10 
ness, which is known as the “Tully Limestone.” This limestone thins out, in proceeding 
westward, before Lake Erie is reached, and it is not represented in Canada. 
VIII. Genusez Stares.—Overlying the Tully Limestone, or in its absence the Hamil- 
ton Group, is a series of black, bituminous, sparsely fossiliferous shales, to which the New 
_ York geologists have applied the name of “Genesee Shales ” or “Genesee Slates.” Professor 
Hall unites these with the Portage Group, and their occurrence has not been satisfactorily 
recognized in Canada, unless they should be represented by the fissile shales of Kettle Point, 
Lake Huron, as has been generally supposed. In this case, the Genesee Shales of Canada 
are very important and interesting, from the presence in them of well-preserved remains of 
plants. 
IX. Portage Group.—This group is composed of a considerable thi@kness of shales, flags, 
and shaly sandstones. Few fossils are present, and the group is not known to be represented 
in Western Ontario. 
X. Curmune GRovup.—lf the Catskill sandstones and shales be regarded as belonging 
to the Carboniferous, the summit of the Devonian System in Eastern America is constituted 
by the so-called “Chemung Group.” This consists of a great series of sandstones and shales» 
containing a considerable number of fossils; but no equivalent of the group has been recog- 
nized in Canada West. 
The following table exhibits, in a summary form, and in ascending order, the various 
members of. the Devonian Formation of the State of New York, with their equivalents in 
Ontario. 
Devonian Strata of the State of New York. Equivalents in Ontario. 
I. Oriskany Sandstone....:............000 .. Sandstones of North Cayuga and Oneida ? 
i Vanda Calla Grit cons fu veieiat ee No equivalent. 
Te Sehoharie Grits! les os esee) o- Asean Sandstones of North Cayuga and Oneida? 
[Or no equivalent ? 
Onondaga Limestone \ 
TWARorniterouadimestone dae eee Corniferous Limestone. 
(= Upper Helderberg Limestones) 
V. Marcellus Shale | 
VI. Hamilton Shales ( ....+... Hamilton Group 
VII. Tully Limestone 
VATE Geneses Shalesec rie. iusecccecnies Nass Fissile Shales of Kettle Point, Lake Huron, 
[with remains of plants. 
PX Orage; GYOUp.-..neeasenacer cus ckare .....No equivalents. 
X. Chemung Group......... Maueeiastajantaltiare No equivalents. 
