fteports and Proceedings. 183 
F.R.S.E., in the chair, Mr. G. C. Haswell, Hon. Sec., read a paper 
On the Age and Fossils of the Silurian Beds of the Pentland Hills. 
He described, and exhibited drawings and specimens of, all the 
fossils yet found in these beds, among which were several new 
species and a number which had not previously been found in this 
locality. Among the new species are three Brachiopoda, given as 
new on the authority of Mr. T. Davidson, F.G.S. They have been 
named Merista? Maclareni, Rhynchonella Pentlandica, and Orthis 
minuta. Among the species new to the locality are some Middle 
Silurian forms, and one specimen of Pterygotus bilobus, showing part 
of the terminal segment and six of the preceding segments tolerably 
perfect. Mr. Haswell showed that in the beds above the village of 
Carlops we have probably the equivalent of the Upper Silurian rock, 
Lower Ludlow and Wenlock Shales, and some red sandstones and 
shales at the source of the Deerhope Burn which are probably older 
than the Wenlock beds, but in these last no fossils have yet been 
found. He also argued that if the order of these beds given by Mr. 
Salter in the Appendix to the Explanation of Sheet 32 of the Geo- 
logical Survey Map be reversed, not only would the section, and its 
relation to the Silurian rocks on the South, be more easily understood, 
but it would do away with the supposition that in this section we 
have no less than three unconformities in the Old Red Sandstone. 
Giascow GroLoeicaL Socirry.—I. The Monthly Lecture, Feb. 
2nd, On the Age of Ice in Scotland, was by the Rev. H. W. Cross- 
KEY, who has for some time past been engaged in the study of the 
subject, and also in working out, with David Robertson, Esq., the 
fauna of the Glacial beds of the West of Scotland, especially the 
more minute forms. The Lecturer described the position and 
characteristics of these beds, which he illustrated by numerous dia- 
grams. He said that there were four distinct deposits, representing 
consecutive periods, during a lengthened and slow upward move- 
ment of the land in Scotland, and referred specially to the beds at 
Fort William, Lochgilphead, Kames in Bute, Lochlomond, Lang- 
bank, Paisley, Jordanhill, and Chapelhall, near Airdrie, representing 
various levels where Glacial shell-beds were now found, varying 
from half-tide at Langbank to 525 feet above the present sea-level at 
Chapelhall. To the venerable President of this Society (James Smith, 
Esq., Jordanhill) is due the honour of establishing the Glacial beds 
as a distinct series, with a characteristic fauna ; and the credit of 
the scientific men of Glasgow is, therefore, peculiarly involved in 
developing this chapter in Geology. The term ‘ Boulder-clay’ is 
very objectionable as applied to the general collection of clays, 
sands, and gravels, indicative of a Glacial epoch. It more correctly 
relates to one term in the series ; and great confusion has arisen 
from the mistake naturally consequent upon a loose phraseology, 
viz., the predicating for a whole series the conditions of one term. 
The phrase ‘ Northern Drift’ is also objectionable; one of the 
peculiar characteristics of the only bed in which the fauna of the 
' period is preserved being, that it is in no sense a drift, but one of 
