APODEMUS 505 
distinct insular races. A. flavicollis appears to be a specialised offshoot 
of the sy/vaticus group; it is quite likely of Eastern origin, its range 
extending from northern India to England, in which latter country it 
is a relatively recent immigrant and has developed as a sub-species, 4. 
jf. wintoni, distinct from the typical continental form. 
The sylvaticus group has a wide range, extending over the whole 
habitat of the genus with the exception of eastern Asia and Japan. 
This group probably originated in western Europe; it is first known 
from the late Pliocene (Forest Bed) of Britain, and all the fossil forms 
hitherto discovered in this country are close allies of A. sy/vaticus. 
A. mystacinus, Danford and Alston (Proc. Zool. Soc., 1877, 279), 
from Palestine, and A. epfzmelas, Nehring (Sztz.-Ber. Gesellsch. Nat. 
Freunde, Berlin, January 1902, 2), from Greece and the Balkan 
Peninsula, are much like the sy/vatécus group in essentials, but differ in 
their large size and rather more primitive molars, #! and 7? retaining 
a distinct cusp 3—an ancient element of which no more than the 
merest trace is normally present in other known species of Apodemus 
(Pl. XXVIIL., Fig. 4). 
A. geisha, Thomas (Azz. and Mag. Nat. Hist., May 1905, 491), is 
confined to the Japanese Archipelago, where its typical form occurs on 
Hondo, Shikoku, and Kiushiu; it is differentiated into distinct sub- 
species on each of several of the islands to the north or south of the 
three named. It is described as a delicate species about equal in size 
to one of the smaller forms of A. sy/vatzcus, but with more of the build 
and appearance of a large harvest mouse; its soft fur does not become 
spiny in summer; it has eight mamme; the skull is very smooth, light 
and delicate, without supra-orbital beads, and with the masseteric 
zygomatic plates but little developed ; cusp 1 is present in 7. 
A. speciosus, Temminck (/auna Japonica, 1845, 52; described from 
Japan), is the type of a widely distributed Eastern group which ranges 
throughout Japan, Korea, Manchuria, and westwards and southwards 
through China; in central Asia it is represented by A. nzgritalus, 
Hollister (Szths. Misc. Coll., March 1913, 1; described from Tapucha, 
Altai Mountains, S.E. of Biisk), and it is there accompanied by a 
member of the sy/vaticus group (dA. s. ¢scherga, Kastchenko), In the 
spectosus group the fur becomes spiny in summer, and there are eight 
mamme; the skull has the margins of the inter-orbital region beaded ; 
the cheek-teeth are like those of the sylvaticus group. A. semotus, 
Thomas (Azz. and Mag. Nat. Hist., May 1908, 447), is an interesting 
representative of the sfecéosus group inhabiting the island of Formosa ; 
this is a dark-coloured, thin-furred form which has lost the anterior 
pectoral mamme, there being but six as in A. sylvatecus, and in which 
m and m? have cusp 7 better developed than in most of the sub-species 
of speciosus. 
VOL, II. 2K 
