80 BIBLIOGRAPHY OF NORTH AMERICAN GEOLOGY, 1906-1907. 
Geinitz, F. E. 
937. Die Eiszeit. — Die Wissenschaft : Sammlung naturwissenschaftlicher 
und inathernatischer Monographien, Heft 16, Braunschweig, Friedrich Vieweg 
und Sohn, 1906. 198 pp., 3 pis., 25 figs. 
Includes a chapter on the glacial period in North America. 
Gentil, L. 
938. [Sur les cendres rejetees par le volcan de la Montague Pel0e le 3 inai 
1902.— Soc. geol. de France, Bull., 4 e ser., t. 2, pp. 320-321, 1002. 
Describes the character of rocks ejected by Mont Pele. 
George, H. C. 
939. The Nipissing mine, Cobalt, Ontario. — Eng. and Min. Jour., vol. 82, pp. 
967-968, November 24, 1906. 
Describes the occurrence of the ores. 
George, R. D. 
940. Polished pebbles. — Science, new ser., vol. 25, pp. 626-627, April 19, 
1907. 
Gibson, Thomas W. 
941. Report of the [Ontario] Bur. Mines, 1907, vol. L6, pt. 1, 248 pp., illus., 
1907. 
Gidley, James Williams. 
942. Evidence bearing on tooth-cusp development. — Washington Acad. Sci.. 
Proc, vol. 8, pp. 91-106, 2 pis., 2 figs., 1906. 
943. A new genus of horse from the Mascall beds, with notes on a small 
collection of ecpiine teeth in the University of California. — Am. Mus. Nat. Hist., 
Bull., vol. 22, pp. 386-388, 2 figs., 1906. 
944. A fossil raccoon from a California Pleistocene cave deposit. — U. S. 
Nat. Mus., Proc, vol. 20. pp. 553-554, 1 pi., 1006. 
945. A new ruminant from the Pleistocene of New Mexico. — U. S. Nat. Mus., 
Proc, vol. 30, pp. 165-167, 3 figs., 1906. 
946. Now or little known mammals from the Miocene of South Dakota. — 
Am. Mus. Nat. Hist., Bull., vol. 22, pp. 135-153, 20 figs., 1906. 
947. A new horned rodent from the Miocene of Kansas. — TJ. S. Nat. Mus., 
Proc, vol. 32, pp. 627-636, 8 pis., 1 fig., 1907. 
948. Revision of the Miocene and Pliocene Equidse of North America. — Am. 
Mus. Nat. Hist., Bull., vol. 23, pp. 865-934, 1907. 
Gilbert, Grove Karl. 
949. The cause and nature of earthquakes. — Min. and Sci. Press, vol. 92, 
pp. 272-273, April 28, 1906. 
950. The investigation of the San Francisco earthquake. — Pop. Sci. Monthly, 
vol. 69, no. 2, pp. 97-115, 14 figs., August, 1906. See also Jordan, D. S., no. 1325. 
951. Crescentic gouges on glaciated surfaces. — Geol. Soc. America, Bull., 
vol. 17, pp. 303-316, 1906. 
Describes the occurrence and character of these markings and gives an explanation 
of their origin. 
952. Moulin work under glaciers. — Geol. Soc. America, Bull., vol. 17, pp. 317- 
320, 3 pis., 1906. 
Poscribps a certain type of rock sculpturing and explains how it was produced by 
the moulin work of a glacier. 
953. Gravitational assemblage in granite. — Geol. Soc America, Bull., vol. 17, 
pp. 321-328, 4 pis., 1 fig., 1906. 
Describes the localization of phenocrysts of feldspar and of hornblende, and of other 
phenomena in granite in the Sierra Nevada Mountains, and explains their assemblage 
as due to gravitational force. 
