391 



hundred square inches ; which, if the gold were equally distributed in a 

 continuous film over the whole surface, would give it a thickness of 

 1-980, 400th part of an inch. A single grain of gold may be beaten out so 

 as to cover seventy-five square inches with a thinness of l-367,650th part 

 of an inch. 



The Secretary read a commitnication entitled " A meas- 

 ured section of the Palaeozoic Rocks of Central Pennsylvania 

 from the top of the Alleghany River Coal Series (on Broad 

 Top) down to the Trenton Limestone, in the Lower or Cam- 

 bro-Silurian System." by Charles A. Ashburner, Assistant 

 on the Second Geological Survey of Pennsylvania. 



Gen. Kane resumed the reading of his communication 

 made at a recent meeting of the Society, describing his per- 

 sonal observations in Mexico, and discussing the ethnologi- 

 cal movements taking place in that part of the American 

 Continent. 



Professor Cope exhibited and described some fossil remains 

 of a Dinosaur, found by Dr. Newberry in 1870, in one of the 

 canons of the mountains of Utah, the first ever discovered 

 in Triassic rocks in that part of the Continent. He com- 

 pared them with others found by himself in 1874, 



Professor Cope exhibited drawings of scratched figures on 

 coal shales said to have been formed in an Indian mound 

 near Davenport, Iowa, and now preserved in the Museum of 

 the Davenport Academy of Sciences. One of these drawings 

 represents a kind of zodiac, and the other numerous forms of 

 animals, some of which are easily recognized, while those of 

 others are unknown. These drawings are of such unusual 

 excellence of design, and the accompanying symbols and let- 

 ters have so Indogermanic an aspect, that doubts were ex- 

 pressed by some of the members present concerning their 



genuineness. 



Pending nominations 830 and 831, and new nominations 

 832, 833 and 834 were read. 



The resolution of the Finance Committee postponed at the 

 last meeting was taken up, and on motion an appropriatioit 



