848 PROCEEDINGS OF THE ACADEMY OF [DeC, 



REPORTS OF THE SECTIONS. 



MiNERALOGICAL AND GEOLOGICAL SECTION. 



The Section has this 3^ear kept up its meetings and field excursions 

 even more zealously than last year, with about double the number of 

 communications, one-third larger attendance on the meetings, 

 one-half more on the excursions, and an increase of more than 

 one-quarter in membership. 



There have been nine meetings, with an average attendance of over 

 11. Communications were made by Miss Emma Walter, on old 

 stream-beds; by B. S. Lyman, on the immense time indicated 

 by erosion; by Prof. B. L. Miller, on graphite occurring in Chester 

 County, Pa.; by B. S. Lyman, on the Bechtel graphite mine, near 

 Boyerstown, Berks County, Pennsylvania; by Miss Mary S. Holmes, 

 on the A'irginia Natural Bridge; by B. S. Lyman, on topography 

 an aid to geology; by Miss Emma Walter, on clay near Saylorsburg, 

 Monroe County, Pennsylvania; by IMr. F. J. Keeley, on the trap of 

 Cape Ann, Massachusetts; by Miss ]\Iary S. Holmes, on some prob- 

 lems suggested by the excursion along the Perkiomen; by ]\Ir. T. 

 Chalkley Palmer, on serpentines of Delaware County, Pennsylvania; 

 by Mr. F. J. Keeley, on serpentines under the microscope; and about 

 20 shorter communications, besides various discussions. 



There were 7 field excursions, with an average attendance of 43. 

 The excursions visited: 1. The crystalline rocks and their minerals, 

 particularly kaolin, between Hockessin, Delaware, and Kennett 

 Square, Chester County, Pennsylvania; 2. The crystalline rocks near 

 Glen Mills and Lenni, on Chester Creek, and at Mineral Hill, Delaware 

 County, Pennsylvania; 3. The crystalline rocks near Avondale, Strath- 

 Haven, Rose Valley and ]\Icdia, Delaware County, Pennsylvania; 

 4. Portions of the New Red Perkasie shales and Pottstown shales and 

 trap, from Lodel Creek to Spring jNIountain, near the Perkiomen, and 

 Schwenksville, ^lontgomery County, Pennsylvania; 5. Portions of the 

 New Red Norristown shales and Gwynedd shales, and some of the 

 gneiss southward, between Noble Station and Doylestown; 6. The 

 crystalline rocks near Newtown Square, Delaware County, Pennsyl- 

 vania; 7. The crystalline rocks between Newtown Square and Media, 

 Delaware County, Pennsylvania. 



The membership of the Section has increased by ten in all, namely, 

 seven contributors and three members of the Academy, one of whom 

 became a member through his interest in the Section. The Section 



