Studies of North American Bees 53 



interstitial with transverso-medial but very distinctly on the basad side, 

 the second submarginal cell much produced on the inner lower angle, the 

 third submarginal narrowed nearly to a point above. Cheeks, pleura 

 below and sides of propodeum with short, fairly copious, white hair, 

 tergites 3-6 with scattered short pale hairs, face and scape with pale 

 hairs. 



Type. — Laramie, Wyoming, June 9, 1893 (collector un- 

 known), 5. 



This is very close to A'', rhodosoinella Ckll., and may indeed 

 prove to be only a form of that species, but seems different in 

 view of the complete mesoscutal line, red upper metapleural plate, 

 largely black propodeum, and dift'erent venation. From N. 

 rhodosonm Ckll., it differs at once in the black facial spot, 

 mesoscutal line, black ventral metapleural plate and different 

 venation. The venation is similar to that of A'^. rohertsonella 

 Ckll., to which species it is also allied, but it differs in the longer 

 third antennal joint, black spot on enclosure, etc. In the preced- 

 ing table of Nebraska species it runs closest to A^. ochrohirta, 

 but differs in the white pubescence, red upper metapleural plate, 

 narrower third submarginal cell, etc. 



Nomada (Nomada) idahoensis n. sp. 



c^. Length 5.5 mm. Head and thorax black, very strongly and closely 

 and rather coarsely punctured, the punctures on vertex and mesoscutum 

 running into striae. Clypeus and labrum black, the former with a very 

 narrow reddish apical line, the lower corners of the face and a spot on 

 the base of mandibles yellow. Scape and pedicel and most of third anten- 

 nal joint black, the tip of third and whole of following joints bright 

 reddish brown with a deep black line above which is not visible from 

 beneath, joint 3 of antennae one-half as long as 4. Tegulae testaceous, 

 infuscated basally. Wings hyaline, apically darkened, nervures fuscous, 

 stigma very dark brown, basal nervure considerably basad of transverse - 

 medial nervure. Mesoscutellum moderately elevated but only feebly 

 bilobed. Legs yellowish brown and black, the black color involving the 

 trochanters and coxae, stripes on anterior femora and tibiae behind, 

 same on middle femora and tibiae and base of femora in front, posterior 

 femora except knees and a stripe in front, posterior tibiae except apices 

 and a median area in front, and the outer faces of posterior basal tarsal 

 joints. Abdomen obscure red, the basal tergite black on basal two-thirds, 

 apices of tergites 1-4 and basal middle of tergites 4 and 5 strongly suffused 

 with dusky, small suboval lateral spots on tergites 2-4 and subdiscal spots 



53 



