198 Dr. Du Riche Preller—Crystalline Rocks of Piémont. 
Above are otstoceras, T. Loscombet, below are latecosta and varieties of 
liparoceras. The Red Band itself yields Davei and various striata. 
Complete specimens are confined to the limestone bands, for in the 
clays they are much. mixed and often only as fragments, casts, and 
moulds. 
Oppel included practically the whole of the Green Ammonite Beds 
in his Davet zone; but in England this should be restricted to the 
Red Band, although fragments of Davei are often found in the clays 
several feet from the Red Limestone. 
For the excellent photograph the writer is indebted to Mr. G. F. 
Strawson. 
Ill.—Tar Crystattins Rock Arnas oF THE PIEMONTESE ALPs. 
I. Sournern anp Wersrern Prémont. 
By C. S. Du RIcHE PRELLER, M.A., Ph.D., M.1.H.E., F.G.S., F.R.5.H. 
InTRODUCTORY. 
N continuation of the preceding paper (Gnor. Mae., April, p. 156) 
which, as a preliminary to the present one, outlined the new 
classification of the crystalline rock formations and the nomenclature 
of the pietre verdi of the Piémontese Alps, I now propose to briefly 
describe the principal pietre verdi areas with which I became familiar 
during a long stay on repeated occasions in Turin. This city, apart 
from its rich collections of the rocks and minerals of the Piémontese 
Alps, is a most central and convenient starting-point for examining 
the different valleys debouching into the plain of the Po from the 
magnificent crescent formed by the Maritime, Cottian, Grajan, and 
Pennine Alps, which, as seen from Turin, afford by far the most 
extensive and fascinating Alpine panorama in Italy. 
The principal pietre verdi areas lie more especially along or near 
the inner belt or concave eastern edge of the Alpine crescent, and 
include, among others, the following mountains and valleys which 
will be referred to in this and a subsequent paper, and all oe which 
form part of the watershed of the Po: — 
Range. Mountain. Altitude. Valleys. 
| 
m. 
Maritime | Montgioie 2,836 |Bormida, Tanaro, Corsaglia, Tllero, 
Vermenagna. 
a Argentera 8,397 | Gesso, Stura di Cuneo. 
Cottian Monte Viso 83,843 |Grana, Maira, Varaita, Po, Pellice, 
Germanasca. 
Be Rocciavré 2,778 | Chisone, Sangone. 
Grajan Rocciamelone 3,537 | Dora Riparia (Susa Valley). 
fs Ciamarella 8,876 | Stura di Lanzo: Usseglio, Balme, and 
Grande Valleys. 
“ Gran Paradiso | 4,081 | Orco, Soana. 
Hf Grivola , 3,961 | Dora Baltea (Aosta Valley), Cogne, 
Valsavaranche. 
- Mte. Emilius |: 3,559 | Dora Baltea, Buthier, Valpelline. 
Pennine Mte. Rosa 4,636 | (Ivrea Belt) @hinsellay Dora Baltea, 
Tourmanche, Gressonay, Cervo, 
Sesia. 
a a 
