Kinsey: Gall Wasp Genus Cynips 
97 
ly of much-branched fibers with a considerable amount of small, open 
space, giving a suggestion of main fibers radiating from the center as in 
the galls of the American subgenus Atrusca. The larval cell usually 
central, oval, averaging 3.5 by 4.0 mm., with a distinct wall but in- 
separable from the spongy filling of the gall, the spongy material 
directly outside the larval cell, sometimes irregularly compacted and as 
hard as the cell wall itself. Attached to the median or lateral veins 
by only a slight point, on the leaves of numerous species of European 
white oaks. 
BISEXUAL GALL. — A small, egg-shaped, thin-walled cell originat- 
ing in the adventitious buds of the older or younger oak stems. The 
cells up to 3.0 mm. in length, their surfaces microscopically puberulent, 
at first red or violet, finally blackened; the entire gall inside the thin 
shell occupied by the larval cell. Sessile on the old bark near the base 
of the trunks, less often on the younger stems, but often on the older 
bark of large stems, a third to a half enclosed by the normal bud 
scales. Known from Quercus pedunculata, Q. sessiliflora, and Q. pubes- 
cens. 
RANGE. — Probably wherever oaks occur in Europe, Asia Minor, 
and northern Africa, with the four described varieties, atrifolii, folii, 
floscuii, and ilicicola, confined to more northern, central, and Mediter- 
ranean Europe and Spain respectively (fig. 15, 16). 
The galls of the typical variety of this species are among 
the commonest and best-known of Central European Cynip- 
idae. This was one of the five species of oak galls known to 
Linnaeus (1758), and later workers on cynipid structure and 
biology, and on gall histology and embryology have usually 
included this species in their studies. 
The variety folii ranges over the whole of Central Europe, 
being replaced in the Mediterranean area of Europe and 
Africa by a very similar insect, variety floscuii (better known 
from its agamic form pubescentis ) which has certainly been 
derived from the same stock as typical folii . The insects of 
the two are so close that most authors have considered them 
inseparable, and no one, except Tavares (1928), has described 
more than color differences which, I believe, are not invariable 
enough for the separation of even the majority of the speci- 
mens. I find the smooth foveal groove, the smoother anterior 
portion of the scutellum, and the enlarged tip of the second 
abscissa of the radius of floscuii will serve for the recognition 
of the insects I have seen. The agamic galls of folii and flos- 
cuii are quite distinct (except in certain transition areas) , and 
this seems to have been the basis on which determinations 
7—45639 
