219 
[Marcou- 
1891. J 
Herman cemetery near Pointe-a-Pizeau. Fossils are found in 
some lenticular masses of magnesian limestone at Pointe-Levis, 
and are distributed in a sporadic way, just like at Phillipsburgh, 
with colonies of forms of the second fauna mixed among supra- 
primordial fossils. 
Both great groups are characterized by the genera of trilobites 
called Dikelocepalus and Batliyurus , which have never been found 
in the typical Champlain system of the New York geological 
survey. The Upper Taconic correspond exactly to the Olenus 
zone of Scandinavia and to the Ffestiniog, Tremadoc, and Arenig 
or Skiddau groups of Segwick in North Wales. t 
Below the Upper Taconic the slates are characterized by a 
fauna entirely primordial, without any mixture of forms recalling 
the second fauna. The principal fossils found in the vicinity of 
Quebec are : Obolella pretiosa and Elliptocephalus ( olenellus ) 
Thompsoni. The thickness of the Middle Taconic cannot be 
given even approximately, because we do not know yet the Lower 
Taconic in that region ; but it must be several thousand feet 
thick. Old volcanic eruptions have left remains in diabase dikes 
and flows, between Etchemin and La Chaudiere rivers, in the 
Middle Taconic group of slates ; but so far the history of those 
volcanos, which have left such conspicuous land-marks at Bel- 
Oeil, is entirely to be written, for neither the geological survey of 
Canada, nor private observers, have yet touched that important 
part of the Lower paleozoic eruptive rocks. 
The quartzites of Montmorency and Indian Lorette are of an 
unknown age. 
In such a mass of broken slates as those of the vicinity of Que- 
bec, it is extremely difficult to use the lithologic character, in 
order to make subdivisions and divisions ; but I have no doubt 
that, if a geologist inhabiting Quebec or Pointe-L6vis devotes 
fifteen or twenty years of constant work to them, that he will 
succeed in giving a rational and clear classification of every foot 
of strata. It is a work of patience and good practical geology. 
Explanation of the Geological Map. — During my first 
visit at Quebec, in September 1849, I made a first rough sketch 
of a geological map, and a general section from Montmorency to 
Chaudi&re’s fall ; giving a copy of both to my friend, the late 
Frangois Xavier Garneau, the historian of Canada, who accom- 
panied me to every locality. Garneau was specially anxious to 
