SLOTHS 175

ralist who was with him. This sea-cow was like a
gigantic manati, and occasionally attained a length of
thirty feet. It had no teeth, but the horny plates in
its palate were enormously developed. The discovery
was much appreciated by the sailors, who took quite
a fancy to sea-cow meat, so much so that in less than
half a century the species became extinct. When
Nordenskjold came home from the Vega expedition,
during which he accomplished the north-east passage
along the northern shores of Asia, he brought home
with him a large number of skeletons of Steller’s sea-
cow. In some of the fossil sirenians, all of which
were of Tertiary age, there were rudimentary legs.
Some of these early forms have been found in
England and some in Jamaica, and they are especially
valuable in indicating the derivation of the Sirenia
from the land mammals.

EDENTATA.—This is another order on the
down-grade, containing several very different groups
once very numerous and connected by intermediate
forms now only found in a fossil state. It is charac-
terised by a general incompleteness of dentition, some
of its representatives having no teeth at all. It is
usually considered as being made up of seven families.
To the first of these, the Bradypodide, the ‘slow-
footed’ animals, belong the sloths, one group of
which has three toes, and nine vertebre in the neck,
the other having two toes and only six vertebra in
the neck. Both groups are confined to Central and
South America, and spend their life among the trees,
feeding on leaves and fruits, and so leisurely in their