252 index. 



Page. 



Nitric acid, method for the determination of 190 



Nucula f! 116, 218 



Ochke, yellow, from Greene county 22, 25, 202 



Ochre, yellow, analysis of 22, 170 



Ochre, yellow, use of 22, 203 



Oil-trough bottom, character of soil of 33 



Oil-trough ridge, section of strata of 34 



Orthis 208, 218 



Orthis crinistria 98, 103 



Ortlwc. ras 208, 220 



Palaeontology, importance of 139-141 



Pearl spar, analysis of 183 



Pecoptiris in shale of coal measures 230-235 



Pilot knob of Carroll county 95 



Pilot mountain of Carroll county 88 



Pine, diggings for silver ore at the, in Greene county 22 



Pinularia in shale of coal measures 227 



Plalicrimis 224 



Poinsett county 30 



amber found in 31 



black wax lands of 31 



earthcraks and sandblows in 31 



lignite of 31 



sandstone of 31 , 32 



Pope county 232 



character of soils in 234 



occurrence of coal in 233 



occurrence of iron ore in 233, 234 



section of strata on Galley creek, in 234 



. section of strata on Illinois bayou, in 233 



Potter's clay in Greene county 21, 202, 203 



Powhatan, zinc ore found in the streets of 212 



Prairie of Benton county, character of soil of 104 



Beatty's 108 



Huzza 94 



Marshall •. 89, 94 



Morell, character of soil of 31 



Prairie county 242 



Prairie county, general character of, and its soil 242 



Productal limestone of Independence county 35 



Productus 78, 218 



cora in limestone 116, 121, 218 



elegans 100, 218 



punctatus in chert 104 



Psilnmelnne, analysis of . . 161, 162, 165 



Psilomelane, method of analysis of 188 



Psilomelune. occurrence of, in Independence county 39 



Pulaski county 237 



analysis of argentiferous lead ore of 240 



analysis of the Newton spring of 241 



character of soils of 242 



Kellogg lead mines of 237, 241 



metamorphic action observable in the strata of 237 



occurrence of blende in 239 



of copper ore in 239 



of iron ore in 239, 241 



of lead ore in 237 



section of strata in 238 



Pyrites, yellow cupriferous, in lignite of Greene county ^25 



Quaternary sandstone, impressions of leaves in 25, 29 



Quartz veins, occurrence of, in Conway county 235 



Quartz veins, occurrence of, in Pulaski county 237 



Randolph county 205 



agricultural resources of 207 



occurrence of iron ore in 206, 207 



Rice's spring of 207 



