d to the deep-sea accumulations of the
same period. Nor can the problem at issue be solved by an appeal
to the phenomena of the British area alone, be the testimony of
these what it may. As a matter of fact, there is at present no
sufficient ground for believing that there is any irreconcilable
discordance between the succession of rocks and of life in Britain
during the period which elapsed between the deposition of the
Upper Ludlow and the formation of the Carboniferous Limestone,
and the order of the same phenomena during the same period in
other regions. Some of the Devonian types of life, as is the
case with all great formations, have descended unchanged from
older types; others pass upwards unchanged to the succeeding
period: but the fauna and flora of the Devonian period are, as
a whole, quite distinct from those of the preceding Silurian or
the succeeding Carboniferous; and they correspond to an equally
distinct rock-system, which in point of time holds an intermediate
position between the two great groups just mentioned. As before
remarked, this conclusion may be regarded as sufficiently proved
even by the phenomena of the British area; but it maybe said to
be rendered a certainty by the study of the Devonian deposits of
the continent of Europe--or, still more, by the investigation of
the vast, for the most part uninterrupted and continuous series
of sediments which commenced to be laid down in North America
at the beginning of the Upper Silurian, and did not cease till,
at any rate, the close of the Carboniferous.

LITERATURE.

The following list comprises the more important works and memoirs
to which the student of Devonian rocks and fossils may refer:--

(1) 'Siluria.' Sir Roderick Murchison.
(2) 'Geology of Russia in Europe.' Murchison (together with De
Verneuil and Count von Keyserling).
(3) "Classification of the Older Rocks of Devon and Cornwall"--'Proc.
Geol. Soc.,' vol. iii., 1839. Sedgwick and Murchison.
(4) "On the Physical Structure of Devonshire;" and on the
"Classification of the Older Stratified Rocks of Devonshire
and Cornwall"--'Trans. Geol. Soc.,' vol. v., 1840. Sedgwick
and Murchison.
(5) "On the Distribution and Classification of the Older or Palaeozoic
Rocks of North Germany and Belgium"--'Geol. Trans.,' 2d ser.,
vol. vi., 1842. Sedgwick and Murchison.
(6) 'Report on the Geology of Cornwall, Devon, and West Somerset.'
De la Beche.
(7)