28 Mammals of Eastern Asia 
China region to the general Siberia-Japan region. Some of these 
are continuously represented throughout the region; others are 
represented in the south and in the north but not in the inter- 
mediate areas. 
Of those sixty-seven distinct types, the northeast-southwest 
contacts of 53 are made by following the contours of the land, 
usually remote from the sea, through various fairly uniform 
altitudinal zones. Another ten species appear to have a coastal 
pattern of distribution, through eastern China and Formosa to 
Korea, the Maritime Province of Siberia, and Japan. Among 
these the Tree Squirrels, Callosciurus, the Shrews Suncus, and 
the Bats Myotis (Chrysopteron), Pipistrellus, Rhinolophus are 
essentially Indo-Malaysian (some also African) tropical groups, 
while the Mole Mogera, the Macaque Lyssodes, the Pig Sus 
leucomystax, the Goat-antelope Capricomis crispus, and the 
Deer Sika apparently evolved right in coastal eastern Asia. 
Capricomis crispus, in view of its relationship to the continental 
C. sumatrensis, may be regarded as also continental; or else 
either the Japanese or the Formosan crispus may have been 
transported in some way. All of these ten groups show substan- 
tial discontinuities in their patterns of distribution. 
There remain four more groups — the Bats Myotis (Leu- 
conoe), the Marten Charronia, the Bear Selenarctos, and Rattus 
rattus — that may have spread either by the littoral route or by 
the hillside route, or by both. The rattus Rats are primarily trop- 
cal ; like Callosciurus, they are represented in Japan by a single 
species. To this fauna, which may have originated in rather 
remote times in the east Asiatic littoral, may be added several 
local northern elements : two Japanese Moles Dymecodon and 
Urotrichus, the Hamster Phodopus, and the Dormouse Glirulus 
japonic us. 
Types of environment such as the valleys of rivers may suc- 
cessively penetrate two or three nearby faunal areas. River 
valleys like the Yangtse, the Mekong, and the Salween may act 
