428 STUART WELLER 
larger representation of mollusks in the Corniferous fauna ; and 
even among the brachiopoda, where the two faunas havea greater 
similarity than elsewhere, they are conspicuously different, espe- 
cially by reason of the absence from the later fauna of genera 
which were conspicuous in the earlier one. Corals were prac- 
tically absent from the Oriskany fauna, but in the Corniferous 
they are everywhere present, usually in abundance, and in some 
portions of the province they must have grown in great coral 
reefs. The cephalopods are among the rarest of fossils in the 
Oriskany fauna, but in the Corniferous there are many of them, 
often of large size, among which are present straight, curved, and 
closely coiled forms. Both in its coral element and in its ceph- 
alopod element, as well as in the remaining mollusks, there is a 
strong suggestion in the Corniferous of a recurrence, with pro- 
found modifications to be sure, of the more ancient Niagaran 
fauna, which had occupied the same province at an earlier period. 
It is altogether probable that the Corniferous fauna was in large 
part truly an evolution product from the Niagaran, after that 
fauna had withdrawn from the interior and had become isolated 
in some province upon the border of the continent after the close 
of Silurian time. 
In its geographic distribution the Corniferous fauna is prac- 
tically limited to the Appalachian basin in all directions except 
to the north. The fauna is not known to occur to the east or 
south of the Appalachian land, which formed the barrier to the 
interior basin in those directions. Neither does it extend 
beyond the Wisconsin-Ozark barrier, which was the western 
boundary of the basin. To the north, however, the fauna occurs 
beyond the interior province, in the Hudson’s Bay basin, which 
then, as now, was probably connected with the Arctic basin. In 
a ‘provisional list of fossils collected between the Long Portage 
of the Missinaibi branch of the Moose River and Moose Factory,” 
Whiteaves' has recorded a list of thirty-three species. Among 
these are some thirteen corals belonging to genera and species 
which occur commonly in the Corniferous fauna of the Appala- 
t Geol, Surv. Canada, ‘Rept. of Prog. 1877-8,” p. 50. 
