10 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



Abdomen broad, moderately shining, well punctured, second seg- 

 ment depressed one-half in middle. First segment with median 

 apical, longitudinal groove. Hair of abdomen short and thin, but 

 covering segments, becoming a little thicker at the apices of segment 

 laterally so as to suggest imperfect bands. 



(This is a red-haired variety of A. tacitula.) 



Type.— Cat. No. 18124, U.S.N.M. 



b 7 . Females. 



a 10 . Scutellum excessively densely and strongly punctured; wings dark. 



ANDRENA PERDENSA Viereck. 



Westlake, Colorado. July 7, 1900. 



Female. — Length, 11 J mm. Black, with short pale ochreous hair 

 on head and thorax above, tubercles, sides of metathorax and an- 

 terior femora beneath. Hair on legs mostly sooty, but orange fer- 

 ruginous on inner side of anterior tarsi, in complete contrast with the 

 black hair of middle tarsi (hind tibiae and tarsi missing). Facial 

 quadrangle rather longer than broad. Process of labrum broadly 

 rounded; clypeus dull, strongly and closely punctured, the lower 

 half with a median smooth line sides of face closely punctured. 

 Facial f oveae as seen from above brown-white, occupying rather more 

 than one-half distance between eye and antenna, but rapidly nar- 

 rowing below, so that at level of antennae they are very narrow, end- 

 ing little separated from eye, at about level of top of clypeus. Fla- 

 gellum obscure brownish beneath; third joint hardly as long as next 

 two combined. Meso thorax and scutellum very densely and coarsely 

 punctured. Area of metathorax with very strong and well-defined 

 ridges, some of them zig-zag. Tegulae large, ferruginous, with a 

 large fuscous patch. Wings strongly brownish, nervures and stigma 

 dark reddish. Basal nervure falling just short of transverse median. 

 Second submarginal receiving first recurrent nervure well beyond 

 middle. Spurs pale ferruginous. Abdomen strongly and quite 

 closely punctured, without hair bands. Second segment in middle 

 depressed about three-fifths. Hair at apex dark fuscous. 



A specimen from Vernon, British Columbia, labelled perdensa, is a 

 different species. It differs from Colorado A. perdensa by the shining 

 clypeus, truncate process of labrum, smaller and not quite so coarsely 

 sculptured area of metathorax, basal nervure meeting transverse 

 median, third submarginal cell longer. The hind tibiae and tarsi 

 are present in this specimen and have brown-black hair. 



Collected June 21, 1903. 



The original A. perdensa came from British Columbia, so perhaps 

 the Colorado insect is not truly of that species. 



6 10 . Scutellum with distinctly separated punctures. 



a 11 . Hind tibae and tarsi black or nearly; second abdominal segment depressed in 

 middle more than half; hair at apex of abdomen pale reddish. 



