162 



of the ra. rectus abdominis. The m. supracostalis has been described 

 by Wood, Pye-Smith, Macalistee, Bochdalek jr., Cals and others. 

 It extends usually downward and medialward from the first or second 

 to the third or fourth rib. Occasionally it is prolonged upward to 

 the transverse process of the sixth cervical vertebra, and sometimes as 



Fig. 2. Shows the muscle filires continued forward in the fascia toward the first 

 costal cartilage. 



reported by Cals it is continuous with the mm. scaleni. Below, it 

 occasionally becomes continuous with the m. obliquus externus abdo- 

 minis and lies sometimes beneath the m. serratus anterior, but more 

 commonly external to that muscle. On account of its position it would 

 seem necessary to adopt Cals' ('04) view that the m. supracostalis re- 



