Studies of North American Bees 49 



cence on the cheeks, pleura, lateral angles of propodeum and tip of abdo- 

 men, becoming distinctly silvery on face and pale ochreous on occiput and 

 mesonotum. 



Type. — jNIonroe canyon, Sioux county, Nebraska, August 23, 

 1908, on SoUdago serotina (R. W. Dawson), (^. 



Paratypes. — Type locality, August 24, 1908 (R. W. Dawson), 

 I J*; Glen, Sioux county, Nebraska, 4,000 feet, August 17, 1906 

 (H. S. Smith), I ^. 



This species is distinct because of its black color and cream- 

 colored maculations from all our other species except A'^. ( Holono- 

 mada) aquilarum Ckll., to which it is related. Compared with the 

 type of that species in the U. S. National Museum it differs at 

 once in having the apex usually more or less notched at tip 

 (evenly rounded and entire in aquilarum) , antennal joint 3 much 

 shorter than 4 (joint 3 slightly exceeds 4 in aquilarum) , yellow 

 lines on collar (this wholly black in aquilarum) , the clypeus and 

 labrum wholly pale, the mesopleura usually pale spotted and the 

 mesoscutellum more strongly bilobed. It is really closest to the 

 New Mexican A^. beulahensis Ckll., but compared with a cotype 

 of that species received from its describer, it dififers chiefly in 

 the cream-colored instead of bright yellow maculations, the 

 wholly pale clypeus, larger lateral face marks, paler wings and 

 more feebly notched apex. A^. interruptella Fowler, from Cali- 

 fornia, is also allied, but has the abdominal maculations yellow, 

 including lateral spots on tergite i, while the upper portion of the 

 clypeus, the tubercles and the mesoscutellum are black, and the 

 venter is more extensively yellow. 



SPECIES FROM OUTSIDE NEBRASKA 



Nomada (Nomada) mediana n. sp. 



1903. Nomada Astori, var. a, Cockerell, Ann. Mag. Nat. Hist., ser. 



7, xir, p. 207. ?. 



$. Length 7 mm. Red, the middle of the face above insertion of an- 

 tennae connected with an ocellar spot which extends on sides of vertex 

 nearly to orbits and not distinctly separated from concolorous areas on 

 the cheeks behind, a narrow line on each side of supraclypeus, pronotum 

 and propleura except collar, three distinct lines on mesoscutum, meta- 

 pleura, depressed sides of mesoscutellum and metanotum, a broad median 



49 



