330 Mr. T. D. A. GockereW—Besa-iptions and 



The smallest American species of tlie genus ; nearest to 

 B. martii, Okll.; from which it differs by the much smaller 

 size, very much finer punctures, more delicate thoracic spine, 

 and the much smaller (almost rudimentary) subapical lateral 

 spines of abdomen. The flagellum is only faintly reddish 

 beneath. 



Hah. Troublesome, Colorado, alt. 7345 ft., June 9, 1908 

 [S. A. Rohwer). 



Osmia hruneri, Ckll., $ . 



At Troublesome, Colorado, Jane 8 and 9, 1908, Mr. S. A. 

 liohwer took both sexes of this species. 



The male is about 8 mm. long-, short and compact like the 

 female, with the most brilliant colours. Clypeus a splendid 

 purple ; sides of face largely green ; vertex blue and purple ; 

 cheeks green ; thorax (including tegula3) yellowish green, 

 bluer at sides ; abdomen brilliant green, bluer at sides and 

 apex ; legs blue-green, but tibioe black or nearly on one side ; 

 hair of thorax above and occiput white without any admixture 

 of black; hair of vertex and cly|)eus black, but that of sides 

 efface white; aj)ical segments of abdomen with black hair; 

 sixth segment with a distinct notch, seventh bidentate. 



In my table in Ann.&Mag. I^at. Hist., Aug. 1907, p. 123, 

 it runs to 0. bennettce, from which it is easily distinguished 

 by the black hair of the clypeus, the shape of the abdomen, &c, 



Osmia gaudtosa, Ckll. 



S . — Florissant, Colorado, at flowers of Mertensia lanceo- 

 lata, June 19, 1908 {S. A. Rohoer). 



1 he specimen has the abdomen more shiny than that of the 

 type, but I believe there is only one species. 



Diandrena nothocalaidis, Ckll. 



Troublesome, Colorado, at flowers of JSothocalals cuspidaUij 

 June 9, many females {S. A. Rohwer). 

 Previously known only from Boulder. 



Andrena pyrrhacita, Ckll., var. mosina no v. 



$ . — Hair of face and front almost entirely black ; clypeus 

 finely punctured, with a very distinct smooth median line ; 

 much black hair at sides of metatliorax ; hair of thorax above 



