36
THE ESSEX NATURALIST.
spores to fall away, when the short clavate columellae are
exposed. In Europe L. Chailletii is not unfrequent on high
ground in Switzerland; it has been found in Bohemia and in
alpine meadows in Dauphine; it has also been recorded from
Mt. Ranier, in the State of Washington, U.S.A.
Perichaena vermicularis forms small fragile curved and often
branching buff plasmodiocarps on decayed leaves and dead
herbaceous stems. Under a microscope, a characteristic feature
is the closely papillose inner surface of the sporangium-wall. It
is not rare in England, having been recorded, chiefly in winter,
from fourteen counties, and also from Scotland and North
Ireland: it is widely distributed elsewhere—from the lowlands
of both temperate and tropical lands, and also from alpine
pastures.
Mucilago spongiosa is a widely-spread species, occurring on
dead leaves, and about dead grass in pastures. The grey sporangia
are somewhat confluent, forming masses one or more inches
across, clothed with a snowy envelope of calcareous crystals.
One other species in Mr. Ross's list deserves special notice,
viz., Comatricha rubens lister; it closely resembles the more
abundant C. pulchella Rost., and differs chiefly in the sporangia
being provided with a cup-like membranous base. Only
two previous gatherings are known from Essex, both found by
Miss Hibbert Ware in Wanstead Park.
THE EVOLUTION OF THE COASTAL
DRAINAGE OF ESSEX.
By RUPERT COLES, B.A., Ph.D.
[Read 24th November, 1934.]
THE subject of the Essex drainage system has been discussed
more than once in the pages of the Essex Naturalist.
The majority of these papers, however, have been more concerned
with the evolution of the river system of Western Essex and its-
relation to the ancient courses of the Proto-Thames and Thames,
rather than with the peculiar hydrological features afforded by
the Essex coast. An account of the Essex rivers by the late
Professor J. W. Gregory1 provides an interesting exception,
inasmuch as this writer considers the origin of the Essex rivers
1 The Evolution of the Essex Rivers. Gregory, J. W.