No. 1626. MAMMALS FROM EASTERN SUMATRA—LYON. 647 
ceous-buff, the fur longer than that on the back and apparently belonging to a 
different pelage. Underparts and inner sides of legs a dirty pale buff, per- 
haps intermediate between cream-buff and broccoli-brown, lightening to cream- 
eolor on the throat, the hairs everywhere except in this cream-colored area slaty 
gray below middle. Face and cheeks an indefinite buffy gray. Feet a dull broc- 
eoli-brown. Ears with a grayish pubescence on both surfaces. Tail with rather 
indistinct rings, of which there are eleven to the centimeter at the middle. At 
first sight it appears naked, but from the edge of each scale there grow two to 
three stiff hairs as long as the width of 14 rings. Color of tail dark brown 
above, faintly lighter below. Head and body 185 mm., tail 235, hind foot with 
and without claws 44.6 and 41. 
With the type is an adult female (b) also marked miilleri from Padang,, 
apparently a typical Mus firmus. It seems hardly probable that the two ani- 
mals are the same. Jiilleri differs in relatively longer tail and narrower less 
distinct caudal annulations. The color is much the same in a general way, 
allowance being made for age, but the whitish area on the throat of miuilleri 
seems to be a distinguishing character. The skulls show one apparently very 
important character that can hardly be due to age—in miilleri the interptery- 
goid space extends forward distinctly beyond edge of last molar, while quite 
the contrary is true in firmus [and also in bullatus|. The anterior portion of 
the rostrum appears to be less heavily built than that of firmus, but this may 
readily be the result of the difference in age. Incisive foramina alike. Mandi- 
ble differs from that of firmus, smaller in size, less prominent protuberance over 
root of incisor, and wider angular process less distinctly drawn inward. Lat- 
eral grooves of palate less well developed in the small skull. 
Cranial measurements of the type of Jus miilleri: Back of frontal to front 
of nasal, 33.4 [34.6] %; nasal, 17 [19]; diastema, 12 [15]; interorbital constric- 
tion, 7 [7]; depth of rostrum behind incisors, 8 [9]; width of both nasals to- 
gether anteriorly, 5 [6]; mandible, 27 [29]; maxillary toothrow, 10 [8.5]; 
mandibular toothrow, 10 [8]; width of both upper incisors together, opposite 
henselion, 3.4 [4.2]. [5.4 in firmus]. Molars apparently the same in the two, 
allowing for age, the rows the same length, but width greater in the younger 
specimen. Pattern not obviously different. 
The above description and measurements show that J/us bullatus 
is evidently closely related to I/. mullert. Unfortunately nothing is 
known regarding the bulle of the latter as that portion of the skull 
is missing. The chief points of difference between J/. miillert and 
M. bullatus are the shorter toothrow of the latter, the absence of a 
whitish throat patch, and of gray bases of the hairs of the under- 
parts. The annulations of the tail in I/us bullatus does not differ 
in appearance from that in A/us firmus. 
MUS FREMENS Miller. 
1902. Mus fremens Miturr, Proc. Acad. Nat. Sci. Philadelphia, March, 1902, 
p. 154, issued June 11, 1902. (Type-locality, Singkep Island.) 
19038. Jlus fremens, MILLER, Proc. U.S. Nat. Mus., XXVI, p. 463, February 
3, 1903. (Specimens from Tapanuli Bay, western Sumatra.) 
1905. Mus fremens, SCHNEIDER, Zool. Jahrb. Syst., XXIII, p. 110. 
Four skins and skulls and one odd skull, all from Aru Bay. 
For measurements see table, page 649. 
“Measurements in brackets are those of the type of Mus. bullatus. 
