CYNIPS KOLLARI. 105 
gall, whereas the true ink-gall yielded 40 per cent. 
more. 
At the time of its appearance in this country the 
manufacture of cloth was a prominent industry in 
Exeter, Tiverton, and several neighbouring towns; 
and large quantities of Cynips tiuctoria were imported 
for dyeing purposes. Whether C. Kollari was intro- 
duced for experimental purposes with the hope of 
superseding the Aleppo species, there is no confirma- 
tory evidence. It will perhaps never be ascertained 
how this species of Cynips origimated in this country. 
_C. Kollart was known prior to that period for very 
many years throughout the whole of middle HEuropean 
countries. 
As the gall spread over the country, and became 
known among entomologists, it was occasionally 
mistaken for three Continental forms of similar 
appearance and habit. One is CO. lignicola, which is 
rather larger than a pea, occurs singly, also in twos 
and threes; it has a large oval larval cell, and is 
generally of a spherical form, but it is distinguished 
by having an outer covering similar in appearance to 
leaf scales. Another form is (. conglomerata, which 
sometimes occurs singly but mostly in dense semi- 
racemous clusters of fifteen to twenty-five individuals, 
also rather larger than a pea. Externally it resembles 
a normal gall of C. Kollari in having a small style, and 
in being hard and brown when mature; also internally, 
in being composed of a spongy parenchyma. C. Kollart 
has also been confused with C. tinctoria, the ink-gall 
from the Levant, on account of its external features. 
Although the normal form of C. Kollari is smooth and 
spherical, an examination of Plate XXXV will reveal 
a remarkable similarity as regards size, shape, papille, 
and ridges. The larval cell in both is central and 
ellipsoidal inform. The imagines also, of each species, 
are much alike. 
The oak-marble is found in great profusion in 
hedges, along lanes, and scrub oaks in coppices. Low 
