Lepilemur sp. (Mammalia, Primates): lateral view of the facial musculature; muscles such as the buccinatorius, orbicularis oris and mentalis are not shown (modified from Jouffroy & Saban, 1971; the nomenclature of the structures illustrated basically follows that used in the present work; anterior is to the right). AUOR, auriculo-orbitalis; AUS, auricularis superior; FRO, frontalis; MAAU, mandibulo-auricularis; NASL, nasolabialis; OCC, occipitalis; OROC, orbicularis oculi; PLAC, PLAM, platysma cervicale and platysma myoides; SCOP, sphincter colli profundus; ZYMA, ZYMI, zygomaticus major and zygomaticus minor.