weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1901. 31 
199 Darton (Nelson Horatio). Comparison of stratigraphy of the 
Black Hills with that of the Front range of the Rocky 
Mountains. 
Abstracts: Geol. Soc. Am., Bull., vol. 12, p. 478 (| p.), 1901; Science, 
new ser., vol. 13, p. 188, 1901. 
200 - - and Keith (Arthur). Washington Folio, Dist. of Columbia, 
Maryland, Virginia. 
U. S. Geol. Surv., Geol. Atlas of U. S., Folio No. 70, 1901. 
Describes geographic and topographic features, the character and 
occurrence of Archean rocks and of the Cretaceous, Eocene, Neocene, 
and Pleistocene strata, the general structure of the Piedmont and ( !< >astal 
plain regions, and mineral resources of the area. 
201 Davis (Charles A.). A second contribution to the natural history 
of marl. 
Jour. Geol., vol. 9, pp. 491-506, 1901. 
Abstract: Am. Geol, vol. 27, p. 186, 1901. 
202 Davis (William M.). An excursion to the Grand Canyon of the 
Colorado. 
Harv. Coll., Mus. Comp. Zool., Bull., vol. 38, pp. 108-201, pis. 1-2, 
figs. 1-18, 1901. 
Abstracts: Geol. Soc. Am., Bull., vol. 12, p. 483 (1 p.), 1901; Geol. 
Mag., new ser., dec. 4, vol. 8, p. 324, 1901; Science, new ser., vol. L3, 
p. 138, 1901. 
Describes the denudation and displacements of the region and dis- 
cusses the origin of the drainage system. 
203 Peneplains of central France and Brittany. 
Abstract: Geol. Soc. Am., Bull., vol. 12, pp. 480-487, pis. 44-45, 1901. 
Discusses the theory of peneplains. 
204 Note on river terraces of New England. 
Abstract: Geol. Soc. Am., Bull., vol. 12, pp. 483-485, 1 fig., 1901. 
Discusses the formation of these terraces. 
205 Current notes on physiography. 
Science, new ser., vol. 13, pp. 152-15:5, L901. 
Contains notes on the Dalles of the Wisconsin and the islands of 
southern California. 
206 Current notes on physiography. 
Science, new ser., vol. 13, pp. 275 276, L901. 
Contains abstract of paper by H. W. Turner on the origin of Yosemite 
Valley. 
207 Current notes on physiography. 
Science, new ser., vol. 13, pp. 351 352, L901. 
Contains abstracts of papers by I. C. Russell on the geology of the 
Cascade Mountains and by W. T. Lee on the glacier oi Mt. Arapahoe, 
