MAMMALS OF THE MEXICAN BOUNDARY, 



367 



Type-locality. Sw eden. 



Description. Size small. Length, 180 mm.; tail vertebrae, 85; 

 hind foot, 19; ear from notch, 15. Color, brownish gray above, paler 

 (sometimes pinkish) below. Mammae, I (often 5) pairs. Iris dark 

 brownish gray. 



Remarks. Found in greater or less abundance in all of thesettlc- 

 ments of the Southwest. In addition to the localities from which 

 specimens are listed, I have seen the house mouse in Prescol i , Arizona, 

 in 1 ss 1 . a i Phoenixin 1885, and al Flagstaff , Arizona, on June 20, 1886. 

 None were seen or heard of in the Mexican towns on the Sonoyta 

 River, in the Slate of Sonora, Mexico. 



Record and measun rru nts of 19 speciim ns of Mus musculus. 



oMammse, (pairs. c Mammae, 5 pairs. Iris dark, brownish gray. » 

 6 Mammae, 5 pairs. tJStrongly yellowish, M run e, 5 pairs. 



Sul.l-iiiulv < IRK IET] N .!•:. 



Grinding teeth rooted and eil her flat tened ( in the 

 Nectomys, etc.) or tuberculated (Onychomys, Baio 

 Oryzomys, Eeithrodontomys, etc.). When tubercul 

 are arranged in two longitudinal rows. 



American Museum of 

 Natural History. 



genera Sigmodon, 

 mys, Pi romys&is, 

 ate, the tubercles 



