NV. W. portion of Lake Huron. 265 
The crystalline grey or brown limestone of the Island of 
Montreal, of the Falls of the Chaudiere on the river Ottawa; 
and of the Falls of oe erage} and Point Aux Trembles 
near Quebec, are example econdary strata assuming 
the structure of the obiastive olla: Their fracture is slaty 
in the large, and imperfectly conchoidal in the small. 
yield to the knife, but not to the nail. Their Rope 3 
face is full of rhomboidal facets, and resembles that 
blende. They are at the same time full of uidalven! turbi- 
nites, pensions of coral, SF fibres of wood, and of small 
prs and the islets on the no re—that of the ana. 
line Range and that of Michilinactinne: 
_'To commence with that of St. Joseph, as being nearest 
the elder rocks, it is of various shades of brown, which are 
usually light. It is soft, knotty, schistose, and of an imper- 
fect conchoidal fracture. 
It seldom shews itself in ledges of more bert two yards 
high, and then is much abe the fragments being mes 
and weathered. The lower strata are often ro a 
tinge—not occasioned by decaying vegetables and re 
fecting the surface, but also the aaped and sound - 
This variety is remarkable for its number of what appear to 
be clove brown shells, oblong, and of the size of rae seeds. 
On Isle Vert, (six miles East of St. Joseph, an 
north shore) this substratum rests upon a very iam blackish 
brown limestone so schistose as to be in fact a shale, as tru- 
ly so as that of Niagara. It contains no shells. It is under 
water. Rhomboidal, pearl, and Tonveous cale Sper aee ‘the 
umeration of its remains is placed in the the 
appendix. I have to lament that Tau am not more familiar 
ith this int re) 
Phe li pares en er line Range although in part 
on the same level with the species just described, bed, differ 
from it in many respects; and thus themselves are not al- 
ways the same. hat a basin of second eposition, 
should contain on ie same in ae rocks of different charac- 
Vor. FI.....No. 
