380 ALLUVIAL CHARACTER OF 



sixty-seven feet. Within the same strata which contain 

 the shells, are often found boughs and trunks of trees, 

 bark and damaged wood. For a large and conclusive 

 body of facts upon this subject, I refer to the valuable 

 work just mentioned, p. 129 133, and 261 263. 



In addition to that mass of evidence, I now mention 

 two more occurrences daring the year 1817. 



My brother, Judge Singleton Mitchill, apprized me in 

 a letter received from him a few days ago (October) that 

 in digging a well in his neighbourhood, on Cow Neck, at 

 North Hempstead, and not more than a mile and a half 

 from the light-house at Sands's Point, shells of clams and 

 oysters were discovered at the depth of forty-five feet. 

 On the same occasion a piece of wood was dug out, pene- 

 trated through and through by the teredo or pipe- 

 worm. The facts are well known to the workmen 

 and neighbours ; and have since been confirmed to me in 

 conversation. 



Our graduate, Dr. Bering, brought, a few weeks ago, 

 to the Lyceum of Natural History the fragments of clam- 

 shells (venus), found in digging a well in Shelter-Island, 

 thirty-five feet below the surface. Shelter-Island is situ- 

 ated between Gardiner's bay and Southold bay, within 

 the north prong of the fork of Long-Island on one side 

 and the southern on the other. It is nearly a hundred 



miles east of New-York city. 







Since this marine alluvion has been hove up, a memo- 

 rable change appears to have been wrought upon the 

 north side of Long-Island. Vast, numbers of loose rocks 

 have been superinduced. They all appear to have been 



