668 
INDEX, 
Elevated country in Canada, 337. 
Elevated lakes, 252. 
Elevation of the hills of the Chemung group, 252; of the 
tertiary on Lake Champlain, 337; of the Ridge road above 
Lake Ontario, 351 ; of rocky strata by the freezing of 
water, 375; of the ancient ocean, 353 ; and depression of 
the waters of the Great lakes, 408. 
Elevation of Monroe county, 422; of Orleans county, 434; 
of Allegany county, 484 ; of Chautauque county, 493, 
Elevation and submergence, evidences of alternate, 321. 
Ellipsolites, 28. 
Encrinal limestone, 145 ; of the Niagara group, 89 ; of the 
Hamilton group, 184, 187, 189, 204, 492. 
Epsomites or lignilites, 130. 
Erie county, rocks of, etc. 469. 
Erie lake, future drainage of, 400. 
Erratic blocks, 424. 
Erroneous opinions regarding the nature of the earliest fos¬ 
sils, 10. 
Errors in identification of strata, 7. 
Euomphalus, 28, 109, 137, 172, 291. 
Evidences of a current from south to north, 397; of the 
former existence of deep lakes in certain river valleys, 
343 ; of higher elevation in many water courses, 353; of 
ancient currents, 457. 
Extent of the Old Red sandstone, 179. 
Extinction of species, 9, 367. 
F. 
Facilities for communication in Steuben county, 481. 
Falls, 225, 377; Genesee lower, 382; Hector, 379; Nia¬ 
gara, 383 ; Portage, 224, 368; Portage lower, 370; Ro¬ 
chester upper, 82, 95; Shelby, 83, 88; Taghannuc, 377. 
Falls, recession of, 378, 381 ; past recession of the Niagara, 
390 ; future recession of the same, 398. 
Fauna of the deep and distant parts of the ocean more likely 
to be uniform and unchanged than near the shore, where 
subjected to the invasion of variable deposits, 515. 
Favositcs, 29, 157, 159, 402, 467. 
Ferns in the Chemung group, 476. 
Ferriferous slate and limerock, 58. 
Fields covered with boulders, 332. 
Filicites, 273. 
Fine beach sand covering conglomerate, 495. 
Firestones, 62, 65, 147, 420, 432, 456, 467, 483. 
Fishes, remains of, 278, 487 ; fossil, found in the central 
portion of the Transition or Silurian strata, 10. 
Fissures in the Corniferous limestone, 169. 
Flagstones and shale of Gardeau, 227. 
Flagging stones, see Building and flagging stones. 
Flagging stones, 448, 452, 458, 476, 477. 
Flat gravel, 240, 260, 323, 324, 474, 488. 
Fluid bitumen in concretions of Marcellus shale, 221. 
Fluor spar, 28. 
Fluviatile deposits of Goat island and the banks of Niagara 
river, 396, 397. 
Fossil bones of quadrupeds, 363, 364. 
Fossil characters of strata, value of, 501. 
Fossiliferous iron ore, 60. 
Fossils not found in the gypseous rocks, 460 ; rarely accom¬ 
pany rippled surfaces, 477 ; of the older rocks, allied to or 
identical with Trochus, Turbo, Nucula, Avicula, &c. 10. 
Fossils of the Potsdam sandstone, 27; of the Calciferous 
sandrock, 28; Trenton limestone, 29; Utica slate, 29; 
Hudson-river group, 30 ; Medina sandstone, 46 ; Clinton 
group, 68 - 77 ; Niagara group, 100 - 117 ; Onondaga-salt 
group, 137, 138; Water-lime group, 142; Oriskany sand¬ 
stone, 148, 149; Onondaga limestone, 157- 160; Corni¬ 
ferous limestone, 170 - 175 ; Marcellus shale, 180 - 182; 
Hamilton group, 195-210; Tully limestone, 215, 216, 
Genesee slate, 221 - 223 ; Portage group, 241 - 247 ; 
Chemung group, 261 - 275; Old Red sandstone, 280 - 283; 
Conglomerate, 291, 292. 
Fossils common to the Clinton and Niagara groups, 75. 
Fossils, changes in corresponding to lithological changes,513. 
Fossils, diminution of in the higher groups in a westerly 
direction, 514. 
Foster, J. H., report on the geological survey of Ohio, 25. 
Fourth geological district, limits of, 1; rocks not reaching to 
any previously well known limit downward, 26; physical 
features of, 405; sources of prosperity in, 499. 
Fredonia, 228 ; lighted by gas, 498. 
Freezing water, action in deepening river channels, 375. 
Fucoides, 28, 46, 69, 77, 228, 229, 241, 247, 439, 480. 
Furrows and striae in conglomerate, 286. 
Furrows, oblique, 331. 
Future subdivisions to be made in groups, 3. 
Galena (see Sulphuret of lead), 431. 
Gardeau shale and flagstones, 224, 227, 463, 467. 
Gardeau slide, 463. 
Garnet sand, 426. 
General features of the strata and physical characters of the 
Fourth district, 12, 13. 
Genesee county, rocks of, etc. 464. 
Genesee falls, recession of, 381. 
Genesee flats, 334. 
Genesee river, 124. 
Genesee slate, 188, 226 ; general characters, 218; extent, 
etc. 219; concretions of, 220 ; localities, 220; thickness, 
221; minerals of, 221 ; organic remains, 221; local details 
of, 452, 457, 458, 462, 467, 473. 
Genesee valley, 189, 217, 220, 372. 
Geodes, see Cavities. 
Geodiferous limerock, 80. 
Geology of New-York, knowledge of, previous to the com¬ 
mencement of the present survey, 7. 
