Ginn — ON CANADIAN CAVERNS. 
131 
water origin), is covered by its ancient soil, with the stems of the 
trees erect as when they grew. This was the ancient land, first 
transformed into a delta, into which the old mighty river poured its 
flood. Here lived the gigantic Iguanodon ; here the Pterodactyles — 
winged lizards — flitted in the dusky twilight ; birds waded in the 
mud ; the 1mm of insects was heard in the air. All, all the strange 
beings of those ancient days have perished, and two thousand feet at 
least of solid earth is piled above their tomb. 
(To he continued.) 
ON CANADIAN CAVERNS. 
By George D. Gibb, M.D., M.A., F.G.S., Member of the Canadian 
Institute. 
The prominent feature of a large portion of the province of Canada 
is the presence of vainous limestone rocks belonging to the Silurian 
formations. Until lately, the existence of caverns in these rocks, as 
well as in those lying subjacent — namely the Lam-entian of Sir 
William Logan, was almost unknown ; as, with the exception of an 
isolated account here and there, no regular description of any cavern 
had appeared. Owing to the labom'S of the Canadian Geological 
Survey, and of several private individuals, a number of caverns have 
been discovered at distances remote from one another ; some of these 
have received but a passing notice in the publications of the Survey, 
and are not, therefore, useful as a means of reference. The present 
communication, it is hoped, will supply that deficiency, as in it I 
purpose to embody short descriptive accounts of all the caverns of 
Canada which are known up to the present time. The details of 
some of them are not so full as could be desired ; nevertheless, with 
all the available sources of information vsdthin my reach, together 
with personal observation in some, on the whole the general descrip- 
tions may be relied upon as accurate, and as containing a correct 
account of the particular geological formations in which they lie. 
For convenience of description, it may be here stated that the 
boimdaries of the province of Canada are at the present time as 
follows : — North by the Hudson Bay Company's ten-itories, and 
shores of James' Bay; on the west by Lakes Huron, Superior, 
Lake of the Woods, Winnipeg, and Red River ; South by Lakes 
Erie and Ontario, and the states of New York, Vermont, and New 
Hampshire ; and to the eastwai'd by the River and Gulf of St. Law- 
