600 ~  MURIDAE—EPIMYS 
z.e,, to the form with brown back and dusky belly ; this course has been 
adopted recently by Bonhote.t 
Distribution :—Described from Egypt, where it is a house rat, 
the present sub-species inhabits much of North Africa; eastwards it 
ranges throughout Arabia and Palestine to India, where to the south 
and east it seems to be represented or replaced by the typical dark- 
bellied form of £. vufescens. It occurs in the regions around the Caspian 
and Black Seas, and we are informed by Andersen that all the 
specimens he collected in Bulgaria were of this type. The great majority 
of the Iberian specimens before us, and some from southern France 
(Biarritz), belong to this form. 
In central and northern Europe it is no doubt occasionally intro- 
duced, but it does not appear to succeed in establishing colonies of any 
importance. No specimens of either “wild-coloured ” sub-species have 
ever been obtained in Norway ; but in the port of Copenhagen “ brown- 
backed ” specimens have appeared recently (Winge). 
In Britain it is frequently introduced from shipping, but many of 
the published records of its occurrence refer to the next sub-species ; it 
is not always easy or possible, however, to determine from the descrip- 
tions given which of the two sub-species is in question. Coward 
obtained &. r. alevandrinus in company with the two other sub-species 
and xorvegicus upon Lundy, and apparently those seen by Millais on 
Whalsey, Shetland (see p. 585), were also referable to the present form. 
In recent times it has been dispersed by commerce throughout many 
parts of Africa south of the Sahara; many specimens from this region 
are in the National collection, and some of them are so dark that it is 
not always easy to distinguish them from £. 7. rvatéus. From America 
we have seen only two specimens—one from the Orinoco, the other from 
Brazil (Minas). 
Description :—BZ. ¢. alexandrinus is indistinguishable from £. r. rattus, 
or the next sub-species, except by its coloration. The upper parts 
vary in colour between some shade of yellowish-brown and light grey ; 
along the middle of the back black hairs are present in variable 
abundance, and to them is due the appearance of dorsal darkening 
frequently seen. The hairs of the ventral surface have slaty or dusky 
bases ; in some specimens the tips of these hairs are dusky also, so 
that the belly is as dark as the flanks, or even as the back; in others 
the ventral hair-tips are yellow, cream, or white in colour, the belly 
being then slightly lighter than the flanks in general colour. The line 
of demarcation along each flank is never sharply defined, and is 
frequently not apparent at all. The feet are brown above, with or 
without dusky markings. 
1 See also Anderson, Zool. of Egypt (Mamm.), 1902, 274, and Bate, Proc. Zool. 
Soc., London, 1904, 346. 
