Proceedings of the American Academy of Arts and Sciences. 

 Vol. XXXIV. No. 15. — March, 1899. 



IV.— CONTRIBUTIONS FROM THE HARVARD MINERALOGICAL 



MUSEUM. 



A COMPARATIVE STUDY OF ETCH-FIGURES. THE 

 AMPHIBOLES AND PYROXENES. 



By R. a. Daly. 



With Fouk Plates. 



