THE MUSCLES OF THE UPPER EXTREMITY. 99 



of those vertebrae that support the free pairs of ribs ; 

 the fibres slightly converge as they pass directly back- 

 wards to become inserted into the middle third of the 

 inferior aspect of the blade of the corresponding scapula. 

 When this pair of muscles contracts they will evidently 

 pull the scapulae directly forwards, and with it, of 

 course, the entire shoulder-girdle, which will articulate 

 like a hinge-joint at the coraco-sternal junction. 



Owen says that " the levator scapulae arises by digi- 

 tations from the pleurapophyses of the last cervical, 

 and the first two dorsal vertebrae ; it is inserted into 

 the posterior part of the dorsal edge of the scapula, 

 which it pulls forwards. In the Apteryx it seems to 

 be the most anterior portion of the series of fasciculi 

 composing the serratus magnus anticus." It will be 

 seen from this description that both its origin and inser- 

 tion is very different in the Kiwi-kiwi from what it is 

 in the Eaven. 



64. The thoraco-scapularis a is the name I here be- 

 stow upon that muscle in Corvus cor ax which arises 

 from the outer aspect of the lower half of the ultimate 

 free rib ; from the middle of the outer side of the next 

 succeeding rib, or true dorsal, and its epipleural 



zeigt in Gegensatze zu den Reptilien namentlich bei den Carinaten 

 eine gewisse Vereinfachung, die z. Th. dadurch entstanden ist, dass 

 ein Theil von ihui sich als besonderer Muskel (Rhomboideus pro- 

 fundus) differenzirt und abgetrent hat " (Gadow quoting Fiirbringer, 

 p. 221). 



1 Probably the muscle here described is the pars posterior (in 

 part) of Gadow's in. serratus superficialis s. thoraci-scajmlaris, the 

 synonymy of which is given under the serratus magnus anticus of 

 the present memoir, No. 59 (which see). 



The remaining part of the pars posterior of Gadow's m. serratiis 

 superficialis, appears to be herein represented by my serratus parvus 

 anticus (No. 66), and the reader's attention is also invited to that 

 muscle. 



H 2 



