EPIMYS 575 
GENUS EPIMYS. 
1867. RATTUS, L. Fitzinger, S¢tzungsb. kats. Akad. Wiss. Wien., math,-nat. Cl., \i., 
Abt., 1, 63, included vattus, decumanus, alexandrinus, and others ; antedated by 
RATTUuUS, Donovan, Naturalist’s Repository, iii., p|. 73, page unnumbered, 1827, based 
on &. donovani from the Cape of Good Hope. (RATTUS, Frisch, Das Natur-System 
vierfliss. Thiere, tn Tabellen, 7 Tab. gen., 1775; and RATTUS, Zimmermann, 
Specimen Zool. Geog. Quad., 344-7, 1777, are not regarded as valid.) 
1881. Epimys, E. L. Trouessart, Bull. Soc. @ Etudes Sci. @ Angers, x, 117 (sub- 
genus); based on Mus rattus of Linnzus (type); Miller, Proc. Biol. Soc., 
(Washington), xxiii., 58, 19th April 1910 (genus) ; Thomas, Av. and Mag. Nat. 
fTist., December 1910, 604 (genus). 
Mus of most authors. 
Classification:—In 1910, Miller adopted Trouessart’s name, 
Epimys (originally proposed as a sub-genus, of which J/us 
rattus, Linneus, is the type), as the generic name of the House 
Rats, and restricted the Linnean genus AZus to Mus musculus, 
Linneeus, and its allies. The genus Afzmys was further 
defined by Thomas (cited above). 
As now understood, Afzmys is the largest genus of the 
sub-family, and includes a great number of Asiatic, Malayan, 
African, and Australian species. Many of these species, par- 
ticularly in Africa, are of small size, and would be termed 
generally “mice” rather than “rats.” 
The genus is doubtless of Oriental origin, and in view of 
its wide natural distribution it must date from a comparatively 
remote epoch. 
In Europe it may have been represented in the late 
Pleistocene (see p. 588); but if then present it subsequently 
died out. It is now represented here only by the two well- 
known species of true rat, /. vattus and £. norvegicus, 
both of which are comparatively recent immigrants from the 
East. £. rattus appears to have been introduced about the 
time of the Crusades, while its rival, 2. mxorvegzcus, did not 
appear here before the beginning of the eighteenth century. 
These two species owe their introduction to Europe, and 
their more recently acquired cosmopolitan distribution, to their 
parasitic habits, and their readiness to take advantage of the 
facilities for travel afforded by human commerce. 
In this genus the external form and skull characters are 
essentially those of typical or but slightly specialised Musvine. 
