1883.] The Pre-Cambrian Rocks of the Alps. 1101 
eruptive masses of Triassic and Eocene time. The writer, how- 
ever, holds with Gastaldi that they are indigenous rocks of pre- 
Cambrian age exposed by geological accidents. 
The uncrystalline rocks of the mainland of Italy are chiefly 
Cenozoic or Mesozoic, and the only Paleozoic strata known are 
Carboniferous, the organic forms of the limestones of Chaberton 
having been shown to be Triassic. Triassic, Liassic, Cretaceous, 
Eocene and Miocene strata are found in different localities resting 
on the various pre-Cambrian groups. In the Island of Sardinia, 
however, all these are overlaid by a great body of uncrystalline 
lower Paleozoic rocks in which the late studies of Bornemann 
and Meneghini have made known the existence of a lower Cam- 
brian fauna, including Paradoxides, Conocephalites and Archeo- 
cyathus, succeeded by an abundant fauna of Upper Cambrian or 
Ordovian age. In the Island of Elba, according to Lotti, rocks 
containing the latter fauna repose directly upon the crystalline 
schists with serpentines. , 
The existence of the younger or Montalban gneiss in Sweden, 
and in the Harz and the Erzgebirge was noticed, and to it were 
referred the Hercynian gneisses and mica-schists of Gümbel. 
The presence both in Sweden and in Saxony of conglomerates, as 
described by Hummel, and by Sauer, wherein pebbles of the older 
gneiss are enclosed in beds of the younger series, was discussed, 
and the direct unconformable superposition of the latter upon the 
older gneiss, in the absence of the Huronian, was considered; 
evidences of the same relations being adduced from the Alps. 
e gneisses of the St. Gothard, as seen on the Italian slope, 
were also referred to the newer series, and the important studies 
of Stapff, in this connection, were discussed. It was declared that 
the views put forth by the author in 1870-71 on the relations and 
Succession of the crystalline stratified rocks in North America, 
and then extended by him to Europe, have been fully confirmed 
y the labors of a great many European geologists, as already 
shown. Those of Hicks, Hughes, Bonney, Callaway, Lapworth 
and others in the pre-Cambrian rocks of the British islands were 
cited in support of these conclusions. It was said that whatever 
may have been the conditions under which these vast series of 
“ystalline stratified rocks were deposited, there is evidence 1n the 
Similarity of their mineralogical and geognostical relations of a 
 Temarkable uniformity over widely separated regions of the 
