VII.] 



CETACEA. 



99 



(ms 2 ) are ankylosed together mesially, but not with the 

 portion of the sternum in front of them. 



m j 



nis 



FIG. 37. Sternum of Cachalot or Sperm Whale (fhyseter macrocephalus'), 2 *j. 



In the Whalebone Whales (Mystacoceti) the sternum is 

 comparatively rudimentary, consisting only of a broad, 



FIG. 38. Sternum of Greenland Right Whale (Balcena mysticetus), T V. 



flattened presternum, produced posteriorly into a xiphoid 

 process in some species. There are never any mesosternal 



H 2 



