:aN 



IMI « \VU>lvN I NTliMOlAXilST. 



perhaps a subspecies of it, bu: the abdominil bands are much paler, and 

 the m.ukings dil)er in many details. 



ilab. — Steamboat Springs, Colorado, May 27, i 9- 



Nottuuia { Gnat hilts ) be/la Cresson. — i 9 • 



Atidtftia pruuoi um Gi//ettei i'VW. — 4 (J 's. 



Atti/rena ( Micrandrena) am/>/i/icata, n. sp. 

 (J. — (Type.) Length, 9 mm., or slightly over ; black, with the front 

 and abdomen very dark bluish ; pubescence white, long on head and 

 thorax, black at sides of face and on upper part of cheeks ; clypeus very 

 pale yellow, with the usual black spats, the lower edge black ; head 

 broader tiian long ; tongue very short ; cheeks ordinary ; front longitudi- 

 nally striate; antenniv black, third joint about as long as the next two 

 together ; mesolhorax microscopically tessellate, with sparse but distinct 

 punctures, shining in the middle ; area of metathorax not defined, granu- 

 lar, slightly plicate basally ; legs black, with white hair, slightly yellowish 

 on inner side of tarsi ; spurs dark ; tegulae dark ; wings smoky ; stigma 

 large, ferruginous ; nervures fuscous ; b. n. falling short oft. m.; first t. c. 

 not ending very close to stigma ; apex of marginal cell on costa ; abdo- 

 men with a sericeous surface, and scattered piliferous punctures only ; no 

 distinct hair-bands, but indications of a fringe on segments 2 and 3 

 laterally ; aj)ical ventral i>Iate emarginale. 



9. — Length, 9 to 1 1 mm.; body colours as in male ; hair of head 

 and thorax above ilightly ochreous ; hair of face, scape, cheeks and pleura 

 black (in Urge specimen pale on upper part of pleura) ; clypeus shining, 

 with well-separated punctures and a median smooth line ; process of 

 labrum narrowly truncate ; antennie dark, third joint longer than next two 

 combired ; front striate ; facial fovere dark seal brown, about half as wide 

 as space between eye and antenna, se|)aratcd from eye by only a shining 

 line, scarcely going below level of anieniut ; scjtellimi very smooth and 

 shining, with scattered punctures ; wings reddish ; middle and hind basi- 

 tarsi large and broad, with black hair ; femora and tibiii* also with black 

 or sooty hair ; apical hair of abdomen soot colour ; second segment 

 depressed nearly one half (less in large specimen) ; pygidial plate triangu- 

 lar, narrow at apex. The large specimen differs in a few details, and 

 might be thought distinct, but I am confident that it belongs with the 

 others. 



//ab. — Steamboat S|)iings, Colorado, May 27. I believe it gathers 

 pollen exclusively from the Cruciferw, principally from Thelypodium. It 



