gramandy's picture

Common Flat Periwinkle

Observed: 21st April 2013 By: gramandy
Kent Wildlife TrustThanet Coast ProjectWildwood Trust
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Common Flat Periwinkle
IMG_1911a
Description:

In the higher eulittoral zone. All the Periwinkles here tend to be black rather than yellow, red, green, banded, etc.

Identifications
Species interactions

No interactions present.

Comments

dejayM's picture

revisit

Graham, isn't there a flat P with this pronounced ribbing somewhere?
It also looks very thin shelled.
ðj

Ian Smith's picture

flat periwinkles never ribbed

Flat periwinkles are never ribbed. This is, without any doubt, Littorina littorea. The second apertural image shows clearly the diagnostic pure white columella with a dark basal mark. See https://flic.kr/p/pfuSfj both it and your image have the juvenile ribbing and thin outer lip of L. littorea.

There is an account of how to differentiate Littorina obtusata from L. fabalis at https://flic.kr/s/aHskPGCpTE

Ian Smith