264
THE ESSEX NATURALIST
beyond the mouth of the Colne (see also Davis, 1967, figs. 1 and
2). This area was subdivided into two portions (A and B in Fig.
Fig. 1. Sketch-map of South-east Essex showing areas sampled by the
survey.
1) along the line of Sales Point, the Blackwater Estuary proper
(A) being investigated by a sampling grid of 54 stations, and the
offshore regions (B) by 16 stations. The position of the Black-
water Estuary stations approximately corresponds with those
given by Davis (1967, fig. 2).
The fauna was sampled by means of a 0.6 m wide oyster
dredge (with a mesh aperture of 38 mm) and a van Veen grab
of 0.1 m2 bite. In addition, two trawls were made, one across
the regions A, B and C of Davis's Fig. 2 (loc. cit.) and one across