Illustrated Index of British Shells / Containing figures of all the recent species

by G. B. Sowerby

13. C. cinereus, Linn.—C. marginatus, Penn.?—Brit. co. generally, C. Valves carinated; margin and valves granulated.

14. C. albus, Linn.—C. asselloides, Lowe.—Northern coasts, R. Marginal granules scaly and large; dorsal gr. smaller than C. cinereus.

15, 16. C. asselus, Chemn.—C. minimus, Cinereus albus.—Brit. co. generally, C. Broad, granules on valves beaded.

17. C. cancellatus, Sowerby.—C. albus, Pult.—Devon, Guernsey, Isl. Man, Oban, Zetland, Loch Carron, R. Narrow, back elevated, else like C. assellus.

Patella. (Limpet.) Sedentary.

18. P. vulgata, Linn.—Brit, generally, Cc. Ribs not toothed.

19. P. athletica, Bean.—Devon, Northumberland, etc., Cc. Ribs toothed.

20. P. pellucida, Linn.—P. lævis, cærulea, Acmæa pel.—British co. generally, C. smooth.

21. —— var. lævis, Penn.

Acmæa, or Lottia.