ns, generally about
three inches long.

There are two species to this genus. Of the TRIAENOPUS EMMONSIANUS we
notice three impressions in relief. In another specimen there is the
appearance of a part of the toes of the Anomoepus Scambus, and on the
upper side are seen two excavations corresponding with the three
impressions. In the last slab, the track of the TRIAENOPUS BAILEYANUS
appears to have been made by two feet placed successively in the same
spot, which led President Hitchcock to suspect it might have been made
by a quadruped. One of the specimens has the Triaenopus tracks
intermixed in a peculiar way with other impressions.

The specimen representing the genus HARPEDACTYLUS is larger than the
preceding; and, though leptodactylous, the toes are much broader and
also more curved, whence the name Harpedactylus, _sickle-finger_, from
_harpe_ and _daktylos_.

* * * * *

GROUP FIFTH.

The fifth group differs much from the four previous ones. In this and
the following groups we pass from the vestiges of birds to those of
other animals, some of which are bipeds, some quadrupeds. Many
impressions are without any distinct character, belonging probably to
the lower animals, to vegetables, and unorganized bodies.

The fifth group comprehends the tracks of an extraordinary animal, the
OTOZOUM.[C] The name which has been given to it is taken from that
of an ancient giant, Otus, who with his brother Ephialtes, according
to heathen mythology, made war with the gods. These fabled giants
were, at nine years of age, nine cubits in width and nine fathoms in
height.

[Footnote C: The specific name of Moodii has been attached to the
Otozoum, from its having been discovered by Mr. Moody.]

The foot is divided into four toes; the two outer of which seem to be
connected by a common basis. The inner toe has three phalanges; the
second toe, also three; the third and fourth toes, four each. The
first is the shortest, the second longer, the third longest, the
fourth shorter than the third. It will appear, then, that this track
differs from that of birds in the number of toes pointing forwards;
these being four, while in birds the forward toes are only three.
There is a difference also in the number and arrangement of the
articulations.

The track in our possession is twenty inches long by thirteen and a
half inches broad. The rock in which it is imbedded is a dark-