154 



SKETCH OF THE HISTORY OF MAMMALIA. 



merit of the skull : the maxillary and intermaxillary- 

 bones are indeed prolonged, but the cranial portion is 

 small, and rises abruptly (see Fig. 99, Skull of" the Ca- 

 chalot in profile). If, however, we look at the upper 

 surface of the skull (Fig. 100), we find the top deeply 

 concave, with a margin continued along the outer edge 

 of each maxillary bone. It is in this concavity principally 

 that the substance termed spermaceti, or more properly 

 cetine, is lodged, and that in such immense quantity as 

 to give to the head its extraordinary size and figure. 

 This substance, in a semi-fluid state, is contained in a 



^^o^-d-i -^^^w^^A^^^^^ 



100. — Skull of Spermaceti Whale, seen fiom above. 



