THE ARCHEAN: NOTE II. 189 
angen gneisses, and micaceous gneisses, with bands of white and 
black mica. (This may be called the Ben Fyn group.) Newer 
than tliese probably are some rocks in the Grampians and along 
the shores of the Caledonian Canal, which I have called the 
Grampian series. They consist mainly of fissile mica-schists, 
flaggy micaceous and chloritic rocks. In the series also are some 
talcose, actinolitic and serpentinous rocks. Bands of limestone 
are also found in them. They probably occur also in Suther- 
land, according to descriptions of Dr. Callaway and Prof. Lap- 
worth, and from the evidence of included fragments in the 
Cambrian conglomerates of these, areas. * * * 
Mr. Hudleston, in a discussion reported in the Geological 
Society's Journal (Q. J. G. S., vol. xxxiv., p. 167), remarks : 
" When instituting a comparison between the St. David's district 
and North Wales, the principal datum-line seems to be the great 
conglomerate taken as the base of the Cambrian, which may be 
deemed fairly synchronous in both areas. The point at issue was 
whether the beds below this, . . . were really Pre-Cambrian, or 
had been metamorphosed and intruded at a subsequent period. 
The contents of the conglomerate were very much in favor of the 
author's views." The author (Dr. Hicks) maintains the Pre- 
Cambrian age of the beds. 
In another discussion (Q. J. G. S., vol. xxxv., p. 326), Mr. 
Tawney, referring to the so-called " Arvonian Rocks," doubted 
the advisability of coining a new formation to include the 
quartzites near Haverford West, and the quartz-felsites and grits 
near Bangor, until their relations had been worked out more in 
detail ; the proofs of unconformity to rocks above and below he 
also regarded as dubious. 
The following views are expressed by Professor Bonney, with 
regard to certain rocks in the Highlands (Q. J. G. S., vol. xxxix., 
p. 161) : " In examining these Highland rocks (and I may say 
others also), I have observed three rather well-marked tyjies, 
indicating stages of metamorphism. In the first it is obvious 
that many of the constituents noticed in the slide, especially 
those of krger size, with most of if not all the feldspar, are 
original Of this stage of metamorphism the rocks 
forming the escarpment of the ' newer gneiss,' in the neighbor- 
hood of the head of Loch Maree, furnish excellent examples. 
"In the second stage of metamorphism, while, when we regard 
D 
