MAMMALS OF THE NATUNA ISLANDS I25 



stead of 50) the rostrum is relatively shorter and broader, and the 

 audital bullae are less elongate antero-posteriorly. Teeth as in Sciurus 

 notatus except that they are uniformly smaller. 



Measurements. — External measurements of type : total length 355 ; 

 head and body 177 ; tail vertebrae, 177 ; hind foot 45 (41). Average 

 and extremes of six specimens fi'om the type locality : total length 356 

 (329-375) ; head and body 186 (177-196); tail vertebrte 170 (152- 

 178) ; hind foot 43.8 (41-45) ; hind foot without claws 40.7 (39- 

 42). 



Cranial measurements of type: greatest length 45.4 (50.4)^; basal 

 length 39 (43) ; basilar length 36.4 (41) ; palatal length 20 (23) ; 

 palatal width between middle molars G (6) \ greatest length of nasals 

 13 (14.8) ; greatest width of both nasals together 6.6 (7) ; interor- 

 bital breadth 15.4 (17) ; mastoid bi'eadth 21 (21) ; zygomatic breadth 

 26 (29) ; depth of braincase at anterior edge of basi-occipital 16 (16.8) ; 

 mandible 28 (30) ; maxillary toothrow (alveoli) 8 (9) ; mandibular 

 toothrow (alveoli) 8 (9). 



Specimens examined. — Seven (one in alcohol), all from the type 

 locality. 



Rejnarks. — This squirrel is recognizable among the members of the 

 S. notatus group by its light colors, and particularly by the pallor of the 

 under parts. In the latter characteristic it is approached by the form 

 inhabiting Pulo Laut, but with this exception it is unique among the 

 fulvous bellied species. The six specimens show no variation worthy 

 of note. 



SCIURUS SERAIS sp. nov. 



Type. — Adult male (skin and skull) No. 104660 U. S. National 

 Museum. Collected on Pulo Seraia, South Natuna Islands, May 29, 

 1900. Original number 415. 



Characters. — Most nearly related to the small, pallid, Sciurus 

 hitescens from Sirhassen Island, but upper parts slightly less pale, 

 and under parts and pale side stripe buff -yellow, the former without 

 admixture of gray. 



Color. — Upper parts as in Sciurus hitescens except that the pale 

 bands on the hairs are more nearly buff than cream-buff. Tail essen- 

 tially as in kS. lutescens but a shade less pale. Under parts buff -yellow 

 darkening in-egularly to dull orange-buff. Dark side stripe broad and 

 well defined. 



Skicll. — The skull closely agrees with that of Sciurus lutescens in 



' Measurements in parentheses are those of an adult Sciurus notatus from 

 Borneo. 



