Abstract: When looking into the available literature on facial musculature and extensive bibliography it became obvious that though the facial muscles of many primates were already worked out in detail, but no mention was found anywhere to the arrangement of the facial muscles in the Presbytis francoisi, P. phayrei and P. cristatus before. The present work has obtained some results as follows:
1. The muscles of subcutaneous colli exist only in m. platysma.
2. Muscles around the mouth include m. or bicularis oris, m. zygomatico--orbitalis, m. levatorlabii superiors, m. triangularis, m. caninus, m. incisivi superiors, m. incisivi inferiors, m. mentalis and m. buccinator.
3. Muscles of the nose involve m. noso-labialis, m. nasalis, m. subnasalis and m. depressoret transversi.
4. Muscles round the eye include m. orbicularis oculi, m. procerus, m. depressor glabellae,m.depressor supercilii and m. corrugator supercilii.
5. Extrinsic and intrinsic muscles of the auricula have m. orbito-auricularis, . m. auricularisposterior, m. trago-helicinus, m. helicis major, m. helicis minor, m. antitragicus and m. obliquis·et transversi.
6.Muscles of the scalp comprise m. frantalis and m. occipitalis.
Compared with facial musculature from other primates, some special musculature characte-ristics in these three leaf monkeys include: 1) m. platysma can be divided into two parts exhibiting not obvious limt, not oplatysma and trachelo platysma. It was reported that some authors draw a line of demarcation between Iwn parts at acromiale in other primates, but at oral anglein three leaf monkeys; 2) In P. phayrei and P. cristatus, similar to that in P. entellus, fibers of the m. platysma on mandible interweaving widely. But only interweave partly in 3 of 4 P.francoisi; 3) m. levator labii superiors, as an independent muscle mass, origins from maxilla and zygoma of the infraorbital margin; 4) In m. triangularis, the superficial part is not present. The deep part, the caput longum, is present. lt originates from the first premolar buccally in one of P. phayrei, but from area under canine of 1nandible in 2 of P. phayrei, 4 of P. francoisi and 2of P. cristatus; 5) m. risorius, similar to the general feature of the Old World monkeys, is absent; 6) m. depressor labii inferiors is absent. ln Cercopi the coidea, Cercopi the dae has this muscle generally, but absent in Colobidae; 7) m. corrugator superecilii continues partly with m. orbito-auricularis, but not in l of P. phayre1 and P. cristatus; 8) m. helicis major is present. A few ofthem have this muscle in primates; 9) Muscles of the scalp originate from forehead and occipi-tal areas, which, similar [o those in Cercopi the coidea, consist of two laytrs.There exist three layers in occipital area, the primary feature, in P. entellus.

Key words: Presbytis francoisi; P.phayrei; P.cristatus; Facial musculature