174 C. LAPWORTH ON GRAPTOLITES 
CAMBRIAN. 
(B.)—CAMBRIAN FORMATIONS. 
B.'—Fine conglomerates, with white quartz pebbles; red, brown, grey and black 
slates. (Localities: Grande Carrière, etc., and flanks of the Shickshock Range). 
B’—Grey, red, brown and black shales, with beds and bands of dolomite. (Localities: 
Les Islets, coast south of Cape Rosier, ete.) Fossils: Dictyonema, Bryograptus, etc. 
[B' and B° may, perhaps, represent both the Upper Potsdam and the Calciferous rocks 
of the western district of New York and central and Upper Canada.] 
ORDOVICIAN. 
(c.)—ORDOVICIAN OR CAMBRO-SILURIAN FORMATIONS. 
(1.) Lower Division or Quebec Group of Logan. 
C'—Hard grey quartzite, quartzose sandstone, limestone, conglomerates, etc, with 
seams of black shale (Ste. Anne, Cape Rosier, Tartigo River, etc., with Levis Trilobites) 
and grey shales with seams of dolomitic rocks. Fossils: Phyllograptus, Tetragraptus, 
Didymograptus. 
C?—Grey, green, purple and clouded shales, interstratified with grey and black 
slates, and passing into 
C2—Hard green and grey sandstones of great thickness, interstratified with red, 
green and grey shales. Localities: Ste. Anne des Monts, Cape Chatte, etc., ete. (Pillar 
Sandstones.) 
The limestone conglomerates, etc., at base of C' may answer to the asserted break 
between the Calciferous and Chazy in New York and elsewhere; and the Pillar Sand- 
stones may come into the place of the Chazy Sandstones of Grenville. In this event, the 
Quebec of this area would answer generally to the Chazy of the west; the Calciferous 
fossils of the conglomerates may be derived from fragments of Calciferous rocks. C', C” 
and C° would answer precisely to Logan’s Levis, Lauzon, and Sillery divisions. 
On the other hand as it appears by no means unlikely, from the fact that westward 
from the mouth of Marsouin River, the beds with Dictyonema sociale seem to lie always 
between the Pillar Sandstones and the local Levis conglomerates and shales, it is possible 
that these Pillar Sandstones are actually below the Dictyonema beds; and thus come 
broadly speaking, into the place of the Potsdam formation. If this be the case, then the 
zones C * of the foregoing sequence would answer to B', and C* to B*; the typical Levis 
strata C' would be the highest formation of the older series, yet recognized in the district. 
In this case also it follows of necessity, that the Griffin Cove and Marsouin River strata of 
the district under consideration must be separated from the so-called Levis strata by a 
gigantic fault or dislocation, as in the neighbourhood of Quebec. 
