PRIMARY SUBDIVISIONS OF THE CETACEANS. 



125 



II. Throat longitudinally plicated. Dorsal fin developed. 



a. Dorsal fin hump-like. Pectorals very long, 

 with the four digits segmented into many 

 phalanges. Megapterin^. 



5. Dorsal fin high, erect, falcate or subfalcate. 

 Pectorals moderate, with the four digits, 

 each having four to six phalanges. Baljenopterin^. 



IV. BAL^NID^ Gray, 



§2. LIST OF GENERA. 

 A. ZEUGLODONTIA. 



I, BASILOSAURID^. 



Basilosaurus Harl. = Zeuglodon Owen. 



n. CYNORCID^. 



Cynorca Cope. 

 Squalodon Grat. 



Pontopona Gray. 



I)iia D'Orb. 

 Platanista Cuv. 



Colophonodon Leidy. 

 Stenodon Van Ben. 



B. DEWTICETE. 



III. PLATANISTID^. 



PONTOPORIIN^. 



Lophocetus Cope (extinct). 



iNlINiE. 



Platanistin^. 



Genera incert^ sedis. 

 Tretosphys Cope (extinct). Priscodelphinus Cope (extinct). 



Zarhachis Cope (extinct). 



IV. DELPHINro^. 

 Delphinapterin^. 

 Delphinapterus Lac.; Lillj.=jBeZM^a Gray. 



Delphinin^. 

 Delphinus Linn. 



Tursiops Gerv. = Tursio Gray. 



LarjenorhyncJuts Gray. 



Solalia Gray. 



Steno Gray. 



Leu<:orharaphu8JA\\].=Delphinap- 



terus Gray (not Lac). 



Monodon Linn. 



Pseudorca Reinh. 

 Orca Gray. 

 Orcaella Gray. 

 Pkoccena Gray. 

 Neomeris Gray. 

 Sacjmatias Cope. 



