utable to French naturalists;[A] and it
seems to be a duty devolving on English and American navigators to
complete the history thus happily begun, and to tell us whether the
Epyornis still exists in the mountain-forests of Madagascar, or at
least present us with its extraordinary relics.

[Footnote A: The following are the names of French travellers, who
have been supposed to have seen the eggs of the Epyornis in the
Island of Madagascar: M. Sganzin, in 1831; M. Goudot, in 1833; M.
Dumarele, in 1848; and M. Abadie, in 1850.]

FOSSIL IMPRESSIONS.--I.

Ichnology, a newly created branch of science, takes its name from the
Greek word _ichnos_, a _track_ or _footstep_, and the tracks
themselves have been denominated Ichnites, or, when they refer to
birds only, Ornithichnites, from _ornis_, a _bird_. And this last term
has by custom been generally applied to ancient impressions, though
not correctly.

Geology has revealed to us not only the remains of animals and
vegetables, but the impressions made by them during their lives, and
even the impressions of unorganized bodies. The first notice of these
appearances was, as often happens, regarded with indifference or
scepticism; but their number and variety enlightened the public mind,
and opened a new source of information and improvement.

The first remarkable observation made on fossil footsteps was that of
the Rev. Dr. Duncan, of Scotland, in 1828. He noticed, in a _new red
sandstone_ quarry in Dumfriesshire, impressions of the feet of small
animals of the tortoise kind, having four feet, and five toes on each
foot. They were seen in various layers through a thickness of forty
feet or more.

Sandstone, in which these impressions are principally discovered, is a
rock composed chiefly of siliceous and micaceous particles cemented
together by calcareous or argillaceous paste, containing salt, and
colored with various shades of the oxide of iron, particularly the
red, gray, brown. It has been remarked by Prof. H. D. Rogers, that the
perfection of the surface containing fossil footmarks is often
attributable to a micaceous deposit. The layers of sandstone have been
formed by deposits from sea-water, dried in succession; such layers
are also seen in the roofing slate. These deposits on the shores of
the ocean, having in a soft condition received the impressions of the
feet of birds, other animals, vegetables, and also of rain-drops,
un