3 



3 



I 

 THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEO. L. GOODALE, JOHN TROWBRIDGE, 

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



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

 WILLIAMS, of New Haven, 



Professor GEOKGE F. BARKER, of Philadelphia, 

 Professor H. A. ROWLAND, of Baltimore, 

 Mr. J. S. DILLER, of Washington. 



FOURTH SERIES. 

 YOL. V— [WHOLE NUMBER, CLV.] 



WITH V PLATES. 



NEW HAVEN, CONNECTICU r 



1898. 



