Valvata. In ponds.
10. V. piscinalis, Müller.—Nerita, Turbo, Cyclostoma fontinalis, obtusa, thermalis, etc.—Fresh-water, C. Subglobose.
11. V. cristata, Müller.—V. planorbis, etc.—Many loc., Mc. Orbicular.
Littorina. On the sea-shore.
12, 13. L. rudis, Donov. (Turbo.)—L. littoreus, etc., L. nigro-lineatus (var. f. 13).—British shores generally, Cc.
14, 15. L. littorea, Linn. (Turbo.)—L. vulgaris, etc.—British shores generally. The common eatable Winkle.
16, 17. L. tenebrosa, Mont. (Turbo).—British shores generally, C. Not thickened at bottom of mouth like L. rudis.
18. L. patula, Jeffreys.—L. labiata, L. jugosa, etc.—Common on our shores.
19. L. saxatilis, Johnston.—L. neglecta.—Probably L. patula var.?
20, 21. L. littoralis, Linn. (Turbo.)—T. neritoides, T. ustulatus, etc,—Brit. co. generally. Depressed above.