; Marco u.] 
66 
[Not. 7, 
imade from 1842 to 1882.” The province of Quebec is comprised in 
what he calls “the southeastern palaeozoic basin.” He colors it, first 
with a large belt of Cambro-Silurian (Champlain) as far as Mont- 
morency falls ; then southeast of it another large band of Cambrian, 
but a special Cambrian of his own comprising the Levis formation 
which he continues to regard as the equivalent of the Chazy and 
Calciferous, placing then the Lower Champlain in the Cambrian ; 
then follows a belt of Pre-Cambrian, composed of metamorphic 
-feldspathic schists and gneiss, and finally a belt of true Silurian 
t(the old upper Silurian of Logan, etc.). 
Here is the order which he gives : 
Silurian (third fauna). 
Cambro-Silurian (Champlain in part). 
Cambrian (Taconic and Lower Champlain). 
Pre-Cambrian (Lower Taconic of Emmons). 
The Silurian (Upper Silurian and even Middle Silurian of Lo- 
gan) occupies a very broad belt covering all the country from 
Lake Memphremagog to the United States boundary lines of New 
Hampshire and Maine, and extending to cape Gaspe. Besides Mr. 
Selwyn has colored three patches of Silurian, close by the southern 
shores of the St. Lawrence, in Yamaska, Artabaska, Nicolet and 
Lotbiniere counties. Later observations made by Mr. R. W. Ells 
had limited considerably the upper Silurian, which is reduced to 
one line of small patches, instead of a broad belt, extending from 
lake Memphremagog to lake Massawipi, Stoke, Dudswell, lake A}d- 
mere, Famine river towards Gaspe, and resting unconformably 
upon what Mr. Ells calls Cambro-Silurian and the so-called vol- 
canic belt, and even over Pre-Cambrian rocks of the eastern town- 
ship ; in reality the line of Silurian patches lies unconformably 
over the Taconic system, which the Canada geological survey 
has always completely passed over unnoticed. The exposures of 
Silurian are small bands or rather patches left by erosion and de- 
nudation of a deposit which once covered an area, three or four 
times larger. As to the three large patches indicated on the map 
near the St. Lawrence river between Yamaska and Lotbiniere, 
there is a mistake. 
The Cambro-Silurian, although differently limited on the map as 
in the different papers published by Mr. Selwyn, covers large areas 
on the south side of the St. Lawrence river and even on the north 
side, which are truly Taconic and have nothing to do with the 
