PHILOSOPHICAL SOCIETY OF WASHINGTON. 65 



Mr. Parker and Mr. Gale followed with remarks on Egyptian 

 antiquities. 



Mr. E. B. Elliott read a letter from Dr. B. A. Gould, Di- 

 rector of the National Observatory at Cordoba, giving an account 

 of 



THE COINAGE OP THE ARGENTINE REPUBLIC, 



as established by an act of the legislative body, which went into 

 effect in October, 1875. 



The Argentine peso-fuerte is of the same value as the Japanese 

 yen; and 1003.08'774pesos-ywer^es are equivalent to 1000 dollars 

 of United States coin, the difference being a little more than ^j^ 

 of 1 per cent. 



Mr. J. W. Powell made a communication on 



SOME TYPES OP MOUNTAIN BUILDING, 



describing several characteristic forms in the Park Range, the 

 Ute, and other mountains in the West, and pointing out marked 

 differences between these formations and those in the Appalachian 

 range. 



99th Meeting. January 29, 1876. 



The President in the Chair. 

 Thirty-five members and visitors present. 

 Mr. W. H. Dall read a paper on 



THE SUCCESSION OP THE STRATA OP THE SHELL-HEAPS OF THE 

 ALEUTIAN ISLANDS. 



(abstract.) 



He showed that the shell-heaps were separated by the strata 

 of which they are composed into deposits of three successive 

 periods. The lower stratum being composed of the I'emains of 

 echini, eaten by the early inhabitants, he termed the Echinus 

 Layer, and the period in which it was formed the Littoral Period. 

 The second, composed chiefly of fish-bones, the Fish-bone Layer, 

 deposited in the Pishing Period. The upper or Mammalian 

 Layer, corresponding to the Hunting Period, was chiefly formed 



