UNGULATA. 
753 
MANATEE (Manatus). 
Ducone (Halicore). 
Neck vertebrze reduced to six. 
Abortive incisors (¥) in both sexes. 
Molars (}}) six or so at a time, 
uniform, with square enamelled 
crowns, and tuberculated trans- 
verse grinding ridges. ; 
Premaxillze almost straight. 
Tail rounded. 
Rudimentary nails on fingers. 
Czecum divided. : 
M, australis and M. senegalensis 
live in the mouths of great rivers 
which flow into the’ tropical 
Atlantic. 
The usual seven neck vertebrae, 
Two tusk-lke incisors persist in 
the inale. ; 
Molars (# or $, 2 or 3 at a time), 
primitive, with persistent pulps 
and no enamel. 
Premaxillze crooked downwards. 
Deeply notched tail. ~ 
Nailless digits. 
Thick and single caecum. 
H, tabernaculi, E. African coast 
and Red Sea ; #. dugong, Indian 
and Pacific Oceans, eastward 
from the home of the last species 
to the Philippines; A. australis, 
E. and N. Australia, 
The genus RAytina was toothless, with a slightly crooked snout, 
small head and arms, and thick naked skin.. Steller’s sea-cow (7. 
stelleri)—the only known species, from the North Pacific—seems to 
have been exterminated about 1768. The tertiary Halétherdum had 
traces of hind-limbs, 
Order UNGULATA 
Hoofed Animals— Artiodactyla, Perissodactyla, Hyra- 
coidea, Proboscidea, and extinct sub-orders. 
This large and somewhat heterogeneous order in- 
cludes pigs, hippopotamus, camels, cattle, deer, tapirs, 
rhinoceros, horses, hyrax, elephants, and some other distinct 
types. 
They are terrestrial, and for the most part herbivorous 
animals. Their digits generally end in hoofs or at least in 
broad flat nails. In the adults of the modern types there 
are no clavicles. The teeth are diverse, the milk set in part 
persistent until the animal attains maturity. 
In the typical Ungulates the feet are never plantigrade. 
In modern types there are never more than four functional 
toes. The os magnum of the carpus articulates freely with 
the scaphoid. The brain is well convoluted. The testes 
descend into a scrotum. The uterus is bicornuate. The 
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