﻿PLATE IV. 



Fig. 



1. Triffonia Scarbur(^ensis,\j)'c. Left valve, Cornbrash, Scarborough. (Page 3 L) 

 2,3.? „ ,, Opposite valves of the same specimen. 



4. 

 5. 



7. 

 G. 



„ Young example. 



Juddiana, Lye. Kimmeridge Clay, Market Rasen ; example with few 

 costse and large tubercles. (Page 25.) 



„ Example with more numerous costse and smaller tubercles. 



Moretoni, Mor. and Lye. Cornbrash, Appleby, Lincolnsliire ; adult 

 specimen. (Page 47.) 



Broiiiiii, Ag. A variety from the Lower Calcareous Grit of Weymouth. 

 (Page 23.) 



