VJ 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWAKD S. DANA. 



ASSOCIATE EDITORS 



Professors GEOKGE L. GOODALE, JOHN TROWBRIDGE, 

 W. G. FARLOW and WM. M. DAVIS, op Cambridge, 



Professors ADDISON E. VERRILL, HORACE L. WELLS, 



LOUIS V. PIRSSON, HERBERT E. GREGORY 



and HORACE S. UHLER, of New Haven, 



Professor HENRY S. WILLIAMS, of Ithaca, 



Professor JOSEPH S. AMES, of Baltimore, 



Mr. J. S. DILLER, of Washington. 



FOURTH SERIES 

 VOL. XXXVIII— [WHOLE NUMBER, CLXXXVIII]. 



WITH FOUR PLATES. 



NEW HAVEN, CONNECTICUT. 



1914. 



2 3>0S48 



