Methods of Stratigraphy. — Wiyichell. 349 
1862,'* that the Huronian of Canada is the equivalent of the 
quartzose member of the Urschiefer of Norway, but he evi- 
dently derived his idea of the Huronian from his knowledge of 
the crystalline schists of lake Superior, and not from a study 
of the true Huronian. But Dr. Bigsby goes much further than 
that, in that he attempts to show, or at least to strongly sug- 
gest, that the Huronian system is not what its authors sup- 
posed it was, but is the equivalent of a system of rocks much 
older; and in this he was followed, as already stated, by Dr. 
T. Sterry Hunt, who derived from his knowledge of the col- 
lections he had seen, and from hand samples sent him from 
the regions of lakes Superior and Huron, the well known 
"greenstone" conception of the Huronian which has been pre- 
sented in Dr. Hunt's papers. 
Without stopping to protest against the position in the 
English geological series in which Dr. Bigsby places the 
Cambrian, it is sufficient here to call attention only to the 
errors that he falls into respecting the Huronian, remarking 
only in passing that he places the entire primordial zone of 
Barrande, Avhether in America, Scandinavia or Bohemia, as 
the "immediate successor of the inhospitable Cambrian." " 
In the first place Dr. Bigsby regards the Huronian as con- 
formable on the Laurentian, which is at variance with the 
statement of Messrs. Logan and Hunt in the original 
announcement of the name,'^ as well as the later descriptions 
by Mr. Logan, notably that in a paper read before the Amer- 
ican Association for the Advancement of Science in 1857.'" 
This is an element in his discussion which affects materially 
the correctness of his conclusions. 
In the next place Dr. Bigsby identifies the "Huronian" of 
the region of Marquette, Mich., with that of the north shore of 
lake Huron from the description of the former by Foster and 
Whitney, which he quotes as follows : "As an alternation of 
beds of great thickness, of gneiss, of chloritic, talcose, argilla- 
ceous and siliceous slate, of quartz, of saccharoidal and crys- 
talline limestones and serpentines, all much contorted, highly 
inclined — nowhere having a sedimentary aspect and most 
'* Canadian Naturalist, vol. vii. pp. 1-20 and 113-127. 
'Uiuart. Jonr. Gaol. Soc. vol. xrx. Part i. p. 43. Nov. 10, 18G2. 
"Esquisse geologique du Canada, j) 29. 
"Report of the A.A.A.S. 1857. p. 4.^. (Part 2.) 
