--The Deep Well at Minneopa, Minnesota. 3 pp.--Bull. Minn. Acad. Nat. Sci., Vol. III., No. 2. HALLOCK, WILLIAM. --Preliminary Report of Observations at the Deep Well at Wheeling, W. Va. 3 pp.--Proc. A. A. A. S. 1891. --(and F. Kohlrausch.) --Ueber den Polabstand, den Inductions--und Temperatur--Coefficient eines Magnetes und ueber die Bestimmung von Trägheitsmomenten durch Bifilarsuspension. 20 pp.--Nachrichten Koenigliche Gesellschaft der Wissenschaften, 1883. HATCHER, J. B. --The Titanotherium Beds. 18 pp., Ill.--Am. Naturalist. 1893. --The Ceratops Beds of Converse County, Wyoming. 10 pp.--Am. Jour. Sci. Feb. 1893. HAY, O. P., PH.D. --The Northern Limits of the Mesozoic Rocks in Arkansas. 30 pp.--Annual Report Geol. Surv. Ark. 1888. HOBBS, WM. H. --Secondary Banding in Gneiss. 6 pp. 1 pl., Ill.--Bull. Geol. Soc. Am., 1891. --Notes on a Trip to the Lipari Islands. 12 pp. 1 pl., Ill.--Wis. Acad. Sci., 1892. --On Intergrowths of Hornblende with Augite in Crystalline Rocks. 1 p.--Science, Dec. 23, 1892. --Phases in the Metamorphism of the Schists of Southern Berkshire. 12 pp. 1 pl., Ill.--Bull. Geol. Soc. Am., Feb. 1893. HOLMES, W. H. --Geology of the Elk Mountains, Col. (1874.) --Geology of Southwestern Colorado. (1875.) --Geology of the Yellowstone Park. (1880.) HOLST, N. O. --Matricit och Marmairolit, tvaenne nya Mineralier fran Vermland. 5 pp.--Aftryck ur Geologiska Föreningens i Stockholm Förhandlingar, 1875. --Om de glaciala rullstensasårne. 16 pp.--Ibid., 1876. --Klotdiorit fran Slättmossa, Järeda socken, Kalmar län. 10 pp. 1 pl.--Ibid., Bd. VII. --Om Ett Fynd af Uroxe i Rakneby, Ryssby Sockenk Kalmar län. 21 pp. 2 pl.--Ibid., Bd. X, 1888. --Hvem fann den norrlandska andesiten? 6 pp. Ibid.--Bd. X, 1888. --Om en Mäktig qvarsit, yngre än olenus-skiffer. 3 pp.--Ibid. Bd. XI, 1889. --Om en nyupptäckt fauna i block af kambrisk sandsten, insamlade af dr N. O. Holst af Joh. Chr. Moberg. 18 pp. 1 pl.--Ibid., Bd. XIV, 1892. --Bidrag till Kännedomen om Lagerföldjen inom den Kambriska Sandstenen. 17 pp. --Ryoliten vid Sjoen Mien. 52 pp. 1 pl., Ill. --Berättelse om en ar 1880, i Geologiskt Syfte Foretagen Resa Till Groenland. 74 pp. 1 map, 1880. HOVEY, EDMUND OTIS. --Observations on some of the Trap Ridges of the East-Haven--Branford, (Ct.) Region. 23 pp. 1 pl.--Am. Jour. Sci., Nov. 1889. HYATT, ALPHEUS. --Remarks on the Pinnidae. 12 pp. --Jura and Trias at Taylorville, California. 18 pp.--Bull. Geol. Soc. Am., Vol. III, 1892. IDDINGS, J. P. --Obsidian Cliff, Yellowstone National Park. 48 pp. 9 pl., 1888. 7th Annual Rept. U. S. G. S. --On the Crystallization of Igneous Rocks. 50 pp.--Phil. Soc. Washington, Vol. XI, 1889.