ll the multitudinous plates to which they owe their
pseudo-name, Polyphractus, in their original places, and bearing unworn
and untarnished their minute carvings and delicate enamel, but existing
in every case as mere detached heads. I found three of them lying in one
little slaty fragment of two and a half inches by four, which I brought
along with me. Mr. Clouston had never seen the curious arrangement of
palatal plates and teeth which distinguishes the Dipterus; and, drawing
his attention to it in an ill-preserved specimen which I found in the
coping of his glebe-wall, I restored, in a rude pencil sketch, the two
angular patches of teeth that radiate from the elegant dart-head in the
centre of the palate, with the rhomboidal plate behind. "We have a fish,
not uncommon on the rocky coasts of this part of the country," he
said,--"the Bergil or Striped Wrasse (_Labras Balanus_),--which bears
exactly such patches of angular teeth in its palate. They adhere
strongly together; and, when found in our old Picts' houses, which
occasionally happens, they have been regarded by some of our local
antiquaries as artificial,--an opinion which I have had to correct,
though it seems not improbable that, from their gem-like appearance,
they may have been used in a rude age as ornaments. I think I can show
you one disinterred here some years ago." It interested me to find, from
Mr. Clouston's specimens that the palatal grinders of this recent fish
of Orkney very nearly resemble those of its _Dipterus_ of the Old Red
Sandstone. The group is of nearly the same size in the modern as in the
ancient fish, and presents the same angular form; but the individual
teeth are more strongly set in the Bergil than in the Dipterus, and
radiate less regularly from the inner rectangular point of the angle to
its base outside. I could fain have procured an Orkney Bergil, in order
to determine the general pattern of its palatal dentition with what is
very peculiar in the more ancient fish,--the form of the lower jaw; and
to ascertain farther, from the contents of the stomach, the species of
shell-fish or crustaceans on which it feeds; but, though by no means
rare in Orkney, where it is occasionally used as food, I was unable,
during my short stay, to possess myself of a specimen.

Mr. Clouston had, I found, chiefly directed his palaeontological
inquiries on the vegetable remains of the flagstones, as the department
of the science in which, in relation to