PLATE XII. 



Zone of Arietites Turneri. 



Fig. 1. Arietites Turneri, Sowerby. Lateral view, natural size, from Bredon, 

 Worcestershire, obtained in cutting the Midland Railway. My collection. 

 2. Front view of siphonal area and line of dorsal suture. 

 8. Back view do. do. 



4. Lateral view of one of Sowerby's type specimens in the British Museum, figured 



as a good example for comparison. 



5. Accurate outline of lateral lobes and saddles, enlarged. 



6. Do. do. of dorsal lobes and saddles, do. 



