550 CETACEA. 



the nasal chamber ; the peculiar relations of the pterygoids ; the minute character 

 of the optic foramina ; the small orbit ; the firm attachment of the periotic to the 

 skull ; the relatively large semicircular canals of the internal ear ; the long cervical 

 region ; the large vertebral metapophyses, and ossified sternal ribs in adult life, 

 along with other peculiarities described in this Memoir at some length, present an 

 assemblage of characters as yet unknown in any other Cetacean. 



