69 



self-same species, our British P. pectinata for example, is found scaled in 

 one habitat and smooth in another. All are of a fibrous brittle texture, 

 often brilliant in colour, though a dull horny olive greatly predominates. 



1 . alta, Sow. 



2. angustana, Lam. 



3. assimilis, Haul. 



4. atro-purpurea, Sow. 



5. attenuata, Reeve. 



6. bicolor, Chemn. 



7. bullata, Swain. 



8. Carolinensis, Hani. 



9. Chemnitzii, id. 



10. Cumingii, id. 



11. deltodes, Menke. 



12. D'Orbiguyi, Hani. 



13. electrina, Reeve. 



14. euglypta, Haul. 



15. fimbriatula, Reeve. 



16. flabellum, Lam. 



17. funiata, Haul. 



18. Gouldii, id. 



19. Hanleyi, Reeve. 



20. hystrix, 27a»Z. 



21. incurvata, Chemn. 



Species. 



22. inflata, Chemn. 



23. Japonica, ZTawZ. 



24. lanceolata, Sow. 



25. lurida, Reeve. 



26. madida, u?. 



27. Maura, -Sow. 



28. Menkii, Hani. 



29. muricata, Linn. 



30. mutica, Reeve. 



31. nobilis, Zz»». 



32. nigra, Chemn. 



33. papyracea, j¥. 



34. pectinata, Linn. 



35. pernula, Chemn. 



36. Philippinensis, Zfa/^. 



37. penna, Reeve. 



38. ramulosa, «?. 



39. regia, Hani. 



40. rigida, Dil/w. 



41. rotmidata, Zm». 



42. rudis, Zwm. 



43. rugosa, Sow. 



44. Kumphii, Hani. 



45. saccata, ZzYm. 



46. sanguinolenta, Reeve. 



47. seminuda, Zr/wz. 



48. seniicostata, Conrad. 



49. serra, Reeve. 



50. serrata, £c£. 



51. squamifera, Soio. 



52. Strangei, TZw^. 



53. Stutchburii, Reeve. 



54. snbviridis, id. 



55. truncata, P/«7. 



56. tuberculosa, Sow. 



57. vespertina, Reeve. 



58. vexillum, Ztorw. 



59. virgata, Menke. 



60. Zebuensis, Reeve. 



61. Zelanica, Gmy. 



Figure. 



Pinna semicostata. PL 29. Fig. 170. Shell of a semitransparent horny 

 substance, copiously scaled throughout. 



Genus 2. MYTILUS. 



Animal; oblong ; mantle sometimes freely open, sometimes closed, 

 loiilt two siphoned orifices and a?i opening for the fool; man- 

 tle margin pin nately fringed in front, simple below; adductor 

 muscles unequal ; foot narrow, ligulate, loitli a bgssal groove. 



Shell; equivalve, obliquely fan-shaped, more or less triangular; 

 umboes sharp, nearly straight, terminal ; anterior side often 



