344 
POPULAR SCIENCE REVIEW. 
whole group consists of metamorphosed secondary rocks there is 
no doubt and no difference of opinion among Italian and French 
geologists. In a memoir recently published by M. Sismonda,* 
one of the most able of the Italian geologists, this gentleman 
describes the delight of himself and his companion, M. Elie de 
Beaumont, when, in 1847, on their way from St. Michel by the 
Perron des Encombres towards Moutiers, they arrived at fossili- 
ferous rock among this wide waste of metamorphosed schists, 
and found it exceedingly productive. He says : “We left St. 
Michel with the intention of reaching Moutiers before evening. 
At the Col des Encombres we found ourselves suddenly enveloped 
in cloud, which soon resolved itself into mist, and then into 
downright rain. We reached the great fossiliferous mass soaked 
to the very bones, and our servant and guide were no better off. 
Notwithstanding this, we spent another three hours in looking 
for fossils. When we had got all we could, we proceeded on 
our way, and did not reach Moutiers till eleven at night, in a 
condition that may be more easily imagined than described.” 
The fossils thus obtained included sixty-three species, of which 
thirty-seven only were determinable. Of these five were lower 
lias, fourteen middle lias, twelve upper lias species, the remainder 
being species found throughout the lias. The position of these 
rocks, as representing the lias generally, is thus placed beyond 
doubt ; but it must not be supposed that . this was the first 
discovery of these fossiliferous deposits in the anthracite group 
of Savoy. So long ago as in 1828 M. de Beaumont had alluded 
to it in his Notice sur un gisement de vegetaux fossiles et de 
belemnites , situe d Petit-Coeur , pres Moutiers , en Tarentaise , 
and the fact is one long recognised in the geology of the Alps. 
The series here dips considerably to the SE., and rises again 
in the valley of the Dora, where it exhibits westerly and south- 
westerly inclination also at a considerable angle. There is a 
synclinal axis between the granite rock crossing at Aiguebelle 
and the gneissic rock to the south-east of the valley of the Dora. 
In the earlier paragraphs of this article the general sequence 
of the rocks in the valley of the Arc has been mentioned, and 
it is easy to show that from the direction of the strike of the 
strata and the curvature of the valley before reaching Modana, 
those are again repeated in the tunnel. They may also be 
observed in crossing the Col de la ltoux, which is a pass from 
Modana to Bardonneche, passing near the Mont Frejus at 
an elevation of about 7,750 feet. As the level of the tunnel 
in the middle is about 4,213 feet above the sea, the rocks 
* Nuove Osservnzioni Geologiche sulle Bocce Antracififere delle Alpi, 
del Com. Angelo Sismonda, Pro r es8ore di Mineralogia nella Iiegia Uni- 
versita di Torino. Turin, 1867. 
