370 
Indiana University Studies 
The insect shows the generic characters of a bisexual Cynips 
as established by the life histories experimentally determined 
for varieties of folii and divisa, and for erinacei. 
The insect belongs to the subgenus Acraspis, as evidenced 
by the character of the hypopygial spine, the wing-body ratio, 
and the blotches (even tho obscure) in the cubital cell. 
The relation to an agamic Acraspis is further proved by the 
close resemblance of gemmuia to bicolens, the experimentally 
demonstrated bisexual form of Cynips pezornachoides erinacei. 
That gemmuia is not also a form of pezornachoides is shown 
by the host on which it occurs, namely Quercus prinoides, one 
of the chestnut oaks. Pezornachoides occurs only on the true 
white oaks of the Q. alba group, and is rigidly excluded from 
the chestnut oaks. 
Cynips hirta and prinoides are the only agamic forms of 
Acraspis known from the chestnut oaks, and prinoides is the 
only Acraspis known from Quercus prinoides. 
Prinoides , then, seems to be the only agamic Cynips of 
which gemmuia might be the alternate, and none of the data 
are in conflict with the conclusion that these two are really 
alternates. 
Cynips (Acraspis) pezornachoides Osten Sacken 
bisexual and agamic forms 
AGAMIC FEMALE. — Thorax much reduced and narrowed; the mes- 
onotum coriaceous to puncto-rugose, sparsely pubescent; parapsidal 
grooves fine but distinct, continuous or more often not quite continuous, 
in variety echinoides extending only a short distance from the scutellum ; 
anterior parallel lines and median groove entirely absent; lateral lines 
nearly or entirely absent; scutellum rugose and hairy, narrow, elongate, 
with a distinctly constricted, small, and rather sharply pointed tip, 
anteriorly depressed but with the foveal groove poorly defined, shallow, 
in large part rugose at bottom; the ridge separating the scutellum from 
the rest of the mesonotum fine and indefinite; mesopleuron entirely 
punctate and hairy; abdomen enlarged, distinctly elongated, not much 
produced dorsally, very much compressed, the second segment covering 
less than half of the abdomen; the entire abdomen naked except for the 
patches of hairs on the second segment latero-anteriorly, with a few 
stray hairs near the ventral margins of the third segment; wings much 
reduced, from 0.14 to 0.23 of the body in length, with hardly a trace 
of venation; length 1.5 to 3.8 mm. 
BISEXUAL FEMALE. — Known only for variety erinacei (q-v.). 
Head, thorax, and abdomen piceous to black (fading quickly in dried 
