152 F^R(3CEED1NGS: BOSTON SOCIETY NATURAL IIISTOKY. 
Emerson has demonstrated tlie (existence of a fault sej)aratinf^ 
the fossiliferous Devonian limestone and the argillites/ so that, 
even if the argiUite be proved Ordovician, its relation to the 
Devonian limeston<* will not uphold the supposition of inter- 
veninf^ mountain-building. 
In these meridional troughs of central New England, through 
which the Lower Devonian sea is supposed to have found its way 
from the maritime provinces to New York,' no traces of Ordo- 
vician strata are found, except around Lake Memphremagog. 
Here tlie structure is very obscure; no two geologists have 
agreed in print on its interpretation, so that we can hardly hope 
to use it in support of such a structural problem as the one with 
which this paper is concerned. We may then dismiss this third 
division of eastern North America as being absolutely non- 
connnittal in evidence. 
Montreal and Vicinity. 
The two localities cited by Dana from around Montreal, in 
the first edition of his Manual, are Ste. Helen's Island and 
Beloeil Mountain. These were both retained in the last edition. 
Though the structure of the rocks in the vicinity of Montreal 
is now valueless as evidence, I shall note in brief the main points 
of the geology there as far as it relates to our problem, because it 
was one of the three localities originally cited by Dana in support 
of the idea of the Taconic folding. 
Ste. Helen s Island. — ^The best account of the geology of this 
island is in a paper by Harvie, from which the following state- 
ment is taken: "The Devonian and Silurian are represented 
solely by inclusions in the [igneous] breccia of Ste. Helen's 
Island. . . . The Ordovician is represented by the Utica, 
Trenton, Chazy and Calciferous formations."^ 
^Emerson, B. K. A description of the "Bernardston Series" of meta- 
morphic Upper Devonian rocks. Amer. Journ. Sci., ser. 3, vol. 40, 
p. 267, 1890. 
-Clarke, J. M. Early Devonic history of New York and eastern North 
America. Mem. N. Y. State Mus., no. 9, pt. 2. p 153-156, 1909. 
'Harvie, Robert. On the origin and relations of the Palaeozoic breccia 
of the vicinity of Montreal. Trans. Roy. Soc. Canada, ser. 3, vol. 3, 
pt. 4, p. 252, 1910. 
