ze 
170 Association of American Geologists. 
clusive as to the opposite opinion. The facts are, that masses exist com- 
posed of whole shells, as at Easton, on the eastern shore of Maryland. 
That in some localities fragments of older fossils are found with them, 
and which must have been thrown amongst the oysters by the waves of 
the estuary from their position below. And again that deposits of the 
shells exist in situations too remote from present oyster beds to have been 
removed by human agency, such as those in Cumberland county, in New 
Jersey ; therefore it would appear that both causes have operated to pro- 
duce them, and that no single generalization can comply with the requi- 
sition of the facts which they present, leading as they do to a twofold, one 
from opposite conclusions, one referable to human, the other, to natural 
causes, and that severally they must be examined in order to ascertain to 
which of the two causes any given mass is to be referred.* 
Larpner VANUXEM. 
Prof. Booth stated that his observations upon these deposits 
had led him to the same conclusion as that which had been arti- 
ved at by Mr. Vanuxem, viz. “that they are sometimes referable 
to human agency, and at others to natural causes.” In answer 
to an inquiry, Prof. B. observed that these shells reduced to pow- 
der had been used with great success in the State of Delaware, 
asamanure. Prof. Hitchcock stated that the fertilizing powers 
of these deposits of shells had also been tested by experiments 
on Cape Cod. Facts were stated by the chairman and Prof 
Mather in regard to beds of oyster shells similar to those descri- 
bed by Mr. Vanuzem, on the Island of Nantucket, and on Long 
Island. 
Prof. Bailey commenced is account of “ Fossil Infusoria,” by 
an exhibition and description of the microscope employed by him 
in his resear 
Messrs. C. Fles B. Trego and B. Silliman, Jun. were ap- 
pointed assistant secretaries. The Association then adjourned 
until 9 o’clock, Thursday morning. 
Third day of meeting, Thursday, April 8, 1841.—The Ass 
‘ciation met at 9 o’clock, A.M. Prof. Silliman in the chair. 
The minutes of yesterday were read and adopted. 
ES 
nee the meeting of the Association, TI Fe found on conversing Sith Dr. Du- 
catel that the i oe bet which I had of his a were founded upon his first re 
tae of 1834, fo two fold d origin. 
eae e should wanda this paper + did: We hot seanes a it would be of service 
Serie _ settles the point in question, which was its object, but it affords # 
to caution in an expression of the pone of others. 
