PLATE XL 



PAGE 



Fig. 57. Ostrka Bourgeoisit. Natural size. 83 



57 a. Hinge. 



Fix 58 6. Upper valve of O. Attwoodii? Natural size. 34 



Fig. 59. Ostrea Veatchii. 34 



From a small and unusually thin specimen. 



Fisr. 61. Ostrea Cerrosensis. Natural size. 35 



