Plate 34 



Photomicrograph of no. 499. Manhattan schist. Taken with plain light, magnification about 

 25 diameters. 



Showing: a Foliate structure, b Quartz (clear grains) abundant, c Biotite (dark smooth 

 flakes), d Fibrolite (fibers and needles), e Pyrite (black large grains). / Garnet (rough gray 

 grains), g Magnetite (small black specks). 



Plate 35 



Photomicrograph of no. i. A typical specimen of Manhattan schist Taken with plain light' 

 magnification about 30 diameters. 



Showing: a Strong schistose structure. 6 Mineral make-up including (i) quartz (clear grains) , 

 (2) muscovite (clear plates), (3) biotite (dark plates), (4) garnet (coarse rough crystals), (s) ii'on 

 oxide, a little (black specks). 



