BY W. J. S. MCKAY. 271 



Innervation. Lateral cutaneous nerve of the thorax (Fig, 

 13, oi, Echidna; fig. 16, 54, Ornithorhynchiis). Also branches 

 from the i.-iv. cervical nerves (figs. 13 et 16, 10); and from the 

 external branches of the posterior divisions of the spinal nerves. 



Westling — Echidna : " Der Panniculus carnosus und seine tie- 

 fern Portionen warden theils von Cervicalnerven, theils von Plexus 

 brachialis-Nerven und theils von den dorsalen Zweigen der 

 Thoracalnerven innervirt." 



Echidna. 



Westling gives but a slight sketch of the panniculus. 



MiVART gives a short account, saying — " It consists mainly of a 

 lajge superficial muscular layer with certain deeper portions, and 

 is firmly attached to the neck and tail and distal portions of the 

 ulna," and under the head of P. major he further notes that the 

 insertion of that muscle "is superficial to the insertion of a deeper 

 layer of the panniculus, while an outer layer of that muscle is 

 superficial to it." 



Leche follows Fewkes, and gives a description of the various 

 divisions of the panniculus, as follows : — 



1. M. dernio-dorsi cervicalis arises from the 8th-10th rib and 

 vertebra, as well as from the aponeurosis of the M. trapezius pos- 

 terior, and terminates by fusing with the cervical portion of the 

 panniculus. 



2. M. dermo-Jiexor antehracJiii (Pars posterior M. latissimi 

 dorsi, Mivart) arises from the 8th-13th rib, and is inserted along 

 the forearm, where it becomes connected with the M. flexor carpi 

 ulnaris. 



3. M. dermo-hrachialis anterior arises from the panniculus, 

 dorsal to the origin of the preceding ; and is inserted in the 

 tuberculum majus humeri, proximal to the insertion of the M. 

 pectoralis major. 



4. M. dermo-hrachialis posterior arises more from the lateral 

 aspect than the preceding, and, splitting into four or five divisions 



