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

by G. B. Sowerby

21. P. scabra, Müller.—Bulla and Scaphander scabra, pectinata, dilatata, and catenulifera.—Northumberland, Zetland, Ireland, etc., Mc., 5 to 50 fath. N. Eu. Oblong, serrated.

22. P. quadrata, S. Wood.—Bullæa and P. scutulum.—Zetland, etc., 10 to 100 fath., R. Striated.

23. P. catena, Mont.—Bulla and Bullæa c., angustata, and punctata,—Brit. co. generally, Mr., 0 to 40 fath. With chain-like sculpture.

24. P. punctata, Clark.—Bulla and Bullæa.—Devon, Swansea, Aberdeen, Clare. In sand, 60 fath., Mc. With punctured sculpture.

25. P. pruinosa, Clark.—Bulla and Bullæa.—Devon, Northumb., Hebrides, etc. Mud, 20 to 70 fath. N. Eu.

Scaphander.

26. S. lignarius, Linn. (Bulla.)—B. oblonga.—Brit. co. generally. 1 to 50 fath. N. and S. Eu., C.

27. S. zonatus, Turt. (Bulla)—Young specimen taken at Zetland by Mr. Jeffreys, resembling older Norwegian specimens. More oval than S. lignarius. Spire umbilicated.

Aplysia.

28. A. hybrida, Sowerby.—Laplysia depilans, A. depilans and punctata.—Brit. co. generally. Among seaweeds, 0 to 6 fath., C.