48 BIBLIOGRAPHY AND INDEX OF N. A. GEOLOGY, [bull. U9. 
311 Hershey (Oscar H.). Pre-Glacial erosion cycles in northwestern 
Illinois. 
Am. Geol., vol. xviii, pp. 72-100, 1896. 
Describes the several peneplains of the region, correlates them with 
others in different parts of the United States and discusses the origin of 
drainage lines. 
312 Hilgard (E. W.). The geologic efficacy of alkali carbonate solution. 
Am. Jour. Sci., 4th ser., vol. ii, pp. 100-107, 1896. 
Describes its occurrence and efficacy as a geologic agent. 
313 Hill (Robert T.). Notes on the geology of Cuba. 
Harv. Coll. Mus. Comp. Zool., Bull., vol. xvi, No. 15, pp. 243-288, 6 pis., 
1895. 
Describes the occurrence of pre-Tertiary metamorphic, igneous, and 
sedimentary rocks, the geologic history of the island as indicated by its 
topography, and the orogenic movements to which it has been subjected. 
314 A question of classification. 
Science, new ser.. vol. iv, pp. 918-922, 1896. 
Discusses the correlation of the so-called Jurassic of the Atlantic 
Coast with the Wealden of Europe, and of the relative importance of 
the evidence presented by Prof. Marsh, of the Jurassic age of the Poto- 
mac formation. 
315 Fundamental geographic relations of the three Americas. 
Nat. Geog. Mag., vol. vii, pp. 175-181, 1896. 
Describes orographic features of the regions. 
316 Hill (Walter Hovey). The Little Giant mine at Warren, Idaho. 
Eng. and Mg. Jour., vol. lxii, p. 417 (£ p.), 1896. 
Gives a brief description of the gold veins of this vicinity. 
317 Hillebrand (W. P.). Remarkable phosphorescence of wollastonite. 
Am. Jour. Sci., 4th ser., vol. i, p. 323 (communicated), 1896. 
Brief note on the phosphorescence of wollastonite. 
318 Hills (R. C). Ore deposits of Camp Floyd district, Tooele County, 
Utah. 
Read before the Colorado Scientific Society, in Denver, Colo., Aug. 6, 
1894, 12 pp. 
Describes the geologic features of the region and the mode of occur- 
rence and character of the gold ores, and discusses their origin. 
319 The Costilla meteorite [New Mexico]. 
Read before the Colorado Scientific Society, in Denver, Colo., Jan. 7, 
1895, 2 pp., 1 pi. 
Describes the characteristics of the meteorite and gives chemical 
analyses of the material. 
320 [Geology of Cripple Creek district, Colorado.] 
In discussion of paper by Whitman Cross on the same subject. See 
No. 150. 
321 Hitchcock (C. H.). Champlain Glacial epoch. 
Abstract: Geol. Soc. Am., Bull., vol. vii, pp. 2-4, 1896. 
Correlates the divisions of the Ice Age by James Geikie with those of 
North America and describes the glacial phenomena of the Champlain 
epoch. 
