and sharply toothed ; the hinge pit (or fulcrum) is broad 
and curved. The attached valve extends in branching 
processes upon the surface it is upon. 
In the description of Gryphaea sinuata mention is 
made of this “ bilobed” Oyster, adhering to a specimen 
of that shell from Folkstone ; there are three attached 
valves upon that specimen, one of which is represented 
at fig. 2. of the plate before us. 
Fig. 3. shews the other valve* probably from the same 
locality. 
We regret that the Oyster from the Isle of Wight, 
mentioned in the same place, is not perfect enough to 
determine whether it be the same species ; some dif- 
ferences are observable, and we have not been so fortu- 
nate as to meet with another specimen. 
