72 NOVA SCOTIAN GEOLOGY—HONEYMAN. 
not wish to refresh my recollection, as I wished to examine them 
in the light of my own experience. This led me to identify the 
rocks with others with which I was well acquainted without any 
reference to the coral in question. The lithology and strati- 
graphical relations and familiar forms of fossils found in certain 
strata, enabled me to correlate the strata with the Middle 
Silurian formations of Eastern Nova Scotia, and led me to seek 
for other familiar forms, and to find them; Petraia was notably 
one of the number. 
It is noteworthy that the Devonian Zaphrentig of Dawson is 
the Petraia Forrestere of Salter, occurring in strata referred 
by him to Mayhill Sandstone, (Intermediate Silurian of Ramsay 
and Salter). This is eminently characteristic of all the Mayhill 
Sandstone localities in Eastern Nova Scotia, which are eight in 
number. In one of these localities in the Marshy Hope, in the 
County of Antigonish, the Petraia strata seem to stand alone. 
In Barney's River, French River, and Sutherland’s River, they 
are associated with Clinton and underlie it, other members of 
the Upper Arisaig series being absent. 
At Lochaber the same strata are associated with C and D 
Upper Arisaig, and underlie them. 
At Ivish Mountain and McLellan’s Mountain they are asso- 
ciated with B’ and D Upper Arisaig and underlie them. At 
Arisaig the Petraia strata (A) are associated with and underlie 
B, and the B’ Clinton of Hall and Dawson, C Aymestry Lime- 
stone, and D Upper Ludlow, cr Lower Helderberg. In Irish 
Mountain and McLellan’s Mountain the Petraia strata are Cen- 
tral Mountain strata in common with the extensive Diorites of 
Devonian age. 
It is also peculiarly noteworthy that the author of “ Acadian 
Geology,” on the faith of “one indistinct specimen of Zaphren- 
tis,” concluded that the Petraia strata of Lochaber was of 
Devonian age, and re-asserted the same opinion about 1874. 
PRE-CARBONIFEROUS ROCKS OF THE PICTOU COAL FIELDS, OF 
DEVONIAN AGE. 
In the Report of Progress of the Canadian Survey from 1866-9 
