PEOCEEDINGS OT GEOLOGICAL SOCIETIES. 
191 
EOREION INTELLIGENCE. 
M. G. de Mortillet has published* a map of the ancient glaciers of 
the Italian flanks of the Alps, in which the former greater extension of 
the glaciers in the quaternary period and their present retracted limits are 
marked out. The space occupied by these glaciers extended to the valley 
of the Stura, near to the Col de Tende, as far as the environs of Udine. 
The author believes that the lakes on the southern flank of the Alps have 
been scooped out of the soft rocks by the grinding action of the glaciers. 
The resume of his theories is, that after the last upheaval of the Alps 
there w ere formed enormous deposits of horizontally stratified alluvium, 
w hich attained great thickness. These alluvial beds exist above and below 
the large Italian lakes ; over them repose the glacial beds, with striated 
pebbles and unrolled erratic blocks. This deposit has been left by the 
glaciers, which then advanced more or less over the plain. 'J'liese glaciers, 
in clearing out the great basins filled with the ancient alluvium, have 
scooped the site of the present valley. They drove before them the mate- 
rials which they brought down, and these were heaped up in their terminal 
moraines. The alluvial beds deposited during the great extension of the 
glaciers, have formed a continuation of the ancient alluvium, and during 
the period of retreat ihe streams of water have deeply excavated the ante- 
rior or older deposits. They have scooped longitudinal terraces, which 
border their present courses, and have not been able to fill up the great 
depressions which now are the lakes. 
An " Essai sur les Conditions genernles des Couches a Avicuhi conforfa, 
sur la constitution geologique et paleontologique speciale de ces meraes 
couches en Lombardie, et sur la constitution definitive de I'Etage Infra- 
Liasien," by the Abbe Stoppani, has been published in Milan (4to. 1861). 
It is divided into three parts — the first containing bibliographical notices, 
or rather an historical resume of the study of the beds forming the horizon 
of the Avicula contorta, followed b}' a description of the characters of these 
beds, and an indication of their thickness. In England they appear to be 
very thin ; on the northern flanks of the Alps they are some twelve metres 
thick ; while in Lombardy they attain to eight hundred or a thousand feet. 
Their geographical area is of considerable extent; they are met with in 
England, Ireland. Wurtemberg. Bavaria, Westphalia, Luxemburg, in 
the departments of the Moselle and the Meurthe, Cote d'Or, Yonne. Ehone, 
Cevennes, Savoy, Switzerland, in the Vorarlberg, and at other points in the 
chain of the Alps as far as Hungary — everywhere forming a convenient 
and decided band. The second part of the Essay gives a more special de- 
scription of these Avicula contorta beds in Lombardy, where they have 
previously been studied by Collegno, Escher, and Omboni. In the third 
part the autlior shows that, on pala3ontoIogical grounds, these beds must be 
placed in the Jurassic series, and that they are sufficiently important and 
sufficiently clearly separated from the beds above and below tliera to form 
a separate division, which he terms the Etage Infraliasien. He indicates 
exactly the synonyms of other countries, tae principal of which are the 
beds of Koessen in Austria ; the " Bone-bed" and ^yhite Lias in England ; 
the " Cloac " of Wurtemberg ; the sandstone of Helmsingen and of Lseve- 
lange, in Luxemburg; the sandstone of Hettange ; the zone of Ammonites 
planorhis and A. angulatus of M. Oppel ; the limestone of Halberstadt ; 
* Atti della Soc. Italiana dc Sc. Nat. in Milano, 1861, t. iii. 
