156 Journal New York Entomological Society. |Voi. iv. 
front edge, with a long oblique testaceous line, a little angulated oppo¬ 
site the base of the clypeus. Antennal tubercle situated on the outer 
edge of a round area opposite the base of the clypeus; supra-clypeal 
piece obtuse, the suture separating it from the epicranium indistinct. 
Clypeus transverse, half as long as broad; the sides very oblique, 
marked by testaceous oblique lines; front edge straight. Labrum 
broad, being one-third as long as broad ; thin, flat, bilobate, overlapping 
the mandibles, but so thin and expanded that they can be seen through. 
Mandibles unusually short, stout, thick and broad, not much longer | 
than broad, unidentate, the outer edge produced into a short obtuse 
point; within curved towards the retreating inner edge. Maxillae 
smaller and slenderer than usual, ending in the maxillary palpi, which 
are short papillae. Labium as usual, with two papilliform palpi, be¬ 
tween which is the rudiment of the lingua, forming a transverse chit- 
inous line. In my two alcoholic specimens the head is bent upon the 
breast, nearly reaching the middle of the body. Ihe body is very 
short and broad, dilating in the middle. The end is unusually acute, 
the lateral region is more prominent, convex and tuberculated than any 
of the genera of other allied families; much more so than in Odynerus. 
The segments are unusually short, dorsally thickened posteriorly, giv¬ 
ing a serrate appearance to the outline of the body, the tip sternally is 
much exserted and of the same size with the tergite; the two forming a 
terminal rounded knob. 
In its round flattened head bent forward and under the body, the 
broad transverse clypeus and broad short bilobate thin transparent 
labrum, and especially the one-toothed, short, broad mandible which 
differs entirely in form from the other genera previously noticed, we 
probably have mostly family characters separating the Pompilidse from 
the Sphegidse and Larridae and other families. It widely differs from 
the larval Pelopceus in its short flattened body and prominent pleurites, 
and thickened rings generally, but it approaches it in the head-char¬ 
acters, which are the most reliable, in its transverse clypeus and thin 
bilobate labrum, and in the short mandibles; but they are still much 
stouter, and the clypeus and labrum are less exserted, while the head is 
shorter, broader and rounder. 
Chalybion cceruleum (. Linn .). 
Larva .—The specimens occurred at Kelly’s Island, Ohio. 
Head longer than broad; full convex, with a slight mesial impres¬ 
sion ; the anterior and inner edge of the eyes marked by a curvilinear 
