157 
of the Appennines. 
shape, being sometimes angular, sometimes rounded, and which 
are connected together by a calcareous mass, or by another of a 
different nature. The cemented masses are sometimes compact, 
sometimes scaly-granular. The cementing mass is either of the 
same substance as the fragments, or it is a compound of clay-slate 
and limestone, which is often iron-shot, and not seldom intermixed 
with scales of talc, by which the rock sometimes inclines to talc- 
slate. The imbedded masses have generally a different colour 
from the basis or ground in which they are contained. In many 
varieties, as in the marble of Seravezza, the colours are strongly 
contrasted ; the imbedded masses being white, and the basis 
brownish. The colouring matter of this cement sometimes pe- 
netrates into the imbedded pieces ; and sometimes the mass of the 
one penetrates into the mass of the other, in the form of veins ; 
a fact which, along with many others of a similar description, al- 
lows us to infer, that the whole mass of this conglomerated marble 
is of cotemporaneous formation, and not an aggregate of true 
fragments. 
The granular and foliated limestone or marble of the Appen- 
nines, may be arranged along with the brecciated limestone. The 
celebrated snow-white statuary marble of Carrara, which has 
hitherto been considered as of primitive formation, is referred to 
the transition series by Professor Hausmann. The marble of 
Carrara occurs along with the brecciated limestone in conformable 
and partly alternating beds, and passes equally into the brecciated 
limestone, and into the bounding grey wacke; and it is so disposed 
in regard to these rocks, that the grey wacke, along with clay- 
slate and compact transition limestone, forms the underlying 
rocks, above which is brecciated limestone, which is covered with 
a mountain mass partly of compact limestone, partly of marble, 
which alternate with each other, or are contained in each other. 
In the neighbourhood of Carrara, there is a considerable stalac- 
titic cave, mentioned by Dante, which agrees, in all its characters, 
with the limestone caves of the transition limestone of Germany. 
The marble of Carrara, our author iriforms us, is flexible when 
in long and thin plates. 
One of the most characteristic of the transition rocks is that 
named Gabbro by M. Von Buch, which comprehends the well 
known Serpentine, the Gabbro of the Italians, and a crystallized 
