1864. | Geology and Paleontology. 477 
tiary strata, yet they are known to have existed at a period as early, 
perhaps, as that of the Connecticut sandstone, the footprints so abun- 
dant in that rock exhibiting characters such as belong normally to this 
class only; but inasmuch as bones of birds have not yet been found in 
the same rock, the fact of the existence of such animals at this remote 
period, can scarcely, as yet, be considered established, although Pro- 
fessor Dana, in analysing a coprolite discovered near the footprints, 
found in it so large a quantity of uric acid as to render it probable 
that it had been formed by a bird. 
If birds existed in the Triassic periods, their descendants or allies, 
must have lived during the deposition of all the succeeding strata ; 
and, until the discovery of the Archcopteryx, this was the only reason 
that could be given for supposing them to have existed during the 
Jurassic epoch. The discovery of that noted fossil supplied a link, 
until then wanting, in the life-history of the class, and thus rendered 
the probability of the Connecticut footsteps being due to birds much 
greater than it was before, by diminishing, in a wonderful degree, the 
gap between the two oldest known indications of ornithic life. The 
Archeopteryx has been described scientifically by Professor Owen, and 
popularly by a dozen or so of soi-disant ornithologists, so that further 
notice of it need not be taken here. 
Most of the bones of supposed birds found in Cretaceous strata 
have turned out to belong to other classes of animals, and in their 
investigation even Professor Owen appears not to have been free from 
error, as he described, under the name of Cimoliornis Diomedeus, some 
remains found by Lord Enniskillen in the chalk near Maidstone, 
which were afterwards shown by Dr. Bowerbank to be reptilian, and 
probably to belong to Pterodactylus giganteus. The result at which 
the author arrives is that the only undoubted evidences of Cretaceous 
birds are—(1), Their remains discovered by the late Mr. Barrett in 
the Cambridge Greensand ; and (2), Those cited by Mr. Harlan from 
the Greensand of New Jersey. 
Respecting the ornithic fauna of the Tertiary period, it must be 
sufficient to remark that remains of about 12 genera, represented by 
many species, have been found in the Paris Basin, besides at least 
seven kinds of tracks; and that the Miocene and later strata have 
afforded still more numerous remains, and the author of this paper 
indicates in it the characters of twelve new species from the Miocene 
strata of the Limagné. It must also be remembered that while a single 
species is of great interest when it constitutes all that is known of a 
fauna, it sinks into comparative insignificance when it forms, perhaps, 
but the fiftieth part of a known population. 
M. Alphonse Milne-Edwards concludes his paper by observing— 
(1) That the existence of Gastornis Parisiensis and of the imprints of 
gigantic feet in the Paris gypsum shows that during Eocene times there 
existed a fauna at least as perfect as that of the recent period ; (2) That 
the birds of the Miocene period differed but little from those of the pre- 
sent day, certain families, however, such as the Phenicopteride, which 
are scantily represented now, being rich in genera and species then ; and 
(8) That in the Quaternary period only the fauna of the present day 
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