weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1898. 159 
Petrology— Continued. 
Rocks described — Continued. 
Mica-schist, Diller, No. 234. 
Mica-schist, Watson, No. 852. 
Microperthite, Weidman, No. 857a. 
Minette, Diller, No. 234. 
Molyhdenite, Turner, No. 778. 
Monzonite, Cushing, No. 181. 
Nepbeline-syenite, Diller, No. 234. 
Nepheline-syenite, "Washington, No. 851. 
Nevadite, Diller, No. 234. 
Nordmarkice, "Washington, No. 851. 
Novaculite, Branner, No. 97. 
Novaculite, Derby, No. 233. 
Olivine-bearing pyroxene andesite, Diller, No. 
234. 
Oli vine-diabase, Diller, No. 234. 
Oolite, Diller, No. 234. 
Orendite, Diller, No. 234. 
Peat, Diller, No. 234. 
Peridotite, Clements, No. 159. 
Peridotite, Diller, No. 234. 
Peridotite, Pratt, No. 635. 
Phonolite, Diller, No. 234. 
Phyllite, Diller, No. 234. 
Porphyiite, Turner, No. 776. 
Porphyritic theralite, Diller, No. 234. 
Pulaskite. Diller, No. 234. 
Pulaskite-syenite, Washington, No. 851. 
Pyroxenite, Diller, No. 234. 
Quartz -al unite rock, Turner, No. 778. 
Qnartz-amphibole-diorite, Turner, No. 778. 
Quartz-basalt, Diller, No. 234. 
Quartz-diorite, Turner, No. 776. 
Quartzite, Diller, No. 234. 
Quartz-norite-gneiss, Diller, No. 234. 
Quartz-porphyry, Ries, No. 658. 
Quartz-porphyry, Spurr, No. 739a. 
Quartz-porpbyry, Turner, No. 776. 
Quartz-schist, Diller, No. 234. 
Quartz-schist, Watson, No. 852. 
Quartz, vein, Diller, No. 234. 
Residual rocks, Diller, No. 234. 
Rhyolite, Diller, No. 235. 
Rhyolite, Emmons, No. 259. 
Rhyolite, Lindgren, No. 492. 
Rhyolite, Smith, No. 714. 
Rhyolite gneiss, "Weidman, No. 857a. 
Rhyolitic obsidian, Diller, No. 234. 
Rhyolitic perlite, Diller, No. 234. 
Rhyolitic pumice, Diller, No. 234. 
Sand, beach, Diller, No. 234. 
Sand, dune, Diller, No. 234. 
Sandstone, Diller, No. 234. 
Saionite, Diller, No. 234. 
Schist, Becker, No. 56. 
Scoria, Diller, No. 234. 
Serpentine, Diller, Nos. 234, 235. 
Serpentine, Merrill, No. 549. 
Serpentine, Turner, No. 777. 
Shale, Diller, No. 234. 
Sinter, Diller, No. 234. 
Slate, Diller, No. 234. 
Soda-microline, "Weidman, No. 857a. 
Stalactite, Diller, No. 234. 
Staurolitic mica«schist, Diller, No. 234. 
Petrology —Continued. 
Rocks described— Continued. 
Steatite, Diller, No. 234. 
Syenite, Becker, No. 56. 
Syenite, Diller, No. 234. 
Syenite-porphyry, Cushing, No. 181. 
Theralite, Diller, No. 234. 
Thomsonite, "Winchell, No. 923. 
Tinguaite, "Washington, No. 849. 
Trachyte, Diller, No. 234. 
Travertine, Diller, No. 234. 
Tuff, Berkey, No. 73. 
Yolcanic bomb, Diller, No. 234. 
Volcanic dust, Diller, No. 234. 
Volcanic sand, Diller, No. 234. 
Zirkelite, Wadsworth, No. 841. 
Pennsylvania. 
Birdsboro trap quarries, Rand, No. 647. 
Blossburg coal region, Hardt, No. 332. 
Concentric weathering, Hopkins, No. 376. 
Copper traces in Pennsylvania, Lyman, No. 
507. 
Feldspars in serpentine, Hopkins, No. 377. 
Fire clays, Hopkins, No. 378. 
Kansan drift in Pennsylvania, Williams, No. 
886. 
Mountain structures of Pennsylvania, Chit- 
tenden, No. 151. 
Slate regions of Pennsylvania, Merriman, 
No. 555. 
Stone, Day, No. 227. 
Subterranean temperatures at Pittsburg, 
Hallock, No. 328. 
Volcanic rocks of Mesozoic age, Goldsmith, 
No. 302. 
Physiographic Geology. 
An old river channel, Veatch, No. 836. 
Bitter Root Forest Reserve, Goode, No. 303. 
Boise folio, Lindgren, No. 492. 
Canyons of Salmon and Snake rivers, Lind- 
gren, No. 494. 
Changes of level in Mexico, Spencer, No. 726. 
Closing of Michigan glacial lakes, Smyth, No. 
716. 
Coal fields of Puget Sound, Willis, No. 894. 
Coal fields of Indian Territory. Drake, No. 239. 
Cote sans Dessein and Grand Tower, Marbut, 
No. 522. 
Cuba, Hill, No. 353. 
Declivities of high plateau and submarine 
valleys, Spencer, No. 731. 
Development of Ohio River, Tight, No. 765. 
Drift phenomena of Puget Sound, Willis, No. 
896. 
Formations and changes of level in Jamaica, 
Spencer, No. 730. 
Geographic development of District of Colum- 
bia, McGee, No. 515. 
Geological conditions at Portage, N. V., 
Clarke, No. 154. 
Geological history of Panama and CoSta Rica, 
Hill, No. 352. 
Geological reconnoissance in Oklahoma, 
Adams, No. 10. 
Geological section across Indiana, Newsom, 
No. 575. 
