REPORT ON THE SPHENISCID.^. 55 



Nerve supply. — Branches from the cervical spinal nerves. 



Remarks. — The cutaneous muscular system of the Penguin includes the constrictor 

 colli, the panniculus carnosus, the dorsal cutaneous muscle, and the " muscle des 

 parures." This system is developed to a greater extent in the Penguins than in any other 

 bird, with the exception of the Apteryx, and is probably related to their aquatic habits, 

 and to the necessity of an arrangement whereby the water may be readily expelled from 

 the interstices of their fur-like plumage. 



4. Subcutaneous abdommalis. 



Suhnitaneus ahdominalis, "Wiedemann. 



Der Bauehhautmuskel, Tiedemann, vol. i. p. 134 



Attachments. — This muscle, which in reality forms a portion of the "muscle des 

 parures," arises from the free cartilaginous extremity of the pubic bone, and passes 

 obliquely forwards and downwards to the posterior border of the sternum. Here a few 

 of the lower fibres terminate in the subcutaneous fascia covering the border of the 

 sternum, but by far the largest portion of the muscle is directly continuous with the 

 " muscle des parures," of which, indeed, it may be considered as constituting the pubic 

 origin. 



Action. — The action of this muscle is doubtful. 



Relations. — This muscle separates the abdominal origin of the semi-membranosus from 

 the superficial surface of the obliquus externus abdominis. 



Nerve supp)ly- — Branches from the last intercostal nerve. 



Remarks. — This muscle is present in every species of Penguin which I have examined. 

 It appears to be simply a backward prolongation of the "muscle des parures." At the 

 same time the distinct insertion of the lower fibres into the subcutaneous fascia of the 

 abdomen, and the fact that it is supplied by nerves from a totally different source, 

 sufficiently justify its description as a muscle distinct from, although actually connected 

 with, the " muscle des parures." Strange to say, this muscle seems to have escaped the 

 notice of Gervais and Alix when drawing up their extremely accurate account of the 

 myology of Eudyptes chrysolophus. 



(b) Muscles of the Vertebral Column. 

 1 . Sacro-lumbalis. 



Costo-cerincal, Vicq d'Azyr, 1774, p. 580, No. 2. 



Der dussere Ruckcirats-Strecker, Tiedemann, p. 289, No. 6. 



Der Riichenmiiskel, Merrem. ' 



