192 Canadian Record of Science. 
following extracts from his report on the country north of 
Lake Huron and east of Lake Superior.’ 
“ Hastward of the village of Parry Sound, along the road 
of the same name, dark, hornblendic gneiss or schist pre- 
vails for a distance of about a mile and a half. A band of 
crystalline limestone, and one of mottled white and black 
diorite, occur in association with these rocks where this road 
crosses lot 28, concession I., township of McDougall.” “The 
rock which is here immediately associated with the lime- 
stone is a remarkable looking diorite, consisting of a white 
ground, thickly mottled with patches of dark-green or 
blackish hornblende, having their longer diameters arranged 
parallel to the general bedding. This appears to be the 
rock which Mr. Vennor has described in the Hastings, 
Lanark and Renfrew region, under the name of ‘ blotched 
diorite.” The rock from near Arnprior is rather coarse- 
grained, and with the naked eye is seen to consist of white 
of bluish-white scapolite, with a rather larger amount of 
what looks like a dark greenish hornblende. In appear- 
ance, the scapolite closely resembles that occurring in the 
Norwegian rock, which has been aptly compared by Brégger 
to wet snow. The rock appears to have an indistinet folia- 
tion, but the specimen sent was too small to show its struc- 
ture distinctly. When thin sections are examined with the 
microscope, the rock is seen to be fresh and almost entirely 
free from decomposition products. The structure is for 
the most part granular, none of the minerals being idio- 
morphic.” The principal constituents are found to be 
pyroxene, hornblende and scapolite; and the accessory 
ones epidote, enstatite, pyrrhotite and rutile. 
The pyroxene is very light in colour and faintly pleo- 
chroic. A=yellowish; H—greenish; @—light green. The 
absorption is @ > >A. Basal sections show well-marked 
prismatic cleavages intersecting at an angle of about 90°; 
1 Reports of Progress of Geological Survey of Canada, 1876-77, 
pp. 199 and 204. 
2 Rosenbusch.—Mikroskopische Physiographie der massigen 
Gersteine. Band II. i. Abtheilung,—1886. 
