UPPER EOCENE STRATA OF FRANCE. 
271 
mammalia are usually isolated, often entire, the most deli¬ 
cate extremities being preserved ; as if the carcasses, clothed 
with their flesh and skin, had been floated down soon after 
death, and while they were still swollen by the gases gene¬ 
rated by their first decomposition. The few accompanying 
shells are of those light kinds which frequently float on the- 
surface of rivers, together with wood. 
In this formation the relics of about fifty species of quad¬ 
rupeds, including the genera Palceotherium (see Fig. 174, p. 
254), Anoplotherium (see Fig. 218), and others, have been 
found, all extinct, and nearly four-fifths of them belonging 
to the Perissodactyle or odd-toed division of the order Pack- 
ydermata^ which now contains only four living genera, 
namely, rhinoceros, tapir, horse, and hyrax. With them a 
few carnivorous animals are associated, among which are 
the Ilijmnodon dasyiiroides^ a species of dog, Canis Parisien- 
sis^ and a weasel, Cynodon Parisiensis, Of the Podentia 
are found a squirrel; of the Cheiroptera^ a bat; while the 
Marsupialia (an order now confined to America, Australia, 
and some contiguous islands) are represented by an opossum. 
Of birds, about ten species have been ascertained, the skel¬ 
etons of some of which are entire. None of them are refer¬ 
able to existing species.* The same remark, according to 
MM. Cuvier and Agassiz, applies both to the reptiles and 
fish. Among the last are crocodiles and tortoises of the gen¬ 
era Emys and Trionyx, 
The tribe of land quadrupeds most abundant in this for¬ 
mation is such as now inhabits alluvial plains and marshes, 
and the banks of rivers 
and lakes, a class most 
exposed to sufler by riv¬ 
er inundations. Among 
these were several spe¬ 
cies of Palceotherium,^ a 
genus before alluded to 
(p. 254). These were 
associated with the A7i- 
oplothe^dum, a tribe 
intermediate between 
pachyderms and rumi¬ 
nants. One of the three 
divisions of this family 
was called by Cuvier 
Xiphodon, Their forms 
were slender and ele- 
* Cuvier, Oss. Foss., tom. iii., p. 255. 
Fig. 218. 
