304 THE CANADIAN ENTOMOLOGIST. 



coming paler on exposure. A patch of black hair on centre of 

 upper surface of thorax. White felt bands on apical margin 

 of segments 3, 4 and 5 narrower (about .15 mm. wide or less 

 in centre of segment 4) and narrowed or interrupted in centre, 

 at least on segments 3 and 4. Pollen brush more extensively 

 red 2. 



2. Hair on segment 6 denser, never mixed with black. Apical 

 felt band on segment 5 never interrupted in middle. Black 

 patch on thorax never large. Red of pollen brush some- 

 what paler latimaniis Say. 



Fredericton, N.B.; Ste. Anne de la Pocatiere, Que.; Ottawa, 



Ont., common on sunflowers; Toronto. Ont.; Aweme, Man.; 



Lethbridge, Alta. ; July and August. 



Hair on segment 6 less dense, usually pale and almost entirely 

 black in specimens from Northern Ontario and Northern 

 Alberta; these specimens and specimens from Victoria, B.C., 

 have the white felt bands, on apices of segment 3 and 4, and 

 also sometimes on segment 5 very weak and widely interrupted 

 in middle. Black patch on thorax larger (in specimens from 

 Northern Ontario and Northern Alberta covering almost the 

 entire upper surface). Red of pollen brush somewhat 



brighter perihirta Ckll. 



Thornloe, Ont.; Cochrane, Ont.; Athabaska, Alta.; Leth- 

 bridge, Alta.; Invermere, B.C.; Penticton, B.C., Keremeos, B.C. 

 and Victoria, B. C. Specimens from the interior valleys of 

 Southern British Columbia are almost indistinguishable from 

 those of latimanus Say. 



Next in importance to the species of the latimanus group in 

 the pollination of alfalfa is Megachile calogasterCk\\.,2i variety of, 

 or closely related to M. melanophcea Sm. M. calogaster has no 

 white felt bands at the apices of any of the abdominal segments, 

 and segments 3 to 5 are black haired. The female has a bright 

 red pollen brush, and the fore tarsi of the males are dilated and 

 pale as in the latimanus group. It is common in Southern Alberta 

 and Southern British Columbia, flying from about the middle of 

 June until about the end of July, that is two or three weeks earlier 

 than those of the latimanus group. It is found on many flowers 

 besides alfalfa. 



