PLATE V. 



Fig. 



1. Nautilus radiatus ; from the Chalk with siliceous grains of Chardstock, kindly 



given me by Mr. Wiest. 



la. Side view. 



lb. Front view, showing the position of the siphuncle, and the ventral 

 depression on the septum. 



2. Nautilus radiatus ; young specimen, with a portion of the cross-striation of the 



young shell preserved. From the Chalk with siliceous grains of Chardstock, 

 in the collection of Mr. Morris. 



3. Nautilus Neocomiensis ; from the Grey Chalk of Urchfont near Devises, in the 



collection of Mr. Cunnington. 



3<2. Side view. 



3^. Back view. 



3c. Septum showing the position ol the siphuncle. 



4. Nautilus undulatus ; from the Chalk with siliceous grains of Chardstock, in the 



collection of Mr. Wiest. 



4a. Side view. 



43. Front view. 



4c. Septum showing the position of the siphuncle. 



