36 J. B, CLELAND. 
The Species of Rodents concerned, and Their Habits. 
The species of rats and mice dealt with in this review 
comprise only the two common rats, Epimys rattus and E. 
norvegicus, and the common house mouse, Mus musculus— 
three species usually and more or less universally associated 
with the habitations of man. 
Epimys rattus (.) (including E. rattus alexandrinus). 
—This is the so-called old English Black Rat. LH. alexandri- 
nus is considered by Oldfield Thomas (MSS. letter) merely 
as a color variety, ‘‘a white or yellow bellied race,’’ of the 
black bellied E, rattus, being ‘‘essentially the same species.’’ 
The colour of #. rattus, in the wider sense, varies therefore 
considerably. Australian specimens are usually greyish- 
brown all over, in colour thus resembling H. norvegicus. 
Not infrequently we find them with light or almost white 
bellies, sometimes with an indistinct fawn edge separating 
the light under-surface from the brown back. Occasionally 
they are of a uniform rich glossy blackish colour, then pre- 
sumably representing the true black rat. Compared with 
E. norvegicus, the chief external specific characters are the 
larger, thinner ears, and a tail longer than the length of 
the body (125 per cent.). The skulls are slightly but 
specifically distinct in the two species. The Black Rat is 
essentially a house and climbing rat, in contradistinction to 
the Norway Rat, which has been designated the Sewer Rat. 
Consequently the former is brought more into intimate con- 
tact with man. 
Under the title ‘‘On the Habits of the Sydney Bush Rat 
(Mus arboricola),’’ Edgar R. Waite’ gives an interesting 
account of the tree-climbing habits and fruit-eating ca- 
pacity of this species at Mosman and in other parts of 
Sydney. He found difficulty in trapping it unless fruit was 
used as a bait. It also ate the seeds of Tecoma australis 
+ Waite, Proc. Zool. Soc., 1897, p. 857. 
