I4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
all parts of the sequence. The brachiopods listed by Twenhofel and Whiting 
(1938), with additions by Cooper, are: 
Ancistrorhyncha ? vacua Cooper 
Camarella ? longirostris Billings = Onychoplecia longirosiris (Billings) 
Camarotoechia orientalis Billings = Rostricellula orientalis (Billings) 
C. pristina Raymond = Rostricellula pristina (Raymond) 
Dactylogonia extensa Cooper 
Glyptorthis cf. bellarugosa (Conrad) = Glyptorthis sp. 
Hesperorthis ignicula (Raymond) 
Lingula huronensis minganensis Twenhofel and Whiting = Lingulella ? huronensis minga- 
nensis (Twenhofel and Whiting) 
Mimella ? minganensis Twenhofel and Whiting = Mimella minganensis Twenhofel and 
Whiting 
Petrocrania prona (Raymond) 
Plectorthis ? piger (Billings) = Mimella piger (Billings) 
Rafinesquina champlainensis minganensis (Twenhofel and Whiting) = Glyptomena cham- 
plainensis minganensis (Twenhofel and Whiting) 
Rhynchocamara varians (Billings) = Camerella varians Billings 
Rostricellula triangulata Cooper 
Schizambon duplicimuratus Hudson = Schizambon duplicimuratwum Hudson 
Correlation of Mingan formation.—The age of the Mingan formation is with- 
out doubt the same as part of the Chazy group of New York; the only question 
is, with what part of the New York section does it correlate? The assemblage 
listed has nothing in common with the older Chazy (Day Point) and is un- 
doubtedly all of younger age. In common with the Crown Point formation of 
New York, which overlies the Day Point formation, it contains Schizambon 
duplicimuratum, Glyptorthis, Dactylogonia incrassata=D. extensa Cooper, Ros- 
tricellula pristina, Onychoplecia longirostris, and Camerella varians. The only 
definite link with the high Chazy (Valcour) is Hesperorthis ignicula, which is 
common in the lower 50 feet of the Mingan section. The reader must be re- 
minded that the Valcour fauna is not yet completely known, particularly the 
portion in Quebec known as the St. Martin formation which contains many ele- 
ments of the Crown Point as the Glyptorthis and Dactylogonia. Consequently 
the correlation is best made with Valcour and Crown Point rather than with 
Crown Point alone. 
The fossils mentioned above as diagnostic of the Crown Point and Valcour 
formations are also reminiscent of species in the Lenoir of Tennessee and the 
McLish of Oklahoma. These formations are correlated (see below) with the 
Crown Point and Valcour of the New York section. This, therefore, seems 
the best assignment for the Mingan formation as well. 
QUEBEC CITY REGION 
The Lévis shales, on the south side of the St. Lawrence, underlie the village 
of Lévis and extend for considerable distances along the St. Lawrence Valley. 
In the vicinity of Lévis these shales contain several boulder beds in which are 
limestone erratics of several ages. Generally these boulders have never been 
dated as younger than late Canadian, but some of the species that have been taken 
