86 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



Measurements. — For external and cranial measurements see table, 

 pages 90 and 91. 



Specimens examined. — Eight, all from Pulo Lamukotan. 



Remarks. — While Sciurus lamucotanus is sufficiently distinct from 

 the Bornean S. dulitensis to be regarded as a separate species, it is 

 not, however, a highly differentiated form. 



SCIURUS SERUTUS Miller. 

 1906. Sciurus serutus Miller, Proc. U. S. Nat. Mus., vol. 33, p. 58, July 23, 1906. 

 One specimen collected on Pulo Serutu, Karimata Islands, in 1904. 



SCIURUS DATUS, new species. 



Type.— Skin and skull of adult female, Cat. No. 145393, U.S.N.M., 

 collected on Pulo Datu, off west coast of Borneo, May 2, 1907, by 

 Dr. W. L. Abbott. Original number, 5153. 



Diagnostic characters. — A "red" bellied, "red" footed member of 

 the Sciurus vittatus group, similar to S. dulitensis of Borneo, but 

 distinctly smaller, and with wider dark side stripes. 



Color. — Type: Upper parts of head and body a fine grizzle of 

 blackish and a dull light cream-buff, in some lights appearing dull 

 olive-buff, the outer light annulations of the hairs being lighter than 

 the inner more buffy ones; upper surface of tail similar in color to 

 upper parts of body, but grizzling much coarser, underside of tail 

 with the cream-buff largely replaced by ochraceous, especially in- 

 middle line, where it is the predominating color; light side stripe 

 (4 by 65 mm.) dull cream color; dark side stripe (10-15 by 80 mm.) 

 blackish, sprinkled with a few light hairs; underparts and inner 

 sides of fore and hind legs ochraceous-buff, rather bright; outer side 

 of fore and hind legs similar to adjacent parts of body; fore and hind 

 feet generally similar to legs, but more ochraceous-buffy; outside of 

 ears, like top of head, inside more ochraceous buffy; orbital ring 

 pinkish-buff. The series of specimens of Sciurus datus is very 

 uniform in coloration, and differs in no essentials from the type. 

 Two examples have the hairs of the underparts rather worn, allow- 

 ing the bases to show and darken and dull the ochraceous buff. 



Skull and teeth. — Aside from their distinctly smaller size these 

 show no noteworthy characteristics. 



Measurements. — For external and cranial measurements see table 

 page 90. 



Specimens examined. — Six, all from Pulo Datu. 



Rem,arks. — In the color'of the under parts and of the side stripes 

 Sciurus datus closely resembles S. lamucotanus; in the color of the 

 upper parts it more nearly resembles S. dulitensis from Borneo. It 

 can be readily distinguished from either, however, by its distinctly 

 smaller size. 



