19 
THE RANGE OF CERTAIN LOWER ORDOVICIAN 
FAUNAS OF THE OTTAWA VALLEY WITH 
DESCRIPTIONS OF SOME NEW SPECIES 
By Alice E. Wilson 
INTRODUCTION 
This paper is a comparative study of the faunal relation- 
ships revealed by collections from the lower Ordovician strata at 
three points in the Ottawa valley, one at Rockland east of Ot- 
tawa, one at Ottawa, and one at MacLaren landing, at the west- 
ern end of lake Deschenes (see Figure 1). The formations repre- 
sented include Chazy, Black River, and Trenton rocks. The 
Rockland and Ottawa sections include beds from the base of the 
Lowville to the top of the Rockland member of the Trenton as 
defined by Raymond. 1 The MacLaren Landing section com- 
mences in the shale and sandstone beds of the Chazy and in- 
cludes the strata up to the lower portion of the Rockland beds. 
The faunal relationships of these strata and the absolute 
conformity of the Rockland beds with the Leray at the Rock- 
land quarry suggested a comparative study of the range of 
species in beds common to the sections measured, and it is for 
this comparative study of range that the corresponding part of 
the Ottawa section has been introduced. 
The author is indebted to Dr. P. E. Raymond for assistance 
in placing some of the more doubtful species, to R. R. Hibbard, 
of Buffalo, who kindly made some of the microscope sections, 
to Dr. R. S. Bassler for advice and assistance in connexion with 
the identification of the bryozoa, and especially to E. M. Kindle, 
whose suggestions and criticisms have been invaluable. 
* 
1 Geol. Surv., Can., Sum. Rept., 1912, p. 349. 
