700 



INDEX 



Cross-bedding, — (Continued) 



of dunes, 47, 48. 

 Crossopterygians, 465, 488. 

 Croxian stage, 402. 

 Crush breccia, 268. 

 Crustacea, Cambrian, 410-413. 



Devonian, 460. 



Mesozoic, 532. 



Ordovician, 435-436. 



Proterozoic, 397. 

 Crustal movements, 112, 257. 

 Crust of earth, 273-274. 

 Crystallization, 349. 

 Ctenodonta nasuta, 433. 

 Cuestas, 225. 

 Cyathophyllum, 445. 

 Cycadales, 565. 

 Cycads, 565-566. 

 Cycle of shore erosion, 231-233. 



of stream erosion, 109-114. 

 Cynognathus, 537. 

 Cyrtodonta billingsi, 433. 

 Cyrtolites ornatus, 434. 

 Cystodictya hamiltonensis, 458. 

 Cystoids, Cambrian, 415. 



Devonian, 457. 



Ordovician, 430. 



Silurian, 446. 



Daemonhelix, 63i-«632. 



Dakota formation, 517. 



Dalmanella testudinaria, 432. 



Dalmanites limulurus, 448, 



Daly, R. A., 246, 247, 309, 336, 392. 



Dana, J. D., 309, 456, 488. 



Dapedius, 534. 



Darwin, C. R., 245. 



Davis, W. M., 86, 246. 



Dawson, W., 632. 



Dawsonoceras americanum, 448. 



Dead Sea, 263. 



Dean, B., 533. 



Deep-sea deposits, 241-243. 



Deer, 618-619. 



Deforestation, effect on streams, 



98. 

 Deformation, 365. 

 Degradation, 87. 

 Deltas, depth of, 132. 



growth of, 130. 



in glacial lakes, 180. 



structure of, 131. 



96- 



De Martonne, E., 53. 

 Dendritic river systems, 103. 

 Density of the earth, 273-274, 

 Denudation of continents, rate of, 118. 

 Deposition along shores, 233. 



by ground water, 60. 



by streams, causes of, 119. 



in lakes, 250. 

 Depression, effect on streams, in. 

 Derbya crassa, 482. 

 Dermochelys, 557. 

 Desert limestone, 62. 

 Deserts, wind erosion in, 46. 

 Devonian period, 452-468. 



climate of, 468. 



duration of, 468. 



in other continents, 455-456. 



life of, 456-468. 



migration and evolution during, 467- 

 468. 



of New York state, 452, 454. 



oil and gas of, 455. 



physical geography of, 453~455- 



plants of, 467. 



thickness of formations of, 453. 



volcanic activity of, 455. 

 Dew and hoarfrost as weathering agents, 



33- 

 Diatomaceous earth, 134, 580. 

 Diatoms, 134, 581, 633. 

 Dibelodon, 614. 

 Dicellocephalus, 402. 

 Dicellocephalus minnesotensis, 412. 

 Diceras, 527. 

 Diceras arietinum, 527. 

 Diceratherium, 606, 607. 

 Dichograptus, 428, 429. 

 Dichograptus octobrachiatus, 428. 

 Dicroceros, 618. 

 Dictyonema flabelliforme, 428. 

 Dicynodon, 537. 

 Didymograptus, 428, 429. 

 Didymograptus nitidus, 428. 

 Dielasma bovidens, 482. 

 Differential weathering, 40. 

 Dikes, 324-325, 327. 

 Dimetrodon, 490. 

 Dimorphodon, 558-559. 

 Dinichthys, 464. 

 Dinosaurs, 539-552, 572. 



migration and extinction of, 549-551. 

 Dinotherium, 615. 

 Diorite, 330. 



