346 PROCEEDINGS OF THE ACADEMY OF [1897. 



black except on first segment; ventral pubescence black, a pale 

 median patch just beyond apex of second segment; sixth dorsal 

 segment entire. This S is like 0. moniana from Pike's Peak, but 

 is separated by the entire sixth segment of abdomen. 



Osmia proxima Cresson. 



This is considered to be the $ of atriventris ; it was described 

 from Maine and British America. At Olympia, Wash., June 24, 

 1895, Mr. T. Kincaid took a $ which is evidently conspecific with 

 an authentic Canadian proxima sent by Mr. Fox. This insect will be 

 recognized by its small size, large head, short subglobose thorax and 

 abdomen, and shining dark blue-green color. The hind margins of 

 the abdominal segments are inclined to be edged with testaceous — 

 in the Olympia insect this is quite conspicuous. The antennas are 

 long, and the flagellum is more or less brownish or rufescent be- 

 neath. The tegulse are greenish in front. The wings are hyaline. 

 Sixth abdominal segment notched. 



Osmia faceta Cresson. 



9 . One collected at Olympia, Wash., June 2, by Mr. T. Kincaid, 

 agrees with an authentic Canadian example lent by Mr. Fox. It is 

 a little greener than that from Canada, but the specific characters 

 are the same. It is especially to be noted that while the ventral 

 scopa is black, there is white hair on the extreme lateral margin of 

 the abdomen, which may run along the margins of the dorsal seg- 

 ments a little way, forming rudimentary bands. The mandibles 

 have a conspicuous subapical band of orange-rufous hair. 



Osmia densa Cresson. 



I have before me an authentic 9 from Colorado, sent by Mr. Fox. 

 It is much like atrocyanea, but the pubescence of the sides of the 

 metathorax and of the tubercles is all white, while it is black in 

 atrocyanea. In densa the pubescence of the pleura is scanty and 

 white, in atrocyanea it is black. 0. atrocyanea has a larger thorax 

 and a somewhat larger head than densa. The following table sep- 

 arates a series of females having the general appearance of densa ; 

 in all, the ventral scopa is black. 



A. Pubescence of pleura, tubercles and sides of metathorax white. 



a. Pubescence of clypeus and sides of abdomen white . . faceta, Cr. 



b. Pubescence of clypeus black, sides of abdomen without conspic- 



uous white pubescence, though there are some white hairs, 



densa, Cr. 

 (0. densa was taken at Olympia, Wash., by Mr. T. Kincaid, 

 June 19.) 



