IXDKX 



973 



Scaphites nodosus, 770 

 Seurboro formation, 917 

 Schist, 56, 57, 86 

 Schistosity, 15, 55 

 Schizocrania filosa, 528 

 Schizodus chesterensis, 614 

 Schizolopha textilis, 526 

 Schizoneura gondwanensis, 671 

 Schizophoria multistriata, 576 



swallovi, 610 

 Schizotreta ovalis, 528 

 Schoharie beds, 561 



creek, 124 



grit, 559 



Schrader, F. C., 569 

 Schuchert, C., 478, 522, 734 

 Schwarz, E. H. L., 575 

 Scoria, 87, 379 

 Scoriaceous texture, 20 

 Scorpions, 654 



earliest, 557 



Scott, E. H., 646, 649, 650 

 Scott, W. B., 504 

 Scour-and-fill, 184 

 Scrope, G. P., 393 

 Scudder, S. H., 595, 654 

 Sea caves, 306 

 Sea-cliff, 303 

 Sea-level, 352 

 "Sea-lily," 532 

 Sea-urchins, Cretaceous, 769, 770 



Eocene, 794 



Jurassic, 715 



Pennsylvanian, 657 

 Sea-water, movements of, 296 

 Secondary enlargement, 43 

 Secular movements, 351 

 Sedgwickia topekaensis, 675 

 Sediment, how carried, 139, 144 

 Sedimentary eon, 431 



rocks, 34, 38, 39, 394 

 Sedimentation, general principles 

 484 



Proterozoic, 450 

 Sediments, induration of, 42 

 Seed-bearing ferns, 595 

 "Seed-ferns," 643 

 Seeley, H. G., 757 

 Seepage, 211 

 Seiches, 332 

 Selma chalk, 745 

 Semi-anthracite coal, 637 

 Seminula argentea, 658 



subquadrata, 614 

 Senecan series, 559, 565 



Senonian series, 757 

 Septaria, 48, 49, 87 

 Serpentine, 50, 80, 87 

 Serrate topography, 107 

 Sevier shale, 510 

 Sewanee coal bed, 625 

 Seward, A. C., 646 

 Shale, 36, 87, 395 



bedding of, 395 



Shaler, N. S., 206, 236, 303, 627 

 Shallow-water deposits, 316-320 

 Sharks, 579, 583, 592 

 Shastan group, 733 

 Shawangunk conglomerate, 543 

 Shear, 63 



Shearing of ice, 282 

 Sheet erosion, 115 

 Shell limestone, 83 

 Shenandoah River, 124 

 Shimek, B., 888, 890 

 Shooting stars, 419 

 Shore-currents, 298 



deposition by, 309 

 Shore drift, 308 

 Shore lines, mature, 307 

 Shoshone series, 752 

 Shrinkage from cooling, 363 

 Siamo slate, 460 

 Siberian region in Permian time, 



696 



Siberian Triassic fauna, 698 

 Siderite, 81 

 Sierra Mountains, 707 



peneplanation in, 810 

 Sierran epoch, 836 

 Sigillarias, 594, 644, 648, 670, 691 

 Sills, 15, 367, 400 

 Silurian igneous rocks, 545 

 Silurian life, 546 



of Europe, 546 



of the West, 543 



oscillations of level during, 544 



period, 536-558 



climate of, 545 



duration of 546 

 Siphonalia marylandica, 827 

 Sirenia, 787 

 Siwalik formation, 820 

 Skertchly, S. B. J., 887 

 Slate, 53, 87 

 Slichter, C. S., 201 

 Slickensides, 65, 410 

 Slope of ice-sheets, 862 

 Sloths, Pleistocene, 922 

 Slumping, 209 



