in America and Europe. 283 
the Harlech Mountains and the Orkneys, and probably also in 
the Western Islands, and in the Grampians of Scotland. Its 
eas in the regions examined by him is generally about N. 
and 8. 
Highlands of Scotland. From this series of light-colored 
gneisses, often very quartzose, with limestone bands, he sepa- 
' Yates, as we have seen, under the name of Lewisian, proposed 
by Murchison for the ancient gneisses of Lewis and others 
of the Hebrides Isles, these, and similar reddish and dark- 
colored hornblendice gneisses which are found in parts of the 
Malvern chain, in the northwest of Ireland, and possibly also 
in Anglesey. This series, according to Hicks, is unconform- 
ably overlaid by the Dimetian, brecciated beds which hoid 
fragments of the older Lewisian oneiss. The strike in these 
older gneisses “ig usually E. and W., or some point between 
that and N.W. and S. BE.” 
Dr. Hicks concludes the above paper by remarking that the 
chief part of these ancient rocks in Great Britain “were until 
recently supposed to be either intrusive masses, or altered sedi- 
ments belonging to tolerably recent times,” and adds, “it is 
becoming more and more an acknowledged fact that the meta- 
morphism of great groups of rocks does not take place so 
readily as was formerly supposed, but that some special condi- 
tions, such as do not ‘appear to have prevailed over this area 
a pre-Cambrian times, were necessary to produce so great a 
result. 
of the Crystalline Rocks of North America, which will 
found in ‘the Geological Magazine for that year (page 466), as 
ili 443. 
well as in Nature, vol. xviii, page 
Montreal, February, 1880. 
