382 



INDEX 



"Phragmoceras beds", 48 



Phyllolepis delicatula, 207, 288 



Physichthys, 168 



Physichthys fioeninghausii, 175 



Physonemus, 140 



Physonemus hamus-piscatorius, 149 



pandatus, 149 

 Pisces, characters of class, 195 



classification of, 68, 69 

 Placodermata, use of term, 159 

 "Placodermi", 158 

 "Placoderms", 142, 158, 161 

 Placoid covering, 95 

 Placothorax agassizii, 168, 175 

 Plaster of Paris, production of, 27 

 Platteville, Wisconsin, oil rock of, 2 

 Platteville limestone, oil rock of, 3 

 Platysomidae, relations of, 255 

 Pleistocene gravels of Iowa, study of, 



6 

 Pleuracanthidae, characters of family, 



103 

 Pleuracanthus, 66, 101 



characters of genus, 103 

 Pleuracanthus decheni, 102 

 Pleuropterygii, 68, 69 



characters of order, 97 

 Poincare, cited, 43 

 Polyodontidae, degeneration of, 256 

 Polypterus bichir, 245 

 Portage beds, New York, fish remains 



from, 100, 113, 135, 139, 142, 179, 



199, 206, 213, 241, 257, 260, 277, 



278, 281, 282 

 Portland cement, production of, 28 

 Pottery, production of, 19, 22 

 Powell county, Kentucky, fish remains 



from, 279, 283 

 Poweshiek county, Iowa, work in, 4 

 Protitanichthys, characters of genus, 



201 

 relations with Titanichthys, 202 

 Protitanichthys fossatus, 201, 278 

 Protochordata, characters of, 52 

 Protodus, 100 

 Protodus jexi, 275 

 Protopterus, 157, 159 



relations of, 208 

 Protospondyli, 69 

 characters of, 63 



Prussia, fish remains from, 119, 167, 

 176, 177, 225-227 



Ostracophores from, 54 

 Psammites de Condroz, Belgium, fish 



remains from, 200 

 ? Psammodes antiguus. 276 

 Psammosteidae, 69 



classification of, 55 

 Psammosteus, 142 

 Pteraspidae, 69 



classification of, 55 



relation of, 159 

 Pteraspis, 58 

 Pteraspis rostrata, 73 

 Pterichthys, 75 



armor of, 58 



characters of genus, 76 

 Pterichthys canadensis, 84 



milleri, 77 



rhenanus, 168 

 Ptycholepis, resemblance of, to Elon- 



ichthys, 274 

 Ptychopterygium, 100 

 Ptyctodonts, dermal plates of, 149 



detached parts of, 138, 143 



enemies of Dipterines, 217 



in Iowa Devonian, 48 



vertebral centrum accompanying. 

 148 

 Ptyctodus, characters of genus, 133 



fin-spines accompanying, 139 



relations of, 120 

 Ptyctodus sp., 281 



calceolus, 128, 133, 137, 277, 281, 286 

 in Lime Creek beds, 49 

 in Sweetland Creek beds, 50 

 in Wapsipinicon beds, 48 



compressus, 135, 286 



eastmani, 131, 149 



ferox, 128, 135, 277, 286 



punctatus, 133, 277 



O 



Quebec, fish remains in. 74, 83, 91. 213. 

 236. 256. 275. 276, 278, 280 



Railway ballast, production of, 23, 24 

 Ramphodus. 121 



