156 The American Geologist. September, 
St. George, Ells* reports among others the following : Sy- 
ringopora hisingeri, Diphyphyllum orundinaceum, Heliop/iyl- 
liun oneidaense, Spirifer cfr. duodeiiarius, S. gregarius, S. 
acuminatus, Leptocoelia flabellites and Schizophoria striatula. 
This enumeration shows that the Onondaga of the Connecti- 
cut trough is identical with that of New York. It is also 
known that the Mississippian Onondaga has considerable in 
common with North Europe and the two regions were un- 
doubtedly in communication. The path was along the shores 
of the great North Atlantic continent (Atlantis) to the north 
of Appalachia and down the Gulf of St. Lawrence through 
the Connecticut straits into the Mississippian sea. This seems 
to be plain enough but to find the Onondaga path into the 
Hudson's Bay is not so easy. It is known that about Mon- 
treal there were rocks of Onondaga age because in the agglom- 
erate of St. Helen's Island occur Dalmanella planiconvexa? , 
Spirifer macer and spirifer cf. — granulosus.^ However, it 
does not seem probable that these rocks extended up the Otta- 
wa basin from the St. Lawrence but rather from the Lake 
Huron region, where the Middle Devonic formations are about 
iooo feet thick, eastward ihrough Georgian Bay, the French 
river in the northwestern part of the Ottawa basin, Lake Tem- 
iscaming. Lake Abitibi, and thence northwestward into the 
Moose river region of James Bay. There are outliers of the 
Niagaran in the Lake Temiscaming region, having the same 
fauna as that of the Manitoulin islands, and it seems natur- 
al to follow the Devonic along - the nearest outcrops of the 
Siluric. 
There is not the slightest evidence to connect the Hudson's 
Bay Devonic area with that of the Dakota sea, and the same 
is true in our endeavors to connect the last named sea with the 
Mississippian sea previous to Hamilton time. The Onondaga 
fauna is the outgrowth of the Oriskanian fauna of the North 
Atlantic type plus the migration during - ' Onondaga time of 
other North Atlantic forms by way of the Connecticut trough 
and invasions from the far south through the Indiana 
basin. The Hamilton fauna is the descendant of that of the 
Onondaga plus north European migrants by way of the Con- 
» Geol. Surv. Canada, Rep. for 1887-8, pt. K, 1889, pp. 9K-11K. 
* Schuchert, Amer. Geol., April, 1901. pp. 251-i.'. 
