PLATE X T I. 



PAOK 



Fig. (50. Ostrea Tayloriana. Natural size. 34 



60 a. Side view. 

 Fig. 62. Terkbratella 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 (tABBH. Natural size. 36 



64 a. Longitudinal section. 



Fi£. 65. KcHiNARACHNrus Brewerianus. 36 



Very slightly magnified. 



65 a. Longitudinal section. 



