PLATE XT. 



Fig. 



la and b. Ammonites Woollgari ; from the Grey Chalk near Lewes ; the original 



specimen in Dr. Mantell's collection, figured in his work, and in the 



' Mineral Conchology,' and now in the British Museum. The portions 



marked R are restored by the artist. 



2a and b. Ammonites Woollgari ; a young specimen from the Middle Chalk near Lewes ; 

 in the collection of Henry Catt, Esq., of Brighton. 



3(7, b, and c. Ammonites Griffith ii ; internal cast from the Hard Chalk of the County 

 of Derry ; fig. 3a has been completed in the inner whorls from another 

 specimen, and fig. 3e drawn from a third specimen, all in the collection 

 of the Museum of Practical Geology, in London. 



