88 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 40. 



of pale ochraceous buff and blackish, the two colors about equally 

 mixed; tail, both above and below similar, but the grizzle coarser and 

 the ochraceous buff predominating on the underside; under parts, and 

 inner side of hind legs, a color closely approaching Ridgway's pink 

 buff, becoming whitish cream color in axillary region and about chin, 

 and nearly as light on inner side of fore legs; light side stripe (6 by 

 50 mm.) buffy cream color, ill defined; black side stripe (12 by 45 

 mm.) blackish, strongly lined with whitish, and many of the hairs 

 with narrow ochraceous buff rings; region of nose, sides of head and 

 neck similar to upper parts, but the ochraceous buff deeper and more 

 conspicuous; a rather poorly denned eyering; ears, inside and out, 

 similar to upper parts. 



STcull and teeth. — Aside from its slightly smaller size and relatively 

 heavier teeth, the skull and teeth of Sciurus arendsis show no differ- 

 ences from those of numerous related forms. 



Measurements. — See table, page 90. 



Specimens examined. — Five, all from Pulo Arends. 



Remarks. — Sciurus arendsis is simply another of the numerous 

 races of Sciurus vittatus, produced by isolation on various Malayan 

 islands. It closely resembles its geographic neighbors, S. sinensis, 

 from Pulo Mata Siri, and S. dulitensis, from the Bornean mainland. 

 It differs from S. sinensis in its smaller size, darker upper parts, and 

 in the possession of numerous white hairs on the under parts, as in 

 S. vittatus albescens (Bonhote) * from northern Sumatra. From the 

 mainland S. dulitensis it is distinguished by its smaller size, lighter 

 coloration, both above and below, and less conspicuous side stripes. 



SCIURUS POLIOPUS, new species. 



Type.— Skin and skull of adult male, Cat. No. 151789, U.S.N.M., 

 collected at Pamukang Bay, southern Borneo, April 5, 1908, by Dr. 

 W. L. Abbott. Original number, 5923. 



Diagnostic characters. — A member of the vittatus group distinguished 

 by a very dull "red" belly and conspicuous gray legs and feet. 



Color. — Upper parts of head and body, a fine grizzle of pale dull 

 buff-yellow and blackish, the two colors about equally mixed; thighs 

 and shoulders similar, but the buffy color becoming gradually 

 replaced by a light gray on the outer side of the fore and hind legs 

 and on feet, lower parts of inner side of fore and hind legs also gray- 

 ish; tail, similar to upper parts of body but the grizzle very coarse, 

 appearing somewhat annulated, and with the buffy color very light 

 above, but darker underneath; under parts, a very dull ochraceous 

 color, ranging from almost clay color in the type to a very dark 



1 Ann. Mag. Nat. Hist., ser. 7, vol. 7, May, 1901, p. 446. 



