structure. The hinge teeth, which are very thick and con- 
spicuous 5 may be traced with attention to fit the other shell 
very conveniently, showing how they lock one into another* 
These shells seem nearly allied, if they are not the same 
species as one figured in tab, 250 of British Mineralogy^ 
which is in flint from Teignmouth, Devonshire. They at 
first sight resemble Venus Islandica, but they do not appear 
to be the same as Mr. Parkinson mentions at p. 188 of the 
third volume of Organic Remains, with which he was fa- 
voured by Capt. Gardner. I have a more similar one in 
sand, it is calcedonic, somewhat translucid with an opaque 
coating, and was sent me by Miss Hill from Blackdown, 
The hinge and contour are sufficiently preserved to show 
that it is not V. Islandica, corresponding with the idea 
that fossil shells do not accord with recent species. 
