224 
1861. — Marcou (Jules). — The Taconic ancl Lower Silurian rocks of Ver- 
mont and Canada ( Proceed . Boston Soc. Nat. Hist., v ol. win, pp. 
239-253, November). At p. 248, there is a “Theoretical section 
of the rocks of the vicinity of Quebec,” with an explanation of the 
superpositions. It is a first attempt at a rational and exact classifi- 
cation of the strata of the environs of Quebec. 
1862. — Billings (E.). — 3. On some new species of fossils from the Quebec 
group. Synchronism of the Pointe-Levis limestones ( new species 
of the Lower Silurian fossils, pp. 57-96, issued June, 1862. Reprinted 
in Paleozoic fossils, vol. i, 1865, with alterations so great as to be 
regarded as another paper. The pages 57 to 67 are entirely different 
from the same pages 57 to 67 of the issue of June 1861. It is an 
incomprehensible confusion, showing the complete state of anarchy 
of the geological survey of Canada, after the publication of 
Barrande and Marco u’s papers on the geology of the vicinity of 
Quebec. 
1862. — Marcou (Jules). — Letter to M. Joachim Barrande on the Taconic 
rocks of Vermont and Canada, August 1862, Cambridge. The 
author gives an “abstract section for the vicinity of Pointe-Levis, 
Chaudiere and Quebec,” with explanations, pp. 9-15. For the first 
time the existence of lenticular masses of limestone, sandstone and 
puddingstone inclosed in the shales are clearly shown and an exact 
classification and nomenclature of all the strata around Quebec is 
given, under the names of : “city of Quebec” group, “Pointe-Levis 
and Redoubt” group and “Chaudiere and Sillery” group for the 
Canadian Taconic. In this paper is the first notice of porphyry or 
diabase inclosed and crossing the strata of the Chaudiere group. 
The paper marks a new departure for the stratigraphy of the en- 
virons of Quebec. 
1863. — Logan (W. E.) — Letter addressed to Mr. Joachim Barrande on the 
rocks of the Quebec group at Pointe-L$vi» ; March 1863, Montreal. 
Reprinted in Canadian Naturalist, vol. win, pp. 183-194. A second 
attempt to explain the stratigraphy of Pointe-Levis, crossing and 
blotting his explanation of 1861, and creating new stratigraphical 
confusions. 
1863. — Billings (E.). — The parallelism of the Quebec group with the 
Ilandeilo of England and Australia, and with the Chazy and Calcifer- 
ous. ( Canadian Naturalist, vol. win, pp. 19-35.) 
1863 — Devine (T.). — Description of a new trilobite from the Quebec 
group. — Olenus? Logani, Pointe-Levis. ( Canadian Naturalist, vol. 
win, April, pp. 95-98.) 
1863. — Devine (T.). — Description of a new triobite from the Quebec 
group. — Menocephalus Salteri , Pointe-Levis. {Canadian Naturalist, 
vol. win, June, pp. 210-211.) 
1864. — Marcou (Jules). — Notice sur les gisements des lentilles trilobitiferes 
taconiques de la Pointe-L6vis, au Canada {Bulletin soc. geol. France, 
vol xxi, pp. 236-250, avril.). A minute description with section 
and map of a part of Pointe-Levis. 
