[TYRRELL] PRESIDENTIAL ADDRESS 9 
contact was observed by Dr. Robert Bell on Nelson river, where the 
upper rock is a mottled dolomitic limestone of a light bluish-grey 
colour. Further down stream the Ordovician is represented by a 
buff coloured dolomite, mottled with yellow, the beds of which vary 
in thickness from two feet down to quite thin layers. These dolomites 
hold characteristic Ordovician fossils, while some of the beds contain 
in addition many flinty nodules. Dr. Robert Bell! also found similar 
limestone farther north on Churchill river, and I found somewhat 
similar coralline limestone overlying Pre-Cambrian quartzites on the 
west side of Churchill harbour. 
On the western branch of Hayes river, down which we travelled 
to York Factory, no Paleozoic rocks of any kind were seen in place, 
and on the eastern branch, or God’s river, none have been recorded 
as directly overlying Pre-Cambrian granites, etc., but on Shamattawa 
river, into which God’s river empties before it joins the Hayes river, 
thin-bedded horizontal limestones outcrop in low shelving exposures 
for 17 miles along its banks, beginning at a distance, measured in a 
straight line. of 65 miles from Beacon Point. I was fortunate enough 
to be able to pay a hasty visit to the lower portion of this outcrop, 
and though fossils were not abundant, I collected representatives 
of 29 different species, which have since been described by Professor 
Wm. Parks of the University of Toronto. Nine of the species were 
found to be typical of the Ordovician rocks of Manitoba or elsewhere, 
twelve were new, and eight were specifically undeterminable. 
East of this outcrop on Shamattawa river, these Ordovician 
rocks are, as far as we know at present, covered by drift for an indefi- 
nite distance. 
Silurian 
On Nelson river, at a distance of 62 miles in a direct line from 
Beacon Point? Dr. Bell records the occurrence of a yellowish-grey 
fine-grained dolomite, rather soft and earthy, containing obscure 
remains of ‘‘Pentamerus’’ (Conchidium decussatum ?) probably of 
Silurian age. No rock in place has been recorded on Nelson river 
below this outcrop, but I found many irregular fragments or masses 
of dolomite of undoubted Silurian age near the mouth of Seal Creek, 
just above the head of tide water, some of which contained numbers 
of well-preserved specimens of Conchidium decussatum, with Acer- 
vularia Austent and Phragmoceras Nelsonense, and also other frag- 
ments of fine-grained thin bedded argillaceous limestone which con- 
1 Report on Churchill and Nelson Rivers, by Robert Bell. Rep. of Prog. Geol. 
Sur., Can., 1878-9, Part C., Ottawa, 1880. 
2Rep; of Pros Geol Sur, Gan 18778, p.12 CC: 
