EXTINCT AND EXISTING GLACIERS OF COLORADO 7 1 



Crosby, W. 0., "The Hanging Valleys of Georgetown, Colorado," Amer. Geol., 

 Vol. XXXII, pp. 42-48, 1903; Tech. Quart., Vol. XVI, pp. 41-50, 1903- 



Cross, Whitman, Pike's Peak Folio, No. 7, Geologic Atlas of the United States, 

 U.S. Geol. Surv., 1894. 



, "General Geology," Telluride Folio, No. 57, Geologic Atlas of the United 



States, U.S. Geol. Surv., pp. 13-1S, 1899. [Reports neve] 

 -, See also under Howe and Cross. 



Cross, Whitman, and Howe, Ernest, "Geography and General Geology of the 

 Quadrangle," Silverton Folio, No. 120, Geologic Atlas of the United States, 

 U.S. Geol. Surv., pp. 1-25, 1905. 



^ "Topography and Geology," Needle Mountain Folio, No. 131, Geologic 



Atlas of the United States, U.S. Geol. Surv., pp. 1-12, 1905. 

 -, "Geography and General Geology of the Quadrangle," Ouray Folio, 



No. 153, Geologic Atlas of the United States, U.S. Geol. Surv., pp. 1-15, 1907- 

 Cross, Whitman, and Spencer, Arthur Coe, "Description of the La Plata 

 Quadrangle," La Plata Folio, No. 60, Geologic Atlas of the United States, U.S. 

 Geol. Surv., pp. 1-12, 1899. 

 Daly, Reginald A., "The Accordance of Summit Levels among Alpine Moun- 

 tains: The Fact and Its Significance," Journ. Geol., Vol. XIII, pp. 105-25, 

 1905. [Discusses sculpturing of mountains by glaciers.] 

 Dartt, Mary, On the Plains and among the Peaks: or. How Mrs. Maxwell Made 

 Her Natural History Collection, Claxton, Remsen & Heflfelfinger, Philadelphia, 



1879. 

 Davis, W. M., "Glacial Erosion in the Sawatch Range, Colorado," Appalachta, 



Vol. X, pp. 392-404, 1904. 

 , "Glaciation of the Sawatch Range, Colorado," Bull. Mus. Compar. Zool., 



Harvard Coll., Vol. XLIX, pp. i-ii, 1905- 

 -, "Hanging VaUeys in General," Science, N.S. Vol. XXV, pp. 835-36, 



1907. [Contains bibliography of papers on main-vaUey troughs "regarded 



as the results of glacial erosion," and especially refers to La Plata Peak, 



Colorado.] 

 Emmons, Samuel Franklin, "Abstract of Report on Geology and Mining 



Industry of Leadville, Lake County, Colorado," Second Ann. Kept. U.S. 



Geol. Surv., for 1880-81, pp. 203-87, 1882. 

 , Geology and Mining Indiistry of Leadville, Colorado, U.S. Geol. Surv., 



Mon., Vol. XII, 1886. 

 , "On Glaciers in the Rocky Mountains," Proc. Colo. Sci. Soc, Vol. II, 



pp. 211-27, 1888. 

 "Pleistocene Geology," Geology of the Denver Basin, in Colorado, U.S. 



Geol. Surv., Mon., Vol. XXVII, pp. 255-74, 1896. 

 , Tenmile Folio, No. 48, Geologic Alias of the United States, U.S. Geol. Surv., 



