Association of American Geologists. 169 
At the mouth of Pickawaxent Creek, about eighty miles below Wash- 
ington, there is an extensive deposit of oyster shells, at which an establish- 
ment has been formed, which, in a few months has converted many thou- 
sand bushels of them into lime. _ Before any excavition of the mass was 
commenced, I had directed the attention of Mr. Downing—one of the 
partners concerned—to the doubtful nature of their origin, requesting 
that all facts tending to throw light upon them should be carefully ob- 
served and preserved. When Mr. D. first went into the country, he was 
in favor of the views of Mr. Conrad ; it was only by the examination of 
the mass at the Pickawaxent, of another not remote from that one, and 
from subsequent observation in the city of Baltimore, showing the amount 
of shells which there accumulates, was he assured that their origin was 
to be referred to man, and not to other | r Epnore elementary powers of na- 
ture. 
The first and most important fact sheer observed, was that neither he 
_hor any of the hands employed in getting out the shells had been able to 
find any two valves which fitted each | other, €xcepting in one instance ; 
a waterman having brought the specimen to him. The deposits having 
the nature of a mass or heap composed of shells whose valves were ta 
tated before being thrown together. 
That in many parts of the mass arrow-heads and fragments of patecy, 
have been found in the progress of excavation—these i in no wise different’ 
from those fi nd in old settlements of the Indians. 
in of the bed is formed of the yellow loam or soil of the 
surface, before ihe shells were Sd u 
That these deposits are at the mouth the creeks, extending ae 
creeks, and rarely exten along the river shore, owing, as Mr. 
ing conjectures, to the excellen hing which the creeks furnish, mal 
which would give to those who umulated the er es ite: ‘ 
tage, 
“ew 
That the shore i is pea on that side of the river where they are found, 
and the recent oyster i in great abundance on that shore, whilst the cheng 
nel is on the Virginia side, and no deposit of oyster shells existed in th 
Section of country. al 
That these deposits are of some comparative antiquity, is to be infe 
om the soil which is found upon them, and the existence of an exceed- 
ingly old cedar growing upon the his of a mass, and from the silence of 
ory or tradition respecting them 
Against these which show an undoubted human origin for these 
rete of oyster shells, there are others cited by Mr. Conrad. which he 
me acquainted with, since this paper was written, which either 
Thad not known or they had epee and are equally con- 
Vol. xu1y No. 1.—April-June, 1841. 
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