CONTENTS. IX 



Lower, or Comanche series 116 



Trinity sands, or Upper Cross Timber division 118 



The Fredericksburg division 120 



Basal beds 121 



Comanche Peak beds 123 



Caprina chalk 124 



The "Washita division 126 



The flagstones 127 



The Upper Caprotina division 121 



The Washita limestone 128 



The Exogyra Arietina clays 128 



The Shoal Creek limestone 129 



The Denison beds 130 



Stratigraphy of the Comanche series 131 



Progress section 132 



Disturbances of the strata 134 



General economic features 137 



THE SOUTHERN BORDER OF THE CENTRAL COAL FIELD, BY W. F. CUMMINS. 



Descriptive Geology . 145 



Introduction 145 



Cretaceous system 145 



Carboniferous 147 



Conglomerate 156 



Petrified wood 157 



Caves 157 



Conclusions 158 



Economic Geology — 



Coal 158 



Gas 168 



OH 161 



Iron 161 



Aragonite 162 



Strontianite 162 



Building stone 162 



Marble 165 



Clays 165 



Lithographic stone 165 



Soils 166 



Water 170 



Mineral water 171 



Saltwater 173 



Water power 174 



Irrigation 175 



Rainfall 179 



Temperature 180 



Timber 181 



THE PERMIAN OF TEXAS AND ITS OVERLYING BEDS, BY W. F. CUMMINS. 



Description 185 



The Wichita beds 187 



The Clear Pork beds 188 



The Double Mountain beds 188 



Overlying formations — 



Dockum beds ' 189 



Blanco Canyon beds 190 



Economics — 



Soils 191 



Fertilizers 193 



Water 193 



Rainfall 194 



Building material 194 



Timber 195 



Salt 195 



