Abstract: 5 masticatory muscles, 9 tongue and hyoideal muscles, 11 laryngeal muscles, 4 nasopharyngeal and pharyngeal muscles of the Baiji, Lipotes vexi-llifer, are described in the present paper.Partial fatty degeneration of the masseter and external pterygoid muscles forms the extra-and intra - mandibular fat bodies respectively. The strong temporalis partly compensate the function of the fatty degenerated masseter.The muscles of the tongue and hyoid are similar to other odontocetes with the exception of the occipitohyoideus. In most odontocete species the connection is with thyroihyal, while in Lipotes this muscle inserts upon inner side of the posterior end of the stylohyal.The larynx is pulled to the ventral surface of the skull by the occipito-thyroid. The tip of the epiglottid tube is close to but not inserted into the posterior nares. In addition to the cricothyreoideus, cricoarytaenoideus dorsalis, cricoarytaenoideus Iateralis,thyreoarytaenoideus and arytaenoideus transversus, there is a single constrictor laryngeus internus in Lipotes as well Delphinapterus.The palatopharyngeus, pterygopharyngeus and sphincter nasopharyngeus constitute a muscular tube connecting the posterior nares and entrance of the larynx.

摘要： 前已报道白鱀豚(Lipotes vexillifer)的皮肤肌、肩和鳍肢肌肉、胸壁肌肉、腹壁肌肉,颈、背和尾部肌肉(周开亚等,1981)。本篇包括咀嚼肌、舌和舌骨部肌肉、喉部肌肉及鼻咽和咽部肌肉。 一、咀嚼肌(图1、2) 咬肌m.masseter很薄,起自颧突后部的腹缘,颧突下方颞肌的筋膜及颧弓的腹缘。纤维尾腹向,止于下颌骨后部下半的外侧。后端有少量纤维绕过下颌骨腹缘,止于下颌内脂肪体,紧贴下颌骨的部分咬肌纤维已脂化形成下颌外脂肪体。咬肌仍有提起下颌的作用,但力量很弱。