BY R, ETHERIDGE, JUN, 161 



Selachian fish, to which the remains just described undoubtedly 

 belong, first make their appearance in the Cretaceous rocks of 

 other parts of the world, and it is exceedingly probable, from these 

 and the other fossils of this formation, that it represents in a 

 considerable degree some portion of that period. 



EXPLANATION OF PLATE. 



Fig. 1. — Otodus appendiculatus, Ag. One of the posterior upper teeth. 



Nat. size. Rolling Downs Formation, Kamileroy. 

 Fig. 2. — Lamna Davimi, Eth. jun. Seven vertebrae, probably of the 



abdominal region, showing peripheral fissures, &c. Nat. size. 



Richmond Downs. 

 Fig. 3. — Ditto. End view of a vertebra to show complete ossification. 



Nat. size. 



II 



