274 Reviews—Dr. Barrois’ Geology of Asturias, ete. 
be convenient to take them in the order of time, rather than to follow 
the arrangement adopted in the work itself. 
“Terrain primitif.’—Some of the Spanish geologists have divided 
the Archzean masses of the province of Salamanca into nine distinct 
stages, thus eclipsing the achievements of Dr. Sterry Hunt in America, 
and of Dr. Hicks in the British Isles. The author is not prepared 
to accept these stages. After referring to the importance of Mac- 
pherson’s work in Western Galicia, he gives his own views of the 
“terrain primitif” in that province. 
The granitoid gneiss, which forms the lowest known stage of the 
Archean system, is wanting in Galicia, where the system is repre- 
sented by two principal groups of distinct beds: the lower is formed 
essentially of mica schists, the upper one of green schists, which 
are chloritic, hornblendic, talecose, or micaceous, along with beds of 
quartzite, sérpentine, etc. Subordinate to the preceding, occur thin 
beds of gneiss, and of garnetiferous hornblende-rocks: the mineral 
composition of these is most elaborately described (pp. 898-406). 
The elements of the crystalline schists (page 393) are entirely 
crystallized, there is no vitreous or amorphous magma. In fact, Dr. 
Barrois’ observations as to their structure correspond with what has 
been noted by M. Michel-Lévy in treating of the gneissic formation 
of Morvan in France. The black mica has no regular erystalline 
outline, and possesses a characteristic arrangement, as seen under the 
microscope; the felspars are irregularly distributed, triclinic felspars 
being rare, whilst quartz constitutes the greater part of the rock. 
“ Roches sédimentaires.” — With respect to the Cambrian and Silurian 
systems, the following table will best explain the lower portion of the 
Palzeozoic column, as developed in the Cantabrian Chain. 
(1. Schists and grit of Corral. { Schists and Quartzites of Corral, 
| Upper Silurian. \  Ampelites. 
Caleareous Schists of El Horno, 
with Endoceras duplex. 
Slates of Luarea with Calymene 
Tristani. Bed of Iron Ore. 
SILURIAN | 2. Schists of Luarca. 
SYSTEM 3 Middle Silurian (2nd fauna). 
in The fauna at p. 457. 
Asturias. 
. Grés de Cabo Busto a scolithes. 
o, Gus be (Calvo ET 0, Variegated grits. Conglomerates 
Lower Silurian. ONS 2 
L and schists. 
\ _ { 1. Limestones and schists with 5 . 
CAMBRIAN Punddetides, \apis sy Vesa ui Rough greenish Schists. 
SYSTEM 50-100 m ©" > b. Limestones (20-60 m.). 
in de c. Schists and Iron Ore (1-2 m.). 
Calan (1st fauna.) 
= d. Greenish Schists. 
Asturias. | 2. Schists of Rivadeo, 3000 m. Le Blush “ Phyllades.” 
This terrane is conformable to the underlying “ primitive formations’’: there is no 
dislocation, disturbance, nor marked lithological change. 
At page 408 we are favoured with an insight into the stratigraphy 
of the Cantabrian Chain, which is illustrated by two large sheets 
of sections in the Atlas, and a sheet of geological sketches. The 
entire coast-section from Villalba to the frontier of the province of 
