FossoriaZ Hjt/menoptera of North America. 365 



Fore pair of trochanters and coxae black, femora scarcely dilated 

 within, the expansion (vexhillum) is convex on its inner edge, beneath 

 irregularly concave, pale, straw yellow ; tibia dilated into a square, 

 subrhomboidal convex plate, as broad as long - , both sides convex, hind 

 margin convex, one-third shorter than the broad, concavo-sinnate an- 

 terior edge, which is externally produced into a blunt, rounded spot; 

 straw yellow, vexhillum becoming brown towards the outer edge, with 

 three alternate light and dark sinuate stripes, parallel to the joint; on 

 the under side of base of joint a blackish dot; tarsal joints testaceous, 

 expanded portious darker without; two hind pairs of femora black, 

 tibia yellow, under side of hind tibiae black-brown; tarsi testaceous 

 brown, abdomen shining black, 3-spotted, the spots or short fascia 1 , 

 broad ovate, not approximating on the median line; basal joint black, 

 convexly swelled above, tumid; spots on 2 — 5 rings with minuter spots, 

 especially the second pair, tip covered sparsely with a slight hirsuties. 



Length of body, .3-1; head and thorax, .lb' ; abdomen, .18 inch. 



9 . differs from the male in having the second joint of antennas 

 entirely yellow; prothorax yellow above, and the enclosure of the 

 propodeum is transversely narrowly banded with yellow, and more hir- 

 sute than in the other sex. Fore coxa and trochanters black; femora 

 with the angles of the joint black, lineated with paler, externally a 

 triangular yellow spot, running beyond the middle of the joint ; tibia 

 simple, yellow, tarsi fuscous ; middle and hind trochanters and femora 

 black; hind tibia yellow, with an internal brown spot near the tip. 



The abdomen is flatter and broader than in % , and the three fascia 

 are correspondingly narrower, but still remote above. The fascia are 

 sinuate, the third pair very narrow above, at the base broadly dilated ; 

 beneath black in both sexes. 



9 . Length, .40; head and thorax, .20; abdomen, .20 inch. 



Illinois, (Norton,) Penn.. (Coll. Ent. Soc. Phil.) 



The cuboidal head, the remote broad, ovate spots on the abdomen, 

 together with the simple antenna and the broad, square plate on the 

 fore tibia are characters easily separating this species, and throwing it 

 into a distinct group of almost subgenera value. 



The female of the present species differs from the foregoing ones in 

 the unusually cubical head, which is scarcely broader than long; ver- 

 tex broad and flat ; front narrower between the eyes than usual, being 

 wholly concealed when the antenna are folded back, the entire front of 

 the head, including the eyes, is transversely oblong, not narrowing be- 

 low at the insertion of the antenna so much as usual. The clypeal 



