PHOCIDJD. / 



double-rooted, the rest simple ; canines moderate ; whiskers crenu- 

 lated ; muffle hairy ; palm and soles hairy ; claws 5-5, elongate. 



12. Trichechus. Muzzle very broad, truncated, swollen and convex 



above ; muffle, palm, and soles chaffy, callous, with the hair more or 

 less worn off in the . adult (hairy when young ?) ; cutting-teeth | in 

 youth, f in adult ; giinders 4-4, truncated, all single-rooted ; camnes 

 of upper jaw very large, exserted. 



** Muzzle of the male 7cith a dilatile appendage; cutting-teeth^; grinders 

 with a large swollen root and a small, compressed, simple, plaited 

 croion; mirffle hairy. Cystophorina. 



13. MoRUNGA. Nose transversely wrinkled above, exsertile ; muzzle of 



the skull broad, truncated in fi'ont ; forehead convex ; hinder palatine 

 bone short, transverse ; hair flat, truncated, close-pressed ; whiskers 

 round, rather waved, thick ; front claws obsolete ; crown of grinders 

 finely plaited. 



14. Cystophora. Nose of male with a large compressed hood extending 



to the back of the head ; muzzle very broad, hairy ; nostrils large ; 

 muzzle of skull broad, narrowed on each side in front ; forehead flat ; 

 palatine bone broad, square ; hair elongate, cylindrical ; whiskers flat, 

 waved ; claws 5-5, distinct ; crown of grinders strongly wrinkled. 



d. Ears with a subcylindrical distinct external conch ; toes of the hind 

 feet stibeqnal, short, with long me^nhranaceotis Jlaps at the end; fore 

 feetfin-Wke ; palm and soles bald, longitudinally grooved ; nose simple, 



with a rather large callous muffle above and betxoeen the nostrils ; 



cutting-teeth |, upper often bifid; grinders -^^ Arctoceplialina. 



15. Callorhinus. Cutting-teeth subequal ; face of skull short; fore- 

 head convex, regularly rounded from the end of the nasal bone to 

 the middle of the vertex ; nasal opening small ; palate rather concave, 

 contracted behind, short, nearly reaching the middle of the zygomatic 

 arch ; lower jaw short, thick, flattened, expanded beneath just in 

 front of the condyle. 



16. AncTOCEPHALTJS. Cutting-teetli subequal ; face of skull elongate ; 



forehead flattened, and nearly horizontal from the nasal bone to the 

 vertex ; nasal opening large, high ; palate rather narrower behind than 

 in front, rather concave, short, not reaching behind the middle of the 

 zygomatic arch ; lower jaw narrow, with a crest-like ridge behind, 

 beneath, just in front of the condyle. 



17. Otaria. Muzzle broad, high in front ; forehead rather convex ; 



occiput high ; cutting-teeth |, upper and outer one very large, like 

 canines; grinders of adult wdth very large roots and small, com- 

 pressed, lobed crown ; palate-bone rather wider behind than in front, 

 long, extending nearly to the articulation of the jaws behind ; lower 

 jaw broad, dilated in fi'ont and behind at the angle ; upper jaw elon- 

 gate, and dilate with age. 



