Three new Forms of Peromjscus, 485 



long, but comparatively harsh; hairs of back about 10 mm. 

 in length. Colour brownish. 



Colour. Upper parts pale brownish with a slight bufFy 

 tinge ; sides scarcely more bufFy than back. Underparts 

 soiled greyish, about as in true leucurusj without fulvous 

 suffusion on chest; chin white; hands and feet white; 

 ankles dusky, the dark colour not passing on to the meta- 

 tarsals ; tail bicolor, white below and for the terminal inch 

 or so all round, blackish above proximally, the two colours 

 passing into each other, not abruptly separated. 



xS/t^/Z with a large rounded brain-case and short muzzle; 

 supraorbital edges square, sharp-edged^ but without vertically 

 rising bead ; palatal foramina almost reaching to the level 

 of m^. 



Measurements of type : — 



Total length 265 raillim. ; head and body 115; tail 150; 

 hind foot, s. u. 27-6, c. u. 29 ; ear 25. 



Skull: greatest length 31*5; basilar length 24; zygo- 

 matic breadth 15*4; nasals, length ITS, interorbital breadth 

 42; breadth of brain-case 14; interparietal 4'2xll'5; 

 diastema 85; palate length 12*5; palatal foramina 6-6x 2-6; 

 length of upper molar series 4*7. 



Hob. San Carlos Yantcpec, Oaxaca, Mexico (between 

 Oaxaca city and Tehuantepec). Altitude 2250 feet. Other 

 specimens from the neighbourhood of Oaxaca city. 



Ti/pe. Female. B.M. no. 3.3.4. 55. Collected September 

 1902 and presented by Dr. Hans Gadovv. 



This fine Peromyacus seems to be a well-marked subspecies 

 of my P. leucurus *, from which it differs by its darker, 

 browner, and less cinereous colour, longer sparser fur, larger 

 ears, and more thickly haired tail. It does not appear to be 

 closely related to any of the forms described by Dr. Merriam. 



AVhile the true P. leucurus is probably an inhabitant of 

 the low sandy flats near Tehuantepec, P. I. Gadovii repre- 

 sents a darker inland form of the same type. 



Peromyscus Beatce, sp. n. 



Characters. Size small medium, about as in P. aztecus ; 

 ears rather large; tail longer than head and body, well 

 haired, though not so thickly clothed as in the other two 

 species now described. 



* Ann. & Mag. Nat. Hist. (6) xiv. p. 364 (1894). The doraal hairs of 

 P. leucurus are said to be " 7 or 8 mm. in length," but only the isolated 

 longer hairs attain this latter length, and were I now describing it I 

 should consider 7 mm. as the full length of the general mass of the fur. 



