PLATE XXXVI. 



CARBONIFEROUS SPECIES. 



Fig. 

 1 



Productus humerosus, Sow. 



personatus, Sow. 



cora, IfOrhigny. 



1". Internal cast of the ventral valve, from the Car- 

 boniferous magnesian limestone of Breedon, 

 Leicestershire. Museum of the Geological 

 Society. I 6 . Interior of the ventral valve (a 

 portion of the beak being removed to show the 

 muscular impressions), from a gutta-percha 

 impression. 



Internal cast, from the same locality. 2 shows 

 the interior of the dorsal valve and beak of 

 ventral one ; 2" the ventral valve, viewed in 

 profile. 



From the original internal cast. The specific 

 claims of this so-termed species cannot be 

 decided, on account of the imperfection of the 

 material at our command. Kendal, West- 

 moreland. British Museum. 



Carboniferous limestone, Settle, Yorkshire. 



