57 
[Marcou. 
number 6, is indicated everywhere without double meaning, and the 
map is absolutely confusing in regard to what Logan intends by 
Quebec group, 5a, Calciferous 5, and Chazy 6, or his idea whether 
the Quebec group is equivalent to the Calciferous and Chazy. 
All the province of Quebec south of the St. Lawrence river is 
colored on the map : first, as Hudson river, a large band extend- 
ing from Missisquoi Bay (Lake Champlain) to Quebec city with 
three large patches of Oneida and Medina (Middle Silurian) ; sec- 
ond, we have a large band, occupying all the county from St. Ar- 
mand to Lake Memphremagog, and extending from New York city 
and Albany to Gaspe, the so-called Quebec group ; and third, the 
eastern townships are entirely covered by a broad belt of Upper 
Silurian, called Oneida, Medina, Clinton, Niagara and Lower Hel- 
derberg, with a few spots of Devonian. Logan extends the Upper 
Silurian through Vermont, New Hampshire and Massachusetts. 
The original area of the Laconic system, colored on the geo- 
logical map of 1844, by Dr. Emmons, is referred by Logan to his 
Quebec group (Calciferous and Chazy) and to the Upper Silurian 
(Oneida, Niagara and Lower Helderberg). 
The large map of 1866, scale twenty-five miles to one inch, called 
a chef d’ceuvre by Mr. Charles H. Hitchcock, contains the same 
classification, nomenclature and colors as the reduced map of 1864. 
In both, the Potsdam is still the lowest and oldest group of fos- 
siliferous strata, lying directly above the so-called Huronian or 
Primitive rocks ; both ignore completely the Taconic series with 
their three faunas, Infraprimordial, Primordial and Supraprimor- 
dial and their enormous thickness of 25,000 feet. 
billings’ classification of 1865. 
In 1865, Billings published a palaeontological classification of the 
Province of Quebec on p. 64 of the first volume of his “Palaeozoic 
fossils.” The object was to show the generic relations of the tri- 
lobitic fauna. 
Trenton 
Chazy 
L6vis 
Calciferous 
Potsdam 
fauna. ' 
“ y Lower Silurian. 
J 
Although a strong partisan of the Taconic system and an ad- 
mirer of Dr. Emmons’ discoveries, Billings was not allowed to use 
