Methods of Stratigraphy. — Winchell. 351 
The true idea of the Huronian is found in the sections given 
in the Geology of Canada^ ISGJ, and this idea is represented 
by the typical Huronian area as mapped between the Thessa- 
lon and Missasaugui rivers, and thence northwestwardly to 
Port Finley and the southeastern shores of lake Superior. 
Jt\ a recent address before the Royal Society of Canada," Dr. 
Robert Bell has presented the views of the present officers of 
the Canadian survey, in support of the expanded Huronian. 
An examination of this interesting paper results in bringing 
out the following points, at variance with what has recently 
been presented by Prof. R. D. Irving and other United States 
geologists. 
1. The original idea of the Huronian, as understood hy 
the Canadian survey, extended from the ^^ Camlrian^^ to the 
Laurentian^ covering all the crystalline schists. Dr. Bell re- 
fers for authority for this to the Geology of Canada., 1863. 
This is a question of fact, and anyone who takes the trouble 
to examine the descriptions of the Huronian, in the Geology 
of Canada. 1803, can satisfy himself quickly. These descrip- 
tions are found on pages 50 to 66, and 841 to 844. We have 
failed to find the term "crystalline schists," or any term that 
can be taken as an equivalent for it, anywhere in those pages 
— or in any other part of the volume where the Huronian is 
mentioned. 
2. The Huronian is conformable on the Laurentian, and 
no instance of unconformity has yet heen found in Canada. 
It is not necessary to repeat what has already been said on 
this point in speaking of Dr. Bigsby's treatment of the Huron- 
ian. Not only did Logan mention, in numerous instances, 
the non-conformity of the Huronian on the Laurentian, but 
recently such have been fully described- by Prof. Irving at a 
point about three miles east of the Thessalon river, on the 
north shore of lake Huron;'- and Prof. Irving's observations 
have been confirmed by a more recent visit to the same place 
by members of the excursion party from the late Toronto 
meeting of the American Association for the Advancement of 
"Trans. Royal Society of Canada, vol. vr, sec. 4, p. 3. 
" Seventh annual report of the U. S. Geol. Survey, p. 429. Logan's 
descriptions of unconf.>rmity are to be found in Oeologij of Canada, IS6S 
p. 50; Proc. Am. Assc. Adv. Sci. 1857, Part 2. p. 45, Ksquisse geolosi- 
que du Canada, 1855, p. 29; Quart. Jour. Geol. Soc, London, vol. 21, 
1865, p. 4(). 
