Class 6. Mammalia. Order 10. Cetacea. 



521 



The cervical region of the vertebral column is very short, but, 

 consists of the usual seven vertebrae, several of which are generally 

 fused ; sometimes, as in the Arctic Right Whale, they ave all fused 



Fig. 417. 



Fig. 418 



Pig. 417. Skull of a Dolphin (Delphinus) from the side. Decreased. — Orig. 



Pig. 418. SkuU of a. Mystaoocete {Balaena japomca], fcetns. Decreased. — After 

 Eschricht. 



occipital condyle, Fr frontal, Ju jugal, L lachrymal. Mid maxilla, n naris, Na nasal, 

 oe exoccipital, Os supraoocipital, Pa parietal, Pal palatine, Pt pterygoid, Pa! premaxUla, Sq 

 squamosal, Ty tympanic bulla. 



in the BalsenopteridEe and some Odontoceti, on the other hand, 

 they are all separate, the centra are flattened discs. Very few of 

 the ribs are attached to the short sternum. The lumbar region is 

 characterised by its great length; sacral vertebrae are not dis- 



