134 HISTORICAL’ PALAIONTOLOGY. 
Canada represent the shallow-water shore-deposits of the same 
period. In fact, the former of these last-mentioned de- 
posits contains no fossils which can be asserted positively 
to be marine (unless the Eurypterids be considered so) ; and 
it is even conceivable that it represents the sediments of an 
inland sea. Accepting this explanation in the meanwhile, 
we may very briefly consider the general succession of the 
deposits of this period in Scotland, in Devonshire, and in 
North America. 
In Scotland the “Old Red” forms a great series of arena- 
ceous and conglomeratic strata, attaining a thickness of many 
thousands of feet, and divisible into three groups. Of these, 
the Lower Old Red Sandstone reposes with perfect conform- 
ity upon the highest beds of the Upper Silurian, the two for- 
mations being almost inseparably united by an intermediate 
series of “ passage-beds.” In mineral nature this group con- 
sists principally of massive conglomerates, sandstones, shales, 
and concretionary limestones ; and its fossils consist chiefly of 
large crustaceans belonging to the family of the Luryfterids, 
fishes, and plants. The J@ddle Old Red Sandstone consists ot 
flagstones, bituminous shales, and conglomerates, sometimes 
with irregular calcareous bands ; and its fossils are principally 
fishes and plants. It may be wholly wanting, when the Upger 
Old Red seems to repose unconformably upon the lower divi- 
sion of the series. The Upper Old Red Sandstone consists of 
conglomerates and grits, along with a great series of red and 
yellow sandstones—the fossils, as before, being fishes and re- 
mains of plants. The Upper Old Red graduates upwards 
conformably into the Carboniferous series. 
The Devonian rocks of Devonshire are likewise divisible 
into a lower, middle, and upper division. The Lower 
Devonian or Lynton Group consists of red and purple sand- 
stones, with marine fossils, corresponding to the ‘Spirifer 
Sandstein ” of Germany, and to the arenaceous deposits (Scho- 
harie and Cauda-Galli Grits) at the base of the American 
Devonian. The J@iddle Devonian or Lifracombe Group consists 
of sandstones and flags, with calcareous slates and crystalline 
limestones, containing many corals. It corresponds with the 
great “Eifel Limestone” of the Continent, and, in a general 
way, with the Corniferous Limestone and Hamilton group of 
North America. The Upper Devonian or Pilton Group, lastly, 
consists of sandstones and calcareous shales which correspond 
with the ‘‘Clymenia Limestone” and “ Cypridina Shales” of 
the Continent, and with the Chemung and Portage groups of 
