OHAP. XVII.] 
MAMMALIA. 
229 
last Catalogue (1873) lie divides the genus into three — Hyrax , 
Euhyrax and Dendrohyrax — the latter consisting of two species 
confined apparently to West and Soutli Africa. 
No extinct forms of this family have yet been discovered ; the 
Hyracotherium of the London clay (Lower Eocene) which was 
supposed to resemble Hyrax , is now believed to be an ancestral 
type of the Suidse or swine. 
Order X. — RODENTIA. 
Family 55. — MURLDiE. (37 Genera, 330 Species.) 
General Distribution. 
Neotropical 
Sub-regions. 
1 Nearctic 
Sub-reqionb. 
Palsearctic 
Sub-regions. 
Ethiopian 
Sub-regions. 
Oriental 
S db-regions. 
Australian 
Sub-regions. 
1 . 2 . 3. 4 
1 . 2 . 3. 4 
1 . 2 . 3 .4 
1 . 2 . 3. 4 
1 . 2 . 3. 4 
— 2 
The Murid re, comprising the rats and mice with their allies, are 
almost universally distributed over the globe (even not reckon- 
ing the domestic species which have been introduced almost 
everywhere by man), the exceptions being the three insular 
groups belonging to the Australian region, from none of which 
have any species yet been obtained. Before enumerating the 
genera it will be as well to say a few words on the peculiarities 
of distribution they present. The true mice, forming the genus 
Hus , is distributed over the whole of the world except N. and S. 
America where not a single indigenous species occurs, being 
replaced by the genus Hesperomys ; five other genera, compre- 
hending all the remaining species found in South America are 
peculiar to the Neotropical region. Three genera are confined to 
the Palsearctic region, and three others to the Nearctic. No less 
than twelve genera are exclusively Ethiopian, while only three 
are exclusively Oriental and three Australian. 
Mus (100-120 sp.) the Eastern Hemisphere, but absent from the 
Pacific and Austro-Malayan Islands, except Celebes and Papua; 
Lasiomys (1 sp.) Guinea; Acanthomys (5-6 sp.) Africa, India and 
