363 
[Marcou. 
1889. It reads as follows : “I am under obligations to you for 
the valuable aid your excellent article, Sur les gisements des len- 
tilles taconiques de la Pointe Levis , gave me during my investiga- 
tions on the ‘Quebec group/ so that I feel called upon to address 
you a letter of thanks.” 
My observations on some other portions of the vicinity of Que- 
bec, although not so thorough as at Pointe Levis, instead of being, 
as Mr. Selwyn says, onty partial and in “ignorance of many most 
important facts,” were made and checked most carefully. In fact 
I saw enough to be able to deal with the strata and their great di- 
visions, as they exist around Quebec city, Pointe Levis and La 
Chaudiere. 
Mr. Selwyn has the advantage over me of time, money and 
assistants ; and it is his duty, as Director of the Survey, to make 
a complete and detailed map and report of the district of the city 
of Quebec, which he says “will soon be ready for publication ;” but 
is far from being yet complete enough to be issued. This work 
ought to have been published many years ago ; for it is an absolute 
necessity to have represented on a good geological map, prepared 
by the Geological Survey of Canada, the fault in the rear of the 
Quebec citadel, the one under the river in front of the fortress, the 
one from Pointe Pizeau to St. Foix, and the geographical distribution 
and description of the four thousand feet of the Hudson river group, 
called Citadel Hill slates, and placed above the Trenton and Utica 
as the equivalent and homotaxis of the four hundred feet of the 
Lorraine shales of the vicinity of Ottawa and the state of NewYork. 
Mr. Selwyn is dissatisfied with my criticism of his geological 
maps and with my conclusions on the singular classifications made 
by his predecessors. He calls them “rash and incorrect” and also 
speaks of “inaccuracies, misstatements, and partial references,” 
and announces that he “will give the final conclusions reached by 
the Survey.” I have criticised Logan and Mr. Selwyn’s works on 
the area of the vicinity of Quebec, for the sake only, of the prog- 
ress of geology and knowledge of truth ; at the special request of 
Barrande, Billings, Jewett and L. Agassiz, who asked me repeat- 
edly in 1860, ’61 and ’62 to explore Pointe Levis and Montmorency 
Fall. My motives are as honorable as it is possible to imagine. 
No pay, no help, no reward of any sort to expect ; great distances 
to travel before reaching Quebec, and hard work at hand when 
