Fig. 



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



toothed. 



20. P. pellucida, Linn. — P. lavis, carulea, Acmaa pel. — British co. 



generally, C. smooth. 

 21. var. lavis, Penn. 



ACM-EA, Or LOTTIA. 



22. A. testudinalis, Muller. — P. Clealandi. — North Ire., C. Oval, 



with tortoise-shell markings. 



23. A. virginea, Miiller. — P. parva, pulchella. — Brit. co. generally, 



Mc. Pale, pink-rayed, shallow. 



Pilidium, or Tectuea. 



24. P. fulvum, Muller. — P. Forbesii. — Clyde, Cork, Zetland, etc., R. 



Propilidium. 



25. P. ancyloide, Forbes. — Lamlash, Ayrshire, etc., R. 



Dentalium, Linn. 



26. D. entalis, Linn.- — Brit. co. generally, C. Smooth, small end 



notched. 



27. D. tapentinum, Lamh. — D. vulgare, striatum, labiatum, politum, 



lave. — South coasts, C. Striated and entire at small end. 



Pileopsis, or Capulus. 



28. P. hungaricus, Linn. — Fool's-cap Limpet. — S.Devon, and Br. co. 



generally, C. 



CalyptbjEa, Linn. 



29. C. sinensis, Linn. {Patella.) — C. chinensis, albida, lavigata. — S. 



Brit., and Chan. Isls., R. With oblique septum. 



