February 17, 1921. 
Canada 
Geological Survey 
Museum Bulletin No. 31 
GEOLOGICAL SERIES No. 38. 
A CONTRIBUTION TO THE DESCRIPTION OF THE FAUNA 
OF THE TRENTON GROUP. 
By P. E. Raymond. 
This report is intended to give the results of a study of a number 
of new or unusual fossils that were found in the Trenton group during 
a study of the Ordovician formations in Ontario and Quebec. Ap- 
pended Is a table of the subdivisions of the Trenton. In this table, 
the Utica is not considered as a separate unit but as a shaly phase of 
the Trenton. The name “Pieton’ 7 having been used by Prof. Cushing 
in 1910 as a formational name for a granite, the name “Oobourg” 
is here used in its stead, the upper Trenton being fossdliferous in the 
vicinity of that town. 
Subdivisions of Trenton Group. 
Ontario 
Quebec 
New York 
Zonal name 
(Ontario) 
Collingwood 
• 
Utica 
(Northern 
New York) 
Asaphus canadensis 
zone 
Upper Cobourg 
(Upper Pieton 
of former papers) 
“ Utica ** 
Upper Oobourg 
(Northern 
New York) 
Hormetoima zone 
or “sponge 1 ' 1 
beds 
Lower Cobourg 
(Lower Pieton 
of former papers) 
Rafinesquina 
deltoidea zone 
Trenton 
(restricted) 
Trenton 
Trenton 
(typical) 
(Trenton Falls) 
Cystid beds 
Prasopora zone 
Hull 
Glens Falls 
Glens Falls 
(Trinucleus beds) 
( Mohawk valley) 
Crinoid beds 
Rockland 
(Triplecia beds) 
Lorette 
(Parastrophia 
beds) 
Dalmanella zone 
10711—1 
