is the _deceiving_ Coccosteus. I disinterred, in the
course of my explorations, as many nodules as lay within reach,--now and
then longing for a pickaxe, and a companion robust and persevering
enough to employ it with effect; and after seeing all that was to be
seen in the bed of the stream and the precipices, I retraced my steps up
the dell to the highway. And then, striking off across the moor to the
north,--ascending in the system as I climbed the eminence, which forms
here the central ridge of the old Maolbuie Common,--I spent some little
time in a quarry of pale red sandstone, known, from the moory height on
which it has been opened, as the quarry of the Maolbuie. But here, as
elsewhere, the folds of that upper division of the Lower Old Red in
which it has been excavated contain nothing organic. Why this should be
so universally the case,--for in Caithness, Orkney, Cromarty, and Ross,
wherever, in short, this member of the system is unequivocally
developed, it is invariably barren of remains,--cannot, I suspect, be
very satisfactorily explained. Fossils occur both over and under it, in
rocks that seem as little favorable to their preservation; but during
that intervening period which its blank strata represent, at least the
_species_ of all the ichthyolites of the system seem to have changed,
and, so far as is yet known, the _genus_ Coccosteus died out entirely.

The Black Isle has been elaborately described in the last Statistical
Account of the Parish of Avoch as comprising at least the analogues of
three vast geologic systems. The Great Conglomerate, and the thick bed
of coarse sandstone of corresponding character that lies over it,
compose all which is not primary rock of that south-eastern ridge of the
district which forms the shores of the Moray Frith; and _they_ are
represented in the Account as Old Red Sandstone proper. Then, next in
order,--forming the base of a parallel ridge,--come those sandstone and
argillaceous bands to which the ichthyolite beds belong; and these
though at the time the work appeared their existence in the locality
could be but guessed at, are described as representatives of the Coal
Measures. Last of all there occur those superior sandstones of the Lower
Old Red formation in which the quarry of the Maolbuie has been opened,
and which are largely developed in the central or _backbone_ ridge of
the district. "And these," says the writer, "we have little hesitation
in assigning to the _