OF THE WOMBAT, KOALA, AND PHALANGERS. 



871 



outer half of tbe scapular spine, Cunningham (2) describes it as 

 two muscles fixed to the whole length of the scapular spine 

 in Ousctts. The conditions in the Phalangers cannot be due to 

 their leading an active arboreal life, as other active animals 

 have a single muscle. They are probably remnants of primitive 

 laminations. 



Text-figure 36, 



Scapular muscles in Fliascolomys mitchelli. 



I-S : infra-spinatus ; L.A.S: levator anguli scapulas ; L.H.T : long head of triceps ; 



0-A : omo-atlantic; S.M : serratiis magnus ; S-S : supra-spinatus. 



Serratus Magnus (text-figs, 36-38) : — In the Marsupialia there 

 is a more or less intimate connection between the levator scapulae 

 and the serratus magnvis, thus showing tha.t these muscles are 

 part of the same sheet. And the origin of the serratus extends 

 from the anterior cervical to the posterior thoracic region. In 

 Plicdanger the origin extends from the second cervical vertebra 

 to the seventh rib. The cervical slips are all distinct. In 

 Pseudochirus there are eight thoracic slips. Tlie cervical slips are 



59* 



