INDEX. 
C39 
TRIAS. 
Trias of the United States, 381. 
Triassic mammifer, North Carolina, 383. 
Triclinic feldspars, 501. 
Tridymite, crystallized silica, 500. 
Trigonellites latus, Kimmeridge clay, 336. 
Trigonia caudata, Neocomian, 310. 
- gibbosa, Portland stone, 335. 
Trigonocarpum ovatum^ and T. olivceforme, 
Coal, 429. 
Trigonotreta undulata^ Permian, 388. 
Tri'lobites of Bala and Caradoc beds, 471. 
-, metamorphosis of, 471, 4S8. 
-of primordial zone, 487. 
TrilocuUna injlata, Eocene, 275. 
Trimmer, Mr., on contorted strata, 179. 
-, on shells of Moel Tryfaen, 186. 
Trinucleus concentricus, T. Caractaci, 472. 
Trionyx, carapace of, Bembridge, 253. 
Tripoli composed of diatomacese, 51. 
Trochoceras giganteus, Ludlow, 463. 
Trophon antiquum {Fusus contrarius), 196. 
- clathratum, Scotch drift, 176. 
Tuff defined, 30. 
-, shelly, of the Grand Canary, 538. 
-, trappean, of Llandeilo rocks, 473. 
-, shelly, of Gergovia, 542. 
Tiqjaia Tayia, recent, 347. 
Turner, Dr., on chemical decorappsition, 
68 . 
Turrilites costatus, Chalk, 299. 
Turritella multisulcata, Bracklesham, 262. 
Tuscany, mineral springs of, 604. 
Tylor, Mr., on amount of subaerial denu¬ 
dation, 114. 
Tyndall, Dr., on slaty cleavage, 594. 
Tynedale fault, 90. 
Tynemouth cliff, brecciated limestone of, 
387. 
Typliis pungens, Barton clay, 259. 
ZINCITES Gryphus, Devonian, 452. 
Unconformability of strata, 94,138. 
Underlying, term applied to plutonic rocks, 
34. 
Unger on American forms in. Swiss Mio¬ 
cene flora, 223, 239. 
-on Miocene plants of Croatia, 243. 
Ungulite, or Obolus grit of Eussia, 477. 
JInio littoralis, 54. 
- Valdensis, Hastings Sands, 317. 
United States, Cambrian of the, 489. 
-, cretaceous rocks of, 307. 
-, Devonian of, 455. 
-, Eocene strata in the, 278. 
-, foot-prints in Carboniferous of, 407. 
-, Lower Miocene of, 248. 
-, Older Pliocene and Miocene forma¬ 
tions of, 227. 
-, Silurian strata of, 478. 
-, Trias of the, 381. 
Upheaval of land more than counteracted 
by subsidence, 116. 
-, power of denudation to counteract, 
105,115. 
Upper Greensand, or Chloritic series, 298. 
Upsala, erratics on modern marine drift 
near, 174. 
Ural Mountains, auriferous alluvium of, 
616 
Uralite, 499. 
U sus spelceus, tooth of, 165. 
Urville, Captain de, on size of icebergs, 172. 
VOLUTA. 
VAL D’AENO, Newer Pliocene of, 207. 
Valleys, origin of, 102. 
Valorsine, granite veins in talcose gneiss 
in, 599. 
Valvata piscinalis, 55. 
Vayiessa Pluto, Lower Miocene, Croatia, 
243. 
Vegetation of the Coal, 420. 
-of the Devonian of America, 455. 
-. See Plants. 
Veins, chemical deposits in, 612. 
-, granite rocks altered by, 559. 
-, different kinds of minerals, 605. 
- See Mineral veins. 
Vein-stones, 610. 
Venericardia planicosta, 260. 
Venetz, M., on Alpine glaciers, 170. 
Ventriculites radiatus, Chalk, 292. 
Verneuil, M. de, on Eussian Silurian, 462. 
-, on Permian flora, 392. 
Vertebrata, progress of discovery of fossil, 
464. 
Vertical strata, 73. 
Vesuvius, Eecent and post-Pliocene vol¬ 
canic rocks of, 525. 
-, basaltic lavas of, 508. 
-, tufaceous strata of, 522. 
-, dikes of, 527. 
Vicarya Lujani, Punfield, 319. 
Vicentin, columnar basalt of the, 511. 
Vienna Basin, Upper Miocene beds of, 224. 
Vine in Upper Miocene beds at (Eningen, 
221. 
Virginia, eighty miles of fault in, 92. 
-coal-field of, 382. 
Virlet, M., on corrosion of rocks near Cor¬ 
inth, 586. 
-on cretaceous traps of Greece, 544. 
-, on fossils in veins, 608. 
-, on volcanic rocks of the Morea, 544. 
Volcanic ash or tuff^ 508. 
-breccia, 509. 
-dikes, 513-516. 
-force and denudation opposing pow¬ 
ers, 117. 
-mountains, structure and origin of, 
494. 
Volcanic rocks defined, 29. 
-, mineral composition of, 498. 
-, Eecent and post-Pliocene, 524. 
-, Pliocene, 529. 
-, Miocene, 536-543. 
—-, Eocene, 543. 
-, Cretaceous and Liassic, 544, 545. 
-, New Eed, Permian and Carbonifer¬ 
ous, 545. 
-, Old Eed Sandstone, 547. 
-, Silurian, Cambrian and Laurentian, 
548, 549. 
-of Auvergne, 640. 
-, columnar and globular, structure of, 
510. 
-of Grand Canary, 528. 
-of Silurian age, 477. 
-, special forms of structure of, 506. 
-, tests of age of, 520-524. 
Volcanoes, extinct, 30. 
-of Auvergne, 495. 
Voltzia heterophylla, Bunter, 380. 
Voluta ambigua, Barton clay, 259. 
- athleta, Barton, 259. 
- Lamherti, coralline and red crag, 196. 
