612 THE PRINCIPAL FEATURES 
THE PRINCIPAL FEA’ 
EDENTATA. SIRENIA. RopENTIA. Uncul 
LCC E in teseancesdiint No incisors nor No incisors nor Incisors 2 or |. Often 1 
canines, molars | canines, or a |} growing from | incisol 
simple with no | single pair grow- persistent pulps, | C@?ines, 
enamelor absent, | ing from persis- | pocanines,molars | C!S°FS 4 ] 
grow from persis- | tent pulps,molars |} with flat complex | be $.4. 
tent pulps, mono- | few or absent. ridges. 1 ‘J 
phyodont. euweys. 
complex 
TEUMO Sa ca disalesavies Plantigrade or Fore-limbs Plantigrade or | Plantig 
prehensile. paddles, hind- | subplantigrade. digitigra: 
. limbs absent. 
Digits usually Digits 5. Digits & usually. Digits 
& but reduced to mostly h 
$ in arboreal. 
Clavicles. No clavicles. _ Clavicles some- Nocla 
times absent. 
Placenta........ Discoidal or Zonary (non- | Discoidal (de- Zonary. 
dome-shaped | deciduate). ciduate). or cotyl 
(deciduate), dif- (non-deci 
fuse or zonary 
(non-deciduate). 
LL AGEP eeessecparissi oe Fossorial or Aquatic, Herbi- Terrestrial, Terre 
Arboreal, In- | vorous. Fossorial, Arbor- | Herbivor 
sectivorous or eal, Herbivorous. 
Herbivorous. 
Distribution.... Neogean Rivers of At- Cosmopolitan, Widei 
realm and Ethio- | lanticand Indian | mainly Neogoean | goean ar 
pian and Oriental | Oceans 30° N. | realm. gean rea 
regions. 
to 30° S 
