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DISTRIBUTION OF EXTINCT ANIMALS. [part ii. 
but in some of the species reaching a larger size ; Propalceoihe- 
rium and Pachyrwlophus of smaller size and having affinities 
for the other genera named ; and Plagiolophus, a small, slender 
animal which Professor Huxley thinks may have been a direct 
ancestor of the horse. In the Lower Eocene we meet with 
Coryphodon , much larger than the tapir, and armed with large 
canine teeth ; Pliolophus, a generalised type, allied to the tapir 
and horse ; and Eyracotherium , a small animal from the Lower 
Eocene of England, remotely allied to the tapir. 
Among the Artiodactyla, or even-toed ungulates, the swine 
are represented by several extinct genera, of moderate or small 
size — Acotherium, Chceropotamus , Cebochcerus and Dichobune, all 
from the Upper and the last also from the Middle Eocene of 
France ; but Eutelodon , from the phosphate of lime deposits is 
large. The Dichobune was the most generalised type, pre- 
senting the characters of many of the other genera combined, 
and was believed by I)r. Falconer to approach the musk-deer. 
The Cainotherium of the Miocene also occurs here, and an allied 
genus Plcsiomeryx from the same deposits as Euteledon. 
The Eocene Anopl other idse were numerous. The Anoplothe - 
rium was a two-toed, long-tailed Pachyderm, ranging from the 
size of a hog to that of an ass ; the allied Eurytherium was 
four-toed ; and there are one or two others of doubtful affinity. 
All are from the Upper Eocene of France and England. 
Rodentia. — Bern ains referred to the genera Myoxus (dormouse) 
and Sciuru^ (squirrel) have been found in the Upper Eocene 
of France ; as well as Plesiardomys , an ektinct genus between 
the marmots and squirrels. The Miocene Theridomys is also 
found here. 
Marsupials— The Didelphys (opossum) of Cuvier, now referred 
to an extinct genus Peratherium , is found in the Upper Eocene 
of France and England. 
General Considerations on the Extinct Mammalian Fauna of 
Europe.— It is a curious fact that no family, and hardly a genus, 
of European mammalia occurs in the Pliocene deposits, without 
extending back also into those of Miocene age. There are, how- 
