Studies of North American Bees $7 



I J*; do., August 25, 191 1, on SoUdago canadensis (O. A. Stevens, 

 No. 2940), I J*. 



Named for Mr. O. A. Stevens of the North Dakota Experi- 

 ment Station, who collected the specimens, in recognition of his 

 work on the relation of insects, especially of bees, to the pollina- 

 tion of Kansas and North Dakota flowers. 



Nomada (Nomada) beulahensis Cockerell. 



1903. Nomada beulahensis Cockerell, Ann. Mag. Nat. Hist., ser. 7, 

 XII, p. 209, c^. 



1905. Nomada beulahensis Cockerell, Bull. 94, Colorado Exp. Sta., 

 p. 74, (^■ 

 Compared with the description of A^. beulahensis Ckll., which 

 species was based on five males from New Mexico, and with one 

 of the cotypes (Beulah, N. M., August, T. D. A. Cockerell) 

 before him, the writer finds a specimen collected at Fargo, North 

 Dakota, August 17, 1911, on Grindelia sqnarrosa (O. A. Stevens, 

 No. 2802) to differ only in very minor color variations, i. e., it 

 lacks the yellow lines on the collar and the spots on the meso- 

 scutellum which are present in most of the New Mexico series. 

 It is of the minimum size given for the New Mexico series (6 

 mm.), and has the lateral face marks produced for some distance 

 up the orbital margin, as mentioned for some specimens of the 

 New Mexico series. This species is certainly close to A'', intcr- 

 riiptella Fowler, but is apparently distinct in the lack of yellow 

 markings on the legs and first abdominal tergite, and the mostly 

 black venter. It is possible, however, that the two will be found 

 to intergrade, in which case the species would be known as inter- 

 ruptella. N. pallidipicta, described on a previous page, differs 

 in the cream-colored ornaments, wholly pale clypeus, pale meso- 

 pleural spot, pale spots on mesoscutellum and collar, paler wings 

 and less distinctly notched apex, and seems to be a good species. 



Subgenus Heminomada Cockerell, 1902 



KEY TO THE NEBRASKA SPECIES 



Feinales 

 First abdominal tergite red, often with more or less black at base and on 

 apical margin, but without a yellow band or yellow lateral 

 spots I 



57 



