168 Association of American Geologists. 



mind impressed when not preoccupied, and when a strong impression 

 is made, be it ever so false, it is no easy matter to free ourselves from it. 

 From this circumstance we can readily foresee the advantage which fu- 

 ture generations will possess over those of the present and especially 

 those of former times. As the progress of knowledge is certain, each 

 day will lessen error and enlarge the domains of truth, and should man be 

 true to his permanent interests, error finally will cease to have existence. 

 Signed, Henry D. Rogers, Lardner Vanuxem, Richard C. 

 Taylor, Ebenezer Emmons, T. A. Conrad. 



Mr. Vanuxem read a paper " On the Ancient Oyster Shell De- 

 posits observed near the Altantic coast of the United States." 



Among the unsettled subjects of geology in our country, is the origin of 

 the deposits of oyster shells, {Ostrea Virginica,) observed in many parts of 

 the Atlantic seaboard, of which a few only of those near South Amboy have 

 come under our notice. But the greater number of those of the largest 

 dimensions are in the waters of the Chesapeake. Some of these southern 

 deposits of shells are enormous, covering, it is said, acres of ground, 

 adding no small weight to the truth of that belief that considers them 

 in situ, as ancient oyster beds, raised from their original position by the 

 uplifting of our coast, of which the fact of their generally holding, if not 

 a real, an apparent similarity of level would seem to be ample confirma- 

 tion. This theory of their being in place, is highly satisfactory, being in 

 accordance with the less modern deposits beneath them, adding one more 

 to the number of elevating movements to which our coast has been sub- 

 jected, thus mutually confirming each other, making the certainty of these 

 movements sure. 



When the nature of their origin was advanced by Mr. Conrad, I con- 

 fessed a decided bias; for I knew not the facts upon which Dr. Ducatel, 

 the geologist of Maryland, maintained the opposite one. None were 

 known to me adverse to the views of Mr. Conrad, for the history of our 

 country afforded no light that could be recollected, either as to the origin 

 of these oyster shell deposits, or to any extraordinary manifestation of 

 gastromic power in the aborigines, in respect of this article of diet, which 

 would lead me to infer their existence, and which the magnitude of some 

 of the deposits required. 



The eastern shore of Maryland presents many deposits of these oyster 

 shells, hitherto until recently, unused and little examined, so far as know- 

 ledge has been received this way. Now, as many of the planters in that 

 section of the country are waking from the deep slumber of the past, and 

 turning their attention to the all-important subject of improving their 

 lands by the use of lime, a few of these deposits have become the sub- 

 ject of investigation, furnishing facts, which, were the same discovered 

 elsewhere, would settle the question of their origin, and in favor of the 

 Maryland geologist. 



