

•vJ^' 



VOL. VI. 



AUGUST, 1898. 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEO. L. GOODALE, JOHN TROWBRIDGE, 

 H. P. BOWDITOH and W. G. FARLOW, of Cambridge, 



Professors O. C. MARSH, A. E. VERRILL and H. S. 

 WILLIAMS, of New Haven, 



Professor GEORGE F. BARKER, of Philadelphia, 



Professor II. A. ROWLAND, of Baltimore, 

 Mr. J. S. DILLER, of Washington. 



FOURTH SERIES. 



VOL. YI— [WHOLE NUMBER, CLVL] 



No. 32.— AUGUST, 189S. 



WITH PLATES II— III. 



NEW HAVEN, CONNECTICUT. 



1898. 



TUTTLE, MOREHOUSE & TAYLOR, PRINTERS. 125 TEMPLE STREET. 



Published monthly. Six dollars per year (postage prepaid). $6.40 to 

 foreign subscribers of countries in the Postal Union. Remittances should 

 be made either by money orders, registered letters, or bank checks. 



