2 Annals Entomological Society of America [Vol. VII, 
of attachment is generally on the midrib (Fig. I, Pl. I), though 
it is often found on the lateral veins. When young it is yel- 
lowish green, but in autumn it becomes yellowish brown, 
much lighter in color than the tinting of the leaf. The gall 
first appears late in June, and reaches full development about 
the third week in August. It is widely distributed, having 
been reported from New England, North Carolina, Iowa, 
Illinois, Indiana, Kansas, Michigan, Ohio, Virginia, Canada, 
and probably Florida and Colorado. 
A longitudinal section through the gall shows that it contains 
several chambers varying from two to eight in number. These 
I have named according to their location. First to be noted 
are the central cavities, (Fig. 2a, Pl. I), which measure 2mm. x 
omm. and are located in the central portion of the growth. 
These are occupied by Dryophanta erinacei and the parasites. 
Second, there are the lateral cavities, (Fig. 2b, Pl. I), situated 
at the side and base of the growth and measuring 114mm. 
x 2mm. These are occupied by inquilines. Lastly, there 
are to be found the peripheral cavities, (Fig. 8a, Pl. II), located 
on the coriaceous portion of the gall, and covered with the 
basal layer of spines. These are 1mm. in size, and are likewise 
occupied by iniquilines. 
The gall was first described by Walsh in 1864 under the 
name Cynips q. erinacei. When Mayr in 1881 established 
the genus Acraspis he included the insect causing this gall, 
which therefore was known as Acraspis erinacei. The first 
description of the insect appeared in a paper by Beutenmiiller 
"09, entitled “Species of Biorhiza, Philonix, and their allied 
Genera, and their Galls,’’ in which he places it in the genus 
Philonix. As will be shown later in this discussion, the insect 
belongs to the genus Dryophanta, and should be known there- 
fore as Dryophanta erinacei (Mayr). 
THE LIFE-HISTORY OF DRYOPHANTA ERINACEI. 
The agamic form of Dryophanta erinacei emerges from 
the oak hedgehog gall about the fifth of November. It varies 
from 1.50 to 3mm. in length. The head is black, rufous 
on both sides of the face, finely punctate, with whitish pubes- 
cence; antennae black, fourteen jointed, with basal joints 
rufous; thorax rufous; plurae black with rufous mark anteriorly; 
all minutely punctate; parapsidal grooves distinct posteriorly, 
