PLATE XXXI. 



PAGE 



Tig. 262. Trigonia Gibboniana. Natural size. 190 



Fig. 265. Aeca dectjrtata. Natural size. 195 



265 a. Id. Opposite side, exhibiting the truncation. 



Fig. 266. Cttculljea Mathewsonii. Natural size. 195 



Fig. 267. Axin^ea (? Limopsis) sagittata. Natural size. 197 



267 a. Id. Surface. 



Fig. 268. A. cor. Magnified. 198 



268 a. Id. Surface. 



Fig. 270. Pecten Californicus. Magnified. 201 



Fig. 271. Lima appressa. Natural size. 203 



Fig. 272. Ostrea malleiformis. Natural size. 204 



Fig. 273. Exogyra parasitica. Natural size, lower valve. 205 



273 a. Id. Upper valve. 



Fig. 274. ? Astroccenia petrosa. Natural size. 208 



274 a. Id. Surface magnified. 



Fig. 275. Indet. 209 



