

THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Established by BENJAMIN SILLIMAN in 1818. 



EDITOES 



JAMES D. and EDWARD S. DANA. 



ASSOCIATE EDITOES 



Professors JOSIAH P. COOKE, GEORGE L. GOODALE 

 and JOHN TROWBRIDGE, of Cambridge. 



Professors H. A. NEWTON and A. E. VERRILL, of 



New Haven, 



Professor GEORGE F. BARKER, of Philadelphia. 



THIRD SERIES. 



YOL. XLIY.— [WHOLE NUMBER, CXLIV.] 



Nos. 259—264. 



JULY TO DECEMBER 1892. 



WITH TEN PLATES. _ 



2 fQ I G: 





NEW HAYEN, CONN.: J. D. & E. S. DANA 

 18 92. 



