TAB. XI. 



Fig. 

 1 — 7. Teeth of Polypti/chodon interruptus, nat. size. 



From the Lower Chalk, near Lewes, Sussex. In the Museum of Mr. Potter, 

 of Lewes. 



8. Tooth of Polyptycliodon continuus (?), nat. size. 



From the Lower Chalk of Sussex. In the Museum of Henry Catt, Esq., of 

 Brighton. 



