the Alps of Piémont and Savoy. 9 
of an average elevation of 8,000 feet, separated by passes up to 
8,000 feet above sea-level. The highest mountain is Montgioie, 
2,630 metres altitude, situated practically in the centre, but both on 
the north and the south the crest-range is flanked by a parallel range 
of somewhat lower elevation. 
The Permian formation occupies, in a width of about 40 kilometres, 
the greater part of the central and also of the northern subsidiary 
range, the declivities of both being deeply eroded by the Tanaro and 
its tributary torrents. On the east the formation thins out towards 
the hills above Savona, and on the west crosses the Stura Valley, 
whence it passes into Dauphiné. The southern subsidiary range 
comprises Monte Abisso, Monte Rocchetta (2,473 metres altitude), and 
some deposits south of Col di Tenda, as part of the Permian 
formation, but is chiefly composed of Triassic and Liassic strata 
bordering on a large area of Eocene albarese limestone and macigno 
sandstone which reaches to the Riviera seaboard of San Remo. 
Besides Rocchetta and Montgioie, the most remarkable Permian 
mountain is Monte Besimanda, 2,404 metres altitude, which is entirely 
composed of that formation and with its double-peaked summit is 
a conspicuous object as part of the northern subsidiary range, being 
situated about 20 kilometres south of Cuneo and 10 kilometres east 
of the Col di Tenda road. The Permian formation, overlying the 
Carboniferous, may be conveniently studied in the outcrops of those 
and other mountains, more especially in the deep and narrow valleys of 
the upper Tanaro and its affluents, one of the most interesting and 
accessible of which is that of the Negrone torrent on the southern flanks 
of Montgioie, where the sequence of strata can be distinctly traced on 
both sides. Another instructive locality is that of the ravines of the 
Bormida torrents east of the Tanaro and south of Monte Settepani, 
where the contact of the Carboniferous and the Permian is well 
exposed at several points. 
Up to the ’eighties the principal authority on the Maritime and 
Western Italian Alps was Gastaldi, who, besides his well-known 
studies on the crystalline and pietra verde rocks and an unpublished 
map of the latter Alps, left a memoir on the former.’ He was at first 
disposed to class the gneissose schists of the Montgioie range with the 
Archean gneiss of the Western Alps; but the Montgioie schists, 
owing alike to their ‘“‘ deficient crystallinity” and to their strati- 
graphical location, presented so puzzling a phenomenon that, pending 
further definition, he designated them as of indeterminate age under 
the name of ‘ apenninite’, as being akin to the Apennines rather than 
to the Alps. As this formation does not extend east beyond the 
Savona hills, and is in no sense characteristic of the Apennines 
proper, the name was obviously a misnomer, and hence Zaccagna, who 
was the first to recognize its true stratigraphical position, chose the 
name of besimaudite, from Monte Besimauda already referred to, as 
typically representative of the gneissiform schist, which has its 
equivalent facies both in the Apuan and the Western Alps, and 
also in the so-called Suretta gneiss of the Spliigen Pass. 
1 “ Fossili Paleozoici Alpi Marittime’’: Atti R. Acad. Lincei, 1877. 
