PLATE XVII. 



\a and b. ''Ammonites Cenomanensis - f from the Grey Chalk of Dover; reduced to two 



thirds its natural diameter; in the collection of J. S. Bowerbank, Esq., 



p. 37. 



la, side view. 



lb, front view. 

 ~ Prota.L*-- j*hcs-(>reei*ti Sj>«M , Geo/ t A/1ai. </» l,£ 3 , tm* /* *^- 



2. Ammonites hippocastanum ; from the Lower Chalk of Man of War Cove, Dorsetshire ; 



in the collection of E. H. Bunbury, Esq., p. 37. 



3a and b. Ammonites hippocastanum, young; from the Lower Chalk of Chardstock; in 

 the collection of E. H. Bunbury, Esq., p. 37. 

 3a, side view. 

 3b, front view. 



4a, b, and c. Ammonites hippocastanum ; a fragment, from the Lower Chalk of Chard- 

 stock ; in the collection of E. H. Bunbury, Esq., p. 37. 

 4a, back view. 

 4b, side view. 

 4c, outline of a septum. , aTov^^Y 



, from the Lower Chalk of 

 Museum, from the collection of Dr. Mantell, p. 38. 



5a and b. Ammonites Goupilianus; from the Lower Chalk of Sussex; in the British 



6. Ammonites Goupilianus ; outline of a septum, copied from PI. xciv of M. D'Orbigny's 

 ' Paleont. Franc. Terr. Cret.,' p. 38. 

 Ittype a G-rosi- SJ> > peJ3U*J>S Gross* •(fj9 l 4 



la and b. Ammonites Velled^e ; from the Upper Chalk near Norwich ; in the collection 

 of F. G. Bayfield, Esq., of Norwich, p. 39. 

 7a, side view. n.b. The umbilicus is represented too large, the artist having 



been deceived by the breaking away of the soft chalk. 

 lb, front view. 



