IV. MYSCA. RIVER MUSSEL. 



An ancient name given to a fresh- water Mussel 

 shell. 



10. Mysca Batava. Dutch River Mussel. 



11. Mysca Pictorum. Painter s Mussel. 



12. Mysca ovata. Oval River Mussel. 



13. Mysca solida. Solid River Mussel. 



V. LIMACELLUS. SHELL-SLUG. 



So named from the slug which bears a shell internally. 



14. Limacelhis Parma. Shield Shell-slug. 



15. Limacellus Unguiculus. Nail Shell-slug. 



16. Limacelhis variegatus. Variegated Shell-slug. 



17. Limacellus obliquus. Ohlique Shell-slug. 



VI. TESTACELLUS. SLUG-SHELL. 



So named from the slug which is furnished with an 

 external shell. 



18. Testacellus Maiigei. Teneriffe Slug-shell. 



19. Testacellus Scutulum. Shield Slug-shell. 



20. Testacellus haliotideus. Ear-shaped Slug-shell. 



