ziPHiiD^. 327 



I should have preferred Hyperoodontidce for the name of this family, 

 as Hyperoodon is the oldest genus ; but it conveys a false impi-ession, 

 caused by a slip of the pen in describing the teeth in the manuscript 

 (or an error of the press in the work) of Otho Fabricius. 



Synopsis of the G-eneea. 



A. Teeth 2 oi- 4, in front end of the lorverjmo, conical. Beak of skull with a 

 high crest on each side, formed by the elevation of the maxillary bones. 

 Hyperoodontina. 



1. Hypekoodon. Beak of the skull straight ; crest of the beak sharp- 



edged above, as high as the occiput. 



2. Lagenocetus, Beak of the skull ascending; crest of the beak flat- 



topped, higher than the occipital. 



B. Teeth 2 or 4, in front eiul of the lower jaw, conical or cylindrical. Beak 

 of skull simple ; intermaxillaries enlarged behind, forming a more or 

 less deep canty round the bloivers. Epiodontina. 



3. Epiobon, Vomer simple, smaller; intermaxiUaries elevated, and 



forming a moderately deep, well-marked basin round the blowers. 



4. Peteorhynchxjs. Vomer swollen, foi-ming a large, elongated tubercle 



between the callous intermaxillaries ; intermaxillaries forming a deep 

 basin round the blowers. 



C. Teeth iti the side of the lower Jaw, co7npressed. Beak of sktdl simple ; 

 intermaxillaries linear, rather swollen on side of blowers. Ziphiina. 



5. BERABDitJS. Teeth in the front of the side of the lower jaw; lower 



jaw simple, tapering. 



6. ZiPHiiTS. Teeth in the middle of the side of the lower jaw; lower 



jaw simple, tapering. 



7. DioPLODON. Teeth in the middle of the side of the lower jaw. Lower 



jaw broad behind, suddenly contracted in front. 



A. Teeth 2 or 4, in the front end of the lower jaw, or often hidden in the 

 gums. Beak of skull with a high crest on each side above, formed by 

 the elevation of the maxillai-y bones. Eyes close to the gape, _ Cei'vical 

 vertebrce all anchylosed. Hyperoodontina. 



Hyperodontina, Gray, Proc. Zool. Soc. 1863. 



Hyperodontina (pars), Gray, Zool. Ereh. 8f Terr, 24; Cat, Cetac, B.M, 



1850, ; Proc. Zool. Soc. 1864, 239. 

 Diodonea (pars), Rafin. Anal. Nat. 60, 1815. 

 Les Heterodontes, Duvernoy, Ann. Sci, Nat. 1851, xv. 23; Arch. 



Naturg. 1852, 21. 



