneath ; thorax 
sparsely and feebly punctured, thickly clothed with pale pubescence ; enclosure 
of raetathorax finely roughened ; wings hyaline, apical margin faintly clouded, 
nervures and stigma testaceous, tegulse piceous; legs blackish, tar.si testaceous; 
abdomen shining, sparsely and very feebly punctured, red, the apical segments 
often blackish at base, and with broad testaceous apical margins, fasciae wanting, 
anal fimbria pale dirty yellow. Length 10 — 11 mm. 
% . — Resembles the female, clypeus with a dense yellowish white beard, flagel- 
lum paler beneath, pubescence a little longer and often more yellowish ; abdomen 
with the segments black at base, reddish beyond, more extensively on the sides, 
and with broad testaceous apical margins; sometimes the abdomen is entirely 
black, on y showing a little reddish at base of testaceous apical margins and on 
extreme sides. Length 8 — 10 mm. 
Four females and ten males, taken iVpril 17th and 21st, on flowers 
of Salix humilis and S. cordata. The sexes were taken in copula. 
Dedicated to Prof J. Perez, of Bordeaux. 
