158 
Journal New York Entomological Society. 
LVoi. iv. 
inner ones are enveloped by the outer pair, which are united into one 
piece in Polistes ; above, a small inner pair lies between, slenderer than 
those beneath. The edges of the abdominal segments are a little more 
thickened than usual, and slightly spinulose; on the side is a promi¬ 
nent long slender tubercle. 
Fig. I. Larva and pupa of Pelopceus cementarins. ( Trouvelot del.) 
Sphex tibialis St. Farg. 
Larva .—The body of the living larva is somewhat flask-shaped, 
slightly flattened, gradually widening from the head towards the pos¬ 
terior fifth of the body. The head is small and not prominent. There 
are 13 segments behind the head; the pleural or lateral ridges are rather 
prominent, those of each segment well defined, the posterior halt of 
each segment much thickened, giving a crenulate outline to the tergum; 
the last segment is full, orbicular, the end of the abdomen being full. 
Fig. 2. Larva of Sphex tibialis ; a, side view of head, enlarged. (Trouvelot del.) 
Stigmus fraternus Say. 
Larva .—Body moderately long, slender, cylindrical, tapering 
slowly towards both extremities; the segments short, very convex, sub- 
