fossils furnished by the better-known
deposits. But I have since seen in abundance shells of the boulder-clay.

There is another scenic peculiarity of the clay, which the neighborhood
of Cromarty finely illustrates, and of which my walk this morning
furnished numerous striking instances. The Giants' Graves--to borrow
from the children of the place--occur on the steep slopes of the old
coast line, or in the sides of ravines, where the clay, as I have said,
had once presented a precipitous front, but had been gradually moulded,
under the attritive influences of the elements, into series of
alternating ridges and furrows, which, when they had flattened into the
proper angle, the green sward covered up from further waste. But the
deep dells and narrow ravines in which many ranges of these graves occur
are themselves peculiarities of the deposit. Wherever the boulder-clay
lies thick and continuous, as in the parish of Cromarty, on a sloping
table-land, every minute streamlet cuts its way to the solid rock at the
bottom, and runs through a deep dell, either softened into beauty by the
disintegrating process, or with all its precipices standing up raw and
abrupt over the stream. Four of these ravines, known as the "Old Chapel
Burn," the "Ladies' Walk," the "Morial's Den," and the "Red Burn," each
of them cutting the escarpment of the ancient coast line from top to
base, and winding far into the interior, occur in little more than a
mile's space; and they lie still more thickly farther to the west. These
dells of the boulder clay, in their lower windings,--for they become
shallower and tamer as they ascend, till they terminate in the uplands
in mere _drains_, such as a ditcher might excavate at the rate of a
shilling or two per yard,--are eminently picturesque. On those gentler
slopes where the vegetable mould has had time and space to accumulate,
we find not a few of the finest and tallest trees of the district. There
is a bosky luxuriance in their more sheltered hollows, well known to the
schoolboy what time the fern begins to pale its fronds, for their store
of hips, sloes, and brambles; and red over the foliage we may see, ever
and anon as we wend upwards, the abrupt frontage of some precipitous
_scaur_, suited to remind the geologist, from its square form and flat
breadth of surface, of the cliffs of the chalk. When viewed from the
sea, at the distance of a few miles, these ravines seem to divide the
sloping tracts in whic