432 AMERICAN HYMENOPTERA. 



as the scape ; third antennal segment somewhat shorter than the 

 fourth and fifth taken together, the fifth longer than the fourth. 



Thorax. — Dorsum covered with yellow pile, this pile reaching down 

 onto the mesopleura to a little below the level of the bases of the 

 wings ; the remaining portions of the mesopleura black ; the meta- 

 pleura black, except for an inconspicuous tuft of yellow hairs usually 

 present just below the base of each hind wing ; sides of median seg- 

 ment entirely dark 



Abdomen. — Dorsum : segment one clothed with yellow pile ; seg- 

 ment two covered with yellow pile, but usually with black pile on the 

 extreme side margins ; segment three with a large patch of yellow 

 pile nearly reaching the side margins at the base of the segment, but 

 on the apical margin reaching only about half-way to the side margin 

 on each side, the rest of the segment being black ; segments four, five 

 and six entirely black. Venter black. 



Wings. — Very dark and with slight violaceous reflections ; the fore 

 pair darkest in the median, submedian and parts of the second dis- 

 coidal cell, and in the anterior portion and about the apex of the radial 

 cell, lightest in the region beyond the veins. 



Legs. — Black. 



Worker. — Much like the queen, but with somewhat lighter wings, and 

 the yellow patch of pile on the third segment tending to cover more of 

 the segment ; face sometimes with a very slight sprinkling of yellow 

 hairs above the bases of the antennae. 



Male. Head. — Face with a large amount of yellow pile above and 

 below the bases of the antennae, usually with a more or less strong 

 admixture of black hairs ; occiput largely covered with yellow pile ; 

 cheeks sometimes entirely dark, but usually with a considerable amount 

 of yellow pile connecting with the yellow on the occiput. Malar space 

 about one-half as long as its width at the apex. Clypeus clothed, but 

 not very densely, with mostly yellow pile. Ocelli placed exactly in the 

 narrowest part of the vertex, the lateral ones about half their diameters 

 from the inner margins of the eyes. Flagellum of antenna fully three 

 times as long as the scape ; third and fifth antennal segments equal in 

 length, the fourth shorter than either. 



Thorax. — Coloration of pile much as in queen, but usually as much 

 as the upper two-fifths of the mesopleura covered with yellow pile, 

 and often even their lower portion with a slight sprinkling of yellow 

 hairs admixed with the black. 



A ddomen.— Dorsum : three basal segments entirely covered with 

 yellow pile ; segment four sometimes entirely black and sometimes 

 with all but the apical margin covered with yellow pile, but usually 

 mostly black with the basal middle bearing more or less yellow pile ; 

 segments five, six and seven entirely black. Venter mostly dark, but 

 usually with more or less yellow pile along the middle line of some of 



