MARYLAND GEOLOGICAL SURVEY 327

MIDDLETON, JEFFERSON. Statistics of the Clay-Working Industries
of the United States in 1894.

16th Ann. Eept. U. S. Geol. Surv. 1894-95, part iv, Washington, 1895, pp.
517-522.

MITCHELL, JAMES A. The discovery of Fossil Tracks in the New-
ark System (Jura-Trias) of Frederick county, Maryland.

Johns Hopkins Univ. Circ. No. 121, vol. xv, 1895, p. 15.

The forms are undoubtedly reptilian and belong to the group of the dinosaurs.
Brief account of their geological occurrence near Emmitsburg.

NEWALL, F. H. Report of Progress of the Division of Hydro-
graphy, 1893-94.

Bull. U. S. Geol. Surv., No. 131, 1895.

House Misc. Doc., 54th Cong., 1st sess., vol. —, No. 318.

"Potomac basin in Maryland, Virginia and West Virginia," stations at Cumberland,
Point of Rocks and Chain Bridge, pp. 87-89.

PARKER, E. W. Coal.

16th Ann. Rept. U. S. Geol. Surv., 1894-95, part iv, Washington, 1895.
Test of Cumberland coal, p. 54; coal in Maryland, pp. 132-137.

———— Mineral Paints.

Idem.
Statistics, p. 696.

PEALE, A. C. Mineral Springs.

Idem.

Mineral springs in Maryland, p. 713.

POWELL, J. W. Physiographic regions of the United States.
The Physiography of the United States.

Geographic Monographs, vol. i, American Book Co., 1896, pp. 65-100, map.
Pages 73-80 deal with the different physiographic regions present in Maryland.

RIES, HEINRICH. Technology of the Clay Industry.

16th Ann. Rept. U. S. Geol. Surv., 1894-95, part iv, Washington, 1895, pp.
523-575.

ROBERTS, D. E. Note on the Cretaceous Formations of the Eastern
Shore of Maryland.

Johns Hopkins Univ. Cir. No. 121, vol. xv, 1895, p. 16.

Enumerates fossils found at various localities which establish the identity of the
Cretaceous on the Eastern Shore.

SWANK, JAMES M. Steel and Iron Industries.

16th Ann. Eept, U. S. Geol. Surv., 1894-95, part iii, Washington, 1895, pp.
219-250.

Maryland statistics, p. 221.