MARYLAND GEOLOGICAL SURVEY 295

KUNZ, G. F. Precious Stones.

Mineral Resources U. S., 1883-84, Washington, 1885.

Mentions Harford county serpentine, p. 776; and also amber from Cape Sable and
Chesapeake and Delaware Canal based on Troost's paper in Amer. Jour. Sci. 1832,
p. 780.

McGEE, W J The Geology of the District.

Evening Star, Washington, July 11, 1885.

Regards the Potomac as the American equivalent of the European Neocomian.

ROBINSON, T. The Strata exposed in the East Shaft of the Water
Works Extension. (Abst.)

Bull. Phil. Soc., Washington, vol. vii, 1885, pp. 69-71.

SCHARFE, WALTER R. The Boundary Dispute between Maryland
and Pennsylvania.

Pennsylvania Mag. Hist., vol. ix, 1885, pp. 241-271.

SPENCER, J. W. Occurrence of Boulders of Decomposition at
Washington, D. C., and elsewhere.

Amer. Nat., vol. xix, 1885, pp. 163-165.

Considers the bearing of decomposition boulders upon the glacial drift.

SWAIN, GEO. F. Report on the water power of the Middle Atlantic
Water-shed.

Tenth Census, vol. xvi, Washington, 1885, pp. 513-660.

Describes the topography, flow, and fall of the principal rivers of Maryland, etc.,
p. 142.

SWANK, JAS. M. Iron ores in the United States.
Mineral Resources U. S., 1883-84, Washington, 1885.

Statistics of pig iron, 1880-84, p. 252. Simply says, " Very little Bessemer pig iron
has been made in Maryland."

WILBUR, F. A. Clays.

Mineral Resources U. S., 1883-84, Washington, 1885.

Mentions clay belt. " Brick made from this clay are noted for their great hardness
and cherry-red color," p. 696. Gives characteristics of pottery made from, clays of
Howard and Anne Arundel counties, p. 700.

WILLIAMS, JR. A. (Editor). Infusorial Earth.

Mineral Resources U. S., 1883-1884, Washington, 1885, p. 720.
Gives occurrence and analysis of " tripoli " from near Dunkirk, Calvert county.
Subsequent remarks (M. R., 1885) show that the output was not over 250 tons in 1885.

WILLIAMS, GEORGE H. Dykes of apparently Eruptive Granite in
the neighborhood of Baltimore.

Johns Hopkins Univ. Cir. No. 38, vol. iv, 1885, pp. 65-66.

Describes the pegmatic dykes at Jones Falls, Orange Grove, Ilchester, Relay and
Avalon.