PLATE XII. 



I'AOE 



Fig. 60. OSTREA TAYLOBIANA. Natural size. 34 



60 a. Side view. 

 Fig. 62. TEREBRATELLA WHITNEYI. Natural size. 35 



62 a. Side view. 



NOTE. This species was originally supposed to be Tertiary; but investigations 

 since the text was printed, develop the fact that it belongs to the Lower Cretaceous. 

 Fig. 63. MORRISIA HORNII. Highly magnified. 36 



Fig. 64. CLYPEASTER GABBII. Natural size. 36 



64 a. Longitudinal section. 



Fig. 65. ECHINARACHNIUS BREWERIANUS. 36 



Very slightly magnified. 

 65 . Longitudinal section. 



