Specific Characters in the Bee Genus Colletes 25 
Las Vegas, two females from Gallinas river at La Cueva, August 
6, and a female from Pecos, August 7. I have examined three 
females from Las Vegas, collected August 9, 10, and 11 by Mrs. © 
Wilmatte P. Cockerell, and four specimens from Arizona—a pair 
taken in Oak Creek canyon in August by Professor F. H. Snow 
and two females taken during August, 1902, in southern Arizona 
by the same collector. Apparently, then, the species is aestival 
(July 16 to August 11) and rather a Transition form. It visits 
the flowers of Petalostemon oligophyllus, Solidago canadensis, 
and Melilotus alba, 
SPECIMENS ExAMINED—Arizona: Oak Creek Canyon, 2; 
Southern Arizona, 2; New Mexico: Las Vegas, 3. 
Colletes compactus Cresson. 
1868. Colletes compacta Cresson, Proceedings of the Boston Society of 
Natural History, xii, p. 166, 2 3 (December 2, 1868) ; original 
description. 
1879. Colletes compacta Patton, [bid., xx, p. 142, 2 o (April, 1879); in 
, table of New England species. 
1895. Colletes compacta Robertson, Transactions of the American En- 
tomological Society, xxii, p. 115 (May, 1895); notes on charac- 
ters and season. 
1896. Colletes compactus Dalla Torre, Catalogus Hymenopterorum, x, 
Seeror ass (1896). 
1903. Colletes compactus Viereck, Entomological News, xiv, p. 120 
(March, 1903); recorded from College Park, Maryland. 
1904. Colletes compactus Robertson, Canadian Entomologist, xxxvi, no. 
9, p. 275, 9, p. 277, do (September, 1904); in table of Illinois 
species. 
1905. Colletes compacta Cockerell, Psyche, xu, p. 86, ¢ (October, 1905) ; 
in table of species. } 
1906. Colletes compactus Robertson, Science, xxiii, p. 309 (February, 
1906) ; seasons, food plants. 
1907. Colletes compactus Lovell, Canadian Entomologist, xxxix, no. 11, 
p. 363 (November, 1907); recorded from Waldoboro, Maine. 
2. Length 10-12 mm. Head broad, orbits slightly converging below. 
Clypeus flat, its punctures coarse and elongate but separate and not form- 
ing striae except at extreme sides, becoming obsolete on a large, broad, 
median sulcus which is dull because of a minutely longitudinally striate 
surface. Supraclypeal area dull and coarsely punctured. Face finely and 
closely punctured, clothed with short, erect, grayish white pubescence with 
a few black hairs intermixed along the sides and becoming denser above 
67 
