214 MILLER 



region, the latter slightly in excess on rump, flanks and shoulders, as 

 well as on sides of body and outer surface of legs. Ventral surface 

 of body and inner side of legs pale drab, Irregularly and faintly 

 washed with brownish yellow. Feet drab-gray. Tail uniform dark 

 brown throughout. Fur of body everywhere slate-gray at base. 



Fur. — The fur is rather short, about 8 mm. in length on middle of 

 back, and everywhere thickly and uniformly sprinkled with well de- 

 veloped, slender, grooved bristles. On lower part of sides the bristles 

 become even more slender, while on ventral surface they are at first 

 sight not noticeably different from ordinary hairs. 



7a//.^The tail is closely and uniformly annulated ; about i6 

 rings to the centimeter at middle. Though sharply distinguished 

 from each other, the rings are very obscurely divided into scales. 

 Tail uniformly clothed with very short hairs (their length mostly 

 about double width of rings) which neither hide the annulation nor 

 form a terminal pencil. 



Feet. — Soles 6-tuberculate, the sixth pad well developed. The 

 surface of the sole appears (on soaking the foot of the dry specimen) 

 to be distinctly and closely reticulate in the region between the pads, 

 but perfectly smooth behind them. 



Skull. — As compared with a skull of ]\Tus concolor from Bhamo, 

 Burmah (No. 1015 19 United States National Museum), that of JSf. 

 obscurus differs noticeably in its larger size, more slender rostrum, 

 and particularly in the less convex profile when viewed from the side. 

 The antorbital foramina are larger than in the related species, and 

 less contracted below. Audital bullie relatively as well as actually 

 larger than in Mus concolor.^ and not very different in form. 



Teeth. — The teeth are essentially as in AIus concolor^ but actually 

 smaller. 



Measure7)ients. — Total length 254; head and body 121 ; tail verte- 

 bra; 133; hind foot 34 (22.6) ; ear from meatus 16; ear from crown 

 13 ; width of ear 13. 



Skull: greatest length 30 (28. 6) ; ^ basal length 26 (24); basilar 

 length 23 (21.8); palatal length 13 (12); least width of palate be- 

 tween anterior molars, 3.2 (2.8) ; diastema 8 (7) ; length of incisive 

 foramen 5.4 (5); combined breadth of incisive foramina 2 (1.8); 

 length of nasals 11 (10.2) ; combined breadth of nasals 3 (3) ; zygo- 

 matic breadth 13.6 (13) ; interorbital breadth 4 (5) ; mastoid breadth 

 12 (12) ; breadth of braincase over rootsof zygomata 13 (12.6) ; depth 



' Measurements in parenthesis are those of an adult female I\[us concolor 

 from Bhamo, Burmah. 



