8 Dr. Du Riche Preller—-Permian in 
conclusive lithological and stratigraphical evidence, they must be 
assigned to the later part of that period, that is, to the Lower 
Permian. The former conclusion was first arrived at in the course of 
the geological survey of the range by Lotti and Zaccagna and upon 
the paleontological authority of the late Professor Meneghini; the 
latter conclusion was chiefly the result of the striking analogy, first 
pointed out by Zaccagna, between the stratigraphical sequence and 
lithological characteristics of the Apuan Alps and the Montgioie 
range of the Maritime Alps which forms the divide between Southern 
Piemont and the Western Italian Riviera. 
The geological survey of the Montgioie range, carried out in the 
eighties, was subsequently extended to a revisionary survey of the 
Italian side of the Cottian, Grajan, and Pennine Alps for the com- 
pletion of the new geological map of Italy then in course of prepara- 
tion and published in 1896; but the latter survey, by Zaccagna and 
Mattirolo, revealed such fundamental differences between the Italian 
interpretations and the existing maps of the French side of the Alps 
that it had, in its turn, to be extended to the French border districts. 
In the result Zaccagna’s conclusions, fortified by his experience in the 
Apuan and Maritime Alps, were fully confirmed, not only as regards 
the continuity of the Permian formation from the Maritime Alps to 
the Western Alps on the French side, but also in relation to the 
pre-Paleozoic formations, a great part of which was’ until then 
regarded by French geologists as of much more recent, that is, of 
later Mesozoic age. 
Having visited the Piémontese, Dauphiné, and Savoy Alps on several 
oceasions, both then and more recently, I propose to succinctly 
review the main features of the Permian formation in the principal 
localities, and also to refer briefly to some of the other important 
points elucidated by the Italian revisionary survey on the French 
side of the Alps. (See sketch-map, p. 10, and plan and sections, p. 11.) 
II. Tue Permian in tHe Maritime Axes. 
As shown in the sketch-plan (Fig. 1, p. 11), the Italian Maritime 
Alps, embracing the Ligurian and the Montgioie ranges, extend from 
Savona west to the River Tanaro, and thence to the Col di Tenda, 
beyond which lie the Mercantour gneiss and granite massif and the 
Cottian Alps. The Montgioie range, in which the Permian formation 
reaches its maximum development, comprises in a length of about 
50 kilom. between the Tanaro—an affluent of the Po—and the 
Col di Tenda road a remarkable series of rugged and peaked mountains 
1 These surveys, accomplished in four consecutive short summer seasons, 
and embracing the Maritime and the whole of the Western Alps, including the 
Mont Blane massif on both sides, constituted on Zaccagna’s part a veritable 
tour de force, enhanced by his exhaustive reports in the Bollettino R. Com. 
Geol. d’Italia of 1887, pp. 346-417, and 1892, pp. 173-244 and 311-404, with 
maps and sections. He also compiled, with Issel and Mazzuoli, an excellent 
geological map 1 : 200,000 of the Ligurian and Maritime Alps for the Italian 
Alpine Club in 1887. The circular examination of the Mont Blanc massif was 
carried out by Zaccagna himself, while a section from the Arve (Chamounix) 
Valley across Mont Blane by the Col du Géant to the Dora Baltea (Aosta) Valley 
was taken by Mattirolo. 
