KUNGL. SV. VET. AKADEMIENS HANDLIMGAK. BAND 60- NIO 6. 5 



the grey phase seems to be more rare. Oiily one of the specimens in the present 

 series (orig. number-71) is in the light phase. In this specimen the underparts are 

 nearest to »Dresden brown» (Ridgway, pl. 15) becoming »mummy brown» on the 

 upper throat. Upper parts of the body paler and more isabelline. On the extreme 

 forehead there is a narrow line of blackish brown, erect hairs. 



Even the small youngs are variable. Thus one of the immature specimens 

 collected at Toembang Maroewe on the 20th of October 1915 is brownish grey above. 

 Top of head, hands and feet, breast and belly brownish black. The other young 

 specimen is fairly similar in colour to some of the lighter coloured adult specimens. 

 In some specimens the whole face is covered with black hairs while in other there 

 is a distinct whitish, rather broad stripe above the eyes covering the extreme parts 

 of the forehead. The lower cheeks are also sometimes whitish, sometimes black or 

 blackish brown. This latter colour variety has been named H. mulleri albibarbis by 

 Lyon (Proc. U. S. Nat. Mus., vol. 40, 1911, p. 142) but it is certainly only a colour 

 variety as both occur together on the same localities and even in the same flock. 

 No cranial differences between H. mulleri mulleri und »H. mulleri albibarbis» have 

 been detected and Lyon's name thus only seems to be based upon a colour 

 variety in a very variable species and therefore not valied as a distinct form. The 

 greyish phase has been separated under the name of H. leuciscus, but this is not as 

 stated by several authors Schreber's leuciscus, which inhabits Java, but only the 

 grey phase of Hylobates mulleri Martin. 



Skull measarcmcnts : 



o 

 No. 57 



9 



No. 21 



9 



No. 50 



No. 24 



ef 

 No. 27 



9 



No. 32 



No. 58 



ef 

 No. 23 a 



9 



No. 28 a 



Greatest length of skull . . . 



104,.-. 



100,1 



108,0 



104,1 



102,0 



105,5 



105,8 



108,5 



102,5 



Condylobasal length of skull . 



78,3 



77,8 



87,5 



80,3 



83,7 



81,3 



83,6 



87,5 



81,0 



Basicranial length of skull . . 



09,4 



G8,0 



77,0 



71,8 



73,3 



08,0 



73,5 



77,0 



70,5 





85,5 



81,2 



87.1 



87,8 



88,7 



86,7 



85,0 



91,0 



84,8 





66,0 



63,8 



67,0 



67,3 



68,5 



69,5 



66,3 



69,9 



66,0 



Greatest width of bruinca.se . 



62,3 



01,3 



62,7 



61,0 



62,7 



63,3 



58,8 



00,1 



00,7 



Least interorbital width . . . 



9,8 



9,2 



10,0 



9,2 



11,2 



10,7 



10.2 



10,0 



12,3 



Least postorbitul width . . . 



47,0 



47,2 



49,1 



45,2 



48,0 



49,8 



46,9 



43,6 



46,8 



Length of pulate from henselion 



38,4 



35,3 



41.2 



39.5 



40,4 



36,2 



39,5 



41,1 



39,2 



Length of upper molar series 



25,0 



23,8 



20,6 



24,0 



25,2 



26,2 



25,0 



20,6 



22,9 



Distance from front of canine 





















to back of last upper molar 



31.5 



30,0 



27,0 



31.0 



31.6 



32,8 



32,2 



32,5 



29,2 



I.ength of lower molar series 



31,2 



28,2 



28,0 



30,0 



31.1 



31,4 



31,0 



30,2 



28,0 



The skull of one of the specimens (orig. number 50) is somewhat anomalous 

 in the way that the third upper molar is totally absent on both sides of the upper 

 jaw. In the lover jaw, however, the third molars are present on both sides but of 

 different size, the one on the left side being the largest. As a rule the third upper 

 molar is the smallest of the true molars, though it seems to undergo a considerable 



