REPORT ON THE SPHENISCID.'E. 71 



as far as the uncinate processes. The fibres cross those of the external intercostals, being 

 directed from behind and above, downwards and forwards. 



Nerve supply- — Branches of the intercostal nerves. 



Remarks. — The anterior fibres which lie between the sternal ribs are the " Musculi 

 interappendiculares costarum " of Tiedemann, the term " Internal Intercostal " being 

 limited by that author to those fibres of the internal intercostals above described which 

 lie between the vertebral ribs. 



7. Scalenus. 



Les muscles qui tiennent la place des scalhnes (one of), Vicc[ d'Azyr, 1774, p. 520, No. 2. 



Rippenhalter, Wiedemann, p. 78. 



Der erste Rippenhalter, Tiedemann, p. 299, No. 1. 



Scalhne, Cuvier, vol. i. p. 218. 



ScaVene, Meckel, vol. vi. p. 216, No. 1. 



Scalenus meclius, Owen, p. 29. 



Scalenus, Selenka, vol. vi. p. 98, No. 12. 



Surcostaux (one of), Gervais and Alix, p. 12. 



Attachments. — The scalenus muscle arises from the transverse processes of the last 

 cervical and first dorsal vertebrse. The fibres pass obliquely backwards and downwards, 

 and are inserted into the second rib above the costal process. As the muscle passes back- 

 wards it entirely envelops the first or rudimental rib in its fibres. 



Action. — This muscle acts as a muscle of respiration, inasmuch as it raises the second 

 rib, and indirectly those succeeding. 



Nerve supply (?) 



Relations. — The large cords of the brachial plexus pass out in front of this muscle, 

 and separate it from the longus colli externus. 



Variations. — In the majority of the birds dissected, I found that the scalenus, as above 

 described, was separable into two distinct portions — an anterior, arising from the last 

 cervical, and a posterior arising from the first dorsal vertebra. In some, however, no trace 

 of this subdivision was recognisable. 



(/) Muscles of the Abdomen. 



1. Transverso-cloacal. 



Attachments. — The muscle so named by Gervais and Alix (p. 16) arises from the trans- 

 verse processes of the third, fourth, and fifth coccygeal vertebrae. Its fibres pass down- 

 wards and forwards, and after crossing the superficial surface of the ischio-pubo-coccygeus, 

 are inserted close to the anus. The anterior fibres pass in front of the anus, and become 

 continuous with the corresponding fibres of the muscle of the opposite side. The 



