194 



A BOOK OF~ WHALES 



The vertebral formula of the Sperm whale is :- 

 C. 7; D. ii ; L. 8 ; Ca. 24=50. 



The atlas alone is distinct, the other cervicals being 

 united with each other, and even sometimes with 

 the first dorsal. In the freedom of the atlas and 

 the fusion of the remaining six Physeter is unique 



FIG. 24. SKULL OF PHYSETER FROM ABOVE. 



(From Flower.) 



r if 



son 





eo, Ex-occipital, s, Squamosal. f, Frontal. ;;, Nasal, ni, Maxilla. 

 eh, Ethmoid. rpin, Right pre-maxilla. Ipm, Left pre-maxilla. vo, Vomer. 



among whales. Another characteristic feature of 

 the atlas is its quadrangular outline. 



As to the dorsal vertebrae (eleven in number if 

 we include the one at the end of the series much 

 resembling the lumbars, but bearing a rudimentary 

 rib), the first nine have somewhat rudimentary post- 

 zygapophyses--" rough processes, which can be 



