22 THE ROYAL SOCIETY OF CANADA 
possibly be regarded as the equivalents of the Laurentian limestone of 
Quebec. The finding of flattened or squeezed corals of Silurian 
character in these crystalline limestones has proved the fallacy of this 
view and has shown that these rocks, like those of Back bay, may now 
be regarded as parts of the same upper Silurian series. 
As for the specimens recently found in the Mascarene series it may 
be said that these when compared with other fossiliferous sediments 
show also a marked similarity as to their actual horizon, and while the 
fossils obtained may not be so satisfactory for determination as those 
from some other localities, the inference from their study as summed up 
by Dr. Raymond points strongly to their upper Silurian age. 
As for the fossils from L’Etang peninsula, which is separated from 
those of Latete head by only a narrow water passage, it may be remarked 
that the fossils which were collected from the south-western extremity 
where the crystalline limestones are well exposed, do not show any 
well-defined fossil forms, those observed appearing to be merely the 
crushed or flattened remains of corals, which have become so 
metamorphosed as to have the structure destroyed and the organism 
so charged with talcose matter as to render the present rock 
a form of talcose schist. Associated with these calcareous ledges are 
characteristic purple, black and green slates, precisely similar to those 
found at Back bay where the organisms are sufficently well-preserved 
to render the forms distinguishable and capable of being determined. 
The strike of these calcareous and schistose strata is north-east across 
this part of Frye island, but in this direction the metamorphism has 
not proceeded so far as to entirely destroy the structure of the organ- 
isms as is the case farther west, and the forms have been recognized 
in a number of cases. Among the species thus recognized may be men- 
tioned Favosites gothlandica, and F. niagarensis, Heliolites, Atrypa and 
Monomorella and a trilobite of the genus Cybele, a form entirely 
unknown hitherto in the American Silurian, which thus gives a European 
tinge to this fauna, while specimens of the large inarticulate brachiopod 
Monomorella suggest the Guelph of Ontario. The horizon is, therefore, 
probably near the top of the Niagara division of the Silurian. 
The presence of large intrusive masses of green diabase in the lime- 
stones and schistose slaty portions is interesting and enables one to form 
some idea as to the causes which have produced such metamorphism 
in these sediments. This is seen in the extension of these crystalline 
limestones from Frye island north-eastward into the L’Etang penin- 
sula, where they are extensively quarried and where the meta- 
morphism may be said to have reached the highest stage. Here the 
same association of the red, green and purple slates occurs as has been 
noted to the south-west on Frye island and on Back bay, and large 
