1877.] Geology and Paleontology. 185 
den are to be counted among the most remarkable acquisitions of modern 
paleontology ; naturalists are compelled to recognize gratefully the labors 
of that great explorer who has gathered so many new facts, and who has 
so well understood the art of selecting such able assistants. From my 
stand-point, it is not the discovery of strange and hitherto unknown 
forms which produces the highest interest in Dr. Leidy’s works on mam- 
miferous fossils, but the discovery of the neighboring forms of our Eu- 
ropean mammiferous fossils, for they show us the ties between the species 
of the Old and the New World; also they let us hope that we may be 
able to understand and discover more easily the connections of the be- 
ings of the geological ages. 
Dicotyles arcuatus looks very much like Cheromorus of the middle 
Miocene of Sausan ; Hyopsodus has molars like the Hyegulus of the 
superior Eocene of Débruge; MMicrosyops is related to the Adapis, a 
genus partly lemurian, partly pachydermatous, which under the name 
of Adapis, sometimes under that of Paleocolemus and also of Aphelo- 
tretum, has left numerous débris in the superior Eocene, and in the lowest 
Miocene. Merychippus looks much like Protohippus, and the latter 
itself seems to be a Hipparion of the Leberon, the island of the superior 
molars of which has been transformed into a peninsula. Archeotherium 
is nothing else than the Entelodon of our inferior Miocene of Bouzon. 
Concerning dentition, Paleosyops, Limnohyus, and Titanotherium resem- 
ble a good deal the Chalicotherium ; this similitude of forms has struck 
me the more, as it shows itself in the species, alike common in America 
and Europe; the Ohalicotherium is found in Europe in the inferior 
Miocene of phosphorites, the middle Miocene of Sausan, and the superior 
Miocene of Eppelsheim. Hyrachius presents us a rare example of the 
passage from the Lophiodon to the tapir; concerning the distinctive 
marks of the latter there appears a last superior pre-molar which is 
simplified, and provided with one single internal denticule, like the _ 
Lophiodon. According to my judgment, the animal lately discovered 
by M. Filhol in the phosphorites of Querez, under the name of Tapirus 
Priscus, is a genuine Hyrachius. The Hyracodon is one more link be- 
tween the Rhinoceros and the Paleotherium ; it is the former which has 
the dental formula of the Paleotherium. The Glurogale of the phos- 
Phorites described by M. Filhgl is the immediate ally of Dr. Leidy’s 
Dinictis. There are found other examples of intermediate forms in the 
Publications of the American savants. If we add, to judge from the 
p of Dr. Leidy, the discoveries in the western Territories of the 
phicyon, Canis, Pseudelurus, Mehacodus, Hyenodon, Hipparion, 
Anchitherium, Rhinoceros, Hyopotamus, Mastodon, very closely related 
to the species we find in France, it becomes singularly probable that the 
west of North America and Europe have been in connection during 
the Miocene period. How could such a thing have happened, if, as able 
geologists believe, the Atlantic Ocean has scarcely changed its place ? 
