PLATE XVI. 



Fig. PAf'rsCc.v ry ■-- 



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. 



1(2 and \b. 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. 



