330 [Deoembp^r 
them agree well with the description of G. q. inanis Osten Sacken. 
The flies came out in June. 
As I did not gather these galls, 1 may be mistaken in the species of 
oak, though from the leaves I judged it to be the species named. 
I have, in my collection, a species of gall from Quercus ilicifolia. 
which nearly resembles, if it is not identical with, one described by 
Baron Osten Sacken (Proc. Ent. Soc. Phil, i, p. 70), and doubtfully 
referred to G. q. arhos Fitch. 
My galls were collected during the winter and spring, but I have 
not yet succeeded in rearing any true gall-flies from them. On the 
first of June, new galls had reached their full size, but were still ten¬ 
der,—quite like the young shoots of which they formed a part. Ex¬ 
amining them on that day, I discovered on them two gall-flies which I 
succeeded in taking. They were females and the ovipositor of each 
was inserted into the gall so deeply that they could not readily free 
themselves, and they were removed by force. 
The punctures were, apparently, directly over the cavities where, in 
this species, the larva is always found. 
These flies evidently belong to the section InquiUnsR. I add a brief 
description. 
Black, head j^ubeseent, face densely pubescent. Antennce 13-jointed, brown, 
terminal joint black or very dark dull brown, much darker than the others. 
Thorax covered with a fine short pubescence, longitudinal lines very fine. Legs 
yellowish brown, middle of femur and tibia darker. Wings hyaline, veins all 
present but nearly colorless, areolet large, indistinct radial area closed. Abdo¬ 
men black, shining. Sheath of the ovipositor turns up abrubtly, higher than 
the back of the abdomen. 
Upon an oak bush covered with galls of G. q. hatatusf I found 
several parasites like the above, except that the antennae had but 12 
joints. 
I have deemed this observation of a parasite gall-fly in the act of 
depositing her eggs, worth recording, as it may throw some light upon 
the question as to the time and manner in which these flies introduce 
their eggs into the galls^—a point upon which Baron Osten Sacken, in 
the paper above referred to, says (1. c. i, p. 49) there have been, as yet, 
so far as he can learn, no “ direct observations.'^ I marked one of the 
galls and shall endeavor to make sure of whatever it may produce. 
During the months of June and July I was in the habit of examin- 
