298 THE MYOLOGY OF THE RAVEN. 



This muscle is best developed, so far as I am at 

 present aware, in some of the Mammalia. 



142. The levatores costarum 1 constitute a series 

 of muscles following in sequence the scalenus medius. 

 The first or anterior one arises from the extremity 

 of the transverse process of the twelfth vertebra, and 

 its fibres diverging as they pass downwards and back- 

 wards become inserted into the anterior free margin of 

 the upper third of the long or posterior free rib, and 

 to the external surface of the same bone, contiguous to 



> o 



this margin. 



o 



The succeeding levator muscles of these ribs arise 

 and are inserted in a similar manner ; coming off from 



' O 



the ends of the diapophyses of all the dorsal vertebrae, and 

 being directed downwards and backwards are attached 

 to the anterior margins of the ribs next behind them, 

 in any case. They, however, grow gradually more and 

 more feebly developed as we proceed in the direction 

 of the pelvis, and are inserted less and less upon the 

 outer surface of the rib to the border of which they 

 are fast. 



143. The appendico-costcdes' 2 ' represent another series 

 of thoracic muscles in birds, and are handsomely deve- 

 loped in the Raven. In each case they arise from 



1 Synonymy in Gadow is as follows (loc. cit., pp. 123, 124) : 



" ISd. MM. LEVATORES COSTARUM. 



Les vertebraux-costaux. Yicq d'Azyr. 

 Die Erheber der Biust. Merrem. 

 Levatores costarum. Tiedernann, 235. 



Owen. 



,, Magnus, p. 222 ; Selenka, p. 98. 



Heber der Eippen. Meckel, System, p. 301, No. 1. 

 Muscles sur-costaux. Gervais et Alix, p. 12." 



2 These muscles are alluded to by Sir Richard Owen in his Anatomy 



