214 I'fi^ American Geologist. October, isas 
aspidian and other fishes. The fish remains obtained in these 
rocks in 1897 have been examined by Mr. A. Smith Wood- 
ward, of the British museum, who thinks that they are either 
uppermost Sihirian or lowermost Devonian. 
From 1872 to the present time Mr. Fletcher has been en- 
gaged in a minutely detailed examination of the geological 
structure of northern and eastern Nova Scotia, for the geo- 
logical survey of Canada, which has published geological maps 
of the greater portion of this area on a scale of one mile to the 
inch. In 1887 he referred to the Devonian system the rocks 
below the Carboniferous conglomerate at loch Lomond, Rich- 
mond county, Cape Breton.* From that point he has since 
traced rocks that he has described as Devonian, on strati- 
graphical and lithological grounds, westward through the pe- 
ninsula of Nova Scotia as far as the head of Cobequid bay 
and along both sides of Minas basin, where he has estimated 
that they attain a thickness of from 10.000 to 15,000 feet.f 
With some Silurian and the associated igneous rocks, he be- 
lieves them to form the mass of the Cobequids. 
Most of these rocks that Mr. Fletcher refers to the Devo- 
nian, had, however, previously been referred to other geo- 
logical horizons. Among the more notable of these are the 
Horton series in Kings county, and the Riversdale series and 
Harrington river rocks in Colchester county. On purely 
pala^ontological evidence the Horton seri'es had been referred 
to the Lower Carboniferous, and the Riversdale series to the 
Millstone grit, by Sir Wilham Dawson, though it is now pretty 
generally conceded that both are unconformably overlaid by a 
marine Carboniferous limestone. 
Owing to circumstances it has unfortunately happened that 
very little palaeontological work has been done in Nova Scotia 
or on Nova Scotian material since 1873. With the view of 
stimulating the prosecution of researches in this direction, col- 
lections of fossils have been made, during the past four years 
and chiefly by Dr. H. M. Ami, of the geological survey of 
Canada, from many localities in the province, and some se- 
lected sets of these fossils have been forwarded to specialists. 
^Geological Survey of Canada, Report of Progress for 1877-78. 
tSee the Annual Reports of the same Survey for 1877-78, 1879-80-81, 
1886 and 1890-91. 
