6 
MUSEUM BULLETIN NO. 17. 
On the east side of the island, fossils were obtained from a 
few square feet of dolomite, only a few inches in thickness. Here, 
both lower Niagara and lower Trenton species occur. The 
former include Pentamerus oblongus Sowerby, and A try pa retic- 
ularis (Linnaeus). The Ordovician fossils are: Receptaculdtes 
oweni Hall ?, Strophomena trentonensis Winchell and Schuchert, 
Daltnanella testudinaria (Dalman) , Rhynchotrema incequivahe (Cas- 
telnau) ?. 
One other Silurian locality was noted. J ust north of Hailey- 
bury wharf some thin limestones protruding through the beach 
gravel furnished A try pa reticularis (Linnaeus) and Gypidula sp. 
This is rather remarkable as at approximately the same elevation 
about one mile farther north, the Black River fossils occur, as 
already mentioned. Between the above localities two exposures 
about 20 feet apart and on the same north-south strike, have 
reversed dips, the one to the north dipping to the east at an angle 
of 19 degrees and the one to the south dipping to the west at an 
angle of 30 degrees- The strata are shattered and appear to 
have been disturbed by an east-west vertical fault. Thus fault- 
ing appears in this case to have been responsible for Ordovician 
and Silurian fossils appearing at the same level. 
We have next to consider: (1) whether the shales lying below 
the Pentamerus horizon are of Ordovician or of Silurian age ; 
(2) the general relations of the Ordovician and Silurian of the 
Lake Timiskaming region including any available evidences of 
faulting or other movements which may have affected the 
Palaeozoic strata. 
(1) From the available field evidence bearing upon the age 
of the shales we can draw only a tentative conclusion. No 
unconformity was observed between the shales and the Niagara 
strata ; and the general relations and characters suggest their 
correlation with the Cabot Head shales of Georgian bay, be- 
longing to the Cataract formation of upper Median age. How- 
ever, the Cabot Head shales of Manitouiin island which are the 
nearest outcrops to the Lake Timiskaming exposures are red 
in colour, and thus are quite different from the shales being con- 
sidered, which approach more closely in character the typical 
