92 



SUPER-FAMILY HALICOEOIDEA. 

 LXI. HALITHERIIDAE. 



Extinct. 



Halitherium Kaup, 1838=Hauanassa v. Meyer, 1838. 



Metaxytherium de Christol. Fucotherium Kaup. 



Halitherium Kaup. Pontotherium Kaup. 



Pugmeodon Kaup. Cheirotherium Bruuo. 



LXII. HALICORIDAE. 



Genus. 

 Halicore Il\iger=Dugungus Tiedm=PZatys<omus Fisch. 



RHYTINIDAE. 

 Genus. 

 Extinct? 

 Rhytina StelleT=Stellerus Desm.=Nepus Fisch. 



SIRENIA? INCERTAE SEDIS. 



Extinct. 



Trachytherium Gervais. 

 Prorastomus Owen. 

 Anoplonassa Cope. 

 Hemicaulodon Cope. 

 Crassitherium Van Beneden. 



VIII. CETE. 



SUB-ORDERS. 



I. IntermaxillarieS expanded forwards, normally interposed between the 

 maxillaries, aud forming the terminal as well as anterior portion of the 

 lateral margin of the upper jaw. Nasal apertures produced more or less 

 forwards, and with the nasal bones freely projecting. Teeth of the inter- 

 maxillaries apparently in normal number (3-j-3), conic ; of the maxillaries, 

 2- or 3-rooted. 



ZEUGLODONTIA, 



II. Intermaxillaries narrowed forwards, forming only the point of the upper 

 jaw, and underlaid by the maxillaries, which form the entire lateral alve- 

 olar margins of the jaw. Nasal apertures far back, near the vertex, and 

 with the nasal bones appressed. Teeth (when present) all single-rooted. 



A. Teeth more or less persistent after birth. Upper jaw without baleen. 

 Supramaxillary expanded backwards over the frontal bones, but not 

 produced outwards in front of the orbits. Kami of lower jaw united by 



