60 CETACEA. 



*** Upper and lower jaw with compressed, permanent teeth. 



6. NEOMERIS. Dorsal none. 



7. PHOC^ENA. Dorsal triangular, in the middle of the back. 



c. Upper and lower jaw with many teeth, rarely deciduous 

 with age. Wings of the jaw-bone horizontally produced 

 over the orbits. Delphinina. 



* Head rounded in front, not beaked. Nose of skull scarcely 

 so long as the brain-cavity. Dorsal distinct. 



8. GRAMPUS. Teeth conical, truncated, early deciduous. In- 



termaxillaries broad. Pectoral ovate. 



9. GLOBIOCEPHALUS. Teeth conical, deciduous when old. 



Intermaxillaries very broad. Pectorals narrow, linear. 



10. ORCA. Teeth conical, acute, permanent. Intermaxillaries 



moderate. Pectorals ovate. 



** Head beaked. Nose of skull as long as or longer than the 

 brain-cavity. 



11. LAGENORHYNCHUS. Head shelving in front. Dorsal ra- 



ther posterior. Nose of skull depressed, expanded. 



12. DELPHINAPTERUS. Head rather convex in front. Dorsal 



none. Nose of skull rather depressed, convex above. 



13. DELPHINUS. Head rather convex in front. Dorsal medial. 



Nose of skull rather depressed, convex above. 



14. STENO. Head rather convex in front. Dorsal medial. 



Nose of skull compressed, higher than broad. Symphysis 

 of lower jaws rather elongate. 



15. PONTOPORIA. Head rather convex in front. Dorsal me- 



dial. Nose of skull rather compressed : high symphysis 

 of lower jaw very long. 



B. Jaws much compressed. Symphysis of the lower jaw very 

 long. Dorsal none. Teeth in both jaws. Fluviatile. 



d. Skull with the maxillary bones simple, expanded over the 

 orbit. Teeth conical. Paddles ovate or oblong. Iniana. 



16. INI A. Teeth rugose, the hinder ones with a rounded tubercle 



on the inner side. 



