534 PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXI. 



NYCTICEBUS HILLERI (Stone and Rehn.) 



1902. Nycticebus coucang hilleri Stone and Rehn, Proc. Acad. Nat. Sci. Phila., 

 March, 1902, issued June 4, 1902, p. 139. 



Distribution. — Prol)ably the mountainous regions of Sumatra, 

 known onl}' from the t_ype locality, Batu Sangkar, Tanah Datar, 

 Padangsche Bovenland, Sumatra. 



Diagnostic eharacters. — Similar to Xyctieehus iiudaimius., but slightly 

 larger, with audital and mastoid bullae not smooth, rounded and in- 

 flated, but irregularl}" grooved instead. 



Color. — Of the two specimens examined one has a general wood- 

 brown effect above with considerable frosting, and the other a very 

 dull ochraceous. Dorsal stripe extends whole length of back but 

 indistinct posteriorlv, dark brown in color. Head markings dull 

 russet, considerably obscured by grayish tips to hair. Underparts 

 dirty buff}^, slaty bases of hairs showing through. 



Skull and teeth. —Skull nearly as large as that of Nycticehus caa- 

 cang. Temporal ridges forming a crest in old age. Upper incisors, 

 four in the young, two in adults. Mastoid and audital bulhe irregu- 

 larly wrinkled. 



Measurements. — See table, page 537. 



Specimens examined. — Two, the type and a paratype. 



Remarks. — This species appears to be a larger mountainous form of 

 Nycticebus malaianns^ from which it seems to differ but slightly. 



NYCTICEBUS NATUN/^ (Stone and Rehn). 



1902. Nydlcehus coucang naUnuc Stone and Rehn, Proc. Acad. Nat. Sci., 

 Phiia., March, 1902, issued June 4, 1902, p. 140. 



Distribution. — Island of Bunguran, North Natuna Islands. 



Diagnostic characters. — Similar to Xyct Icebu.s malnianus., hat darker 

 in color and with dusky hands, feet, and ears. 



Color. — Upper parts generally similar to Ridgway's russet, a slight 

 amount of frosting. Dorsal stripe extending entire length of back, 

 ])ut indistinct on rump, broadest over shoulders, dark brown, almost 

 blackish in places; on crown of head and face markings, like Ridg- 

 way's burnt umber, but lighter: rings about eyes almost black. 

 Underparts general!}' dark ochroceous buff' except on throat which is 

 grayish. Upper surfaces of hands and feet irregularly blotched with 

 blackish, ears with l)rownish black. 



Skull and teeth. — The skull of Xyctieehus nj/tu/t^ does not differ 

 appreciabl}' from skulls of X. /nalaianus. The interorbital con- 

 striction is not so pronounced and the mastoid bulhe are a little less 

 inflated. Four incisors are present in the upper jaw. 



Measurements. — See table, page 537. 



Specimens examined. — One, the tj'pe, Cat. No. 104599, U.S.N.M. 



Remarks. — This species appears as a slightly differentiated form of 



