BEES OF THE FAMILY ANDRENIDAE— TIMBERLAKE 397 



4. Sagittae not so thick and blunt at apex and not spreading apart at their 



tips 5 



Sagittae very broad and blunt at apex, their tips spreading apart. 



chlorogaster 



5. Clypeus more or less broadly black on upper margin; sides of face with 



black hair; flagellum dark; dorsal margins of sagittae rather broadly 



reflexed just beyond basal bulbous part nitidicornis 



Clypeus narrowly black on upper margin; hair of face entirely, or almost 

 entirely, whitish; flagellum ferruginous beneath; dorsal margins of 

 sagittae not reflexed just beyond basal bulbous part radialis 



ANDRENA (MICRANDRENA) MICROCHLORA SUBALIA Cockerell 



Andrena microchlora subalia CocKERELL, Pan-Pacific Ent., vol. 12, p. 143, 

 1936 (female; in part). 



In the United States National Museum are 30 females, San 

 Francisco, Calif., March 16, 1913 (J. C. Bridwell) ; 5 females. 

 Mount Hamilton Range, Santa Clara County, April 26, 1913 

 (Bridwell) ; and 2 males, Berkeley, March 15, 1913 (Bridwell). 

 In the Riverside collection is a female from Pullman, Wash., May 

 11, 1922 (Melander), and a pair from Corvallis, Oreg. (Scullen), 

 the female taken April 26, 1928, and the male, on Taraxacum, 

 April 17, 1929. 



Cockerell described subalia from the coastal region of northern 

 California, but confused two species in his material. The type 

 and a cotype taken near Lower Lake, Lake County, at a yellow 

 umbellifer are virtually indistinguishable from females of micro- 

 chlora from Boulder, Colo. The remainder of the material, as far 

 as I have examined it, is referable to A. nitidicornis Cockerell, 

 and it is probable that Cockerell was led to separate subalia be- 

 cause of the inclusion of this extraneous material. The male of 

 microchlora from Boulder, however, has the pubescence of the 

 face entirely white, while the males from the Pacific coast have 

 much black hair on the sides of the face and behind the summits 

 of eyes. For this reason alone, the race subalia appears to deserve 

 recognition. 



The female of microchlora can be distinguished from the fe- 

 males of the chlorogaster group by the duller, more finely granu- 

 lar-tessellate and much more hairy mesoscutum, and by the 

 upright, and but little curved scopal hairs of the hind tibiae. 



ANDRENA (MICRANDRENA) CANDIDIFORMIS SEMOTULA Cockerell 



Andrena semotula COCKERBLL, Pan-Pacific Ent., vol. 12, p. 149, 1936 (male). 



This is only a weakly distinguishable race of Andrena candidi- 

 formis Viereck and Cockerell, the male having the stigma more 

 or less infuscated and the flagellum black. It occurs in the moun- 

 tains of southern California and northward along the coast to 



