Field Studies of the Non-Social Wasps 395 
The males of this species sleep in the low grass. I 
have taken them thus, about the middle of June, at two 
widely separated points, while sweeping the grass at 
twilight. 
Odynerus (Stenodynerus) pennsylvanicus Sauss. [S. 
A. Rohwer. ] 
A twig of soft wood taken in a park in St. Louis on 
February 13, 1920, contained a brood of these wasps. By 
March 30 the three lower cells contained quiet young in 
the prepupal stage, all very much alike in the degree of 
development, and the top cell had a perfectly formed 
pupa, legs, antennae, etc., all yellow, with the eyes just 
taking on a little darker shade of yellow preparatory to 
becoming pigmented. This latter one was injured in 
cutting the twig. The stalk was provided with a trans- 
parent wall and the occupants were watched to see if 
they would mature in the inverse order of the deposition 
of the eges—the last egg to become the first-born and the 
first egg to become the last to emerge. 
This twig had not been excavated by the mother of 
this brood, but had been used previously by some other 
occupant. The four cells measured 14, 4, 54, and 5¢ 
inch in length; the plug serving as a floor and the parti- 
tions were 14, 3/16, 14, 3/16, and 1% inch, the last serving 
as a roof. There was a vestibule of 34 inch above this, 
and it had no mud plug over the opening. Here, too, I 
found the vestige of a cocoon in the form of a thin cover- 
ing, the edges of which adhered to the round wall of the 
channel. In one ease this disk was directly above the 
head, and in another it was plastered against the ceiling. 
In one of the other two it was in the same form, but much 
abbreviated, and the surplus splashed on the side of the 
cell; in the other and last cell it consisted of only a trace 
