CRYSTALINE ROCKS OF N. S& AND CG. B.—HONEYMAN. 1293 
and olivine. 2nd. A boulder of Basalt. When I was surveying 
parts of the Counties of Digby and Yarmouth, Trans. Inst. 187, 
I observed at the Weymouth Station of the Railway a large, 
rough-looking boulder; breaking part of it I found it to be basaltic. 
It was considerably weathered and easily broken. Examining the 
pieces macroscopically I found it replete with crystals of olivine 
of considerable size. These, like the rock, had suffered from 
decomposition and were very friable. Regarding it as different 
from the basalt of Blomiden in having olivine, I called it an 
“Olivine Basalt.” The examination of the preceding basalt shews 
that this is a useless distinction. As fas as I can find this is the 
first time that olivine has been found in these basalts. (a.) Exam- 
ined with crossed nicols the section of this boulder surpasses the 
other in brilliancy. The crystals are similarly pervaded by parallel 
lines. Turning the polariser, these are also trichroic. Before the 
polariser is turned, the vivid chromatic polarisation of the quartz 
is greater than that of the preceding section. The unchanging 
greenish brown colour shows the presence of augite, dark forms 
are also seen but they are small. A erystal of olivine of bright 
green colour adds to the variety. (b.) Examined by the micros- 
cope in sunshine, the small dark forms are seen to be of 
magnetite and to be arranged in groups rather prettily. The 
erystal of olivine is seen to be surrounded with a decayed crust 
which has lost its green color. Smaller crystals, (broken,) are 
seen in different parts of the section. The constituents of the 
boulder are thus, labradorite, augite, quartz, olivine, magnetite. 
2nd. Basaltic dyke at Jebogue Point. I have partially 
described this already, as peculiar and interesting because pene- 
trating Cambro Silurian rocks. I would now describe the section 
more particularly. (qa.) In the polariscope with crossed nicols, it 
appears dark, with faintish light, excepting when it is surveyed 
throughout, the crystals of good size are seen divided by a median 
line. Turning the polariser these erystals are brilliantly trichoic. 
They are therefore labradorite twins. Numerous small crystals 
are also seen, which are also trichroic and give considerable 
brightness to the section when the nicols are parallel. The dark 
‘brown colour is constant, indicating a predominance of augite. 
