INDEX. 259 



New Hope school house 91 



Nidular sandstone 80 



Nuttall, Thos., botanical work of 158-9 



Nyctaginaceae 214 



Nympheaceae 164 



Oil and gas 126, 127, 128 



Oleaceae 202 



Onagraceae 183 



Ophioglossaceae , 239 



Orchidaceae 221 



Organization of Washington county 142 



Origin of topography 1,2 



Orobanchaceae 209 



Osage creek . . 20 



Overflows of White river , 18 



Oxford's bend 17 



Pacific Railway reports 100 



Palmar 227 



Papaveraceae 164 



Parks, Robert 72 



Parrick's ridge 6, 86, 108 



Passifloraceae 184 



Pedaliac=ae 210 



Pentremites 73,92 



Pentrimital limestone 83-92,151 



local details 84 



occurrences 84 



Petroleum, indications of 48,127 



Phytolaccaceae .... 215 



Pierce mountain 83,86 



section of 141 



Pinnacle 9 



Piperaceae 216 



Plant list 162 



Plantaginaceae 213 



Plants affected by soil .., 246 



fossil 96 



of Arkansas . 155-242 



worthy of cultivation . 250 



Platanaceae 219 



Polemoniaceae 204 



Polygalaceae 168 



Polygonaceae 215 



Pontederiaceae 226 



Population of Washington county 142 



Portulacaceae 169 



Prairie Grove, chert at , 34 



spring at , 23 



topography 9 



Price Mountain syncline 114 



Primulaceae ... 201 



Privett's coal bank 99 



