264
THE ESSEX NATURALIST
ACKNOWLEDGMENTS
Acknowledgments are due to Mr H. Fish, B.Sc, Pollution and
Fisheries Inspector, for his encouragement in the compilation of
this paper, and to the Chairman and Members of the Essex River
Board for permission to publish the same.
I would also like to thank Mr K. Renault for his help in
preparing Fig. 6, and Mr W. Young, B.Sc, of the Biology Depart-
ment, Mid-Essex Technical College for many helpful suggestions
and discussions leading to its completion.
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Carpenter, K. E. (1928). Life in Inland Waters. London.
Hartley, P. H. T. (1940). The Food of Coarse Fish. Sci. Pub. Fresh-
water biol Ass., 17.
Huet, M. (1954). Biologie profits en long et en travers des eaux courantes.
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Hynes, H. B. N. (1960). The Biology of Polluted Waters. Liverpool U.P.
Macan, T. T. (1949). A Key to the British Fresh and Brackish-water
Gastropods. Sci. Pub. Freshwater biol. Ass., 13.
Mann, K. H. (1954). A Key to the British Freshwater Leeches. Sci. Pub.
Freshwater biol. Ass., 14.
Mann. K. H. (1962). Leeches (Hirudinea). International Series of Mono-
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Hymenoptera at Fingringhoe Wick
By Peter D. Stebbing
The Fingringhoe Wick Nature Reserve is situated on the
western bank of the River Colne in northern Essex. The terrain
is an overgrown quarry with numerous ponds. The area in 1963
(9th-11th September, actual dates of the author's visit) was over-
grown with gorse, brambles and sparsely covered with grass. There
was also a thicket of young trees and a lake covering 11/2 acres. In
order to study the area, the reserve was divided into five main
sections.
1. The Saltings: very flat, with many creeks and saltwater
run-offs, virtually colonised mud flats. So that more localized
records could be obtained this area was subdivided into the
north and south mud flats.