Marsupialia
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Marsupialia n 1 :
coextensive with the subclass Metatheria [
synonym :
{
Marsupialia }, {
order Marsupialia }]
Marsupialia \
Mar *
su `
pi *
a "
li *
a \
(
m [
aum ]
r *
s [=
u ]`
p [
i ^]*[=
a ]"
l [
i ^]*[.
a ]),
prop .
n .
pl . [
NL .,
fr .
L .
marsupium a pouch ,
bag ,
purse ,
Gr .
marsy `
pion ,
dim .
of ma `
rsypos ,
ma `
rsipos .] (
Zool .)
A subclass of Mammalia ,
including nearly all the mammals of Australia and the adjacent islands ,
together with the opossums of America .
They differ from ordinary mammals in having the corpus callosum very small ,
in being implacental ,
and in having their young born while very immature .
The female generally carries the young for some time after birth in an external pouch ,
or marsupium .
Called also {
Marsupiata }.
[
1913 Webster ]
marsupialian
Mammalia \
Mam *
ma "
li *
a \,
n .
pl . [
NL .,
from L .
mammalis .
See {
Mammal }.] (
Zool .)
The highest class of Vertebrata .
The young are nourished for a time by milk ,
or an analogous fluid ,
secreted by the mammary glands of the mother .
[
1913 Webster ]
Note :
Mammalia are divided into three subclasses ;
[
1913 Webster ]
I . {
Placentalia }.
This subclass embraces all the higher orders ,
including man .
In these the fetus is attached to the uterus by a placenta .
[
1913 Webster ]
II . {
Marsupialia }.
In these no placenta is formed ,
and the young ,
which are born at an early state of development ,
are carried for a time attached to the teats ,
and usually protected by a marsupial pouch .
The opossum ,
kangaroo ,
wombat ,
and koala are examples .
[
1913 Webster ]
III . {
Monotremata }.
In this group ,
which includes the genera {
Echidna }
and {
Ornithorhynchus },
the female lays large eggs resembling those of a bird or lizard ,
and the young ,
which are hatched like those of birds ,
are nourished by a watery secretion from the imperfectly developed mammae .
[
1913 Webster ]
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