MARYLAND GEOLOGICAL SURVEY 293

WEBSTER, A. L. On an excursion Map of Baltimore and its neigh-
borhood.

Johns Hopkins Univ. Cir. No. 30, vol. iii, 1884, p. 80.

Gives an account of the sources and formation of the Field Club map.

WEEKS, JOSEPH D. Eeport on the Manufacture of Coke.

Tenth Census, vol. x, Washington, 1884.

For manufacture and use of coke in Maryland, see p. 25.

WHITE, C. A. A review of the Fossil Ostreidae of North America,
and a comparison of the Fossil with Living Forms. Appendix I by
Angelo Heilprin: North American Tertiary Ostreidae. Appendix
II by John A. Rider: A Sketch of the Life History of the Oyster.

4th Ann. Rept. U. S. Geol. Surv., 1882-83, Washington, 1884, pp. 281-430.

(See Heilprin.)

WILLIAMS, GEORGE Pl. Preliminary notice of the Gabbros and
Associated Hornblende rocks in the vicinity of Baltimore.

Johns Hopkins Univ. Cir. No. 30, vol. iii, 1884, pp. 79-80.
Distinguishes and describes " Anorthlte amphibolite " and olivine bronzite gabbro.

———— Note on the so-called Quartz Porphyry at Hollins Sta. north
of Baltimore.

Johns Hopkins Univ. Cir. No. 32, vol. iii, 1884, p. 131.

Shows Tyson's " quartz porphyry is an autoclastic rock formed from adjacent gneiss
during dynamic metamorphism."

WINSOR, JUSTIN (Editor). A Narrative and Critical History of
America. Vol. iii. English Explorations and Settlements in North
America, 1497-1689. Houghton, Mifflin & Co., Boston, 1884.
pp. 127-169, 517-562.

Contains interesting notes on the gradual recognition of the resources and physical
features of the state. Chapter on Maryland by W. T. Brantly; that on Virginia by R.
A. Brock.

1885.
ANON. General Mining News—Maryland.

Eng. and Min. Jour., vol. xl, 1885, p. 422.

Purchase of Frederick county property by a California mining company.

——— General Mining News—Maryland.
Eng. and Min. Jour., vol. xl, 1885, p. 294.
Search for silver ore in the vicinity of Cumberland.

ARMSTRONG, S. C. (compiler). Coal.
Mineral Resources U. S., 1883-84, Washington, 1885.

General remarks on George's Creek Coal field, pp. 49-50; statistics on coal product,
1880-1884, p. 12.