EXPLANATION OF ADDITIONAL PLATES. 



A Section of BaH'iS Cave, in SchoIiaTic county. From Mr. Mather. (See page 227 of this volume.) 



Plans and Sections of the Shawangunk Lead Mine, near Wurtzboro', iji Sullivan county. From the 

 drawings furnished hy Mr. Cotheal, of New- York. (Sec pages 50 and 411.) 



View of the Coal Hill or Rossie Lead Mine, in Rossie, St. Lawrence county, as it appeared in the sum- 

 mer of 183G. (See pages 48 and 413.) 



Map of the Lead Vein in Rossie, St. Lawrence county. (See the pages just referred to.) 



Ground Plan of the Beds and Veins of Magnetic Iron Ore, or Magnetic Oxide of Iron, at Adirondack, 

 Essex county. (See page 16.) 



Map of Mining District of Monroe, Orange county. Reduced from the copy furnished by Peter Town- 

 send, Esq. (See page 5.) 



View of the Strata of Potsdam Sandstone, (composed chiefly of quartz,) as exhibited at the " Walled 

 Banks," about four miles from the village of Keeseville, Essex county. 



Hopper-form cavities and crystals of Marly Clay, at Bull's (Quarry, Madison county, and at Camillus, 

 Onondaga county. (See page 119.) 



