17, 1 8 External casts of dorsal valves with portion of the shell adhering 

 Grande Grlve limestone : division 2. Grande Greve 



Stropheodonta parva Hall 

 protype avita no\ . 



Page )88 



19 Exterior of dorsal valve, showing broad and well divided fascicles of 



plications, x 2 



20 Interior of dorsal valve with cardinal process and denticulations. x 2 



21 Exterior of dorsal valve with fascicles but slight!)' divided, x 2 

 Grande Greve Hnicstonc ; division 2. Grande Greve 



Stropheodonti magniventer Hall 



Page 184 



22 A small ventral valve exposing the cast and showing the large flabellate 



muscle scar 

 Grande Greve limestone ; division 2. Grande Greve 



23 A large internal cast of the ventral valve 



Grande Grtve limestone. Perce Rock 



321 



