Mollusca

Summary

The Mollusca are fairly well represented in the county of Cambridge, since 101 of the 143 or so British species have been recorded. This is, however, a larger total than those of all the bordering counties except Essex, yet it seems probable that further search may add to the present list. Exploration has no doubt been restricted by the facts that the large towns are at the north and south ends of the county and that the intermediate region is one of small villages and scattered farmsteads. At the same time the comparatively recent alteration in the physical features of much of the county demands attention in considering its fauna. The draining of the Fenland has during the last 300 years converted vast areas of brackish tidal waters into dry land, and so the absence of at least some of the xerophilous species common enough in other parts of England is not difficult to understand.

Beyond this it would be hazardous to say much, for our knowledge of the molluscan fauna of the central districts is at present very inadequate, and much remains to be done in the exploration of the region through which the Bedford Levels run, the tidal waters of those artificial streams, and of the region forming the Isle of Ely, before we can consider that the mollusca of the county have been fully recorded.