[Footnote 1: The absence of any keel on the breast-bone and some other
osteological peculiarities, observed by Professor Marsh, however,
suggest that _Hesperornis_ may be a modification of a less specialised
group of birds than that to which these existing aquatic birds belong.]
[Footnote 2: A second specimen, discovered in 1877, and at present in
the Berlin museum, shows an excellently preserved skull with teeth; and
three digits, all terminated by claws, in the fore limb. 1893.]
[Footnote 3: I use the word "type" because it is highly probable that
many forms of _Anchitherium-_like and _Hipparion-_like animals existed
in the Miocene and Pliocene epochs, just as many species of the horse
tribe exist now, and it is highly improbable that the particular species
of _Anchitherium_ or _Hipparion,_ which happen to have been discovered,
should be precisely those which have formed part of the direct line of
the horse's pedigree.]
[Footnote 4: Since this lecture was delivered, Professor Marsh has
discovered a new genus of equine mammals (_Eohippus_) from the lowest
Eocene deposits of the West, which corresponds very nearly to this
description.--_American Journal of Science,_ November, 1876.]