284 AMERICAN HYMENOPTERA. 



IVings. — Strongly stained with brown, the fore pair lightest in the 

 middle portion. 



Legs. — Coxae black ; trochanters mostly dark, but often with con- 

 siderable light pile on their lower sides ; femora and tibiae dark. 



Worker. — Much like the queen, but the wings usually somewhat 

 lighter. 



Male. Head. — Shaped much like that of queen. Face, above the 

 bases of the antennae, sometimes entirely black, but usually with a 

 patch of whitish and black pile mixed extending both above and below 

 the bases of the antennae ; occiput with a triangle of yellow pile and 

 pile of the same color running out from it on each side along the 

 occipital ridge ; ventro-lateral sides of head mostly dark, but often 

 with considerable light pile, this connecting with the occipital triangle. 

 Malar space longer than its width at the apex, about one-third as long 

 as the eye. Clypeus with middle part smooth and shining and at least 

 the anterior portion not very well covered with pile. Flagellum of an- 

 tenna from three and one-half to four times as long as the scape ; fifth 

 antennal segment somewhat longer than the third, the fourth distinctly 

 shorter than either. 



Thorax. — Coloration of pile much as in females, but the lower parts 

 of the mesopleura usually with more or less scattering yellow pile and 

 occasionally covered with it to the bases of the legs ; upper ends of 

 metapleura, close under the bases of the wings, often with a notice- 

 able touch of yellow. 



Abdomen. — Dorsum : first four segments entirely covered with yel- 

 low pile ; segment five entirely black, partly black and partly yellow 

 in varying proportions, or entirely yellow ; segment six often entirely 

 black, but usually with the apical margin more or less heavily fringed 

 with yellow ; segment seven mostly black, but usually with a few light 

 hairs on the sides. Venter occasionally almost entirely black, but 

 usually with the apical margins of all, except the basal and apical, 

 segments well fringed with light hair. 



Genitalia. — Outer and inner spathas like those of B. appositus (fig. 

 138). Claspers and sagittse as already described for the group (figs. 

 61 and 68) ; not separable by any noticeable structure from those of 

 B. appositus. 



Wings. — Considerably lighter than those of queen. 



Legs. — Coxae mostly black, but often with a few light hairs about 

 their tips ; trochanters usually with considerable light pile on their 

 lower sides; femora occasionally entirely dark, but usually with con- 

 siderable light pile ; tibiae dark. 



Dimensions . — Length : queen, 15 mm. to 19 mm. ; worker, 10 mm. 

 to 15 mm. ; male, 12 mm. to 15 mm. Spread of wings : queen, 32 

 mm. to 39 mm. ; worker, 26 mm. to 32 mm. ; male, 26 mm. to 31 mm. 

 Width of abdomen at second segment: queen, 8 mm. to 9| mm.; 

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



