INDKX 



691 



Columbia River, 107 

 Columbia M-ri.-s, 652 

 Columnar stnu'turr, 247. 248 

 Columnaria alveolata, 385 

 Comamlu-an angiospcrms, 528 

 Comatulu-an, distinct from Cretaceous, 



S2i 

 Comanchean fossils, 528 



'IVxan. 530 



Comanchean of Mexico, 525 

 Comanchean period, 521-531 



close of, 526 

 Comandu-an system, distribution of, 



$aa 



Comarocystis punctatus, 384 

 Compound alluvial fan, no 

 Concretions, 287, 288 



in Cretaceous, 536 

 Cohdylarthra, 566, 567 

 Conemaugh series, 443 

 Conglomerate. 267, 271 



>t thicknesses of, 191 

 Conifers. Jurassic, 515 

 Conocardium prattenanum, 437 



trigonale, 416 

 Consequent streams, 6t 

 Constellaria polystomella, 383 

 Continental creep, 350 



glaciers, 127 



shelves, 171 



Continent-forming movements, 221 

 Contour maps, 17 

 Conularia trentonensis, 381 

 Conus diluvianus, 597 

 Cook, G. H., cited, 523 

 Copper in Michigan, 337 

 Coral reefs, oldest, 391 

 Corals, Cambrian, 362 



Cretaceous, 555 



Devonian, 414, 417 



Jurassic, 509 



Mississippian, 415, 420 



Ordovician, 384, 385 



Pennsylvanian, 468 



Silurian, 398 



Triassic, 500 

 Corbula aldrichi, 573 



blakei, 500 



idonea, 595 



Corbula (?) persulcata, 531 

 Cordilleran ice sheet, 613 

 Cordilleran Mountains, age of, 541 



region, Proterozoic rocks of, 340 

 Conlaites, 424, 458, 459, 462, 476 

 Coroniceras bisulcatum, 508 



Corniferous formation, 402 

 Corrasion, 73, 78 

 Correlation, basis of, 346-349 

 Corrosion, 73, 80 

 Cotylosauria, 478 

 Cowles, H. C., cited, 20 

 Crag and tail, 156 

 Crania Icelia, 382 

 Crassatellites alaeformis, 574 



marylandicus, 595 

 Craters, 230 

 Crazy Mountains, 543 

 Creep, 40, 75 



continental, 350 

 Creodonta, 566, 567, 570 

 Crepidula fornicata, 597 

 Crepipora hemispherica, 383 

 Cretaceous fossils, 554 

 Cretaceous life, 546 

 Cretaceous period, 521, 532-555 



climate of, 545 



close of, 541, 542 

 Cretaceous plants, 546, 547 



saurians, 546 

 Cretaceous system, 533 



structure of, 532, 535, 540 

 Crevasses in glaciers, 135 

 Crinoids, Cretaceous, 555 



Devonian, 418 



Jurassic, 509 



Mississippian, 437 



Ordovician, 383 



Silurian, 396 

 Cristellaria gibba, 572 



radiata, 572 



Criteria of glaciation, 610 

 Critical level, 170, 455 

 Crocodiles, Cretaceous, 549 

 Crocodilians, 514, 519 

 Croll, James, cited, 649 

 Cross, Whitman, cited, 40, 489, 504, 



538, 539 



Cross-bedding, 192, 270, 271 

 Crustacea, Cambrian, 359 



Jurassic, 510 

 Crustal movements, amount of, 224 



cause of, 224 

 Crustal shortening, 223 

 Cryphasus boothi, 419 

 Crystals, growth in lava, 251 

 Crytina hamiltonensis, 416 

 Ctenodonta nasuta, 381 



pectunculoides, 381 



recurva, 381 

 Culm, 431 



