ORDER CETACEA. 



Eefore entering upon the details of the respective groups, taken 

 seriatim as tabulated, I may remark that, with three or four exceptions 

 only, in all the known species of the toothed whales (Odontocete) those 

 which possess dorsal fins or distinct dorsal protuberances, have the 

 cervical vertebrae more or less anchylosed 1 ; whereas in those kinds 

 where the dorsal fin is absent, the neck vertebrae are free 2 . The reverse 

 of this singular union of two apparently unconnected, but important 

 parts of organic structure occurs in the whalebone whales (Anodon- 

 tocete), the dorsal-finned species having the cervical vertebrae in most 

 instances free, while those without the back fin, with the exception of 

 the scrag whales, have the vertebrae of the neck anchylosed into one 

 solid mass. 



Thus, by the examination of the cervical vertebrae of any cetacean 

 skeleton set up in a museum, the dorsal outline of the living animal 

 can with considerable accuracy be traced. 



1 Cervical vertebrae of Delpliinus tursio (Tursio truncatus), are said by Cuvier to 

 be free ; Pontoporia blainvillii, cervical vertebrae free Burmeister. 



2 By the same author (Cuv.), the neck vertebrse of Delphinus (Delphinapterus) 

 Peronii are anchylosed, and also that of Delphinapterus (Neomeris) phoceenoides. 



