264 Geology and Mineralogy of the 
latitude of the Manitoulines. With the exception of the 
narrow selyage of transition and primitive on the North main- 
land, the whole of Lake Huron rests on secondary lime- 
stone. I have myself noticed it encroaching on those elass- 
es as far East as the river des Francois on the North shore 
—and found it to be the only livingrock in the South and in 
the Manitouline chain of Islands; including that of St. Joseph. 
The calcareous basin of Lake Huros (and the remark 
may Me extended to Lower and Upper Canada) differs from 
urope* in essential particulars: in being often 
Tetrergsialline and full of organic remains while in contact 
with the oldest rocks—without observing their direction and 
inclination, Again in the Canadas, limestones deposited in 
the midst of fletz countries are sometimes highly crystalline 
and crowded with fossilized animals. ) 
The following facts illustrate these observations. 
Between the mouth of the River Des Francois and the 
groupe. of eas 8 named La Cloche, there are several isles 
aeons ; ude | we centre or nucleus is of gneiss, lof- 
sone NNER a broad zone of dark coloured 
iene] limestone wiih is loaded with vegetation. I 
landed on one of them and found the rock to be soft and 
knotty, and full of organic remains. The same appesiaeey 
occurs between La Cloche and Messassaga. 
A gentleman of the party met with an island off the River 
salon composed of a number of parallel ridges of gran- 
ite much disturbed and broken; whose intervals contain 
l limestone thus. [See the Plate, fic, 2. 
- Inthe rear of the promontory of the Cedar Island, passage 
near Kingston, on Lake Ontario, I observed horizontal 
compact, dull, brown limestone overlying gneiss in a simni- 
Jar manner. F. arther east, in the contracting portion of pete 
Ontario, this Rock forms the immediate bank with 
primitive emerging behind it thus. [See the Plate fig. 3] 
The intervals of these mounds te often (as in Lake Hu- 
Ton filled with secondary lim 
oceurrence nearly. the same’ wads place at the Falls 
of. “Montmorenci near bec 
Repeated instances are a with j in the thousand slands 
where _ —* Psat ~~ in hor- 
zontal aay on granite 
* Europe, however, does contain a few similar scenes 
