KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 60- NIO 6. 



37 



in the specimens from Central Borneo and thus they somewhat resemble Callosciurus 

 baluensis 1 Bonh. and C. suffusus* Bonh. from which they, hovvever, may easijy be 

 distinguished by their smaller size. In the Central Bornean specimens the upper 

 parts of the body are darker than the same parts of the Eastern specimens and there 

 is also a slight indication of a rufous ring round the eye. Miller has recently 

 (Smiths. Inst. Misc. Coll., vol. 61, No. 21, 1912, p. 23) described a »new» subspecies 

 under the name of C. dulitensis dilutus 3 which is very similar to C. v. dulitensis, 

 merely >differing» in the colouration of the underparts which are »more dull and 

 more diluted with white». These differences are not valid for creating a new form, 

 as specimens with a whitish shade on the underparts and specimens with creamy 

 buff underparts occur at the same localities. It is neither a seasonal phase, as is 

 clearly shown by the present series, nor are there any cranial differences. Miller 

 also states that >in true dulitensis the red tends towards orange, while in dilutus it 

 is more ochraceous. It would, however, be impossible to sort out the two lots with 

 any degree of certainty if the skins were thrown together without labels». In some 

 of the present series the colour of the under parts more intend to red, while in other 

 specimens it is ochraceous and therefore I can state with absolute certainty that 

 Miller's dilutus is not valid as a distinct form. 



Skull measurements of Callosciurus vittalus dulitensis Bonh. 



9 



No. 122 



No. 102 Xo. 73 No. 125 No. 105 No. 03 No. 1 13 No. 84 No. 128 No. 5313 No. 5320 



Greatest length of skull 49,2 



Longth from condylus to gnathion 45,2 



Basicranial length of skull . . . 42,2 



Zygomatic width 27,8 



Createst width of braincase . . . 



Least interorbital width 



Least postorbital width 



Length of nasals mesially .... 

 Breadth of combined nasals ante- 



riorly 



Breadth of combined nasals poste- 



riorly 



Diastema 



Length of foramina incisiva . . . 

 Length of upper toothrow (alveoli) 



22,1 

 15,7 

 17,0 

 14,0 



6,0 



5,0 



11,4 



2,5 



9,0 



4S.4 



44,3 



41,7 

 27,5 

 21,5 

 1 5,5 

 16,8 

 12,0 



t ; ,i 



2,0 



11,1 



2,8 



8.9 



49.7 

 45,1 

 41,9 

 29,1 

 22,6 

 17,7 

 17,2 

 14,3 



(i,4 



2,8 

 10,5 

 2,3 



9,0 



48,0 

 45,1 

 42,0 

 29,1 

 22,1 

 16,3 

 17,2 

 13,7 



2,8 



10,6 



2,5 



9,2 



48,3 

 44,2 

 41,1 

 28,7 

 22,8 

 17,1 

 17,8 

 14,0 



7,0 



3,2 



11,2 

 2,4 



48,4 

 45,0 

 41,9 

 29,9 

 22,8 

 17,0 

 17,6 

 13,4 



t'>,5 



3,2 

 11,3 

 2,9 



8,7 



49,4 

 45,3 

 42,7 

 27,8 

 22,1 

 16,0 

 17,2 



13,4 

 6,2 



45,3 



43,6 



42,7 



40,7 



27,8 



27,8 



22,1 



22,0 



16,0 



16,0 



17,2 



17,4 



48,1 

 43,6 

 40,7 

 27,8 

 22,6 

 16,0 

 17,4 

 14,3 



5,8 



48,9 

 43,4 

 40,2 

 27,4 

 21,5 

 16,3 



17,2 

 14,4 



6,4 



3.0 2.0 3,2 

 11,5 10,8 11,2 



2,9 ! 2,6 2,8 



8.1 9,0 9,1 



26,8 

 21,9 

 17,0 

 16,8 

 14,1 



6,7 



3,0 



10,6 



2,8 



9,0 



44.3 

 41,9 

 28,0 

 22,2 

 16,1 



17,3 



13,8 



6,5 

 3,0 



11,0 

 2,4 



9.0 



1 Type locality: Mount Kina Balu, N. Borneo (1000 ft.1. 



2 Type locality: Tutong River, N. W. Borneo. 



3 Type locality: Tanjong Batu, S. E. Borneo. 



