INDEX. . 587 



Page. 



Occurrence of ocher 243 



orpiment 183 



ozokerite 453 



pyrophyllite 323 



realgar 183 



smaltite 186 



strontianite 280 



sulpliur 177 



triphylite 391 



wolframite 355 



Oceanica, distribution of Hpecimens in 124 



Ocher 239 



otxairrence of 243 



origin and mode of occurrence of 241 



( paint ores) bibliography of . . *. 245 



pre.paration of 242 



uses of 244 



Ohio Centennial Exposition 13, 69 



Oldroyd, T. S. , contributions from 29 



Omaha International Exposition, assortment of ores and economic products 



from Central and Western States received from 37 



Opal 216 



Origin and mode of occurrence of bauxite 231 



calcite 259 



clays 325 



ocher 241 



sulphur 174 



silica 218 



diamond 166 



halite 196 



rock phosphate ^ 358 



of bituminous compounds 430 



coal series 423 



corundum 223 



deposits of Ijauxite 237 



gypsum 407 



manganese oxides 255 



nitrates .♦ ;^9o 



Orpiment 183 



bibliography of 184 



occurrences of 183 



uses of 184 



Orthite 311 



Osgood, Wilfred H. , examined the wren-tits 59 



mice and fox furnished to 60 



reference to use of ornithological collections by 34 



title of paper by 143 



Osteology 68 



Oxides 215 



))auxite 229 



chromite 246 



corundum 220 



diaspore 239 



