180 Fietp Museum or Naturat History — Zoétocy, Vou. XI. 
Genus EPIMYS Trouessart. 
Epimys Trouessart, Catal. Mamm. Viv. et Foss., Bull. Soc. d’Etudes, 
Sci. d’Angers, X, 1881, p. 117. Type, by subsequent designation, 
Mus rattus Linn. Miller, Proc. Biol. Soc. Wash., XXIII, 1910, p. 58. 
Front teeth (incisors) 2 in each jaw; no premolars; upper molars 
or grinding teeth having tubercles on crowns arranged in three lon- 
gitudinal rows as in Mus; ‘‘molars slightly graduated in size from first 
to third, the anterior tooth not tending to assume the main function 
of the toothrow, the posterior tooth not tending to disappear, enamel 
folding of upper molars directly referable to a simple g-cusped pattern 
and its reductions, the outher margin of M! and M? never with more 
than three cusps, the inner margin of same teeth never with more 
than 2 cusps, M! usually with 5 roots, its first lamina not distorted 
by the backward displacement of antero-internal tubercle; upper incisor 
moderately compressed, set at such an angle that its outer side is 
worn smoothly away by action of lower teeth.’’ (Miller.) 
Epimys norvegicus (ERXLEBEN). 
Norway Rat. Brown Rat. House Rat. 
[Mus] norvegicus ERxLeBen, Syst. Regni Anim., I, 1777, p. 381. JACKSON, Bull. 
Wis. Nat. Hist. Soc., VI, 1908, p. 20 (Wisconsin). Haun, Ann. Rept. Dept. 
Geol. & Nat. Resources Ind., 1908 (1909), p. 492 (Indiana). 
Mus decumanus Kennicott, Trans. Ill. State Agr. Soc., I, 1853-54 (1855), p. 579 
(Illinois). Ruoaps, Proc. Acad. Nat. Sci. Phila., 1896 (1897), p. 192 (Tennessee). 
Neotoma floridana Woon, Bull. Ill. State Lab. Nat. Hist., VIII, 1910, p. 550. 
Type locality — Norway. 
Distribution — Nearly cosmopolitan. In America generally distributed 
throughout the country wherever there are habitations of men. 
Description — Hair coarse; general color brown, darkest on middle of 
back; under parts pale grayish brown; tail scaly and very scantily 
haired; tail not longer than head and body, usually less. 
Measurements — Total length, about 15.50 in. (394 mm.); tail vertebra, 
about 7.12 in. (180 mm.); hind foot, 1.75 in. (45. mm). 
This species was introduced in North America some time during the 
latter part of the eighteenth century and in spite of all attempts to 
exterminate it, it has thrived and increased to a remarkable degree. Of 
its habits little need be said. They are destructive to property and in 
agricultural districts consume a large amount of grain and food of every 
kind wherever they can find it. They are also objectionable from an 
