PLATE XVI. 



Fig. 



la, b, and c. Ammonites Rhotomagensis ; from the Grey Chalk of Bonchurch, in the 

 Isle of Wight; reduced to two thirds its natural diameter; in my 

 possession. 



\a and lb. Side and front views of the complete specimen. 



\c Inner whorl of the same specimen. 



2a and b. Ammonites Rhotomagensis ; from the Grey Chalk of Bonchurch ■ of the 

 natural size ; in my possession. 



3« and b. Ammonites Rhotomagensis ; a very young specimen, from the Grey Chalk of 

 Bonchurch ; in my possession. 



4. Ammonites Rhotomagensis ; outline of the septum of a specimen from the Grey Chalk 

 near Lewes. 



