396 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



San Jacinto River, at 2,100 feet, on Salix, February 22 (Timber- 

 lake) . 



The female collects pollen, as far as is known, only from Salix. 



The following females, with no associated males, have whitish 

 facial foveae as in radialis, but they may belong with chlorogaster, 

 as the color of the foveae may not be always distinctive : 2 from 

 The Dalles, Oreg., May 2 and 3, 1927 (Scullen) ; 1 from Marion, 

 Oreg., May 13, 1928 (A. Gray) ; 1 from Salt Lake City, Utah, 

 May 4, 1913 (Timberlake) ; 1 from Sand Flat, Calaveras County, 

 Calif., 5,000 feet, June 11, 1930 (D. W. Clancy) ; and 1 from 

 Berkeley, April 7, 1935 (R. M. Bohart). The two females from 

 Visalia, recorded above under chlorogaster, also have whitish 

 foveae, but are associated with males with definite chlorogaster 

 characters. 



ANDRENA (MICRANDRENA) NITIDICGRNIS CockereU 



Andrena nitidicomis Cockerell, Pan-Pacific Ent., vol. 12, p. 144, 1936 (male). 



This is another sibling species diflEicult to distinguish, at least 

 in the female sex, from A. chlorogaster and A. radialis. It was 

 described from Garberville, Humboldt County, Calif., but I have 

 taken it in southern California, in the foothills of the San Gabriel 

 Mountains, up to an elevation of about 1,500 feet on Ceanothus, 

 and also at The Gavilan, Riverside County, on Salix. 



The male has much black hair on the face and behind the sum- 

 mits of eyes, and the yellow of the clypeus covers not much more 

 than half of the disk. The parameres of the stipites are not angu- 

 late on the inner margin, the apical expanded part being elongate 

 oval; and the bulbous basal part of the sagittae bears a distinct 

 median impression apically. 



These three sibling species are separated in the key, the char- 

 acters given for the males having greater value : 



KEY TO SPECIFIC CHARACTERS IN ANDRENA CHLOROGASTER, 

 A. RADIALIS. AND A. NITIDICORNIS 



1 . Females 2 



Males ^ 4 



2. Stigma and nervures ferruginous, facial foveae more or less pallid; scopal 



hairs of hind tibiae more distinctly curled - 3 



Stigma and nervures reddish brown; facial foveae pale brown, more pallid 

 below; scopal hairs more erect on outer face of hind tibiae. 



chlorogaster 



3. Basal area of propodeum nearly uniformly finely granular; facial foveae 



whitish, tinged with brown above „ radialis 



Basal area finely rugulose except on margins ; facial foveae more brownish. 



nitidicornis 



