ovi Rodenti A. MAMMALIA. Rodentia. 
Family — LE PORID^. 
One species only of tliis fiiinily is known to Sontli 
America, viz.: the Lepus hraziliensis. 'I'lie sub- 
family Myoxini is wholly of the Old \Vorld. 
Family— SCIURIDyE. 
Murray enumerates eleven species of this family in 
the genus Hciurus. None of Fteromys is known 
in South America — nor are the genera Tamias, 
Spermophilus, Oynomys and ArctoniyS. 
Family -MURID a:. 
Of this family, CastorincB is absent in this conti- 
nent, the Beavers being confined to the northern half 
of the hemisiihere. The Arvicolince are also missing 
here. 'J'he genus Reithrodon is represented in this 
region by three species, all being found on the 
southern coast, near Straits of Magellan ; later 
writers place them in the genus Ochetodon. Of the 
Murime (or Mouse proper), only two species are 
known in South America. 'J’he sub family Hespero- 
myincB is represented pretty fully in South America. 
Calomys has thirteen species, ranging from the ex- 
treme north to Fatagonia. llabrothrix has nine 
species and one extinct fossil. Oxymycterus has 
six species, in J’eru, Brazil and Chili, ilolochilus 
has five species, I'anging over the entire continent. 
Alzodon and Drymoinys have each one species, the 
former at an elevation of 14,000 feet. 
Geographical Distkibutio.v of Rodents. 
'i'liE SciURiDyE, according to Wallace, as we have 
previously recorded, present in eight genera from 
one hundred and eighty to two hundred species, 
none being indigenous to the West Indies, Australia 
and Madagascar. 'I’lie southernmost limit in South 
vVmerica is Paraguay. ^ 
Of the genus Sciurus, one hundred, and twenty 
s])ecies are recognized. Sciuropterus has sixteen to 
nineteen; 'i’ainias, five; Siierniophilus, twenty-six; 
Arctoinys, eight. 
Andrew Murray remarks, in his Geographical Dis- 
tribution of Mammals : “Anatomically and jdiysio- 
logically considered, the best classification of the 
Squirrels is into true Squirrels and Jilarmots — a di- 
vision which, with the exception of a single genus, 
(Tamias). corresponds very nearly to the terresf rial and 
arboreal Squirrels. 'J’he terrestrial Squirrels consist 
of the Marmots (.Arctoinys), the Prairie Dog (Cyno- 
niys), and the Sperniophiies. 'J'he genus 'J’ainias is 
also terrestrial, but in structure and affinity belongs 
to the arboreal section, which, besides it, contains 
the true Squirrels (.Sciurus), the Spiny Squirrels 
(Xerus), and the Flying Squirrels (Pteroniys). Jake 
the I lanisters and some other Rodents, a consider- 
able proportion of the Squirrels jiossess cheek 
pouches. All the Sperniophiies and 'I'amias have 
largely developed internal cheek pouches; and Arc- 
tomys has traces of them. In a family containing 
such an army of species as the Squirrels, one is glad 
to be able to break it up into brigades. After separ- 
ating them from the Marmots, Ground Squirrels and 
Flying Squirrels, we have a very homogeneous section 
— the Squirrels proper — which peculiarly require 
farther subdivision, but for which it is scarcely pos- 
sible to find good sectional characters. One small 
section may be, without inconvenience, taken from 
it, viz., the Bristly Squirrels (Xeri). 'J’hese are 
Squirrels with bristles or siiines in their fur, and are 
confined to Africa, south of Sahara. ’I'lie remaining 
are still numerous — about one hundred and eighty 
species — of which the one half are synonyms; and I 
have little doubt that, if the remainder were sub- 
jected to the same stringent scrutiny that Audubon 
and Bachman’s North American species have under- 
gone at the hands of Dr. JJaird, they would be cor- 
respondingly reduced.” 
'J’he g&nws. Sciuropterus is most largely represented 
in the Indian Archipelago — about a third of the 
whole are North American — and a single species 
(Sc. volans) is found in North-eastern Europe and 
North-western Siberia. 'I’here are fifteen species in 
all (a less number than given by AVallace) ; though 
the latter author jirobably includes the six or seven 
species of J^teromys in the genus Sciuropterus. 
'J’he six or seven forms embraced by Fteromys. ac- 
cording to Murray, are peculiar to blast India and the 
Archipelago, lie also jilaces two species of 'I’amias 
in Jturope and Asia, and the remaining “four or five” 
species in America. 
Of the Sperniophiies, Murray enumerates’ “ twenty- 
five species, of which one is extinct, and has left 
traces in the bone breccias of France and Germany.” 
Of the others, “ nine are Old M'^orld and fifteen North 
American species.” None are found south of the 
temperate latitudes of the northern hemisphere. 
“Only two occur in Iturope.” No Sperniophiies are 
seen on the eastern border of the American continent. 
Cynomys. the genus which includes the Prairie 
Dogs, is entirely North American. 
Arctoinys, the Marmots, according to Murray, are 
represented by seven species, three of which inhabit 
the Old World, the remaining species being peculiar 
to the New. 
'The Muridaj, according to Andrew hlurray, are 
represented by twenty-seven species of Arvicola, not 
found on the American continent ; these are mostly 
indigenous to l^urope and Asia, one being African. 
'The latter determination he doubts, however. None 
are found in South America. 
Of the Si*ALACiN.aE, as recorded by Murray, eighteen 
species are of the Old World, mostly in the northern 
parts of Europe and Asia. 'I’lie curious forms of 
Blind Mole-rats are from South Africa. None of 
this group are American. Wallace makes seven 
genera and seventeen species, grouiied under the 
family term Spalacidm. 
'J’he SACCOMYiNyE, in Murray’s arrangement, are all 
American, and confined to the northern hemisphere. 
Wallace gives six genera and thirty-three species, 
embraced in the family Saccomyidce. 
