Callochiton septemvalvis. Cornwall, England. September 2004.
Copyright D. Fenwick, www.aphotomarine.com/index.html
The head and tail valves of C. septemvalvis are often darker than the intermediate valves, but this distinction is lost on specimens like this with dark intermediate valves.
Girdle colour is usually similar to that of the adjacent valve, often with a transverse cream band by sutures i/ii and vii/viii, and occasionally other sutures (see 68 Tonicella marmorea COMPARISON Callochiton septemvalvis ). On this dark specimen the ’snake skin’ pattern of the girdle spicules (see 71 Tonicella marmorea COMPARISON Callochiton septemvalvis ) is not easily seen.

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