lxiv
Journal of Proceedings.
first distinguished from O. eichornii, Ehr., by Mr. Kent in November,
1871, specimens reaching him from Stourbridge, Worcestershire (' Manual
of the Infusoria,' 738). He goes on to say:—"Quite recently, October,
1881, the author has obtained luxuriant colonies of this species attached
to Myriophyllum growing in a pond in Epping Forest, visited in con-
nection with a field-day of the Essex Field Club. It was observed of
examples preserved for some days that the zooids freely abandoned then-
original mucilaginous zoocytium, and, reattaching themselves inde-
pendently, were scarcely distinguishable during such isolated condition
from those of Gerda fixa, D'Udk." Stichotricha secunda, Perty. (rare),
Litonotus fasciola, Ehr., with plenty of Chilodon cucullulus, Mail. Most
of the species were in abundance.
In Monk Wood, Mr. Henry Corder noticed a peculiar gall-like formation
on the leaves of the Wood-Violet (Viola sylvatica), and the same were
afterwards found in abundance by Mr. W. Cole. The leaves of the plant
are curled, thickened and folded over, taking a purplish hue, and forming
little chambers which sometimes contain a small orange-coloured larva.
Specimens were afterwards submitted to Mr. E. A. Fitch, F.L.S., who is
of opinion that they are the work of a Gall-gnat (Cecidomyia) hitherto
unrecognised in Britain. Mr. Fitch has favoured us with the following
note:—
Cecidomyia violae, F. Low, in Essex.
I have examined the supposed galls sent me by Mr. Corder and Mr.
Cole. From the first specimens received I thought they were only abortive
cleistogamic flowers of the Violet (Viola sylvatica), but from the later
specimens I have the orange cecidomideous larva; in some numbers,
proving them to be pseudo-galls and the work of gall-gnats. I have but
little doubt that they are the work of Cecidomyia viola, a species only
described last year (1881) by Dr. Franz Low, although his galls occurred
on Viola tricolor, and these are on V. sylvatica. After fully describing the
male and female gall-gnats, Dr. Low proceeds as follows :—
"The larva; of this gall-gnat are pale orange-red; their third and
fourth segments are darker orange-red. They live in numbers in rosette-
like leaf-galls on Viola tricolor, and pupate therein in white cocoons.
These leaf-rosettes occur at the tips of the stalks and on the side-shoots
which originate at the axis of the stalk ; by the action of the gnat-larva?
the internodes become greatly shortened, thickened, and altered in diffe-
rent ways, so that the leaves become crowded closely together. The
adjacent leaves are affected as follows: they remain very short, are not so
deeply cleft as the normal ones, are somewhat thickened and rolled
inwardly towards the upper side from both edges in the shape of a cornet,
and are covered with a very rich growth of hair. Flowers on a very
short, thick, twisted stalk, and which do not become fully developed,
usually occur between the leaves. In such flowers the calyx is generally
malformed like the above-mentioned leaves, the petals are generally green
and deformed, and the organs of fructification wholly or partially abor-
tive. This gall has hitherto only been observed in the months of July,
August, and September, at which time the gall-gnats emerge. I first
found it in 1878 in great numbers at Payerbach, in Lower Austria, in a
fallow field, and since then at Baden in a stubble. Herr Alfred Hetschko
sent it me at the end of August, 1879, from Ellgoth, near Teschen, in
Austrian Silesia, and, according to a short note from Herr D. H. E.
v. Schlechtendal, he also finds it at Zwickan, in Saxony."—(' Verhand-
lungen der k.-k. Zoologisch-botanischen Gesellschaft in Wien,' vol. xxx.,
p. 35, 1881).