AND QUARTZ DEPOSITS OF ASSYNT. 351 
beds is also calcareous), that, on laying open some of the 
masses with the hammer, my first impulse was to examine 
them for the characteristic ichthyolites. In brief, the stone of 
not a few of the subordinate beds of this deposit cannot be dis- 
tinguished from Caithness flagstones of the more rubbly kind, 
and are totally unlike any primary rock with which I am ac- 
quainted. We find them associated, however, with other rocks 
of a widely different character, such as traps of the porphyri- 
tic and green-stone series; but though these assume, in con- 
formity with the general arrangement of the deposit, the form 
of strata, they are in all probability mere plutonic injections 
info the body of the deposit, and newer, not only than the 
strata over which they rest, but also than the strata by which 
they are overlaid. In some instances, these trap beds cross 
the line of stratification. There occur, however, in the lower 
parts of the limestone division, intercalated strata of quartz 
rock, mechanical in its structure, which must be regarded as of 
the same age as the calcareous beds with which it alternates. 
The limestone is of various colors and qualities ; and we find 
each stratum retaining its peculiar character and tint for great 
distances together. Some of the strata are earthy, and of a 
chocolate brown approaching to red; some minutely crystal- 
line, and of various tints of gray ; some nearly white, on at 
least their weathered surfaces; and some, as on the farm of 
Auchmore, about a mile from the parish church, well nigh 
black, and, like the limestones of the ichthyolite beds of the 
east coast, strongly bituminous. Like the limestone of most 
other localities, and of almost all ages, this calcareous deposit 
is a cavernous rock. There occur in it in this neighborhood 
several picturesque caves by the side of a tumbling stream, 
within less than half an hour’s walk of Inch-na-damph; and 
the famous cave of Smoo, at Durness, so graphically described 
by Sir Walter Scott, is hollowed in what appears to be the 
