252 



NEW YORK STATE MUSEUM 



Ordovician system, see Lower Silurian 



system. 

 Organic rocks, 125 7 . 

 Oriskany sandstone, 157 s , 159 1 , 191 2 . 

 Orleans county, hydraulic cement, 156 6 . 

 Orthoclase, 1211, 1251. 

 Oswego county, Hudson river group, 



149 6 . 

 Outcrops, 2383-39*. 

 Oysters. 173 2 ; of Tertiary period, 175 7 . 



Packard, A. S., First lessons. in zoology, 

 extract from, 132. 



Palaeontology, 129 3 -30 2 . See also Fos- 

 sils. 



Palaeozoic series, 141 6 -70 5 ; outcrops 

 in New York, 1346, 2429-432. 



Palaeozoic time, 135 8 . 



Palisades, igneous rocks, 124 5 , 140*, 

 1717; trap-rocks, 184*, 2049. 



Peat, 227 7 . 



Pentamerus limestones, 201 5 . 



Periods, 1361. 



Permian formation, 169 8 -70 1 . 



Petrified wood, 1791. 



Petroleum, 227 8 . 



Phosphate of lime, localities producing, 

 233 8 . 



Photographs, 110 8 ~lli. 



Physiography of New York, 134!-35 3 . 



Plagioclase, 1213-1251. 



Plants, classification, 133 1 ; develop- 

 ment, 1421, 169 5 ; of Cambrian sys- 

 tem, 146 s ; of Carboniferous system, 

 170 5 ; of Devonian system, 165 9 ; of 

 Mesozoic time, 170 7 ; of Tertiary 

 period, 175 7 ; of Upper Silurian sys- 

 tem, 158*. 



Pliocene, 1749. 



Plutonic rocks, 124*, 125 2 , 139 2 . 



Pocono group, 166 5 . 



Porphyry, 125 s . 



Portage group, 164 2 , 193*. 



Potsdam group, 142 8 , 144*-45 9 . 



Potsdam sandstone, 144 5 -455, 187 5 -883. 



Potter's clay, 120 8 . 



Pottery, manufacture of, 174 2 . 



Pottsville, conglomerate, 167 2 -69 8 . 



Precious metals, see Gold ; Silver. 



Proterozoic series, 141*. 



Proterozoic time, 135 8 . 



Putnam, B. F., article on iron ores, 



2145. 

 Putnam county, calciferous limestone, 



1473. 

 Pyrite, localities producing, 231 9 . 

 Pyroxene, 121?, 121», 182*. 

 Pythagoras, geologic observations, 



1137. 



Quartz, 120*5, 120 9 , 125 2 , 2249. 

 Quartzite, 1206, 143*. 

 Quaternary system, 175 8 -79* ; fossils of, 

 1786-79*. 



Red sandstone, 1717, 1951. 



Eeindeer, fossil, 178 9 . 



Rensselaer county, rocks, 143 3 ; fossils, 

 143 8 ; roofing slate, 144 1 . 



ReDsselaer plateau, 1519-52 1 . 



Reptiles, of Carboniferous system, 

 170*; of Cretaceous period, 174 6 ; of 

 Jurassic period, 172 6 ; of Mesozoic 

 time, 170 7 : of Trtiary period, 175 6 ; 

 of Triassic period, 172 2 . 



Rhyolite, 1253. 



Ries, Dr. Heinrich, photographs by, 

 1109. 



Road metal, 1596, 1847, 1915, 204*-8 2 ; 

 quarries, 204 5 -5 6 ; requisite qualities, 

 207 8 . 



Rock cities, 167 6 . 



Rock salt, 1227, 1256. 



Rockland county, calciferous lime- 

 stone, 147 3 . 



Rocks, 123!-26 2 ; defined, 1197. See also 

 Igneous rocks ; Metamorphic rocks ; 

 Sedimentary rocks. 



Roofing slate, 1261, 1433, 1439-441, 1961. 



Rosenbusch classification, 124 8 -25 3 . 



Rossie hematites, 219 6 . 



Rubies, 122 8 . 



