382 THE DEVONIAN OF CAPE BRETON—GILPIN. 
Mira Bay. All Isle Madame (Arichat Island) is occupied by 
it, except a narrow fringe of carboniferous extending from Gran- 
dique westwardly along the north shore, and a few patches of 
felsites, ete., near Arichat town and Petit de Gras Harbor. It is 
met again on the Guysboro’ shore, and extends nearly to the 
mouth of the Strait of Canso where it crosses into Cape Breton 
again. Here it stretches along the shore from Port Hastings to 
Low Point, and extends inland about six miles, among the spurs 
of the band of crystalline limestones, gneisses, etc., which is 
best known by its exposure at Whycocomah. From this it will 
be seen that the extent of these measures in Cape Breton is 
limited, and that they donot form mining or agricultural dis- 
tricts. They are most particularly presented to the traveller 
passing through Lennox Passage, where he sees the low, mon- 
otonous, spruce-covered hills of Arichat Island, broken by few 
clearings and animated only by the huts and stages of the 
fishermen. 
In the district lying east of St. Peter’s, the presence of great 
masses of igneous rocks, has permitted of bolder outlines, and 
the Devonian is presented in rolling hills, with narrow irregular 
valleys. Prior to the surveys made by Mr. Fletcher, of the Geo- 
logical Survey, these measures were generally referred, without 
much comment, to the lower Carboniferous. In reporting on the 
field work of 1877, he says of the two basins of metamorphic 
rock running parallel to the great felsite series, that the first, 
stretching from Mira River to Upper Marie Joseph, is character- 
ized by primordial fossils. The second, probably Devonian, is 
characterized by more recent shells and plants. It contains 
masses of granitoid and trappean rock, and the associated strata 
bear a close lithological resemblance to the Cordaite shales and 
Dadoxylon sandstones of St. John, New Brunswick. 
These strata, in the St. Peter’s district, present numerous out- 
crops, but are so contorted that no continuous section can be 
given; nor can any reliable estimate be formed of their thickness, 
The various sections are composed chiefly of coherent grits, 
sandstones, areno-argillaceous shales, sometimes quartzo-felspa- 
thic, greenish, blueish, reddish, purple, gray or whitish. Car- 
