Fossils Near Montreal. — Schuchert. 253 
Oriskanian reminders, like, R. near musciilosa, S. murchison, 
S. near arenosus, prove that the Saint Helen's Island Helder- 
bergian is pretty well up towards the top of the New York sec- 
tion, and may represent both the Becraft and Kingston zones. 
Spirifer macra and 5. granulosus establish the fact that, 
in the region of Montreal, there was once a formation of marine 
origin later than the Helderbergian and as recent as the Onon- 
daga* (Corniferoiis) ; further, that the agglomerate of Saint 
Helen's Island and other places about Montreal is not older 
than late Middle Devonic time. Its age is probably more re- 
cent, and there may be further paleontologic evidence in the 
agglomerate. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
The Calcareous Concretions of Kettle Point, Lanibton County, Ontario. 
By Reginald A. Daly. (Jour. Geol, S, 135-150.) 
The concretions occur in a horizontally bedded, fissile, black, 
bituminous shale of middle Devonian age. They are approximately 
spherical ; one to three feet in diameter, and possess a radial crystalline 
structure. An analysis of one of the concretions shows 88.42 per cent, 
of calcium carbonate, only 2.99 per cent, of magnesium carbonate, and 
the remainder consists of iron oxide, insoluble residue, hydrocarbons 
and water. The most remarkable feature is the mechanical displace- 
ment and deformation of the enclosing shales which the growth of 
the concretions has involved. The pressure or "live force" of the 
growing concretions or aggregate of spherical radiating crystals has 
even been sufficient to induce a true slaty cleavage in the shale at some 
points. The main thesis of the author is to demonstrate that this great 
centrifugal pressure is compatible with the persistence of the capillary 
film investing the growing crystal or concretion and without which 
its continued growth would be impossible. The explanation, which, 
it would seem, must be generally accepted, is based upon the experi- 
ments of Jamin leading to the conclusion that equilibrium may exist 
between two unequal pressures affecting the ends of a capillary tube, 
provided a column of liquid occupying the tube be interrupted by 
bubbles of air. The presence of the latter excites capillary attraction 
which is so strong as to take up several atmospheres of pressure ap- 
plied at one end of the tube. The force so expended is represented in 
the compression of the air bubbles and in changing the form of the 
air menisci ; surface tension is thus overcome. The movement of the 
bubbles progressively decreases in the direction of the greater pres- 
sure until one is reached which is not disturbed at all so long as the 
