INDEX 



395 



Phenacodus, 319. 



Phosphate, 132, 311. 



Physiographic provinces of United 

 States, 382. 



Pictet, F. J., 260. 



Piedmont Plateau, 45, 53, 82, 86-87, 

 90, 251, 292. 



Pirsson and Schuchert, 33. 



Pithecanthropus, 327, 374-375. 



Pittsburg coal bed, 106. 



Placentals, 318. 



Placenticeras, 260. 



Plaesiomys, 95. 



Planetesimal hypothesis, 37-39. 



Planets, 35-36. 



Plants, classification, 11-14; earliest 

 forms, 70-71; Cambrian, 71; Or- 

 dovician, 91; Silurian, 113; Devo- 

 nian, 132-133; Mississippian, 153- 

 154; Pennsylvanian, 169-172; Per- 

 mian, 190; Triassic, 212-213; 

 Jurassic, 227-228; Cretaceous, 

 256-258; Tertiary, 311-313. 



Platyceras, 136. 



Plectambonites, 95. 



Plectorthis, 95. 



Pleistocene epoch (see Glacial epoch) . 



Plesiosaurs, 263, 265-266. 



Pleurocystis, 93. 



Pleuromaria, 136. 



Pliocene series, 281-282, 284, 286- 

 287, 289-290. 



Pocono sandstone, 143, 145, 148. 



Podokesaurus, 271. 



Porifers, 13, 15; Cambrian, 72 

 Ordovician, 91; Silurian, 113-114 

 Devonian, 133; Mississippian, 155 

 Pennsylvanian, 173; Permian, 191 

 Triassic, 213; Jurassic, 228; Cre- 

 taceous, 258; Tertiary, 313. 



Portage formation, 120, 124. 



Potomac series, 244, 276. 



Potsdam sandstone, 57, 62. 



Pottsville series, 158, 161-163. 



Poughquag quartzite, 57. 



Primates, 319, 326-327. 



Proboscidians, 319, 322-325, 371. 



Productus, 135, 156. 



Proterozoic (see also Algonkian) era, 

 32, 42, 47-55; life of, 53-54; 

 climate, 55; glaciation, 55; eco- 

 nomic products, 55. 



Protohippus, 320-321. 



Protorohippus, 320. 



Protozoans, 13-15; Cambrian, 71- 

 72; Ordovician, 91; Silurian, 113; 

 Devonian, 133; Mississippian, 154; 

 Pennsylvanian, 172-173; Permian, 

 190; Triassic, 213; Jurassic, 228; 

 Cretaceous, 258; Tertiary, 313. 



Pseudodiadema, 229. 



Pterichthys, 138. 



Pteridophytes, 11, 133, 154, 170-172, 

 212. 



Pterodactyls, 263-271. 



Pterosaurs, 215, 234, 263, 271-272. 



Pulaski formation, 78. 



Pyrenees Mountains, 305, 306, 307, 

 368. 



Quaternary period, 32, 328-381; 

 origin of name, 328; Glacial epoch, 

 328-364 (see also special heading); 

 non-glaciated regions, 365-367; life 

 of, 369-381; Mammals (except 

 Man), 369-372; Man, 372-381. 



Quebec, 122, 125. 



Quicksilver, 227. 



Radiolarians, 13, 15, 53, 72, 91, 133, 

 154, 190, 228. 



Rancocas formation, 237, 241. 



Raritan formation, 237, 240. 



Recapitulation, law of, 232-233. 



Recent epoch, 328. 



"Red Beds," 181-182, 188, 194, 197, 

 204, 205, 210, 211, 220, 221, 274. 



References, general geological, 33-34. 



Reptiles, 13, 22; Pennsylvanian, 173, 

 179; Permian, 192-193; Triassic, 

 215-216; Jurassic, 233; Creta- 

 ceous, 262; Mesozoic, 263-273; 

 Tertiary, 317. 



Republican River formation, 282, 

 289. 



Restinson, 304. 



