290 BIBLIOGRAPHY AND CARTOGRAPHY

AYDELOTT, WM. T. Report of Commissioner of Maryland for
Surveying and Marking the Boundary Line between the States of
Maryland and Virginia. Annapolis, 1884. 22 pp.

Md. House and Senate Doc., 1884, K.

BROWN, T. Report of T. Brown, Inspector of Mines for Allegany
and Garrett counties. Annapolis, 1884. 64 pp.
Md. House and Senate Doc., 1884, D.

CHESTER, FREDERICK D. The Quaternary Gravels of Northern
Delaware and Eastern Maryland, with map.

Amer. Jour. Sci., 3rd ser., vol. xxvii, 1884, pp. 1S9-199.

The author divides the formations into the Philadelphia Clay and the Red Gravels
and concludes that at the close of the Glacial period the land was depressed at least
350 feet.

———— Preliminary notes on the Geology of Delaware—Lauren-
tian, Paleozoic, and Cretaceous Areas.

Proc. Acad. Nat. Sci., Phila., vol. xxxiv, 1884, pp. 237-259.
This paper describes the area adjoining Maryland and shows the relationship of
the Maryland deposits to those of New Jersey.

CLARKE, F. W. Report of work done in the Division of Chemistry
and Physics. 1883-84.

Bull. U. S. Geol. Survey No. 9, Washington, 1884, p. 9.

Also House Misc. Doc., 48 Cong., 2nd Sess., vol. xvi, No. 41.

Analysis by T. M. Chatard of gahnite from near Colesville, Montgomery county.

FRAZER, P., JR. The Peach Bottom Slates of Southeastern York
and Southern Lancaster Counties.

Trans. Amer. Inst. Min. Eng., vol. xii, 1884, pp. 355-358. Plates and
section.

(Abst.) Amer. Jour. Sci., 3 ser., vol. xxix, 1884, p. 70.

Discussion of a section along the Susquehanna river northward from the Maryland
line. Also a letter from Prof. James Hall regarding the probable age of the slates,
which he considers are either the Hudson river or the Quebec group from the presence
of forms allied to Holymenites, Lamnantes lagranger and graptolithus.

———— An Hypothesis of the Structure of the Copper Belt of the
South Mountain.

Trans. Amer. Inst. Min. Eng., vol. xii, 1884, pp. 82-90, map.

GANNETT, HENRY. A Dictionary of Altitudes in the United States.
Bull. U. S. Geol. Survey No. 5, Washington, 1884, pp. 129-132.
House Misc. Doc., 48th Cong., 2nd sess., vol. xvi, No. 41.
A large number of altitudes is given.

HEILPRIN, ANGELO. Contributions to the Tertiary Geology and
Paleontology of the United States. 4to. 117 pp., map. Phila. 1884.