VII.] 



CETACEA. 



99 



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

 portion of the sternum in front of them. 



FIG. 37. Sternum of Cachalot or Sperm Whale (fkyseter tnacrorefkalux), fa. 



In the Whalebone Whales (Afystacoceti} the sternum is 

 comparatively rudimentary, consisting only of a broad, 



FlC. 38. Sternum of Greenland Right Whale (Baftma myslicetut), /,. 



flattened presternum, produced posteriorly into a xiphoid 

 process in some species. There are never any mesosternal 



H 2 



