Has. D. Walcott, 



/ U. S. Geol. Survey. 



■ite-j 



JANUARY, 1898. 



Established by BENJAMIN SILLIMAN in 1818. 



T H E 



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 GEORGE F. BARKER, of Philadelphia, 

 Professor H. A. ROWLAND, of Baltimore, 

 Mr. J. S. DILLER, of Washington. 



FOURTH SERIES. 



YOL. Y— [WHOLE NUMBER, CLV.] 



No. 25.— JANUARY, 1898. 



WITH PLATES I— II. 



NEW HA YEN, CONNECTICUT. 



1898. 



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