Review of Recent Geological Literature. 245 
Cambro-Silurian system, while from the evidence furnished by the 
Levis limestone conglomerates it is evident that these rocks should be 
assigned, from the presence of fossils in the paste or matrix, to the Cal- 
ciferous formation. These conglomerates and the associated srapto- 
litic Levis shales clearly overlie the red and green shales of the Sillery 
which contain Obolella pretiosa and Lingulfe, and which are now 
regarded by the author as constituting presumably the upper part of 
the Cambrian system, though there appears to be a transition from the 
upper part of the red slate series into the lowest fossiliferous zone of 
the Levis or Ordovician as seen by the extension downward from 
the base of the Levis of certain graptolitic forms into the upper beds 
of the Sillery. The red and green shales however contain Obolella and 
Lingular which are not found in the Levis at all, and in the interstrat- 
ified black shales, Dictyonema sociale and several other forms occur, 
which, according to Lapworth, are more characteristic of the Cambrian 
than the Ordovician. 
Of the limestone conglomerates three fossiliferous zones are clearly 
recognized. Of these the lowest which is associated with the Sillery 
rocks, contains Olenellus thompsoni and other Cambrian forms in 
abundance in the pebbles but no forms newer than Cambrian. The 
second zone or of that of Levis is associated with the graptolitic shales 
of that locality. In this zone the Potsdam or Cambrian fossils are 
confined to the boulders, while the paste contains Calciferous species. 
The third is associated with the Trenton Utica beds of Quebec city. 
From all the evidence presented, both from the stratigraphical stand- 
point and from the fossils, there is apparently no further doubt as to 
the relatively lower positions of the Sillery division, a point long in 
dispute, and which, by the present determination, renders the eluci- 
dation of the complicated structure of the interior, to the south and 
east, much more easy to understand. 
The Pre-Cambrian rocks constitute a well defined anticlinal which 
traverses a large portion of the country in a north-easterly direction at 
some distance from the St. Lawrence. These are flanked, on either 
side, by certain beds of quartzite, black, green and purple slates, with 
small areas of limestone which are regarded as of lower Cambrian 
age, and which in character are precisely similar to those which flank 
the Green mountains of Vermont in which Mr. CD. "Walcott found his 
lowest Cambrian fauna. In connection with the rocks of the Cambrian 
system are also included large areas of dioritic and serpentinous rocks, 
the latter of special economic importance from the fact that they con- 
tain asbestos in quantity at several points. 
The pre-Cambrian rocks consist largely of crystalline schists, chlo- 
ritic, talcose and micaceous, with which are frequently associated 
nconsiderable areas of green chloritic, and generally massive dioritic 
rocks. All these are regarded as the extension of the Sutton mountain 
anticlinal north-eastward, described in the preceding report. A num- 
ber of sections across the scries shows the anticlinal structure at every 
