14 THE MYOLOGY OF THE RAVEN. 



barely perceptible fan-like muscle in the abdominal 

 integument. This is soon gathered, as it passes forwards 

 and upwards, towards the head of the corresponding 

 humerus, into a decided, long narrow fasciculus of fibres, 

 to be finally inserted by a very pretty little fan-like 

 expansion of thin glistening fascia into the tendon of 

 the pectoralis major just below its insertion. In the 

 Apteryx the dermo-humeralis " is inserted fleshy into 

 the proximal part of the humerus " (Owen). In either 

 case it depresses the humerus in the last-named- bird by 

 acting directly upon the bone, while in the Raven it is 

 an auxiliary to the great pectoral muscle. 



13. The der mo -pectoralis is a muscle that corre- 

 sponds to the dermo-dorsalis of the back, and is simply 

 the evident muscular stratum underlying the feather- 

 quills of the tracts of these appendages, that are found 

 on either side of the robust chest of this bird, running 

 in the longitudinal direction. 



Either of these muscles disappears anteriorly over the 

 orio-in of the cleido-trachealis, while behind their ter- 



o 



minal fibres merge imperceptibly into the integument 

 after passing the hinder tips of the postpubic elements 

 of the pelvis. Acting from the anterior skin insertion, 

 these muscles raise the feathers of the chest, the action 

 being reversed by the muscle contracting from the 

 opposite extremity. 



