304 BIBLIOGRAPHY AND CARTOGRAPHY

HOBBS, WM. H. On the Paragenesis of the Allanite and Epidote
as Rock-forming Minerals.

Amer. Jour. Sci., 3rd ser., vol. xxxviii, 1889, pp. 223-228.
(Abst.) Amer. Nat., vol. xxiii, 1889, p. 721.

A study of the epldote-allanite iutergrowths found in the porphyritic granites of
Ilchester, Md.

KNOWLTON, F. H. Fossil Wood and Lignites of the Potomac For-
mation. (Read before Amer. Assoc. Adv. Sci. 1888.)

Amer. Geol., vol. iii, 1889, pp. 99-106.

Occurrence at Ft. Washington, White House Landing, Washington City, Baltimore,
etc., pp. 101-103. Determination of the trees, pp. 104 et seq. Resume of Bull. U. S.
Geol. Surv. No. 50.

(Abst.) Proc. Amer. Assoc. Adv. Sci., vol. xxxviii, 1889, pp. 206-208.

Amer. Geol., vol. iv, 1890, p. 324.

———— Fossil Wood and Lignite of the Potomac Formation.

Bull. U. S. Geol. Surv. No. 56, Washington, 1889.

House Misc. Doc., 51st Cong-., 1st sess., vol. xxxii, No. 244.

Maryland references, pp. 38-43.

McGEE, W J The Geological Antecedents of Man in the Poto-
mac Valley.

Amer. Anth., vol. ii, 1S89, pp. 227-234.

Gives an account of the geological, topographic and climatic history of the Potomac
from Mesozoic time.

———— Administrative Reports. Geologic and Paleontologic In-
vestigations.

8th Ann. Rept. U. S. Geol. Surv., 1886-1887, Washington, 1889, pt. i, p. 167.

MARSH, O. C. Administrative Reports. Geologic and Paleonto-
logic Investigations in Maryland.

9th Ann. Rept, U. S. Geol. Surv., 1887-88, Washington, 1889, pp. 114-115.

The results proved conclusively that the Potomac, as shown in the typical localities
in Maryland, is of Upper Jurassic age, and contains a rich and varied vertebrate fauna.

MERRILL, G. P. The Collection of Building and Ornamental
Stones in the U. S. National Museum.

Smithsonian Rept., 1886, pt, ii, 1889, pp. 277-648, plates 1-9.
Over twenty references to Maryland building stone resources.

MEYER, OTTO. Upper Tertiary Invertebrates from the West Side
of Chesapeake Bay. (Read Aug. 1888.)

Proc. Acad. Nat. Sci., Phila., 1888, vol. xl, 1889, pp. 170-171.
Describes Allgena sharpi (n. sp.) and others, but the localities are indefinite, possibly
from Yorktown, Va.