240 
GEOGRAPHICAL ZOOLOGY. 
[part IV. 
Canada and as far south as Northern Pennsylvania, and west to 
the Mississippi (Plate XX., vol. ii. p. 135); an allied species in- 
habiting the west coast from California to Alaska, and inland to 
the head of the Missouri River ; while a third is found in the 
north-western part of South America ; Cercolabes (12 sp.), ranges 
from Mexico and Guatemala to Paraguay, on the eastern side of 
the Andes; Chcetomys (1 sp.), North Brazil 
Extinct Cercolabidce . — A large species of Cercolabes has been 
found in the Brazilian caves, but none have been discovered in 
North America or Europe. We may conclude therefore that 
this is probably a South American type, which has thence spread 
into North America at a, comparatively recent epoch. The 
peculiar distribution of Cercolabes may be explained by suppos- 
ing it to have migrated northwards along the west coast by means 
of the wooded slopes of the Rocky Mountains. It could then 
only reach the Eastern States by way of the forest region of the 
great lakes, and then move southward. This it may be now 
doing, but it has not yet reached the Southern States of Eastern 
North America. 
Family 67. — HYSTRICIIEE. (3 Genera, 12 Species.) 
General Distribution. 
N EOTROPICAL 
SUB-REGIONS, 
N E ARCTIC 
Sub-regions. 
Pal^earctic 
Sub-regions. 
Ethiopian 
Sub-regions. 
Oriental 
Sub- regions. 
Australian 
Sub-regions. 

C 
- a --| 
P • 2 . 3 - 
1 . 2 . 3 . 4 
1 
The true Porcupines have a very compact and well-marked 
distribution, over the whole of the Oriental and Ethiopian regions 
(except Madagascar), and the second Pakearctic sub-region. 
There is some confusion as to their sub-division into genera, but 
the following are those most usually admitted \—Hystrix (5 sp.), 
South Europe to the Cape of Good Hope, all India, Ceylon, and 
South China; Atherura (5 sp.), “brush-tailed porcupines,” in- 
habit West Africa, India, to Siam, Sumatra, and Borneo ; A can- 
thion (2 sp.), Nepal and Malacca, to Sumatra, Borneo, and Java. 
Extinct Hysiricidce — Several extinct species of Ilystrix have 
