1899.] THE MYOLOGY OF THE EDENTATA. 317 



front of the thigh and buttocks. Some fibres also find their way 

 to the inner side of the thigh and there blend with the gracilis. 

 Anteriorly the more ventral fibres, to which alone the name of 

 abdomino-humprahs should be applied, pass deep to the pectoarls 

 and are inserted partly into the ribs and partly into the pectoral 

 ridge of the humerus. The more dorsal part of the pannicular 

 sheet, or dorso-hameralis, is partly inserted with the abdomino- 

 humeralis, deep to the pectorals, and partly runs to the fascia of 

 the dorsal surface of the arm and the posterior border of the outer 

 end of the spine of the scapula. In our specimens of Manis 

 the platysma is quite rudimentary, though it appears to be well 

 developed in Manis javanica (34) (Macalister). In the Oryctero- 

 podidcB (35, 36) there seems to be a remarkably well-developed 

 panniculus. We have not, unfortunately, had the opportunity 

 ourselves of dissecting the Aardvark, but the descriptions of the 

 platysma in this animal which are at our disposal are quite clear, 

 and seem to show that it there reaches a development superior to 

 anything which we have as _7et met with in our researches into 

 mammahan musculature. It is described as passing from the 

 zygomatic region over the neck and shoulder and arm to the 

 radial side of the forearm. Humphry (36) and Cuvier and 

 Laurillard (37) both figure this extensive platysma, and both also 

 figure a very well-marked sphincter colli or sterno-facialis running 

 backwards to the hinder end of the sternum, superficial to the 

 pectorals, Galton (35) describes a muscle running from the 

 orbicularis oris to the hinder end of the thorax, where it is 

 attached to the mid-line of the sternum : this, there can be little 

 doubt, is the sterno-facialis (c/. " Lectures on the Muscles of 

 Mammals,'"' Journ. of Anat. & Phys. vol. xxxii. p. 430). The 

 same author states that part of this muscle passes under the jaw 

 and round the neck, a fasciculus which quite clearly corresponds 

 to the sphincter colli of other mammals. The abdomino-huraeral 

 part of the panniculus in this animal is also well developed (37). 



Facial Muscles. — There is little of special interest to note with 

 regard to the facial muscles of the Edentates, and there is so much 

 variety in the terminology employed by different writers that a 

 satisfactory generalization is most dittieult. All the animals seem 

 to possess the orbiculares palpebrarum et oris, levator labii 

 superioris, zygomaticus, depi'essor labii inferioris, and retractor 

 naris, as well as anterior, superior, and posterior auricular muscles, 

 the last-mentioned being usually the best developed of the three. 

 The muscles of the face in Myrmecophaga have been described in 

 great detail by Owen (Trans. Zool. Soc. vol. iv.). 



In Bradypus the zygomaticus is well marked, whilst the most 

 remarkable feature in the Dasypodidce and Manidce is the great 

 development of the retractor naris, which rises from the zygoma 

 and passes directly forwards to the snout and is evidently a 

 valuable adjunct in rooting and grubbing. 



Masseter. — In Bradypus (1) the muscle is bilaminar, but the 

 two layers are not very easily separable, The superficial rises 



