64 
Proceedings of Royal Society of Edinburgh. 
theory of their origin, a convincing indication that such movements 
have extensively prevailed, and must have left a corresponding effect 
on the structure of our mountains. At the same time, it is undeniable 
that there has been enormous subsequent removal of material, and 
that in many cases the structure due to subterranean causes has been 
so smoothed over and obliterated to the eye that it is only in acci- 
dental sections they can be traced at all. 
I have now only to add, that since this paper was read before the 
Society, a correspondent, Mr Peter Macnair, Perth, has sent to me 
some specimens of annelid tubes and castings, from a rock high up 
Craig-na-Challeich, one of the mountains above Killin, at the western 
end of Loch Tay, in Perthshire. These markings exhibit all the 
characteristic features before specified and described. They are on 
the weathered surface of a rock highly silicious and micaceous, and 
are more distinctly marked on that surface than any I have found 
in a similar position. A band of limestone lies below the quartzite 
near the base of the mountain, and these two beds are separated 
from each other by many other beds of conformable quartz-schists. 
These details I state from a very clear section kindly furnished to 
me by Mr Macnair. Now that we are all put upon the scent, I 
have no doubt whatever that the Inveraray annelids will be found 
to have had many countrymen and companions in the central as well 
as in the south-western Highlands. 
