ie, from my old acquaintance the
Cephalaspians of Cromarty. The animal matter which the bony plates and
scales originally contained has been converted, in both the Gamrie and
Cromarty ichthyolites, into a jet-black bitumen; and in both, the
inclosing nodules consist of a smoke-colored argillaceous limestone,
which formed around the organisms in a bed of stratified clay, and at
once exhibits, in consequence, the rectilinear lines of the
stratification, mechanical in their origin, and the radiating ones of
the sub-crystalline concretion, purely a trick of the chemistry of the
deposit. A Pterichthys in Dr. Emslie's collection struck me as different
in its proportions from any I had previously seen, though, from its
state of rather imperfect preservation, I hesitated to pronounce
absolutely upon the fact. I cannot now doubt, however, that it belonged
to a species not figured nor described at the time; but which, under the
name of _Pterichthys quadratus_, forms in part the subject of a still
unpublished memoir, in which Sir Philip Egerton, our first British
authority on fossil fish, has done me the honor to associate my humble
name with his own; and which will have the effect of reducing to the
ranks of the Pterichthyan genus the supposed genera _Pamphractus_ and
_Homothorax_. A second set of fossils, which Dr. Emslie had derived from
his tile-works at Blackpots, proved, I found, identical with those of
the Eathie Lias. As this Banffshire deposit had formed a subject of
considerable discussion and difference among geologists, I was curious
to examine it; and the Doctor, though the day was still none of the
best, kindly walked out with me, to bring under my notice appearances
which, in the haste of a first examination, I might possibly overlook,
and to show me yet another set of fossils which he kept at the works. He
informed me, as we went, that the Grauwacke (Lower Silurian) deposits of
the district, hitherto deemed so barren, had recently yielded their
organisms in a slate quarry at Gamrie-head; and that they belong to that
ancient family of the Pennatularia which, in this northern kingdom,
seems to have taken precedence of all the others. Judging from what now
appears, the Graptolite must be regarded as the first settler who
squatted for a living in that deep-sea area of undefined boundary
occupied at the present time by the bold wave-worn headlands and blue
hills of Scotland; and this new Banffshire locality not only great