PLATE II. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18. 

 19. 

 20. 

 21. 



Guinensis. 



Brevis. 



Thuelcha. 



Pygmseus. 



Ambiguus. 



Cultellus. 



Planus. 



Legumen. 



Dombei. 



Javanicus. 



Caribseus, 



Coarctatus. 



Strigilatus. 



Radiatus. 



Politus. 



Candidus. 



Solidus. 



Inflexus. 



Orbiculatus. 



Costatus. 



Medius. 



Maximus. 



Minimus, 



Bidens. 



Tenuis. 



Novaculina. 



Californianus. 



Acutidens. 



Acuminatus. 



30 

 31 

 32 

 33 



Glauconome Chinensis. 

 Rugosus. 



Solenella Norrisii 

 Pholadomya Candida. 



34. Panopea Aldrovandi. 



35. 



36. 



37. 



38. 



39. 



40. 



41. 



42. 



43. 



44. 



45. 



46. 



Zelanica. 

 — ' Australis. 



Arctica. 



Glycimeris Siliqua. 

 Mya Truncata. 

 Arenaria. 



■ Cancellata, 



Semistriata. 



Anatina Lanterna. 



Truncata. 



Subrostrata. 



Globulosa. 



47. Periploma Trapezoides. 



48. Argentaria. 



49. Planiuscula. 



50.* Obtusa? 



5 1 . Tiiracia Pubescens. 



52. Plicata. 



53. ■ Similis. 



54. Conradi. 



55. Convexa. 



56. Corbuloides. 



57. Curta. 



58. Anatina ? Nicobarica. 



* The shell from ■which this figure is copied is, I find, perfectly distinct, though 

 not at first sight to be distinguished from the remaining epecies of this genus. I will 

 now describe, suggesting for it the name of Obtusa .- — Very obtusely trapeziform, 

 its outline totally devoid of angularities, very inequivalve, very fragile, dull yel- 

 lowish white : very inequilateral, the sides rounded, edge of the longer posterior one 

 obliquely and continuously united to the somewhat arcuated ventral ; anterior side 

 very short, roughened by minute punctures, and very much narrowed by the sudden 

 declivity of the dorsal edge ; anterior slope with minute and crowded concentric 

 wrinkles, and bounded posteriorly in the more convex valve by a slightly impressed 

 radiating hollow, 1J..1|. — America. California? 



