NILS GYLDENSTOLPE, THE SWEDISH ZOOLOG1CAL EXPEDITIONS TO SIAM. 



Hylobates lar. Linn. 



Plate I. Fig. 1. 



§ Doi Par Sakeng, Northwestern Siarn, 12 /^ 1914. — <$ Koon Tan, Northern Siarn, 7 /6 1914. — 

 $ Koon Tan 19 / a 1914. ■ J Koon Tan 19 /g 1914. — <? Koon Tan 23 / 5 1914. — $ juv. Koon Tan !3 / 5 

 1914. — ^ juv. Koon Tan ia / 3 1914. 



Gibbons, belonging to this species, were fairly common among the mountain forests 

 in the North of Siarn. In the parts of the Siamese Malaya visited during my journey I 

 also found them abundant on the Tenasserim boundary. At this latter locality they 

 were, however, very shy and more of ten heard than seen. They are generally going about in 

 small parties guided by an old male. Captured as a young they become very tame and 

 are often kept as a pet both by the natives and by the European residents. 



One of the female specimens shot at Koon Tan on the 19th of September had a 

 small almost naked young twined round the breast. I tried to keep the poor little thing 

 alive but it soon died. 



Tlie Siamese name is »Chanee». 



Skull measuremenfcs 



ö* 



Greatest length 



Basicranial length 



Condylobasal length .... 

 Occipitonasal length .... 



Zygomatic width 



Width of brain case .... 

 Least postorbital breadth . . 

 Least interorbital breadth . . 

 Snout across last premolar . 

 Front of canine to back of m 3 

 Length of palate mesially . . 

 Length of upper molar series 

 Length of lowor molar series 



101,0 

 73,0 

 82,0 

 86,5 

 69,0 

 67,8 

 48,2 

 12,5 

 32,1 

 32,5 

 38,1 

 25,2 

 30,0 



103,6 mm. 



72,5 » 



84,0 » 



86.2 » 

 70,0 » 

 69,0 » 

 46,0 » 

 10,0 » 

 29,5 » 



32.3 » 

 40,0 » 

 25,2 » 

 30,7 » 



106,5 

 79,1 

 84,0 

 88,6 

 68,0 

 69,0 

 44,0 

 ll.i 

 31,0 

 33,5 

 38,2 

 25,5 

 30,2 



105,0 mm. 

 81,6 

 87,0 

 86,0 

 68,0 

 67,5 

 44,2 

 11,0 

 32,6 

 34,7 

 42,0 

 28,0 

 31,5 



Hylobates pileatus. Gray. 



Along the coasts of the Gulf of Siarn another species of Gibbon is said to occur. 

 I never myself met with this species in the wild state, but during my stay in Bangkok 

 I was shown one specimen kept in captivity by the Swedish Consul General Mr. A. Mohr. 



It was a typical specimen of Hylobates pileatus Gray and belonged to the white 

 phase. It was said having been captured somewhere down the coast, most probably in 

 the Chantaboon Province. 



During his recent journey to south-eastern Siarn Mr. C. Boden Kloss also obtained 

 several specimens (vide: Proceedings of the Zoological Society of London 1916 p. 29). 



