GENERAL VIEW OF ORGANIC REMAINS. 
63 
palaeontological evidences of its age, which are not so clearly exhibited in any othei 
country. The Old Red Sandstone of the British Isles, for example, which is charged 
with peculiar ichthyolites, several of which have been already alluded to as also 
common to our Russian deposits, has never yet afforded a single species of the 
Mollusca so prevalent in the slaty limestones and schists of Devonshire, that have 
been placed upon the same parallel. On the other hand, Devonshire, the Bou- 
lonnais, and the greater part of the Rhenish provinces, where these Mollusca abound, 
contain none of the Scottish ichthyolites. In one part of Belgium and in the Eifel 
only, have one or two fossil fishes been found, associated with the other members of 
that fauna. The examination of Russia has, therefore, not only enabled us to 
trace these deposits over an enormous area, but also entirely dispelled any doubts 
which might have existed in respect to the identity of the Old Red Sandstone of 
Scotland with those slaty rocks of Devonshire and the Continent with which it had 
been compared b It has, in short, offered numberless proofs, that the ichthyolites 
and mollusks, which in Western Europe are separately peculiar to smaller detached 
basins, were here cohabitants of many parts of the same great sea. If our re- 
searches in Russia had led to no other result, they would, we conceive, have well 
repaid our labours. 
The fauna of the Devonian rocks of Russia is, indeed, most remarkable in 
presenting to us a number of forms of each great class of animals, which are posi- 
tively identical with species hitherto known only in deposits of the same age in 
Western Europe. Thus, among the Mollusca, these rocks contain many species 
of shells which are undistinguishable from published Devonian species. The most 
characteristic of these have been already cited in the previous pages, or aie men- 
tioned in the tabular view attached to the Map, and the remainder will be enume- 
rated, and the whole described in the concluding or Third Part of this woik. 
We may, however, enumerate two or three general results of our inquiry. The 
genus Serpula, for example, no trace of which has been discovered in the Silurian 
rocks, here makes its first appearance. The Orthoceratites with annular siphons, 
and of which the 0. cochleatum is the type, are peculiar to this system. Among 
other important distinctions between this group and that which lies beneath it, are 
the appearance, for the first time in ascending order, of Spirifers with simple plaits, 
and the great profusion of Terebratuke ; the last-mentioned genus being very rare 
> See Geol. Trans., vol.v. p. 633, vol. vi. p. 221. Sedgwick and Murchison. 
