SPECIMENS 



OF 



PINNIPEDIA. 



Family I. TRICHECIDiE. 



No external ear ; no scrotum ; upper canines grow into 

 long, powerful tusks; the other teeth with single 

 roots relatively small and simple. Skull with an 

 alisphenoid canal. Hind feet, toes can be turned 

 forwards. Inner wall of orbit complete, that of 

 zygomatic fossa defective. Anterior nares terminal ; 

 astragalus without calcanear process. 



I. TRICHECHUS. (Tr.) 



Trichechus, Linnwus, Syst. Naturae, 1735. 



A bulky animal, the adult male being about 10 feet 

 long ; skin with short hairs, yellowish brown, darker 

 on venter ; soles of manus and pes bare and rough ; 

 head rounded, muzzle short, broad, with stiff whiskers; 

 eyes small ; tail short ; dorsum of digits with nails ; 

 mamma? four. 



(1) Trichechus ROSMARUS. (Tr. r.) (Auctorum.) 



(Walrus, Morse, Sea Horse.) 



Hard palate truncated, reaching hamular pterygoids 

 and in line with anterior border of glenoid fossa; 

 zygomatic arch not bulging ; orbits relatively small. 

 Tympanies not swollen, rough on inferior surface. 



Permanent dentition : in. a T)' c. y ; , post - canine 



3 3 .3311 



or molars 'o = 18. Milk dentition: in. o o- c. -^ -^, 



p.c. I ^ = 34. Vertebral formula C.Di.L.S.Cdj., = 43. 



44 



163 



