84 
Journal of the 
nlicroliths found ill it, are included in tlie triclinic felspars. I 
observed also, as rare inclusions, more or less regularly formed, 
minute plates of yellowish-brown mica. Magnetite and a few 
exceedingly minute acieular colourless microlitlis complete tlie list 
of inclusions. 
(b) . Mica .—Mica is frequent in occurrence, both as completely- 
formed crystals or as irregular flakes. Its size varies down from 
porphyritic crystals to the minutest flakes visible with a power of 
GOO linear. These microlitlis are in the ground-mass. 
Its colour is light brown, and it is strongly dichroic, in shades 
of light yellow to nearly black. Substances included in the mica 
are of great rarity. The only instance I met with was a small 
portion of the ground-mass, and a few minute apatite needles. 
(c) . Magnetite . — Magnetite is rare, unless the minute black 
specks and opaque black dust-like particles in the ground-mass 
may be referred to this species. 
The Bitlgolmk Dykes . — All the dykes in this neighbourhood 
have a strong resemblance to each other, and, so far as their 
microscopic features are concerned, may be described as a whole. 
Before doing so, I must, however, give a few particulars as to the 
physical features of these dykes, which I extract from notes I 
made at Bulgoback. 
In crossing the low watershed at the source of Granite Creek, 
dykes are to be seen in different places traversing the granite. 
The strike of these dykes varies from N. 25° W. to N. 35° E. 
From the appearances I observed, where one of them crosses a 
gully, its dip is probably to N-. GO 3 W. at about 70°, and its 
width, so far as can be estimated from surface indications, 
10 to 15 feet. On the weathered surfaces are irregular patches of 
whitish felspar, and more or less irregularly formed crystals of 
black hornblende. The dyke stone is somewhat tougher than that 
at Granite Creek. 
Other similar dykes occur in the hills along which the road 
ascends, and again descends, after crossing Bulgoback Creek. 
One of these stands out of the ground for some chains, in a strike 
of N. 30° E., and may be, perhaps, 10 to 15 feet in width. It 
weathers into rounded blocks of a grey colour. When freshly 
broken, the surfaces show a compact dark grey ground-mass, 
with irregular crystals of translucent colourless to opaque white 
