IV 



INDEX. 



Pecopteris chcerophylloides 404 



Pecopteris dentata 404 



Pecopteris elegans 408 



Pecopteris flavicans 404 



Pecopteris hemiteloides 401 



Pecopteris villosa 402 



Peltodus 862 



Peltodus unguiformis 868 



Petalodus curtus. ." 355 



Petrodus pustulosus 869 



Physonemus gigas 873 



Pike county, geology of 24 



Pike county, Niagara limestone in 26 



Pike county, Kinderhook group in 27 



Pike county, Burlington limestone in. ... 29 



Pike county, Keokuk group in 31 



Pike county, St. Louis group in 82 



Pike county, Coal Measures in 82 



Pike county, Quaternary system in 35 



Pike county, economical geology of 37 



Platysomus circularis 847 



Poecilodus convolutus. 866 



Polyrhizodus Littoni 357 



Polyrhizodus truncatus 357 



Potters' clay 60, 71, 86, 162, 204,^221, 262 



Rhabdocarpus 461 



Rhabdocarpus clavatus 461 



Rhabdocarpus mammillatus 461 



Rizodus reticulatus 849 



Riuodus 374 



Sandalodus missus 369 



Schizopteris 411, 418 



Schutzia 427 



Schutzia bracteata 427 



Schuyler county, geology of 76 



Schuyler county, Quaternary system in . . , 76 



Schuyler county, Coal Measures in 77 



Schuyler county, St. Louis group in 84 



Schuyler county, Keokuk group in 84 



Schuyler county, economical geology of. .. 85 



Sigillariae semina 463 



Sigillaria alternans 447 



Sigillaria I'istii 447 



Sigillaria coirugat^ , , . 445 



Sigillaria Massiliensis .....' 448 



Sjgillaria spinulosa 447 



Sigillarioides 449 



Sigillarioides radicans , . . .449 



Sigjllarioides stellaris .4,50 



Sphenopteris elegans 410 



Sphenopteris gracilis 408 



Sphenopteris mixta 409 



Sphenopteris scaberrima 408 



Sphenopteris trifoliata 410 



Sphenophyllum cornutum 421 



Sphenophyllum filiculmis 422 



Springs, mineral 22, 80, 148, 189 



Springs, Perry 40 



Springs, Versailles 73 



Staphylopteris 405 



Staphylopteris asteroides 406 



Staphylopteris sagittatus 407 



Staphylopteris Wortheni 405 



Stark county, geology of 325 



Stark county, Quaternary^deposits in 326 



Stark county, Coal Measures in 326 



Stark county, economical geology of. ... 330 

 Stark county, soil and agriculture of . . . . 333 



Stigmaria elliptica 461 



Stigmaria umbonata 452 



Stigmarioides 452 



Stigmarioides aflinis 455 



Stigmarioides linearis 455 



Stigmarioides selago 458 



Stigmarioides truncatus 453 



Stigmarioides villosus 454 



Stigmarioides? rugosus 470 



Syringodendron cyclostigma 449 



Syringodendron pes-capreoli 448 



Syringodendron Porteri 448 



Tazewell, McLean, Logan and Mason coun- 

 ties, geology of 176 



Tazewell, McLean, Logan and Mason coun- 

 ties, boundaries of. 176 



Tazewell, McLean, Logan and Mason coun- 

 ties, geological formations in 177 



Tazewell, McLean, Logan and Mason coun- 

 ties, Drift section of 178 



Tazewell, McLean, Logan and Mason coun- 

 ties, Coal Measures In 179 



Tazewell, McLean, Logan and Mason coun- 

 ties, economical geology of. 1 8/7 



Trigonocarpum noeggerathii 460 



Trigonocarpum olivaeformis 460 



Ulodendron 434 



Ulodendron elongatum , 437 



Ulodendron ellipticum ^ 486 



Ulodendron jnqjus 435 



