108 MAIN : AN AMERICAN FUNGUS NEW TO EUROPE.
the bodies of house-flies attached to window panes in the autumn.
A photograph of the specimen, twice natural size, is shown
on p. 107. I transferred some of the spores, which were abundant,
to a moist cell, but they did not germinate.
The specimen was submitted to Mr. K. G. Blair, of the
British Museum (Natural History), who kindly identified the
fly as Hyetodesia erratica, Fln., one of the Anthomyidae, an insect
recorded from many cf our midland and southern counties.
Mr. J. Ramsbottom, of the Botanical Department of the
Museum, reported that the fungus was Entomophthora americana,
Thaxt., recorded from New England and North Carolina, but
apparently not previously recorded from Europe and certainly
not from Great Britain. Its describer, Roland Thaxter, gives1
as hosts—"Diptera: Musca domestica, M. vomitoria, Lucilia
caesar, and numerous other large flies." He also says :—
"This common species is frequently met with from June
to October on the borders of woods, near brooks, or in shrubbery
about houses. The host is generally found fixed to the under,
rarely on the upper, side of leaves or on bare twigs, a few feet
from the ground. It can readily be distinguished by its general
habit from any species known to me, with the exception of
E. echinospora, since the rhizoids, instead of growing out in
the form of numerous scattered threads, are developed in an
even layer around the host's body, forming, with the conidio-
phores, a continuous mat-like covering, which becomes often
dark rust-coloured on exposure to the weather. The mass
of conidiophores is at first pure white, and in a moist chamber
grows with great luxuriance."
Mr. Ramsbottom adds:—"I have never seen such a luxurious
growth of any of the Entomophthoraceae as in the specimen
sent. The change in colour and the general macroscopic char-
acters mentioned by Thaxter are noticeable. The conidia are
elongate-ovoid, with a broad evenly-rounded apex, and taper
to a papillate base, often slightly bent to one side. Within the
spores are fatty bodies, frequently numerous, often of variable
shape and size. E. ovispora has similar conidia, but peculiar
cystidia are present, structures which are absent in E. americana."
My thanks are due to Charlie Thrussell, who found the
specimen, and to Messrs. Blair and Ramsbottom for the identi-
fications and notes.
1 "The Entomophthoreae of the United States," in Memoirs of Boston Soc. of Nat. Hist.
vol. iv., pp. 133-101 1888).