ANTICOSTI ISLAND FAUNAS. 
21 
paper considerable emphasis was placed on the presence of this 
species 1 , there considered a variety of T. ortoni; but further study 
has shown that it is specifically distinct from that species and 
only varietally different from the Old World T. insularis. 
The Chicotte formation carries a pronounced coral fauna of 
which most of the species are those which are common in the coral 
zones of lower horizons. The writer does not consider that 
the stratigraphic position of the coral fauna means anything in 
relation to correlation, for the Anticosti section proves without 
question that coral deposits are not necessarily of great horizontal 
distribution and may recur again and again with the faunal 
components practically the same. On stratigraphic grounds it 
is correlated for the present with the Irondequoit-Rochester of 
the New York section. 
Elsewhere in the Anticosti embayment there are extensive 
Silurian deposits; but they are either somewhat younger than 
those of Anticosti or present a different type of sedimentation. 
Thus the Black Cape section of Chaleur bay, recently described 
by Clarke 3 , begins with what appears to be the probable 
equivalent of the upper Jupiter River or the Chicotte, while 
the Arisaig section begins with a black shale lithology with a 
corresponding faunal assemblage, the result being that few spe- 
cies are common to the two series or deposits. These indi- 
cate that the Arisaig section begins with the equivalent of the 
upper portion of the Gun River formation and then continues 
upward nearly to the Devonian, 
In terms of the European section, stratigraphic grounds 
would assign the Becsie River and Gun River formations to the 
Lower Llandovery; but, excepting the upper zones of the Gun 
River, the fauna gives little support. The upper zones of 
the Gun River record the appearance of Pentamerus oblongus, 
Clorinda liguifera, Coelpspira hemispheric a, Stricklandinia david- 
soni (represented in Europe by S. lens ) which make their ap- 
pearance in the Lower Llandovery, but become abundant in the 
Upper Llandovery. These and other species and their vertical 
Schuchert and Twenhofel, Bull. Geol. Soc. Am., Vol. 21, 1911, p. 712. 
8 Clarke, Guide Book No. 1, pt. 1, International Geol. Congress, 1913, 
pp. 110-113. 
