Reviews—Dr. Charles Barrois—Geology of Asturias. 235 
an upper division of chloritic taleose and other schists, with subordinate 
beds of quartzite, serpentine, etc. 
The Cambrian rocks consist of slates and ‘“‘phyllades”’ with beds of 
quartzite and limestone, having a thickness of about 3000 metres, and 
they are intercalated in the Cantabrian mountains, between the Primi- 
tive crystalline schists and the Silurian rocks (grés d Scolithes). The 
system contains the Primordial fauna of M. Barrande, in its upper 
part, but the author has not been able to recognize any important line 
of division between this and the much thicker lower azoic portion of 
the system. Together they appear to represent the Harlech, Llanberis, 
Longmynd, and Menevian groups, and the Lingula Flags and Tremadoe 
Slates. 
The Silurian rocks, which attain a thickness of from 700 to 1000 
métres, are grouped into Lower, Middle and Upper Silurian, and 
include the second and third faunas of Barrande. The beds are said 
to rest conformably upon the Cambrian rocks, and to be overlain con- 
formably by the Lower Devonian strata. 
The Devonian strata, consisting of limestones, slates, and red sand- 
stone, reach a thickness of about 1000 métres. They are a conform- 
able series, and are divided into eight zones distinguished by litho- 
logical as well as paleontological characters. The grouping adopted 
by Dr. Barrois is as follows :— 
( Upper. (cee. 
Frasnian. 
Devonian ~+ Middle. Givetian. 
Eifelian U 
| Lower. } Coblenzian eee 
ower. 
Taunusian. 
{ Gedinnian (not represented). 
The Carboniferous strata repose transgressively on Devonian, Silurian, 
and Cambrian rocks, but on the eastern borders of the Devonian area, 
where the oldest Carboniferous strata are met with, they rest conform- 
ably on the Devonian rocks. 
‘he Carboniferous strata, which attain a thickness of upwards of 
2000 métres, are thus grouped :— 
Coal-measures ( Upper Coal-measures. 
Carboniferous (Houiller) { Middle Coal-measures. 
Anthraciferous Carboniferian (Sub-Carboniferous, or Bernician). 
On page 358, the Permian strata (Ifimophyres de Gargantada) are 
bracketed with the Carboniferous system. 
A- concluding chapter is devoted to the phenomena which have 
modified the Paleozoic strata since the period of their formation. 
The former existence of glaciers, in the Quaternary period, on the 
Cantabrian mountains, as evidenced by the accumulations of drift, 
and various other agents of denudation, as well as those of disturb- 
ance, are briefly mentioned. 
This is but a bald outline of a work which embodies the results not 
merely of extensive study in the field, and of very painstaking literary 
research, but also of much original work on the rocks and fossils and 
the problems connected with them. It is not without a slight feeling 
of amazement that we contemplate the many-sided labours of Dr. 
Barrois—the notes on the mineral characters of the various igneous 
