392 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



ANDRENA (MICRANDRENA) PIPERI Viereck 



Andrena piperi Viereck, Can. Ent., vol. 36, pp. 189, 196 (female), 1904. 



The type locality is Pullman, Wash., but the species ranges to 

 southern California. It is a common winter and spring bee at 

 Riverside, and the female collects pollen from Cruciferae, espe- 

 cially from Alyssum, Brassica, Capsella, and Sisymbrium. I have 

 one female collected at Salt Lake City, Utah, May 4, 1913; a 

 male from Riparia, Wash., April 8, 1908 (Aldrich) ; a male from 

 Merrill, Oreg., from wild mustard. May 10, 1929 (C. C. Wilson) ; 

 besides many from Riverside. 



In the U. S. National Museum is the following material : 1 fe- 

 male. Mount Hamilton Range, Santa Clara County, Calif., April 

 26, 1913 (J. C. Bridwell) ; 1 female, Berkeley, April 19, 1915 

 (E. P. Van Duzee) ; 2 males, Sacramento, March 6, 1931 (C. C. 

 Wilson) ; 8 males, Stanford University, March 4-24, 1910 ; 4 

 males, Stanford University, March 21 and 24, 1915 (H. Mor- 

 rison) ; 2 males, 3 females, Redlands (F. R. Cole) ; and 1 male, 

 Claremont (Baker). 



The male has not been described, and in the National Museum 

 material two manuscript names were attached to specimens of 

 this sex by Viereck. It may be distinguished from males of other 

 North American species of this group by means of the following 

 characters: Integument black, with a slight aeneous tinge; the 

 clypeus yellow, with two minute black dots. Wings faintly dusky, 

 with ferruginous stigma and nervures. First abscissa of radius 

 more or less short or punctiform. Antennae moderately long, with 

 joint 3 longer than 4, but distinctly shorter than 4 plus 5. Head 

 and thorax dull, granular-tessellate. Enclosure very large, finely 

 granular-rugulose, the sculpture somewhat coarser than that of 

 remainder of propodeum. Pubescence usually white, and very long 

 and copious on the cheeks, sides of thorax, and on the front 

 femora. 



ANDRENA (MICRANDRENA) CHLOROGASTER Viereck 



Andrena chlorogaster Viereck, Can. Ent, vol. 36, pp. 189, 196 (female), 1904. 

 From Oregon and California there are now known three very 

 similar species of Micrandrena, which are distinguishable with 

 difficulty in the female, but which are surely distinct by the char- 

 acters of the male, especially those of the genitalia (cf. key, 

 page 396). With only a few specimens at hand from Oregon, it 

 is impossible to be sure about the correct usage of the name 

 chlorogaster, but I have provisionally assigned the name to a 

 species which ranges from Corvallis, Oreg., southward to River- 

 side County and Santa Catalina Island, Calif. A. chlorogaster 



