12 Bulletin y 68 



Silurian Formation in Central Virginia. 



Amer. Jour. Sci., 3d ser., vol. xviii, p. 16-29, sec^tions, 

 1879. 



(Silurian Rocks of the Great Valley of Virginia with 

 Their Subdivisions, Compared with Equivalent Epochs 

 of Dana's Manual, p. 142. Ibid. p. 29). 



On Dufrenite from Rockbridge County, Virginia. 



Amer. Jour. Sci., 3d ser., vol. xxii, pp. 65-67, 1881. 



Geology and Mineral Resources of the James River Val- 

 ley, Virginia. (New York, 8°, 119 pp , map, 1883). 

 Geol. Record, 1880-84 inch, London, 1888, p. 353. 



Geology of the Blue Ridge near. Balcony Falls, Virginia. 



A modified View. 



Amer. Jour. Sci., vol. xxviii, 3d ser., pp. 221-223, 1884. 

 Geol. Record, i88o-'84 incl., London, 1888, p. 353. 



Campbell, J. ly. & H. D,, Report on the Snowdon Slate 

 Quarries, Virginia. ("Virginia," 4 pp., map, 1884). 

 Geol. Record, 1880-84 incl., London, 1888, p. 353. 



William B. Rogers' Geology of the Virginias. A Re- 

 view. 



Amer. Jour. Sci., vol. xxx, 3d ser., pp. 357-374, 1885. 

 Ibid., vol. xxxi, 3d ser., pp. 193-202, 1886. 



Geological notes for Railway Stations, Mainly in the 



Western Part of the State. 



McFarlane's Geol. Ry. Guide, 1890, 2d ed., pp. 383-385. 



Campbell, M. R., The Big Stone Gap Coal Field of Vir- 

 ginia and Kentucky. (A discussion of the paper of James 

 M. Hodge, p. 922). 



Trans. Amer. Inst. Min. Engrs. , vol. xxi, pp. 1004- 1005, 

 1892-93. 



Geology of the Big Stone Gap Coal Field of Virginia 



and Kentucky. 



Bull. U. S. Geol. Surv., No. iii, pp. v & 106, 3 pis., 6 

 maps, 1893. 



(Absi.) Amer. Geol., vol. xiv, pp. 392-393, 1894. 



Tertiary Changes in the Drainage of Southwestern Vir- 

 ginia. 



Amer. Jour. Sci., 3d ser., vol. xlviii, pp. 21-29, maps, 

 1894. 



