30 



Genus 5. ACjVLEA, Eschscholtz. 



Animal ; with two subulate tentacles bearing eyes on the outer 

 sides of their swollen bases ; mantle-margins fringed ; branchia 

 forming a pectinated plume, lodged in a cervical cavity ; foot 

 large, ovate, ivith plain sides. fForbes.J 



Shell ; ovate, depressly conoid ; apex approaching the anterior 

 margin, smooth or radiatety striated. 



The shells oiAcmtBa (Tectum, Audouin; Patelloidea, Quoy and Gaimard; 

 Lottia, Gray) are so like those of Patella, that it is not possible to separate 

 them entirely without an examination of the animal. A few of the typical 

 forms of the genus are known, but it is not improbable that the list of 

 Patella includes many species belonging to the genus Acmaa. The only 

 point in which the animals differ is the arrangement of the branchise. In 

 Patella they form an encircling cord of minute close-set plates, whilst in 

 Acmaa they form a plume lodged in a cavity of the neck. 



The Acmaa inhabit Australia and the western coast of South America, 

 and two species, A. testudinalis and virginea, frequent our own shores and 

 the seas of northern Europe, to which may be added two small British 

 species, described as genera by Forbes and Hanley, Pilidium and Propi- 

 lidium, of which the animals are without eyes, and their shells have more 

 the appearance of minute Emargimda, without the slit. 



1. aeruginosa, Midd. 



2. alveus, Couth. 



3. Ancyloides, Forbe 



4. ancylus, Esch. 



5. araneosa, Gould. 



6. Asmi, Midd. 



7. cassis, Esch. 



8. conica, Gould. 



9. conoidea, Quoy. 



10. conspicua, Phil. 



11. cymbiola, Gould. 



12. digitalis, Esch. 



13. discors, Phil. 



14. elongata, Quoy. 



15. flammea, id. 



Species. 



16. fragilis, Quoy. 



17. fulva, Midler. 



18. fungus, Meusch. 



19. leucopleura, Gmel. 



20. limbata, Phil. 



21. melanoleuca, Gmel. 



22. melanosticta, id. 



23. mitella, Menke. 



24. orbicularis, Quoy. 



25. parasitica, D'Orb. 



26. patina, Esch. 



27. persona, id. 



28. personoides, Midd. 



29. pileolus, id. 



30. pileopsis, Quoy. 



31. pintadina, Gmel. 



32. pustula, Helb. 



33. rugosa, Quoy. 



34. scabra, Gould. 



35. scurra, Lesson. 



36. septiformis, Quoy. 



37. squamosa, id. 



38. stellaris, id. 



39. striata, id. 



40. subrugosa, D'Orb. 



41. testudinalis, Mull. 



42. textilis, Gould. 



43. variabilis, Sow. 



44. virginea, Miill. 



45. viridula, Lam. 



