PLATE XIII 



PHOTOMICROGRAPHS OF SCHIST 



Fig. 1. Mica -feldspar-quartz schist. 



Southeast corner West 116th Street and Broadway, New York City. 

 Magnified 22.5 diameters. 



Fig. 2. Gray gneissoid variety of schist. 



West 42nd Street, near 5th Avenue, New York City. 

 Magnified 22.5 diameters. Crossed nicols. 



Fig. 3. Mica schist. 



Verplanck, Westchester County, New York. 

 Magnified 22.5 diameters. Crossed nicols. 



Fig. 4. Mica schist. 



North of Croton-on-the-Hudson, Westchester County, New York. 

 Magnified 22.5 diameters. 



Fig. 5. Staurolite mica schist. 



North of Croton-on-the-Hudson, Westchester County, New York. 

 Magnified 22.5 diameters. 



