Rodenti A. MAM JI ALIA. Rodentia. 
civ 
and tlieir cry is such as to easily deceive one in respect 
to the point from wliicli it proceeds. 'J'hey sit erect, 
like the Marmots, and in no way resemble Hares in 
habits.” 
South American Rodentia. 
Waterhouse, in his work On, the Arrangement of 
the Rodentia, divides the order Rodentia into three 
great families — the Mice, the i^orcupines and the 
Hares. Subsequently he added the Squirrels. Mur- 
ray has added two families, which include Hyra.x and 
'I’o.xodon. In considering the South American forms, 
we will follow the arrangement exhibited by Andrew 
Murray [Di&tr Unit ion of Mammals, 1866). 
Family— HIS'I’RIOID^. 
'Phis family embraces, besides the Porcupines, the 
(lavies, or tluinea Pigs, the Chinchillas, the Chilian 
Squirrels, or Octodons, the Spiny Rats, and the Pacas 
and Agoutas. 
THE CAPYBARA {Hydrochoerus capyhara, Erxl .) — 
Plate 11, fig. V. — 'I’his bears a local name of Water 
Hog, its generic title meaning the same, and its 
habits and aspect suggest a relationship to the 
pachydermatous animals. It is well known as the 
largest living Rodent, its size being about that of a 
half-grown Hog. This creature is not familiar, 
though of late it is occasionally seen alive in the 
Zoological Collections. It is fond of the water, and 
dives with great facility, remaining under the surface, 
it is said, eight or ten minutes. Its food is entirely 
vegetable. It is gregarious in habit, herding upon 
the baidis of streams, where it finds ready meims of 
seclusion by diving — its sluggish habit and bulky 
form rendering it an easy prey to the Jaguar or other 
large Cats. It ranges over the whole of South 
America, east of the Andes. 
THE PATAGONIAN CAVY {DoUehotis patagoniea) 
is like a long-legged Hare. It differs from the Cavies 
generally in having quite conspicuous ears; and its 
tail is more developed. Mr. Darw'in, who visited the 
region, says : “ 'I’his animal is found where the country 
is a desert. It is a common feature in the landscape 
of Patagonia to see two or three Cavies hopping 
about, one after another, in a straight line, over the 
gravelly plains which are thinly clothed with a few 
thorny Inishes and a withered herbage.” This crea- 
ture is also called Mara. It does not buri'ow, but 
nests in a form. 
GUINEA PIG [Caviacobaya). — 'I'his is a well-known 
animal, but most absuidly named, as it is neither a 
Pig nor a Guinea animal. Possibly it may have 
been called Guiana Pig originally, as it is said to 
have descended from the wild species that is indigen- 
ous to Rrazil and Guiana. It is too familiar to 
require more notice. 
Sun Famii.y— CIIINCHILLINAE. 
'I'he Chinchillas are especially circumscribed, be- 
ing found only in South America. 'J'hey have four 
molars, rootless, in each side of the jaws, and smooth 
and simple incisors. 'I’he true Chinchillas have four 
toes, with a rudimentary fifth on the fore-feet, and 
four on the hind-feet. 'J’hey are gregarious, feeding 
on roots, and live in burrows or in rocky hillsides. 
'I’he species C. lanigera is prized for its fur; and tiie 
demand is said to sensibly encroach upon their num- 
bers. 'J’he ancient Peruvians are said to have used 
this fur in the manufacture of their fine fabrics. 'I’he 
hinder limbs of these creatures are elongated, being 
nearly twice the length of the fore limbs. 'J’he ears 
are notably large ; the clavicles are well formed ; and 
the tail is developed to a tufted and quite ornamental 
feature. 
THE CHINCHILLA {Chinchilla lanigera)— F\g. 48, 
vol. i, p. I4I — is about the size of a full-grown Rat ; 
the tail being five or six inches in length, and so 
clothed with hairs as to give an aspect of greater 
size to the creature. 'I’he fur is an ashy-gray ; the 
inferior parts whitish. A peculiar aspect is given 
them by the great size of the eyes and globular 
shape of the large ears. 'I’here are also abundant 
whiskers. In habit, this little animal is exceedingly 
docile, and is much prized in its native regions as a 
house pet. Like some other Roilents, they are e.x- 
tremely jirolific, otherwise they would long since 
have been extinct. 
• THE CHINCHA [Lagotis cuvieri) is much like the 
ordinary English Rabbit in size and general appear- 
ance; particularly, it has Rabbit ears; hence the 
generic name. It lives on the western slope of the 
Andes, where it is gregarious, occupying the burrows 
of other animals, or the loose stony localities of the 
mountain sides. 
Another species, L. pallipes of Rennet, is much 
like the present. It is a singular fact that the fur of 
these animals comes off the skin immediately after 
death, at the least touch. 
THE VISCACHA [Lagostomys triehodaclylus) is not 
to be confounded with the preceding, which some- 
times bears the same name. 'This species is also 
called Riscaciio and Marmot Diana. It occupies 
the eastern slope of the Andes, where it was seen in 
companies by Mr. Darwin and others, living in holes. 
A singular habit is related by the former: “'J’he 
Viscachas drag every hard objtsct to the mouths of 
tln'ir burrows. Around each group of holes man_y 
bones of cattle, stones, thistle stalks, Imrd clumps of 
earth, etc., are collected into a hea}), which frequently 
amounts to as much as a wheelbarrow would con- 
tain.” No explanation has yet been given of this 
singular habit. 
An extinct genus, Archaeomys, with two species, 
is found in Europe. 
Sub-Family— OGTODONTINA. 
'I’hese animals are related to the preceding, and 
their habits are much the same; their range being 
chiefly along the Andes and their base. Many of 
them inhabit the west side of the mountains. 'J’he 
molars have no true roots. The members of the 
family are mostly small, with strong fore-feet, armed 
with powerful claws. 'I'he hind-feet in most are 
