OLD RED SANDSTONE OF WESTERN EUROPE. 397 
ward extension of the deposits we are now tracing, and to connect the area, 
which has been already described, with the last outlier of the flagstones. Half 
a mile to the west of the promontory the fine-grained pink granite passes 
under grey, green, and yellow sandstones, portions of which may be seen 
adhering to the sea-face of the underlying rock. There may be in all from 80 
to 100 feet of these sandy strata at this locality. They are, however, banded 
with well-marked flagstones and calcareous shales, containing abundant and 
excellently preserved remains of Dipterus, Osteolepis, and Coccosteus. One of 
the most remarkable of these associated beds occurs near the base. It is a 
striped limestone, like that referred to as lying among the sandstones on the 
east side of Bighouse Bay. The occurrence of workable limestone in the Old 
Red Sandstone of the district was noted in the early memoir of SEDGwick and 
Mourcuison.* ‘The seam, three or four feet in thickness, lies imbedded among 
calcareous shales. It is dull blue to grey, or pale brown, on the fresh fractures, 
but weathers with a yellowish crust. It is finely striped by its lamine of deposit, 
along many of which lie numerous minute oval calcareous grains, and some 
larger oval cavities filled with crystalline calcite. I observed no organic 
remains in it. But the white calcareous bodies often suggested to me the 
¢yprid cases of other Palzeozoic limestones, particularly that of Burdiehouse, to 
which the rock now referred to bears a further striking resemblance in its 
abundant fine pale and dark laminz. Some bands of the limestone resemble 
cornstone, and have a strongly foetid odour when broken. 
The sandstone strata, with their interbedded calcareous flagstones, shales, 
and limestones, are well displayed on the cliffs at the mouth of the Baligill 
_ Burn, whence they strike inland, passing under the hamlet of Baligill, and 
SY 
a 
—— 
fanging south-westwards by the village of Strathy. As shown by the shore 
cliffs, they pass up into flagstones of the usual type. These overlying strata form 
a noble range of precipices nearly 300 feet in height as far as Strathy Bay, 
Where they seem to be thrown against the crystalline rocks by a fault flanking 
the east side of Strathy Point. In these cliffs the Caithness flagstones finally 
disappear in a westerly direction. Yet they retain unchanged to the last their 
normal and distinctive features—vertical and overhanging walls, defined by 
clean-cut joints, striped by the rapid alteration of harder and softer layers, 
projecting in huge quadrangular buttresses, trenched by dark perpendicular 
goes, and fretted into stack, skerry, and cave by the restless waves at their 
base. 
Coast Section from Dunnet Head to Duncansbay Head.—The section now 
to be described, though inferior in the impressiveness and variety of its cliff- 
scenery, is unquestionably the most varied and important in Caithness as 
* Op. (cit, pa kole 
VOL. XXVIII. PART II. 5.1L 
