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

by G. B. Sowerby

Pleurobranchus.

29. P. membranaceus, Mont. (Lamellaria.)—Devon, Arran, Cork, etc. Low-water, Mr. Broad, flexible.

30. P. plumula, Mont. (Bulla.)—Guernsey, Devon, Skye, etc. Littoral, R. Narrow, less flexible.

Spirula.

31. S. Peronii—Once taken near Swansea, imperfect.

PLATE XXI.

Limnæus. In and near fresh-water.

Fig.