152 AMERICAN HYMENOPTERA. 



swollen. The coloration of the pile possibly quite variable., but the heads 

 of the females and the pleura and legs of all castes dark and the apex of 

 the abdomen almost always white above in all castes. Wings rather 

 light. 



Typically : the dorsjim of the thorax yellow, with a black interalar 

 band, arid the three basal dorsal abdominal segments yellow. 



Queen. Head. — Pile almost entirely dark, sometimes with an incon- 

 spicuous admixture of very short tawny whitish hair with the longer 

 dark hair on the occiput and on the face above and below the bases of 

 the antennae. Malar space considerably shorter than its width at apex, 

 nearly one-fifth as long as the eye. Clypeus, for most part, entirely 

 smooth. Ocelli large and placed distinctly below the supra-orbital 

 line, but slightly above the narrowest part of the vertex, the lateral 

 ones much nearer to the margins of the eyes than to each other. Third 

 antennal segment nearly as long as fourth and fifth taken together, 

 the fifth longer than the fourth. 



Thorax. — Dorsum yellow, with a well defined black band between 

 the bases of the wings (this band is apparently somewhat variable in 

 width, being, in one of the specimens before me, very nearly half as 

 long, from front margin to rear margin, as it is wide, from wing base 

 to wing base, while, in the other specimen, it is not nearly half as long 

 as wide); a naked area present on the middle of the disc. Mesopleura 

 somtimes entirely dark and sometimes with the yellow pile on the 

 front part of the dorsum extending down to somewhat below the level 

 of the bases of the wings. Metapleura and sides of median segment 

 entirely dark. No light or yellow tufts behind or beneath the bases 

 of the wings. 



Abdomen. — Dorsum : segments one and two yellow ; segment three 

 entirely yellow or with some black hair on the very hind margin, espe- 

 cially toward the extreme sides ; segment four clothed entirely with 

 white pile or mostly white with black pile on the very basal portion, 

 especially the anterior corners ; segment five white ; segment six 

 mostly dark in the middle, but with some white hair on the sides. 

 Venter mostly dark, but with the sides of the apical margin of the 

 fifth segment fringed more or less with whitish hair. Epipygium with 

 a short and very broad and shallow longitudinal median impression 

 toward the apex. Hypopygium without a distinct median carina. 



Wings. — Very light for a Bonibus queen ; only very moderately in- 

 fuscate ; perhaps best described as light, almost transparent, brown. 



Legs. — All the pile, including the corbicular fringes, dark brown or 

 black. 



Worker. — Like the queen, but with distinctly darker, rather strongly 

 infuscate, wings. Clypeus with very sparse, but coarse, punctures. 



Male. Head. — Face bearing a mixture of dark and whitish or pale 

 yellow pile above and below the bases of the antennae (most of the 

 light pile is very much shorter than the dark hair of the mixture) . 



