380 AMERICAN HYMENOPTERA, 



the scape ; the third antennal segment and the fifth subequal in length, 

 the fourth shorter than either. 



Thorax. — Sometimes bearing only yellow pile ; the region between 

 the wings and the scutellum usually more or less dark, often being as 

 dark as in the females ; the scutellum sometimes entirely yellow, with 

 the interalar region at the same time dark ; anterior part of dorsum 

 and the pleura almost always entirely covered with pure yellow pile, 

 but the metapleura sometimes dark ; sides of median segment usually 

 yellow, but sometimes dark. 



Abdomen. — Dorsum: segments one and two with yellow pile; seg- 

 ment three often almost entirely yellow, but as often with only an api- 

 cal fringe of yellow hairs ; segment four often entirely black, but usu- 

 ally with some yellow pile, especially along the apical margin ; seg- 

 ment five sometimes entirely black and sometimes with the basal por- 

 tion black and the apex light ferruginous ; segments six and seven oc- 

 casionally entirely black or black with a few yellow hairs admixed, 

 but usually light ferruginous. Venter, for the most part, rather heavily 

 clothed with pale yellow pile, occasionally mostly dark as in the 

 females. 



Genitalia. — Outer spatha (fig. 125) rather short and wide ; the ante- 

 rior margin deeply incurved ; the lateral margins nearly straight and 

 converging rapidly posteriorly ; the posterior margin somewhat vari- 

 able, but usually nearly straight ; the anterior lateral projections 

 rounded at the end ; the ventral surface bearing a scattering of moder- 

 ately long hairs towards the hind margin. Inner spatha (fig. 144) 

 with the sides of the anterior margin bent backward slightly ; the side 

 margins strongly incurved ; the posterior margin nearly straight, the 

 apical portion being quadrangular ; a small central fenestra usually 

 present ; the ventral surface of the apical portion bearing long hairs 

 (especially on the sides) and with these hairs rather thickly placed. 

 Claspers like those of B. mixttis Cress, (figs. 108 and 109). 



Wings. — Somewhat lighter than those of the queen ; subhyaline. 



Legs. — Coxse, trochanters and femora always bearing a large amount 

 of yellow pile ; fore and middle tibiae always with considerable ferrugin- 

 ous pile on their outer sides ; posterior tibiae with outer faces convex 

 and mostly naked, at least in the apical portion, and the fringes long 

 and, for the most part, pale ferruginous ; posterior metatarsi with rather 

 long and ferruginous hind fringes. 



Dimensions. — Length : queen, 13 mm. to 17 mm. ; worker, 9 mm. 

 to 13 mm.; male, 11 mm. to 14 mm. Spread of wings: queen, 29 

 mm. to 34 mm. ; worker, 22 mm. to 28 mm. ; male, 24 mm. to 29 mm. 

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

 worker, 5 mm. to 7 mm. ; male, 6 mm. to 8 mm. 



Redescribed from ten queens and many workers and males. 



Habitat. — I have records of this species as follows : Alaska 



(Yukatat, Virgin's Bay, Sitka, Ft. Wrangel, Seldovia, Ju- 



