3Q 





THE 



AMERICAN 



JOURNAL OF SCIENCE 



EDITORS 



JAMES D. and EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors JOSIAH P. COOKE, GEORGE L. GOOD ALE 

 and JOHN TROWBRIDGE, of Cambridge. 



Professors H. A. NEWTON and A. E. VERRILL, of 

 New Haven, 



Professor GEORGE F. BARKER, of Philadelphia. 



THIRD SERIES. 



YOL. XLVL— [WHOLE NUMBER, CXLYL] 



Nos. 271—276. 



JULY TO DECEMBEB, 1893. £ 5~6 I G3 



WITH XI PLATES. 



31 Motey--; 



NEW HAYEK", CONN.: J. D. & E. S. DANA. 



1893. 



