Rodenxia. MAMMALIA. Rodentia. 
pentadactylous, while some are tetracliictylous. Sev- 
eral fossil extinct forms have beeis found in South 
America. 
BENNET’S HABEOCOME (Hahro'coma lennetii ). — 
I’his form exhibits, in common with others of the 
family, remarkably large auditory bullae ; and there is 
the unusual number of seventeen ribs. 'J’he incisors 
are narrow ; and the crowns of the superior molars 
have a single fold internally; those of the inferior 
are angular, and directed forward. The ears are 
large and nearly naked ; the whiskers long. The 
feet are four-toed ; and the tail is of medium size. 
The pelage is soft and close. Another species, H. 
cuvieri, is much the same. 
CUMMINGS’ OCTODON [Octodon degus) .—'\'\\\s \a a 
Chilian species ; called, also, the Chilian Squirrel, 
from its habits of climbing. The aspect is much as 
with the Chinchillas, with large, round and naked 
ears. It burrows and lives in communities, and has 
some of the habits of the Eabbit. Two other species 
are known, as follows: 0. bridgesii and 0. peruana. 
THE SCHIZODON [Sehizodon fmcus). — I'his is an 
inhabitant of the eastern slope of the Andes. Its 
habits are nocturnal. One species only is known. 
THE SPALACOPUS [Spalacopus pc&ppigii, Wagler). 
— T'his is found in Chili, with habits similar to the 
preceding. One other species is known only — -S. 
noctivagus. The generic name is probably from a 
resemblance of the ears to those of the Spalax. 'This 
latter species has a glossy and rich purple-brown fur. 
The incisors are of a pale yellow in front. The 
molars are indented on either side, so that the figure 
eight is clearly represented ;■ hence the family name, 
from Octo-don. The ears, unlike the preceding forms, 
are very small ; and the tail is very short. 
BRAZILIAN CTENOMYS [Gtenomys iraziliensis, 
Waterli.)—'\'\ns is peculiar to Brazil and neighboring 
countries. The molar-teeth are simple, decreasing 
in size from before backwards, the last one with a 
semi-cylindrical form, the upper series being obliquely 
lunated, with the concavity directed outwards ; the 
form of the lower group is oval. 'J'he eyes and ears 
are small ; the tail is short ; the fore-feet furnished 
with powerful claws, at the base having certain stiff 
hairs, directed inwards; these probably give the 
name — Gtenos, the Greek for comb, referring to these 
comb-like hairs. Habits are like those of the family. 
Other species are C. boliviensis, C. leucodon and C. 
magellanicus. 
Sub-Family — ECHIMYINJE. 
Spiny Rats are the animals embraced in this 
group. They are not attractive, and appear to be 
less known than most others. One genus, Pteromys, 
is found at the Cape of Good Hope, and another, 
Aulacodus, in West Africa. 
An extinct genus, Carterodon, is found in the 
bone caves of Brazil. Genus Caproniys, with two 
species, is found in Cuba. Seven other genera are 
found in South America, represented by twenty-one 
species. The Caproniys is represented by C. prehen- 
silis, and C. pilorides. They are confined to the 
¥ol. I. — o. 
cv 
West Indies. In habit they are slow and somewhat 
Bear-like. Obiedo described one as being named 
locally CiiEms. Another form in this group is Pla- 
giodonta ffidium, found in St. Domingo. 
THE COYPU (Myopotamm coypiis, Molina) — Plate 
1C, fig. 51.— This is a notable form. A specimen of the 
adult Coypu is in the American Museum, in Central 
Park, N.Y., and, as there represented, it is a mammoth 
Rat. Its length is about two feet six inches, having 
all the aspects of the common Norway Rat. It is a 
native of the streams in the region of the Amazon. 
It is a lively animal, having some of the habits of the 
Beaver. Its tail is round, and like that of the Rat. 
The fur is used largely in the hat manufacture. It 
is said that 800,000 skins have been imported into 
Great Britain, under the name of Neutria skin. 
Cercomys is represented by one species. Pteromys 
has one species in Africa. Dactylomys has three 
species; Loncheres, nine; Mesomys, two ; and Echi- 
mys, five. 
Sob-Family— DASYPROC'ITNH:. 
The genus Coelogenys has two extinct species in 
the caves of Brazil. 
PACA [Gmlogenys paca, Linn.) — This is also called 
the Sooty Paca. On account of two cheek pouches 
seen in this genus, the name Coelogenys — meaning 
hollow-cheeked — is applied. 'I’he exterior of the 
cheek bone is singularly rough, and the bone remark- 
ably developed. This is a very pleasing-looking 
species ; prettily spotted. Its length is about two 
feet. It is quite stout and heavy. Its propensity to 
eat the sugar-cane rendei's it a troublesome creature 
to the planters of the West Indian Islands. It bur- 
rows like the Rabbit. Its flesh is esteemed a luxury ; 
but the fur is of no value, being harsh and wiry. 
AGOUTI [Dasyprocta agouchy, Erxl.) — This is a 
comparatively familiar animal, being often seen in 
Zoological Collections,^ alive. It is nocturnal in 
habit, and is said to eat meat at times, as is the case 
with some other Rodents. The name Dasyprocta 
refers to the curious mat of hair which hangs over 
its hind-quarters. It is a native of Central .South 
America. Seven species are enumerated ; and one 
fossil and extinct from the bone caves of Brazil. 
S ub-Family — H YSTRI CINJE. 
Among the Porcupines of South America is the 
genus Chsetomys, with one species. Cercolabes is 
represented by six species and three fossil ones. 
CffiNDOO, OR BRAZILIAN PORCUPINE [Gercolabcs 
preliemilis). — This is a remarkable creature in its 
armor of spines and its prehensile tail, as well as 
peculiarly-armed claws. Its habits are arboreal, find- 
ing its food among the lofty branches of the forest, 
in which it continually dwells. Including the tail, it 
is about three feet in length. It is nocturnal, sleeping 
most of the day. One species of this genus, the 
palidus, is a native of the West Indies. An extinct 
genus is found in two fossil species in Europe. One 
species is found in Eastern Mexico. Three extinct 
fossil species are known from the bone caves of Brazil. 
