Report of National Museum, 1890.— Merrill. 



Plate CXIX. 



Fig. 1. Chert breccia cemented by zinc blende. (Cat. No. 72794, U. S. N. M.) 



Fig. 2. Felsite breccia formed of felsitic fragments embedded in a matrix of the same composition. 

 (Cat. No. 35961, U. S. N.M.) 



