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244 GEOGRAPHICAL ZOOLOGY. [part iv.
uniformity of climate, would naturally lead to less development
of such a group as this, than in the vastly more extensive
and varied and almost equally luxuriant PaLiearctic region of
Eocene and Miocene times ; while on the other hand the greater
number of the smaller Carnivora in the tropics during the Plio-
cene and Post-Pliocene epochs, would be a constant check upon
the increase of these defenceless animals, and no doubt exter-
minate a number of them.
The Eodents thus offer a striking contrast to the Ungulates
and these two great orders afford an admirable illustration of the
different way in which physical and organic changes may affect
large and small herbivorous Mammalia ; often leading to the
extinction of the former, while favouring the comparative develop-
ment of the latter.
Order XL—EDENTATA.
Family 71.—BEAD ^PODID^. (3 Genera, 12 Species.)
|
|
Neotropical I Nearctic
StlR-REOIONS.
I
SUB-REOIONS.
PaL/EARctic
PtIB-REOIONS.
General Distribution.
I
|
2.3 — —
Ethiopian
SUB-REGIONS.
Oriental I
SDB-BEQIONS. |
Aostbalian
SCR-REOIONS.
The Sloths are a remarkable group of arboreal mammals,
strictly confined to the great forests of the Neotropical region,
from Guatemala to Brazil and Eastern Bolivia. None are found
west of the Andes, nor do they appear to extend into Paraguay,
or beyond the Tropic of Capricorn on the east coast. The genera
as defined by Dr. Gray in 1871 are :
—
Cholcepus (2 sp.), " Sloths
with two toes on fore limbs, sexes alike," Costa Eica to Brazil
Bradi/pus (2 sp.), " Sloths with three toes on fore limbs, sexes
alike," Central Brazil, Amazon to Eio de Janeiro ;
; ;
Ardopithecus
(8 sp.), " Sloths with three toes on fore limbs, males with a
coloured patch on the back," Costa Eica to Brazil and Eastern
Bolivia (Plate XIV., vol ii. p. 24).