20 THE ROYAL SOCIETY OF CANADA 
extreme limit, show that these altered sediments originally con- 
sisted of shales and sandstone, gradually passing into slates 
and quartzites, or have become altered into schists such as 
taleose, micaceous and other varieties, associated with calcareous 
layers. These have all been subjected to a great amount of squeezing 
by which many of the diabase or associated rocks have acquired a 
schistose structure, and the rocks themselves are either thrown into a 
series of sharp folds or are often in a nearly vertical position, the schists 
being interbanded with areas of greenstone or diabase of various kinds, 
or in places such diabase masses are replaced by areas of felsites which 
pass into granites. Very often these schistose rocks appear to be non- 
fossiliferous; but sometimes certain schistose portions, associated with 
the diabase layers, together with bands of sedimentary rocks, are found 
in narrow bands in which quantities of well-defined Silurian fossils can 
be recognized; but owing to the great amount of squeezing to 
which these have been subjected, the organisms are often so excessively 
distorted as to render their determination a matter of very great difficulty 
and uncertainty. 
Among various localities from which specimens of fossils have been 
obtained along the shores of Passamaquoddy bay, the following may 
be mentioned. The containing rocks are frequently felspathic schist, 
hard and flinty, greyish-green and purple in colour, and the presence 
of intrusives is very common. Among these a small collection was 
made on the shores in the upper portion of Oak bay, in 1904. It is to 
be regretted that of this small collection most of the specimens were 
lost in transport; but the upper Silurian aspect of those retained was 
marked, and a few specimens from an earlier collection were examined, 
the opinion having been expressed by E. Billings that these latter were, 
in so far as they could be determined, of upper Silurian age. In fact, 
the strata, which are sometimes highly fossiliferous and are cut by 
gabbros and other rocks of clearly later date and intrusive in the 
slaty portions, can therefore scarcely be supposed to form portions 
of Pre-Cambrian rocks to which horizon certain areas of similar aspect 
seen along the St. Croix river in the vicinity of St. Stephen were at one 
time tentatively referred. 
Comparing the rocks here found with those which make up large 
portions of Campobello and Deer islands, and which were at one time 
supposed to be possible equivalents of Pre-Cambrian (Kingston) strata 
in this area, it may be said that in the course of our examinations 
of these areas several occurrencesof fossils were observed, but inall cases 
they appeared to be too indistinct to do more than show their possible 
character without attempting to determine their exact horizons. These 
rocks consist of slates interbedded with diabases and felsites and the 
