^7? £7 73 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWAKD S. DANA. 



ASSOCIATE EDITORS 



Professors GEOKGE L. GOODALE, JOHN TROWBRIDGE, 

 W. G. FARLOW and WM. M. DAYIS, of Cambridge, 



Professors ADDISON E. YERRILL, HORACE L. WELLS, 

 L. V. PIRSSON and H. E. GREGORY, of New Haven, 



Professor GEORGE F. BARKER, of Philadelphia, 

 Professor HENRY S. WILLIAMS, of Ithaca, 

 Professor JOSEPH S. AMES, of Baltimore, 

 Mr. J. S. DILLER, of Washington. 



FOURTH SERIES 

 YOL. XX— [WHOLE NUMBER, CLXX.] 



WITH 15 PLATES. 



NEW HA YEN, CONNECTICUT. 



1905 



jfsm 



