place they continue to form high cliffs, covered in a similar manner by trap, and extending along the coast for a considerable space towards Holme. Limestone occurs together with the sandstone in the interval last described, but the shore is so difficult of access on account of its rocky boundary, the want of creeks or harbours where a boat may land, and the general prevalence of a heavy sea, that it is not possible to trace every point, nor, consequently, to perceive where the changes of the strata take place; while, from the mural front and excessive height of the cliffs, they are themselves absolutely inaccessible. To add to the difficulty, the limestone when weathered puts on the grey colour and aspect of the sandstone so perfectly, that it is often difficult to distinguish them, when even within reach, without the assistance of a recent fracture.
I must here premise that the whole of the strata hereafter to be described, as well as those new mentioned, have a regular and even dip towards the north-west, which is at a small angle, although no opportunity is offered of ascertaining its quantity. In this respect they are conformable, if they are not absolutely consecutive, to the Strath limestone, and I may add that this dip is apparent over the interior country wherever they can be seen, while at the same time it is indicated generally by the gradual disappearance of the lower beds on the west side of the promontory, their thickness amounting on that shore to a few feet only, while on the east side it reaches to many hundreds. I need scarcely say that cases of obvious disturbance connected with the interference of trap must be excepted from this general rule. I
Passing Holme the shore becomes occasionally more easy of access, although the mural line of cliff continues, and here limestone strata are found to have succeeded to the sandstone. These strata contain spheroidal concretions similar to those which attend the
