Specific Characters in the Bee Genus Colletes 27 
of mesothorax close but quite separate; apical tarsal joints brownish; 
pectination of tibial spurs indistinct; abdomen slender and elongate, its 
puncturation close and quite coarse, the first segment rather abundantly 
pilose, the third segment distinctly punctured; ventral valve of apex not 
bicarinate; fasciae on apical margins of segments 1-6, indistinct on base 
of segment 2, distinctly continued on venter; hind tarsi more slender, basal 
joint four and one-half times as long as wide, middle joints twice as long 
as wide. 
Genitalia——Stipes notched, its apex small, claw-like and heavily haired; 
sagittal rods parallel throughout, abruptly much thickened from base to 
‘middle; volsella rather large; seventh ventral plate with costae heavily 
chitinized and connected by a transparent, sparsely haired, membranous 
central portion, the internal costae heavily fringed externally, the external 
costae oblong, heavily haired and with dense externo-terminal tufts. (Plate 
~ 
1, figures 5 and 5a.) 
Type LocaLiry.—Connecticut ; types in collection of American 
Entomological Society. 1 eras 
The peculiar sculpture of the metathorax easily distinguishes 
compactus, especially when taken with the bicarinate apex of the 
females and the subquadrate malar space of the males. Mr. Cres- 
son had cotypes from both Connecticut and Illinois, but I have 
considered the former locality as most typical of the species, which» 
is a wide ranging one. Present information shows a distributiom 
from southern Maine (Waldoboro) and New Hampshire (Pel- 
ham) south through New Jersey, Pennsylvania, Maryland, and 
Virginia to Georgia (Atlanta), and west to Wisconsin (Milwau- 
kee), eastern Nebraska (Lincoln and West Point), Colorado, and 
Arizona (Southern Arizona). The southwestern specimens are 
conspicuous by their pallor and the reduction of the black thoracic 
hairs, these’ being entirely absent in the males. It is distinctively 
an autumnal species, flying in the North Atlantic states from Au- 
gust 31 to October 14 and reaching its maximum abundance dur- 
ing latter September and early October. Robertson gives its sea- 
son in southern Illinois from August 26 to October 19, and says 
it is oligotropic on Compositae. In the East it is found most fre- 
quently on the various species of goldenrod (Solidago), and is a 
common species, though outnumbered by americanus and armatus. 
SPECIMENS ExXAMINED—Arizona: Southern Arizona, 1; Col- 
orado: 3; Georgia: Atlanta, 1; Illinois: Carlinville, 2; Maine: 
69 
