154 
of crystals and possessmany advantages over 
the Mereator’s projection or the ordinary 
maps which are practically pictures without 
definite mathematical proportions. Pro- 
fessor Penfield has constructed a series of 
scales which correspond to the projections 
of arcs by the stereographic method, and 
which enable one to measure distances be- 
tween points of the earth whose latitudes 
and longitudes are known. Great accu- 
racy can be obtained even when the projec- 
tions are made on a circle whose diameter 
is less than six inches. The paper appears 
in the January number of the American 
Journal of Science and should be read by all 
teachers of geography. 
The Paleozoic Limestones of the Kittatinny 
Valley, N. J.: Henry B. Ktmuen, Tren- 
ton, N. J.,.and Sroart WELLER, Chicago, 
Til. 
The Paleozoic limestones of the Kitta- 
tinny Valley are divisible into the Kitta- 
tinny formation beiow and the Trenton 
above. The former is a magnesian lime- 
stone, probably 3,000 feet thick, and ranges 
from lower Cambrian into the Calciferous, 
with no structural or marked lithological 
differences. The Trenton limestone, about 
135 feet thick, carries in its lower beds the 
Black River fauna, making‘it the equivalent 
of the lower Trenton of New York. A con- 
spicuous and widespread basal conglom- 
erate at the bottom of the Trenton rests 
upon the eroded surface of the Kittatinny 
formation. The lithologicaland faunal char- 
acteristics of the formations were described 
and their structural relations shown. The 
extent and importance of the basal con- 
glomerate were outlined. 
In discussion, M. R. Campbell inquired 
if the Trenton conglomerate changed in 
thickness from northwest to southeast. 
Mr. Kimmel replied that it did not, gener- 
ally, although there was some variation in 
that the conglomerate appears to have been 
SCIENCE. 
(N.S. Vou. XIII. No. 317. 
formed at the foot of cliffs. Mr. Campbell 
stated that he had noted somewhat similar 
relations in Virginia, but that the con- 
glomerate appeared on the northwest sides 
of the valleys and not on the southeast. 
He explained it as due to an interval of 
erosion and to the direction of the currents. 
N. S. Shaler cited parallel conditions in 
Kentucky and remarked the tendency of 
the limestones to thicken toward the north- 
west, not only in the Trenton but in the 
Lower Carboniferous and in the Coal Meas- 
ures as well. He explained this by an Ap- 
palachian island to the eastward. J. M. 
Clarke mentioned a basal conglomerate in 
the Trenton near Albany, with fossiliferous 
pebbles containing a different fauna from 
the cement. J. F. Kemp cited a conglom- 
erate of boulders of gneiss enclosed in a 
limestone cement in the thin Trenton 
outlier, within the southern Adirondack 
erystallines, at Wellstown, N. Y. The 
boulders are several inches in diameter, are 
similar to the neighboring gneisses and 
have apparently been dropped by floating 
ice.. T. C. Hopkins remarked the Trenton 
conglomerate of the Nittany Valley, Penn., 
and its likeness to that of New Jersey. 
The Niagara Group along the Western Side of 
the Cincinnati Antichine: Aue. F. Forrsts, 
Dayton, Ohio. 
The paper described the lithology, pale- 
ontology and physiography of the Niagara 
Group, with special reference to Middle Ten- 
nessee. It was the continuation of an inves- 
tigation which had been partially described 
to the Society at a previous meeting, and 
which had for its object the determination 
of the time of upheaval and the structural 
relations of the Cincinnati uplift. Mr. 
Foerste traced the several component strata 
from north to south on both sides of the 
great fold, from Ohio into Central Tennes- 
see, and especially emphasized the excellent 
section presented at Newsome, Tenn. He 
