E. Hitchcock, Jr., on a new species of Clathropteris. 25 
In the Cabinet of Amherst College is a fine specimen of a radi- 
ating Clathropteris (that is its apex) from the quarry of Roswell 
Field in Gill, Mass., and although nearly one quarter of the circle 
is lost, yet as many as 17 distinct fronds can be counted radiating 
from one stem. Although the reticulated character of this speci- 
men is rather obvious, it was not noticed till the more recent spe- 
cimen from East Hampton was discovered.* 
In the same cabinet is another obscure specimen of the Cla- 
thropteris from the banks of Connecticut river in Montague, two 
miles southwest of Field’s quarry, a sketch of which is given in 
my father’s final report on the Geology of Massachusetts, vol. ii, 
p. 452. : 
onclusions.—The above facts make it almost certain that a 
species of Clathropteris occurs in the sandstone of the Connecti- 
cut valley not far from its center, measuring across the strata, and 
near to the interstratified beds of trap both above and below. 
Now since this fern is found in Europe only in the upper part of 
the Trias, and the lower part of the Lias, it is very probable that 
it occupies the same geological position here. If so we ascertain 
the existence of a zone of rock in the Connecticut valley not far 
rom the junction of the Lias and the Trias. And since two 
measurements of sections across this valley show a thickness of 
sandstone strata both above and below this zone thicker than the 
Lias and the Trias of Europe, the probability seems very strong, 
that the equivalents of both of these rocks exist here, and not im- 
probably some others both older and newer. 
we can rely with confidence upon this geological zone, it 
will form’a convenient starting place for tracing out other older 
and newer formations. 
It will be seen that while the above conclusions sustain the 
opinion lately advocated with much ability by Prof. W. B. Rogers 
Am. Jour. Sci. Jan., 1855, p. 123), that the Lias sandstone exists 
in the valley of the Connecticut, it makes the opinion also proba- 
ees since advanced by my father that the Trias also exists 
ere. 
_ The radiations in the specimen above noticed appear to be dis- 
tinct and entire fronds, and so resemble those on fig. 2, as to 
make it probable that the latter also are fronds and not pinnules. 
* Ihave reason to suppose that this specimen has been mistaken for a Zamia. 
Stconp Serms, Vol. XX, No. 58,—July, 1855. 4 
