
INDEX. 
Coral reefs, formation of, 464; argument 
from as to subsidence, 282, 464 
Coral rock, 167; joints in, 503 
Corals as fossils, 611 
Corbicula, 866, 875 
Corbula, 795, 840*, 856 
Cordaites, 729, 731, 752 
Cordierite, 79 
Cormorant, fossil, 881 
Cornbrash, 790, 792 
Corniferous Group, 704 
Cornstone, 112 
Cornubianite, 580 
' Cornulites, 664, 682 
Corries, origin of, 927 
Corsite, 143 
Corundum, 67; artificial formation of, 
302 
Corydalis, 780* 
Coryphodon, 840 
Coseguina, eruption of, 217, 219 
Cosmoceras (Ammonites), 791*, 793* 
Cosmogony, 6 
Cotopaxi (see Andes) 
Crag deposits, 873 
Crane, fossil, 881 
Crania, 665, 669*, 805 
Crannoges in peat bogs, 460 
Crassatella, 847 
Crater, volcanic, 198, 242 
- COray-fish, geological action of, 455 
Credneria, 803 
Crematopteris, 761 
Creosaurus, 801 
Crests of mountains, origin of forms of, 
925 
Cretaceous rocks, metamorphosed, 834 
Cretaceous System, 801 
Crevasses in glaciers, 404 
Cricket, early form of, 732 
Crinoidal Limestone, 168, 722 
Crioceras, 807, 808* 
Cristellaria, 803* 
Crocodilus, 832; earliest known types of, 
763, 776 
“Crossed Nicols,” use of in petrography, 
189 
Crossopterygidx, 710 
Crotalocrinus, 678 
Crumpling of strata, 519 (see Plication) 
Crust of the earth, condition of first 
formed, 12; oxidation of, 30; mean 
density of, 42; definition of, 42; tem- 
perature of, 45, 49, 55, 912; thickness 
of, 52; composition of, 56, 57; flexures 
of, 913 
Crust of weathered rocks, 334 
Cruziana, 650 
Cryptocaris, 664 
Cryptoclastic structure, 88 
Cryptocrystalline structure, 87, 88 
Cryptomerites, 792 
Crystalline minerals, 60 
Crystalline rocks, 110 
948 
Crystalline structure of rocks, 86, 103; 
production of in stalactites, limestones, 
&e., 354 
Crystallites (see also Microlites), 99, 100, 
in decomposing glass, 333; in fused 
sandstone, &e., 575 
eae of rocks, experiments in, 
Crystals in rocks, 95; inclosures in, 95 
Ctenacanthus, 699, 725*, 732 
Ctenodonta, 651*, 665, 679* 
Ctenodus, 724 
Ctenoptychius, 724, 732 
* Cuboides beds,” 701 
Cucullza, 697, 698*, 818, 844, 881 
Cucullella, 678 
Culm, 748 
Cunninghamites, 803 
Cupressinoxylon, 859 
Cupressocrinidz, 696 
Cupressus, 786 
Curculionide, fossil, 775 
Currents, tidal, 419 ; ocean, 420, 434 ; cause 
of, 421 
Curtonotus, 697 
Curvature of rocks, 514, 913 
Custard-apple, early species of, 838, 855 
“ Cutters ” and “ backs,’ 502 
Cyathaspis, 712 
Cyathaxonia, 664 
Cyathina, 804, 860 
Cyathocrinus, 664, 696, 722*, 753 
Cyathophora, 793 
Cyathophyllum, 664, 696, 721* 
Cybele, 664 
Cycadinocarpus, 772 
Cycadoidea, 772 
Cycadospadix, 772 
Cycads, fossil, 761, 772, 804 
Cyclas, 817 
Cyclocladia, 728 
Cyclolites, 804 
Cyclone waves, 423 
Cyclonema, 666 
Cyclopteris, 708, 715, 726, 757, 760 
Cyclostigma, 717, 736 
Cyclostoma, 859, 866 
Cyclotus, 857 
Cynodon, 841 
Cyphaspis, 677* 
Cyphosoma, 805 
Cyprea, 840, 862, 881 
Cypress, early forms of, 838, 866 
Cypricardia, 789 
Cypridina, 696, 697* 
Cypridinenschiefer, 696 
Cyprina, 818, 844, 873, 896 
Cypris, 828 
Cyrena, 790, 817, 840*, 856, 866 
Cyrtia, 696 
Cyrtoceras, 666, 698 
Cyrtotheca, 655 
Cystideans, 650, 664; as type-fossils, 615 
Cystiphyllum, 696 
