E M Shells of Massachusetts, 
Massachusetts may almost be said to be destitute 
of fossil shells. None have been found which do 
not also exist in d recent state in the immediate vi- 
cinity. It is true that at Gay Head, Martha's Vine- 
yard, the most fertile locality for fossil remains in the 
State, they are found at an elevation of many feet 
above the ocean; and they are also found buried 
many feet below the diluvial sands of Nantucket, — 
and its neighbourhood. Still, they are the recent 
shells of the vicinity, hardly yet fossilized, few in 
number, and seeming to have been. buried at no very 
distant period. In the interior, we find in the sedi- 
ment of ponds, especially those in the neighbourhood 
of Pittsfield, myriads, of the species of Planorbis, 
Limnæa, Physa, and Cyclas now living in the same 
waters, which are forming beds of marl there. In — — 
the vieinity of New Bedford, Professor Adams dis- 
covered a bed of the shells of Pholas costata, a Spe" 
cies which is now extinct here, and is not found 
living within 12 or 1500 miles. Yet, from the væ — 
rious ages of the specimens and their integrity in 
their most delicate portions, it is evident that they - 
once lived where they are. now found, and that they 
have, from some cause, become entirely extinct- 
This is not the only instance of a similar catastrophe. — : 
It-is well attested, that native oysters were abun ant — 
within the extremity of Cape Cod, previous to about 
the year 1780, when they were entirely. destroyed ; 
and immense beds of shells still remain to attest the 
fact. It is said that the cause of their death. was . 
what is called a ground frost, that is, a degree of 
80 great as to coat the bed of the sea, where the oy 
