MAMMALS OF LIBERIA 597 
Rattus norvegicus norvegicus (Erxleben). Norway Rat 
Mus norvegicus Erxleben, Syst. Regni Anim., vol. 1, p. 381, 1777: Norway. 
In color much like the Roof Rat, but ears small and tail about as long only as head and body, 
instead of longer. Introduced. 
The Norway Rat is a more terrestrial species than the preceding, making 
burrows about buildings and along banks, while the Roof Rat is a climber, though 
both forage about a great deal on the ground. The Norway Rat, too, is in general 
more northern in its natural distribution and is usually much less common in 
warm countries than is the Roof Rat. Of the many rats we saw captured, all 
were of the latter type, but Biittikofer claims to have captured the Norway Rat 
at Robertport. It must be relatively uncommon, however. It is interesting 
that neither Biittikofer and his associates nor our party found any evidence of the 
introduction of the common House Mouse. It is likely that it may occasionally 
be found in the port of Monrovia but would perhaps become established with 
difficulty on account of coming into competition with the Multimammate Rats. 
Cricetomys gambianus liberiae Osgood. Giant Rat 
Cricetomys gambianus liberiae Osgood, Ann. Mag. Nat. Hist., ser. 8, vol. 5, p. 281, 1910: 50 miles 
inland from Monrovia, Liberia. 
A giant species, two feet or more in length, the long tail with a white tip; general color above 
light chocolate brown, slightly mixed with black; below, shading into whitish or grayish white, 
feet silvery. Widely distributed in tropical Africa, with sundry local races. 
We were unfortunate in failing to secure specimens of this large rat though 
apparently it is not uncommon. Bittikofer found it living in old termite hills 
whence it is often dug out by the natives. He records it from Bavia, Buluma, 
and the Junk, Du, and Farmington rivers. He adds that in captivity it soon 
becomes rather tame though always ready to bite, and will sit up on its haunches 
to eat, using its tail for a support like a miniature kangaroo. Like the latter it will 
sometimes leap forward on its hind feet alone. Miller records a single specimen 
from Mount Coffee. Osgood described this slightly differentiated local race from 
two specimens in the British Museum collected by A. Whyte fifty miles inland 
from Monrovia, and records a third from Sierra Leone. 
Dephomys defua (Miller). Bristly Rat 
Mus defua Miller, Proc. Washington Acad. Sci., vol. 2, p. 635, 1900: Mount Coffee, Liberia. 
A medium-sized rat, head and body about 128 mm., tail 187, the tail bare except at the end 
where it is slightly hairy; color above ochraceous, darkened in the mid-line of back by numerous 
black hairs, many of which on the rump project noticeably beyond the rest of the pelage, and are 
conspicuous by reason of their shiny ochraceous tips; sides clearer ochraceous, feet the same; lower 
side whitish, the hairs gray at base and showing a buffy wash in the mid-ventral region. 
This rat was first made known by Miller on the basis of a specimen obtained 
at Mount Coffee and Thomas later (1926) erected a special genus for it, pointing 
out that in its possession of numerous conspicuous bristly hairs on the rump it 
showed an approach to Stochomys, found farther to the east and south in the 
Cameroons. We secured two additional specimens, one on the Du, July 27, 
