of Vermont and Canada. 101 
2, ADDITIONAL EVIDENCE ON THE AGE oF THE RED SANDROCK. 
During the last summer Mr. J. Richardson, of our Survey, 
was engaged under the direction of Sir W. E. Logan in making 
an examination of the rocks on both shores of the Straits of 
Belle Isle, the object being to find if possible a section in which 
the sequence of the lower formations might be seen to better ad- 
vantage than they can be in the disturbed region of Canada 
ast. He returned in October, having been completely success- 
ful. On the North shore of the Straits he found at the base of 
the series 141 feet of sandstone holding Scolithus linearis rest- 
ing upon the Laurentian formation; and lying upon the sand- 
stone 231 feet of limestone with P. Zhompsoni, P. Vermontana, 
and a number of other species of which I shall give a list far- 
ther on. On the south shore of the Straits he found a great se- 
nes of limestones, the lower part of which undoubtedly belongs 
to the Calciferous sandrock formation. The upper portion may 
belong in part to the Chazy and Black River, but the fossils ap- 
pear to be all new species and have not yet been studied sufli- 
cently to decide with certainty from their aspect alone. The 
sandstones and limestones on the north shore of the Straits ap- 
Pear to be of the age of the Potsdam of Pennsylvania and Ten- 
nessee. The form of the Scolithus is identical with that which 
Cccurs in these two States, and some portions of the rock is a 
Se red sandstone exactly like meena sent to me about a 
®ar ago from Tennessee, by Prof. Safford. 
ince the date of my pine note published in this Journal in 
September last (before quoted), the Red sandrock of Vermont 
ie slate near the ‘unction of the two formations in the first mile 
South of the headin beyond which the rocks were not 
;~amined. Dr. P. J, Farnsworth of Phillipsburgh also col- 
lected fragments of trilobites one mile east of the sandrock and 
about a mile south of the boundary in Vermont. _ : = 
tong to a species of Asaphus. On the west side of this os 
‘fosure of the Red sandrock,'three-fourths of a mile south of th 
» I found another locality of Conocephalites, but the species 1s 
different from that noticed in my former communication. Ihave 
described it under the name of C. arenosus. 
