268 



Dr. H. R. Storer presented, in the name of Dr. D. H. 

 Storer, some specimens of very large Oyster Shells, probably 

 Ostrea Virginica, taken from the milldam by Samuel 

 Nicolson, Esq. 



Mr. Nicolson, who was present, was introduced to the Society 

 by Dr. Storer. He stated that, thirty-five years ago, having 

 occasion to remove a portion of the flats beneath one of the 

 large wheels in the mills on the milldaVn, he had found a bed of 

 these shells two or three feet below the surface, forming a porous 

 mass, through which the tide ebbed and flowed. The shells had 

 also been found in the channel of Charles River, a quarter of a 

 mile from the dam, and he supposed that there was an extensive 

 bed of extinct oysters lying between these two points. The 

 shells are long and slender, many of them attaining a length of 

 12 or 13 inches. 



Mr. T. J. Whitemore remarked that this oyster has been well 

 known in Charles River for many years, and that occasionally 

 living specimens are yet found there. 



Dr. C. T. Jackson remarked that there is an ancient oyster 

 bed, near Boothbay, Maine, now sixty feet above the surface of 

 the sea. No living oysters are found in the vicinity. 



Prof. Wm. B. Rogers said an oyster of this character was 

 found lying over the newest tertiary, near the mouth of the 

 Rappahannock River, of post-pliocene age. He had noticed, 

 that in shape, and in the peculiarity of the hinge, these speci- 

 mens were identical with those from the Rappahannock River. 



Dr. H. R. Storer reported the results of some recent 

 experiments upon the cohesive properties of different sizes 

 of Gutta Percha Pipe, made in connection with Mr. Charles 

 Stodder. 



The first trial was with one thousand feet of a pipe, of one 

 inch internal diameter and one and three sixteenths external 

 diameter, intended for an aqueduct at West Cambridge. Upon 

 applying a pressure of 80 lbs. to the square inch, a fine hole was 

 discovered ; this hole being closed with a hot iron, a pressure of 



