8 [232] A. Winchell on Fossils from the Potsdam, etc. 
stems are an inch, and a quarter in diameter; the transverse sec¬ 
tion oblong, rounded at. the ends, or, in other cases, more nearly 
a circle. The branches are uniformly much smaller than the 
main stem, and leave it at an angle of about 30°. One of the 
most marked peculiarities of the species is the somewhat regular 
transverse constrictions, which occur at intervals of about half 
an inch, in most of the specimens. At these constrictions the 
fucoid has shown a disposition to separate, so that most of the 
fragments present sharply truncate extremities. Surface smooth. 
This fucoid is found abundantly scattered over the surfaces of 
slabs of dark red, fine-grained sandstone, from the north flank 
of the Porcupine mountains, Lake Superior. 
Collected by Dr. Douglass Houghton, in 1840. 
Pal^eophycus informis, n. sp. 
Fucoid apparently consisting of fleshy, leaf-like masses, having 
an irregularly triangular, elongate, or variously amorphous out¬ 
line. In some instances it would seem that a hollow, conical 
piece had been compressed so as to present two opposite edges. 
Sometimes an irregularly elongate piece presents occasional en¬ 
largements and tuberculous eminences. There are some indica¬ 
tions that the plant was branched, some of which consist in the 
close approximation of co-adapted edges without complete junc¬ 
tion. The surfaces are smooth and shining. The fragments 
vary from half an inch to two inches in width. 
Abundant in dark red sandstone from Montreal river, Lake 
Superior—a region where Col. Whittlesey estimates the forma¬ 
tion to attain the enormous thickness of 15,000 feet. ( Proc . Bbst. 
Soc. Nat. Hist., ix, July, 1863.) 
Collected by Dr. Houghton, in 1840. 
Similar but thinner and more ill defined fucoids occur in red 
sandstone three miles west of Eagle river; and again in white 
sandstone near Carp river, on the south shore of Lake Superior. 
In associating these remains with others from the Potsdam 
sandstone of Wisconsin, I do not intend to express any opinion 
whether the Lake Superior sandstone is of Mesozoic age, as ar¬ 
gued by Jackson and Marcou; or of the age of the Chazy for¬ 
mation, as recently concluded by the Canadian geologists (at 
least in reference to the St. Mary’s sandstone) ; or the prolonga¬ 
tion of the lowest fossiliferous sandstones of Wisconsin, as 
thought by Messrs. Foster and Whitney, and formerly by Hall, 
and still earlier intimated in the unpublished notes of Dr. Hough¬ 
ton ; or finally, as now intimated by Hall, a formation ranging 
from a horizon below the fossiliferous sandstones of Wisconsin 
to the top of the Chazy formation or St. Peter’s sandstone. 
University of Michigan, Dec. 11th, 1863. 
