292 AMERICAN HYMENOPTERA. 



both back under the bases of the wings and to the bases of the legs. 

 Metapleura and sides of median segment occasionally entirely dark, 

 but usually with more or less light hair and often with light pile only. 

 Colors of thorax as a whole sharply defined. 



Abdomen. — Dorsum : first two segments always entirely covered 

 with pure whitish-yellow pile; third segment mostly black, but always 

 with a touch of light pile on the extreme side margins and often with 

 a more or less strong fringe of the same color extending inward more 

 or less toward the middle line along the apical margin ; fourth seg- 

 ment very variable, often entirely covered with ferruginous or whitish 

 yellow pile (of varying shade) and as often enitrely black ; fifth seg- 

 ment usually entirely covered with ferruginous or whitish yellow pile 

 (of greatly varying shade), but sometimes with such a strong admix- 

 ture of black hairs as to make this color greatly predominant ; sixth 

 segment always entirely black, except for rusty tip. Venter some- 

 what variable, but usually clothed (except first and last segments) for 

 most part with light pile. 



Wings. — Subhyaline ; the fore pair darkest on median and submedian 

 cells and on anterior part of the radial cell and about and beyond its 

 apex. 



Legs. — Coxse sometimes entirely black, but usually with a more or 

 less noticeable amount of light hair ; trochanters seldom without a 

 considerable amount of light pile on the lower side ; fore and middle 

 femora often entirely dark, but usually with a slight touch of light 

 hair at their bases ; hind femora usually with a conspicuous amount 

 of light hair at least on basal portion, rarely entirely dark ; fore and 

 middle tibiae, except rusty outer sides of apices, entirely dark ; cor- 

 bicular fringes usually more or less strongly ferruginous, but often 

 entirely black. 



Worker. — Like the queen, but with pile on metapleura and sides of 

 median segment never entirely dark, usually entirely light; posterior 

 and middle coxae, trochanters and bases of femora never without some 

 light hair ; pile on dorsal abdominal segments four and five usually 

 much more strongly ferruginous than in case of queen and also the 

 venter with this ferruginous pile sometimes extending slightly onto the 

 side margins of the corresponding segments. 



Male. Head. — Shaped as in queen. Face with a large patch of 

 yellow pile between and below the bases of the antennae, this patch 

 widely separated from the inner margins of the eyes on each side and 

 sometimes with black hairs admixed ; occiput bearing a median tri- 

 angular patch of sometimes pure yellow pile, but usually with a very 

 slight admixture of black hairs ; ventro-lateral portions of head usu- 

 ally with considerable yellow pile. Malar space about one-half as 

 long as eye ; clypeus mostly covered up with pile ; flagellum of an- 

 tennae about three times as long as the scape ; fifth antennal segment 



