Field Studies of the Non-Social Wasps 377 
Several nests from various localities and different 
years showed so much similarity, in all points excepting 
the diversified filling, that detailed descriptions of the 
individual nests seem superfluous. The nests were found 
in old hollows in the pith-chamber of elder, sumac and 
horseweed. 
The parasites Cleptes sp. [S. A. Rohwer], Ellampus 
sp. [S. A. Rohwer] and Chrysis sp. emerged from the 
nests of S. niger. 
Silaon sp. [S. A. Rohwer].—The little builder of this 
nest could not be definitely identified by the one male 
Specimen available; the habits are evidently so similar 
to those of §. niger that I entertain a strong suspicion 
that this may be the same, but while doubt remains I 
shall list it separately. 
The nest was in a sumac stem taken at Wickes on 
June 28, 1918. The tunnel curved at the top enough to 
hold in place a plug, 44 inch deep, of strange construc- 
tion; it was a motley mass, some bits of soil, grasshop- 
per’s dung, a dead Chrysomelid beetle, the shedding- 
skin of a small spider, bits of dried leaves and stems 
and various other indistinguishable ingredients. For 
*4 inch below this the tunnel was hollow; then came an- 
other mass of the same detritus 114 inches long, and 
including five cocoons of a dirt-gray color and 5 mm. 
in length. They were not spaced with any system, nor 
was there any evidence that the packing material had 
been arranged to form partitions, but the entire mass 
was a jumble. Below this, the channel was packed for 
3 inches with roughly bitten pith; this had evidently 
been left by Hypocrabro stirpicolus, for it was inter- 
Spersed with the remains of flies. 
All this would indicate that this helpless little mother 
cannot bite out her own tunnel, cannot make her parti- 
