weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1896. 59 
418 Knowlton (F. H.). The Tertiary Horas of the Yellowstone 
National Park. 
Am. Jonr. Sci., 4th ser., vol. ii, pp. 51-58, 1896. 
Gives a hrief account of the geology of the Park, names the fossil 
plants found in the Tertiary heels, and discusses the relations of the 
present and Tertiary floras. 
419 Report on a collection of fossil plants from Morgan to wn,W.Va. 
Am. Geol., vol. xviii, pp. 370-372, 1896. 
Gives a list of species collected in the Glacial beds of this locality. 
420 Description of a supposed new species of fossil wood from 
Montana. 
Toney Bot. Club., Bull., vol. xxiii, pp. 250-252, pi. 271, 1896. 
Describes Pityoxylon pealei n. sp., from Miocene strata of Montana. 
421 Kraatz (K. von). Note on the formation of gold ore. 
Am. Geol., vol. xviii, pp. 100-108 (translated by N. H. Winchell), 1896. 
Discusses the various theories as to the origin and deposition of gold- 
ore bodies. 
422 Kiimmel (Henry B.). Note on the glaciation of Pocono Knob and 
Mounts Ararat and Sugar Loaf, Pennsylvania. 
Am. Jour. Sci., 4th ser., vol. i, pp. 113-114, 1896. 
Gives the author's recent observations on the glacial geology of the 
region. 
42.3 Ladd (George T.). Notes on certain undescribed clay occurrence 
in Missouri. 
Science, new ser., vol. iii, pp. 691-693, 1896. 
Describes the occurrence of fireclay in the Paleozoic rocks of Missouri. 
424 Lakes (Arthur). Sketch of a portion of the Gunnison gold belt, 
including the Vulcan and Mammoth Chimney mines [Colorado]. 
Am. Inst. Mg. Engrs., Trans., vol. xxvi, pp. 440-448, figs. 1-2, 1896. 
Describes the igneous rocks of the region and the occurrence of 
gold ores. 
425 Cripple Creek [Colorado]. 
Sci. Amor. Suppl., vol. xlvi, pp. 17192-17193, 1896. 
Describes the occurrence of the gold ores of Cripple Creek, Colorado. 
426 The placers of North America. 
Colliery Eng., vol. xvi, pp. 195-197, 1896. 
Describes the character and distribution of placer deposits in differ- 
ent parts of North America. 
427 The Oquirrh Mountains or the Mercur mining district [Utah]. 
Colliery Eng., vol. xvi, pp. 243-245, 1896. 
Describes the geologic features of the region and the occurrence of I he 
gold and silver ores. 
