12. TKTCTIECnUS, 



35 



Overs. Kongel. Danske Vidensk. 1860, 698; Arch. Naturg. 1801, 

 100. AU the specimens I have seen seemed to belong to a single 

 species. 



12. TRICHECHUS. 



Muzzle very broad, truncate, 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 A in young, ^ in 

 adult ; grinders || in adult, truncated, all single-rooted ; canines, 

 upper very large, exserted. Eyes prominent ; tail none. 



The skin is covered with small ovate scales. Nose with very rigid, 

 white, compressed, pellucid bristles, rounded at the end. Fore feet 

 small ; outer and hinder edge of the upper side bald, rest covered with 

 hair ; front claw rudimentary ; skin of the soles rigid, warty. Hind 

 feet rather large ; first and fifth toes elongated, with a distinct flap 

 and rudimentary claw ; three middle ones shorter, with subacute 

 claws. Tail rudimentary. 



Fig. 12. 



Trichechus Rosmarus. Skull : adult. 



The skull differs fi-om the other Earless Seals in having a distinct 

 alisphenoid canal, like the Eared Seals ; and it agrees with the Ear- 

 less ones in having no postorbital process, and the mastoid process 

 strong and salient, its surface continuous Avith the auditory buUte. — 

 Turner. 



In the young there are in the upper jaw three incisors on each 

 side, the first or inner extremely small, the second a httle larger, 

 and the third or outer disproportionately large, being equal to the 



D 2 



