Reports and Proceedings. 285 
broken sheets and streams over the Old Red Sandstone, on one side, 
and the Coal-series on the other,—that immense coulées of basaltic 
rock, connected with the trap-masses of the hills, cut right into the 
Coal-measures, altering in a remarkable way all the beds along the 
places of contact, converting coal into coke, sandstones and shale 
into quartz-rock, opal, jasper, or hornstone. Such a stream occurs 
in Corrie Glen, near Kilsyth; another crosses the west part of 
Craigmaddie Moor, throwing up the Coal-measures out of their usual 
position; a third is that through which the great tunnel of the 
Waterworks was carried, near Milngavie. Besides, the members of 
the Coal-series about Lennoxtown include conglomerates in which 
pebbles and lumps of the Old Red Sandstone occur,—in fact, this 
conglomerate was derived from the waste mainly of the Old Red 
Sandstone formation ; and it is hardly conceivable that if trap-rock 
had covered the Old Red then as now, fragments of them should not 
be found in those conglomerates, whereas no such trap-fragments 
have ever been found. Dr. Bryce then adduced cases of the same 
kind from the opposite side of the district. On the Gleniffer Braes, 
about Johnstone and Kilbarchan, and round by Houston and Bishop- 
ton, igneous intrusive masses alter and upturn the coal, inverting the 
dip, and towards the borders run in upon the Old Red Sandstone, 
while streams and sheets of trap, descending from the Old Red hills 
of the coast-range, cross the frontier-line of the new formation, and 
pass on to cover the outcrops of the Carboniferous strata. These 
facts making a clear case in favour of the view that all the trap- 
rocks of the district in question are of one age—an age posterior to 
the complete development of the Coal-series, Dr. Bryce expressed a 
hope that the Geologists of the Survey would reconsider their opinion, 
and pronounce in accordance with this evidence. He said the ques- 
tion was certainly not one of any practical value; but it had an 
important bearing on physical geology. In conclusion, Dr. Bryce 
mentioned several illustrative cases, one of which was especially in 
point. In the great promontory of Ben-More, opposite to the Mull 
of Cantyre, a vast range of columnar greenstone rests on the Coal- 
formation, altering the upper beds, and at the southern end of the 
precipice abuts at the same level against strata of white Chalk, 
which is altered to the state of a flaky saccharcid limestone, closely 
resembling Carrara marble, and showing no trace whatever of any 
fossil. Had it not been for the character of its contact with the 
Chalk, the trap would have been regarded as of a much greater age 
than really belongs to it. 
In a paper on a section near Inch-na-damff (Sutherland), the 
Chairman gave a general sketch of the Assynt district, with its 
succession of Fundamental Gneiss, Cambrian sandstone, and Lower 
Silurian quartz-rocks and limestones. ‘The particular section de- 
scribed involved a point in dispute between Sir R. Murchison and 
Professor Nicol, of Aberdeen, relating to the existence of an upper 
quartzite on the limestone. Mr. Crosskey’s observations. confirmed 
the view taken by Sir R. Murchison. ‘The paper concluded with a 
reference to the discovery of forms of animal life in the lower half 
