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

by G. B. Sowerby

16. N. nitida, Donovan.—Nerita and Natica catena, nitida, Alderi, glaucina, etc.—Brit. co. generally, 4 to 90 fath., C. Oblique, marked with undulating lines.

17. N. monilifera, Lamk.—Nerita glaucina, catena, etc.—Near water-mark, in sandy places generally, C. Whorls rounded.

18. N. sordida, Phil.—N. fulva, plumbea, etc.—Scilly, Cape Clear, Zetland, etc., 25 to 90 fath., R.

19. N. pusilla, Say.—N. Grœnlandica, livida, alba.—Northumberland, Yorkshire, N. Eu., 45 fath., R. White; umbilicus small.

Recluzia.

20. R. aperta, Jeffreys.—Natica aperta, Lovén?—Zetland, Rr.

Velutina.

21. N. lævigata, Linn. (Helix.)—Bulla, Velutina, etc.—Brit. co. generally, 1 to 30 fath., N. Eu., C.

22. N. flexilis, Mont. (Bulla.)—Coriocella and Sigaretus plicatilis.—N. Scot., 25 fath., Rr.

Lamellaria.