OF THE WOMBAT, KOALA, AND PHALANGERS. 



S7'6 



Muscles of the Ventral Abdominal Wall : — In the Plialangers at 

 my disposal the muscles of the ventral abdominal wall were all 

 firmly united together and the linea alba was very obvious. The 

 rectus abdominis had eight intersections, and the first one was 

 so wide that there is apparently a rectus abdominis and rectus 

 thoracis. This condition was also present in Young's specimen of 

 Phascolarctos (14). In Phascolarctos and Phalanger the pyrami- 

 dalis conceals the rectus, and gets one insertion into the sternum 



Text-fisfure 38. 



TRAPEZIUS. 



Scapular muscles in Phascolarctos cinereus. 

 Letters as in text-fip;. 36. 



and last costal cartilage, but it is not so extensive in Phascolomys. 

 These animals are, however, essentially similar as regards all the 

 muscles of the ventral abdominal wall. 



Dorsal Abdominal Muscles : — The quadratus lumborurn is well 

 developed in Phascolomys and the Phalangers. In Phascolarctos 

 it is more primitive, for it is practically absent, or, as Young (14) 

 suggests, it maybe replaced by intertransverse muscles connecting 



