PLATE 37 



Leptostrophia magnifica var. tullia (Billings) 



Page 191 



1 A normal ventral valve 



2 Enlargement of sculpture 



3 Internal cast of ventral valve 



4 A ventral valve with oblique corrugations on the hinge 



5 A larger and more transverse shell 



6 A partial internal cast of the ventral valve. This is Billings's original 

 Grande Grtve limestone. Perce Rock 



Strophonella leavenworthana Hall 



Page III 



7, 9 Dorsal valves showing the concave visceral region and deeply 



deflected margins 

 8 Internal cast of the dorsal valve 



St Alban beds. Grande Cavee, Griffon Cove river 



Strophonella punctulifera (Conrad) 



Page m 



10 A somewhat exfoliated ventral valve 



1 1 External cast of ventral valve 



St Alban beds. Cape Rosier Cove 



Strophonella ampla Hall 



Page 197 



12 External cast of a ventral valve 



Grande Greve limestone ; division 2. Grande Greve 



326 



