44 TRANSACTIONS OF THE [fEB. 9, 



by Prof. Putnam in the "Mounds" of the Scioto and Miami 

 Valleys. 



February 9th, 1885. 

 Stated Meeting. 

 The Librarian, Dr. A. A. Julien, in the chair. 

 Thirty persons present. 



Prof. H. L. Fairchild exhibited a specimen of Anthracite 

 from Scranton, Penn., filled with flattened concretions. In 

 the center of each concretion an exceedingly thin fibre of 

 silicious matter. These are all arranged parallel with the de- 

 posit. 



Mr. p. H. Dudley showed the silicious fibres with the 

 mici'oscope by polarized light. 



Dr. a. a. Julien drew attention to the analogy between 

 the concentration of thin, silicious matter in the coal and the 

 formation of flint in chalk. 



Prof. G. E. Bailey read a paper, on 



THE TIX DEPOSITS OF THE BLACK HILLS OF DAKOTA. 



(Illustrated hj ores, samples of tin, and photographs of the re- 

 gion and mines.) 



Fel)ruary 16th, 1885. 

 Stated Mep:ting. 

 The President, Dr. J. S. Newberry, in the chair. 



A large audience present in the east lecture room of the 

 Li])rary Building, Columbia College. 



Mr. a. C. Hamlin delivered the first lecture of the Popular 

 Lecture Course, on the 



MOSQUES OF CONSTANTINOPLE. 



(Illustrated with lantern views.) 



