144 The American Geologist. March, isoo 
find a marked resemblance both as regards the optical char- 
acteristics of the individual minerals and the relative quanti- 
ties of each component. 
While making a hasty review of the ''Report of Progress 
(1886) of the Canadian Geol. Survey" numerous references to 
intrusive rocks were noted in an article by Hugh Fletcher 
Esq. on the geology of the eastern counties of Nova Scotia. 
During a short visit to my native province I made a hasty 
trip over parts of Pictou and Antigonish counties, so well 
described by Mr. Fletcher, with the intention of finding a few 
of the "intrusives" referred to. Owing to the short time at 
my disposal I succeeded in finding but two eruptive masses. 
On Arisaig coast at the mouth of McAra's brook, was 
found amygdaloidal trap interstratified with lower Carbonif- 
erous conglomerates, and at many places breaking through 
the bedding of the conglomerate in a very irregular and com- 
plicated manner. A short distance northeast of this point 
another trappean mass was found presenting similar condi- 
tions. The conglomerate is but slightly altered at the point 
of contact. So irregular was the mass that it was impossible 
to obtain any definite information concerning its dip or actual 
thickness. Whether, the ejection of this rock was contem- 
poraneous with that of the numerous Triassic patches to the 
west, there does not at present appear any evidence ; but fur- 
ther examination may prove that such is the case. In its 
macroscopic characters the rock resembles very closely the 
vesicular traps of cape Blomidon. Its lower specific gravity, 
however, (2.748) proves it to be much less basic. 
Under the microscope the rock proved to be composed 
mainly of feldspar, with irregular patches ofaugiteand a whit- 
ish mass, a secondary product probably derived from the feld- 
spar. The feldspar which is probably plagioclase,istoomuch 
decomposed to show any very decided optical properties. Their 
typical lath-shaped or rod-like form, however, is fairly well 
exhibited. The augite is scattered through the rock-mass in 
small, irregular patches, presenting no crystalline form, but 
in a few cases sufficiently fresh, and presenting cleavage 
cracks, and optical properties sufficient for orientation. No 
magnetite was observed in any of the sections from this local- 
ity. While the rock is made up of the same mineral constit- 
