ds (_Cursores_) we meet with
the great _Gastornis Parisiensis_, which equalled the African
Ostrich in height, and the still more gigantic _Dasornis
Londinensis_; remains of a Partridge represent the Scratching
Birds (_Rasores_); the American Eocene has yielded the bones of
one of the Climbing Birds (_Scansores_), apparently referable
to the Woodpeckers; the _Protornis Glarisiensis_ of the Eocene
Schists of Glaris is the oldest known example of the Perching
Birds (_Insessores_); and the Birds of Prey (_Raptores_) are
represented by Vultures, Owls, and Hawks. The toothed Birds of
the Upper Cretaceous are no longer known to exist; but Professor
Owen has recently described from the London Clay the skull of a very
remarkable Bird, in which there is, at any rate, an approximation
to the structure of _Ichthyornis_ and _Hesperornis_. The bird
in question has been named the _Odontopteryx totiapicus_, its
generic title being derived from the very remarkable characters
of its jaws. In this singular form (fig. 227) the margins of
both jaws are furnished with tooth-like denticulations, which
differ from true teeth in being actually portions of the bony
substance of the jaw itself, with which they are continuous, and
which were probably encased by extensions of the horny sheath
of the bill. These tooth-like processes are of two sizes, the
larger ones being comparable to canines; and they are all directed
forwards, and have a triangular or compressed conical form. From
a careful consideration of all the discovered remains of this
bird, Professor Owen concludes that "_Odontopteryx_ was a
warm-blooded feathered biped, with wings; and further, that it
was web-footed and a fish-eater, and that in the catching of
its slippery prey it was assisted by this Pterosauroid armature
of its jaws." Upon the whole, _Odontopteryx_ would appear to be
most nearly related to the family of the Geese (_Anserinoe_)
or Ducks (_Anatidoe_); but the extension of the bony substance
of the jaws into tooth-like processes is an entirely unique
character, in which it stands quite alone.

[Illustration: Fig. 227.--Skull of _Odontopteryx toliapicus restored.
(After Owen.)]

The known _Mammals_ of the Mesozoic period, as we have seen,
are all of small size; and with one not unequivocal exception,
they appear to be referable to the order of the Pouched Quadrupeds
(_Marsupials_), almost the lowest group of the whole class of
the Mammalia. In the Eocene rocks, on th