«^4o [April 1, 



The name Lower Productive coal measures, still in use for the sake of 

 convenience, is a purely local and relative term, without classical value. 

 When first applied by the First Geological Survey of Pennsylvania, it was 

 intended to include the workable productive- coal beds of Western Penn- 

 sylvania with their associated strata lying between the coal measure con- 

 glomerate and the Mahoning sandstone, or base of the Barren measures. 

 At that time the conglomerate was supposed to be one solid bed of rock, 

 subject only to local variations in thickness and in the proportion of sand- 

 stone to conglomerate. 



But within the past five years a study of it has shown it to be a variable 

 group of hard and soft strata, including workable coal beds with their under 

 clays. It therefore properly forms a part of the Lower Productive Coal 

 Measure Series ; and only thus can the parallelism of the Ohio and Penn- 

 sylvania sections be made good. 



Stated Meeting, A'pril 1, 1881. 



Present, 10 members. 



Vice-President, Mr. E. K. Price, in the Chair. 



Sig. Damiano Muoni signified his acceptance of member- 

 ship, by letter dated Milan, January 20, 1881. 



Mr. Joseph J. Lewis, accepted membership, by letter 

 dated West Chester, March 24, 1881. 



Letters acknowledging the receipt of Proceedings were 

 received from the Philosophical Society at Q-lasgow, March 

 9 (106) ; the Fondation Teyler, Harlem, 3 Mars (105, 106 

 and List) ; the American Ethnological Society, ISTew York, 

 March 24 (107) ; and J. H. C. Coffin, Washington (107). 



Letters of envoy were received from the Geological 

 Survey of Pennsylvania, Harrisburg, March 29, and Dr. 

 Peters, Kiel, February 23, 1881. 



Dr. Nolan informed the Society by letter that a box of In- 

 dian relics had been sent to the care of the Academy of 

 ITatural Sciences, by Mrs, Haldeman, for the American 

 Philosophical Society. On motion these were ordered to be 

 deposited in the Academy's museum, and Dr. Horn was 

 appointed to verify the list. 



Donations for the library were reported from the Asiatic 



