166 Descriptions and Records of Bees. 



warm reddish ; antennae black ; vertex dull, not punctured ; 

 mesothorax dull, without any distinct punctures ; area of 

 metathorax dull, without plicae ; tegulae piceous. Wings 

 hyaline, the large stigma and nervures dull ferruginous ; 

 second s.m. broad, receiving first r. n. before middle. Legs 

 black, with pale hair, that on inner side of hind basitarsi 

 very pale ochreous. Abdomen broad, dull, with a slight 

 satiny gloss, impunctate ; second segment feebly depressed 

 about two-fifths ; white hair at sides of first segment, and 

 segments 2 to 5 with long white hair- bauds, very weak in 

 middle of second, apical hair slightly brownish. 



Indian Creek, Nampa, Idaho, at flowers of willow, 

 April 26, 1916 {Goldie McGlothlen). 



Easily known from A. niyritarsis, V. & C, aud A. brachy- 

 carpce, V. & C, by the dull abdomen, with the surface micro- 

 scopically cancellate. It is nearest to A. nudiscopa, Vier.> 

 and A. mustelicolor, Vier., but is smaller, with reddish facial 

 fovea? and wings not reddened. These two species have not 

 yet been fully described, but I have specimens determined by 

 Viereck. The hind basitarsus of opacissima is slender, only 

 about half as broad as the tibia at end, a character of nudi- 

 scopa (syn. angustitarsata, Vier., fide Viereck in litt.) rather 

 than must eh color. On the other hand, the dull minutely- 

 roughened clypeus is that of mustelicolor rather than nudi- 

 scopa. The paler, dark margined stigma 'also distinguishes 

 the new species from my example of nudiscopa. 



Andrena politissima, sp. n. 



$ . — Length a little over 9 mm. 



Black, shining, the head and thorax with long pale hair, 

 distinctly ochreous dorsally ; clypeus with very long hair; 

 facial quadrangle broader than long; process of labruni 

 narrowly truncate ; malar space short but distinct ; clypeus 

 shining, with distinct rather dense punctures, no smooth 

 median line ; facial foveae rather broad, very pale ochreous ; 

 antennae black, third joint little (about 4 per cent.) shorter 

 than next two combined; mesothorax and scutellum shining, 

 with strong scattered punctures ; postscutcllum prominent 

 in middle ; area of metathorax distinctly defined, dull, with 

 a median ridge and rather weak though large oblique lateral 

 plicae, giving a fluted effect; tegnlae piceous. Wings dusky, 

 greyish, yellowish basally ; stigma and nervures dusky red- 

 dish; second s.m. about as broad as high, receiving first r. n. 

 about middle. Legs black, with pale hair; middle and hind 



