ame two
workers also carried on further researches upon the same rocks of the
continent, where already several others, F. Roemer, H. E. Beyrich, &c.,
were endeavouring to elucidate the succession of strata in this portion
of the "Transition Series." The labours of these earlier workers,
including in addition to those already mentioned, the brothers F. and G.
von Sandberger, A. Dumont, J. Gosselet, E. J. A. d'Archiac, E. P. de
Verneuil and H. von Dechen, although somewhat modified by later
students, formed the foundation upon which the modern classification of
the Devonian rocks is based.

[Illustration: Distribution of Devonian Rocks]

_Stratigraphy of the Devonian Facies._

Notwithstanding the fact that it was in Devonshire and Cornwall that
the Devonian rocks were first distinguished, it is in central Europe
that the succession of strata is most clearly made out, and here, too,
their geological position was first indicated by the founders of the
system, Sedgwick and Murchison.

_Continental Europe._--Devonian rocks occupy a large area in the
centre of Europe, extending from the Ardennes through the south of
Belgium across Rhenish Prussia to Darmstadt. They are best known from
the picturesque gorges which have been cut through them by the Rhine
below Bingen and by the Moselle below Treves. They reappear from under
younger formations in Brittany, in the Harz and Thuringia, and are
exposed in Franconia, Saxony, Silesia, North Moravia and eastern
Galicia. The principal subdivisions of the system in the more typical
areas are indicated in Table I.

This threefold subdivision, with a central mass of calcareous strata,
is traceable westwards through Belgium (where the Calcaire de Givet
represents the _Stringocephalus_ limestone of the Eifel) and eastwards
into the Harz. The rocks reappear with local petrographical
modifications, but with a remarkable persistence of general
palaeontological characters, in Eastern Thuringia, Franconia, Saxony,
Silesia, the north of Moravia and East Galicia. Devonian rocks have
been detected among the crumpled rocks of the Styrian Alps by means of
the evidence of abundant corals, cephalopods, gasteropods,
lamellibranchs and other organic remains. Perhaps in other tracts of
the Alps, as well as in the Carpathian range, similar shales,
limestones and dolomites, though as yet unfossiliferous, but
containing ores of silv