NATURAL SCIENCES OF PHILADELPHIA. 275 



December 3. 

 The President, Dr. Ruschenberger, in the chair. 

 Twenty-five members present. 



Joseph Willcox made the following remarks about some glacial 

 scorings lately observed by him in St. Lawrence County, N. Y. 

 Between the village of Rossie and Morristown, on the St. Lawrence 

 River, a distance of eighteen miles, the country is generally a level 

 plateau. The hard potsdam sandstone, alternating with calci- 

 ferous sandstone, underlies a soil so thin that in many fields the 

 use of the plow is impracticable; and fence posts are rarely placed 

 in the ground. 



Over this territory rounded boulders of granite are scattered 

 in great profusion ; though no outcrop of this rock is visible for 

 many miles. The sandstone is frequently exposed to view to the 

 extent of many yards, and on its surface the glacial marks made 

 by the boulders of granite during their passage are exhibited 

 in great perfection. An examination made with a pocket compass 

 applied in three places at intervals of several miles determined 

 the course as N. N. East w T ith little variation. No glacial marks 

 w r ere observed on the calciferous sandstone, as this rock is 

 disintegrated with too much facility to retain impressions of this 

 character for a long period of time. 



For a distance of thirty miles north of the St. Lawrence, between 

 that river and Rideau Lake, the country is level and characterized 

 by the absence of streams of w r ater. The only rocks observed in 

 position were the calciferous sandstone and limestone. Though 

 rounded boulders of granite w r ere abundant, none of the rocks 

 were sufficiently durable to retain the glacial marks. On the north 

 shore of Rideau Lake, in Burgess, is the remarkable locality for 

 apatite (phosphate of lime). 



This mineral is found in the Laurentian rocks ; generally in 

 gneis, but occasionally in limestone. It is nearly always associated 

 with black mica (biotite). About 100 tons per week of apatite 

 are mined, which is all shipped to Europe. 



December 5. 



meeting of the conchological section. 



Dr. W. S. W. Ruschenberger, Director, in the chair. 



A communication was read from Hon. J. A. Lapham, of 

 Milwaukee, Wis., dated November 26, and accompanied by a 



