A Y/7 



T II E 



AMERICAN 



JOUKNAL OF SCIENCE. 



EDITORS 



JAMES D. and E. S. DANA, and B. SILLIMAN. 



Professors ASA G1JAY, JOSIAII P. COOKE, 

 JOHN TROWBRIDGE, of Cambridge, 



II. A. NEWTON and A. E. YKUHI 



Professor GEORGE F. DAIJKK1!. ov Philadkuhiia. 

 THIR.D SERIES. 



VOL. XXIV. -[WHOLE NUMBER, CXXIVJ 

 Nos. 139—144. 



JULY to DPX'KMBKR. 1882. 



NEW HAVEN, CONN. : J. D. k E. S. DANA. 

 1882. 



