THE DERMAL MUSCLES. 13 



one of the most conspicuous of the cutaneous system. 

 It arises by a thin fascia from the outer aspects of the 

 third and fourth true vertebral ribs, at the bases of their 

 epipleural appendages, and from the fascia between 

 them. From this point it passes forwards and upwards 

 as a thick muscular bundle, loosely attached to the skin, 

 until it arrives in a point at the inner end of the integu- 

 mental duplicature behind the humerus. Here it be- 

 comes a small and slender tendon lying between these 

 skin flaps in the line of their posterior margin, as far as 

 the elbow-joint, where the tendon spreads out to become 

 attached to the fascia in the locality, and covering the 

 olecranon of the ulna. By extending the elbow-joint it 

 assists in elevating the wing. 1 



12. The dermo-humeralis 2 arises as a broad but 



1 Owen describes for the Apteryx a dermo-costalis which " arises 

 fleshy, from the costal appendages of the seventh and eighth ribs. The 

 fibres pass forward and join those of the preceding muscle [dermo- 

 iliacus] to be inserted into the scapular integument " (Anat. of Verts., 

 vol. ii., pp. Ill, 112). I made several special dissections for the 

 very purpose of finding this muscle in the Raven, but my investiga- 

 tions lead me to believe that it does not exist in our present subject. 



2 Fiirbringer and Gadow have divided the M. PECTORALIS into 

 three parts, and the dermo-humeralis as here described for the 

 Raven corresponds to the third part, or the PARS ABDOMINALIS 

 (Fiirbringer). 



Gadow presents us with the synonymy of the dermo-humeralis as 

 follows : 



" III. Pars abdominalis (Fiirbringer). 

 Subcutaneus abdominalis. Wiedemann, Tiedemann, 100. No. 5. 



,, Watson, p. 55. 



Subcutaneus thoracis. Tiedemann, 100, No. 4. Prechtl, 71. 

 Ohne Namen erwahnt. Schopss, p. 112. 

 Dermo-humeralis. Owen, p. 24, 

 Panniculus carnosus (second portion). Reid, p. 139. 

 Muscle des parures. Gervais et Alix, p. 401. 



Watson, p. 81." 



