370 AMERICAN HYMENOPTERA. 



Worker. — Much like the queen, but the amount of yellow pile on the 

 face usually less, this sometimes being reduced to a mere tuft between 

 the bases of the antennae ; occiput usually with dark and yellow pile 

 mixed, but occasionally entirely dark ; the femora often with very little 

 light pile. 



Male. Head.—F&ce largely covered with a dense patch of pure yel- 

 low pile ; occiput largely covered with yellow pile ; cheeks bearing a 

 large amount of yellow hair, this connected with the yellow on the 

 occiput. Malar space much longer than its width at apex, fully one- 

 third as long as the eye. Clypeus mostly covered up with yellow pile. 

 Flagellum of antenna about three times as long as the scape ; the third 

 antennal segment longer than the fifth, the fifth longer than the fourth. 



Thorax. — Clothed mostly with yellow pile, but the dorsum with 

 black and yellow pile mixed between the wings. 



Abdomen. — Dorsum : segments one and two entirely covered with 

 yellow pile ; segments three and four clothed with ferruginous pile ; 

 segments five, six and seven dark, but sometimes with a slight ad- 

 mixture of light hairs. Venter clothed mostly with light pile. 



Genitalia. — Very much like those of ceiiiralis. 



Wings. — Somewhat lighter than those of the queen. 



Z,(?^5.— Coxae, trochanters and femora all with a large amount of 

 light yellow pile ; fore and middle tibiae with considerable light or fer- 

 ruginous pile ; hind tibiae with outer faces slightly convex and naked, 

 the fringes mostly yellow ; hind metatarsi with posterior fringes light 

 yellow or ferruginous. 



Dimensions. — Length : queen, 13 mm. to 16 mm. ; worker, 9 mm. 

 to 12 mm. ; male, 11 mm. to 12 mm. Spread of wings: queen, 27 

 mm. to 34 mm. ; worker, 19 mm. to 27 mm. ; male, 25 mm. to 26 

 mm. Width of abdomen at second segment : queen, 7 mm. to 9 mm. ; 

 worker, 4j mm. to 7 mm. ; male, 5 mm. to 6 mm. 



Redescribed from many queens (one a homotype) and 

 workers and two males. 



Variation. — I have seen specimens which show a complete 

 gradation of the typical form, above described, into the fol- 

 lowing color variants : 



Color Variant 1. — {B. dimidiatus Ashm., pars.) . Queen and worker 

 like the typical females, but with the extreme sides of the third dorsal 

 abdominal segment bearing black pile and with a considerable por- 

 tion of the fourth dorsal segment largely clothed with dark pile. Four 

 specimens from Fox Point, Alaska, and six workers and one male from 

 British Columbia (Metlakatla). 



Color Variant 2 .—{B . dimidiatus Ashm., pars.). Queen and worker 

 like the typical females, but with all the dorsal abdominal segments 

 beyond the second entirely dark. One queen from Blue Mountains, 

 Washington, one worker from Fox Point, Alaska, and one worker and 



