MARYLAND GEOLOGICAL SURVEY 299

————Ovibos cavifrons from the Loess of Iowa.

Amer. Jour. Sci., 3rd ser., vol. xxxiv, 1887, pp. 217-220.

A brief discussion of the conditions along the Middle Atlantic slope during Qua-
ternary time. All notes on the size of the boulders deposited in the Susquehanna,
Patapsco and Potomac deltas in Quaternary time.

STEVENSON, JOHN J. Notes on the Lower Carboniferous groups
along the easterly side of the Appalachian area in Pennsylvania and
the Virginias.

Amer. Jour. Sci., 3rd ser., vol. xxxiv, 1887, pp. 37-44.

General discussion of the " Umbral " and " Vespertine," containing notes on the
" Umbral " of Maryland, pp. 42-44.

SWANK, JAS. M. The American Iron Trade in 1886.
Mineral Resources U. S., 1886, Washington, 1887.
Gives statistics on production of iron for the year 1886, p. 18.

———— The American Iron Industry from its Beginning in 1619
to 1886.

Idem, pp. 23-38.

Gives a few Interesting historical details concerning the iron industry of Maryland
in early times.

WHITE, I. C. Rounded Boulders at High Altitudes along some
Appalachian Rivers.

Amer. Jour. Sci., 3rd ser., vol. xxxiv, 1887, pp. 374-381.

Especially pp. 279 and 80 which deal with the bowlders on the eastern side of the
Alleghanles. Considers these deposits to be due to different causes; submergence about
Washington—even to Cumberland—ice dams (Wright) on western slopes, and snow slides
which dammed the mountain streams.

WILLIAMS, G. H. On a Plan Proposed for Future Work upon the
Geological Map of the Baltimore region.

Johns Hopkins Univ. Cir. No. 59, 1887, pp. 122-123.

———— Notes on the minerals occurring in the neighborhood of
Baltimore. 18 pp. Baltimore, 1887.

The minerals are described " in preliminary way " and are enumerated according to
their paragenesis in seven classes.

1888.

ANON. Provisions for establishing meridian lines in the State of
Maryland and for observing the magnetic variation. Maryland Code,
vol. i, pp. 424-426. 1888.

ASHBURNER, CHAS. A. Coal.

Mineral Resources U. S., 1887, Washington, 1888, pp. 169, 171, 177, 263-
270, 337.

Statistics of coal trade, wages and shipment.