278 
PEOFESSOE  OWEN  ON  THE  ^MEGATHEEPOI. 
Desckiption  of  the  Plates. 
PLATE  XVIII. 
Oblique  front  view  of  the  skeleton  of  the  Megatherium,  on  the  scale  of  half  an  inch 
to  a foot,  showing  the  true  position  of  the  manubrium  stemi,  and  the  articulation  there- 
with of  the  clavicles. 
PLATE  XIX. 
Eig.  I.  Inner  surface  of  the  scapula,  one-fourth  the  natural  size. 
Fig.  2.  Glenoid  cavity  and  acromiocoracoid  arch. 
PLATE  XX. 
Fig.  I.  Under  surface  of  the  right  clavicle. 
Fig.  2.  Front  view  of  the  left  humerus. 
Fig.  3.  Back  view  of  the  left  humerus. 
Fig.  4.  Head,  or  proximal  articular  surface,  of  the  left  humerus. 
Fig.  5.  Distal  articular  surface  of  the  left  humerus. 
PLATE  XXL 
Fig.  1 Antero-radial  surface  of  the  left  ulna. 
Fig.  2.  Proximal  end  of  the  ulna. 
Fig.  3.  Distal  end  of  the  ulna. 
Fig.  4.  Anterior  surface  of  the  left  radius. 
Fig.  5.  Proximal  end  of  the  radius. 
Fig.  6.  Distal  end  of  the  radius. 
The  above  figures  of  Plates  XX.  and  XXI.  are  less  than  one-fourth  the  natural  size. 
PLATE  XXII. 
Dorsal  or  upper  surface  of  the  bones  of  the  right  fore-foot : less  than  one-half  the 
natural  size. 
