34 sillier — A iVeyr Sqidrrel from liorueo. 



ference is particularly noticeable posteriorly. The greatest breadth of 

 braincase in each of two Bornean specimens is 19 mm., while in three 

 topotypes of S. tenxiU it is only 17. G mm. The interorbital breadth on 

 the contrary is nearly the same in the two species, while there appears 

 to be no difference whatever in the breadth of rostrum. Viewed from 

 the side the peculiarities in the skull of the Bornean animal are even 

 more apparent. The depth of braincase from middle of parietal to 

 lower edge of audital bulla is fully 2 mm. greater than in Scvurus tenuis 

 while the depth of rostrum is barely equal to that of the mainland 

 animal. In Scmrus 2)arvus the ratio of least rostral depth to the cranial 

 depth just defined is about 41; in S. tcnvis it is about 49. The ventral 

 aspect of the skull shows no peculiarities. 



Teeth as in Sciunis tenuis. 



Measurements. — External measurements of type (a well made .skin): 

 total length, 285: head and body, 165; tail vertebrte, 125; pencil, 45; 

 hind foot, 37.6 (35); ear from meatus, 13.8; ear from crown, 10. 



Cranial measurements of type: greatest length, 39; basal length, 31.6; 

 palatal length, 16.6; length of nasals, 11.4; greatest breadth of nasals, 

 5.4; interorbital breadth, 13.4; zygomatic breadth, 23.6; greatest breadth 

 of braincase, 19.4; cranial depth from middle of interparietal to lower 

 rim of audital bulla, 17; least depth of rostrum, 7; mandible. 21.6; 

 maxillary toothrow (alveoli), 7; mandibular toothrow (alveoli), 7.2. 



S'perimens examined. — Two, the type and one from Spitang. 



Remarks. — A series of Bornean specimens may show that Sciurus par- 

 vus differs from S. tenuis externally as well as in cranial characters. 

 The Spitang skin is distinctly the more gray of the two, but as it was 

 taken in July and the type specimen in October the difference is proba- 

 bly seasonal. In color it is approached by a specimen of 8. tenuis taken 

 at Singapore in May. Except in external appearance the Bornean 

 animal in no waj' closely resembles the small Sciurus procerus of Bun- 

 guran Island, North Natunas. 



*Published here by permission of the Secretary of the Smithsonian 

 Institution. 



I 



