CHAP. XVII.] 
MAMMALIA. 
241 
been found in the Pliocene and Miocene deposits of Europe, and 
one in the Pliocene of Nebraska in North America. 
Family 68. — CAVIIDAE, (6 Genera, 28 Species.) 
General Distribution. 
Neotropical 
Sub-regions. 
Neargtio 
Sub-regions. 
PAL.-E ARCTIC 
SUB-REGIONS. 
Ethiopian 
Sub-regions. 
Oriental 
Sub-regions. 
Australian 
Sub-regions, 
i . a . 3 . 4 
The Cavies and Agoutis were placed in distinct families by 
Mr. Waterhouse, in which he is followed by Professor Carus, but 
they have been united by Professor Lilljeborg, and without pre- 
tending to decide which classification is the more correct I follow 
the latter, because there is a striking external resemblance be- 
tween the two groups, and they have an identical distribution in 
the Neotropical region, and with one exception are all found east 
of the Andes. Dasyprocta (9 sp.), the agouti, ranges from Mexico 
to Paraguay, one species inhabiting the small West Indian islands 
of St. Vincent, Lucia, and Grenada ; Ccdogenys (2 sp.), thepaca, is 
found from Guatemala to Paraguay, and a second species (some- 
what doubtful) inEastern Peru; Hydrochcerus (1 sp.), the capybara. 
inhabits the banks of rivers from Guayana to La Plata ; Cavia 
(9 sp,), the guinea-pigs, Brazil to the Straits of Magellan, and one 
species west of the Andes at Yga in Peru ; Kerodon (6 sp.), Brazil 
and Peru to Magellan ; Dolichotis (1 sp,), the Patagonian cavy. 
from Mendoza to 48° 30' south latitude, on sterile plains. 
Extinct Caviidaz. — Hydrochcerus , Ccelogcnys , Dasyprocta , and 
Kerodon, have occurred abundantly in the caves of Brazil, and 
the last-named genus in the Pliocene of La Plata. Hydrochcerus 
has been found in the Post-Pliocene deposits of South Carolina. 
Cavia and Dasyprocta are said to have been found in the Mio- 
cene of Switzerland and France. No well-marked extinct genera 
of this family have been recorded. 
If the determination of the above-mentioned fossil species of 
Cavia and Dasyprocta are correct, it would show that this now 
VOL. II. It 
