BULL. GEOL. SOC. AM 



VOL. 10, 1898, PL. 40 



FiGUUE 1.— ^'EI.^• Of Bl.ACK iUuTITE AND GvKXET 



In granites of Masons island, Mystic harbor. Vein is vertical in the quarry and is 2 inches wide 



KlUlRE 2.— PEIiJIAlTI'E J)1KES 



Cutting Cambrian schists, near Watson's pier, west side of Narragansett l:>ay 



**^>^-^j?y 



FiGtTKE 3.— Near View of two of the PEiiMATiTE Veins shown in Figure 2 

 PEGMATITE VEINS AND DIKES, AND VEIN OF BIOTITE AND GARNET 



