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MONTESSORI ZOOLOGY : External Parts of Mullusca

The Mollusk

Mollusks have a soft body
and many have a hard shell.


The body is soft and unsegmented.
The mollusk' s body is protected by
a shell or a tough wrapper.


On the tip of each of the longer 
tentacles of the snail is an eye. If an 
eye is damaged, it regenerates itself.


The tentacles are slender, hollow tubes.
Some mollusks have one or two pair of
tentacles (snails, slugs); some have eight or
ten long tentacles (octopuses, squids); and
some do not have any tentacles (clams).


As it grows, the mollusk adds coil
after coil to its shell, building the shell
from the open end as it needs more room.


 The mouth of the mollusk
contains rows of very small teeth.


The mantle is a skin-like organ.
In some mollusks the mantle produces
the substance that makes the shell
(snails, whelks, clams). For other mollusks,
the mantle forms a tough wrapper
around the body (octopuses, squids).


The foot of the mollusk is tough and
muscular. The foot contains glands
which pour out a slimy fluid for
a snail to move over a surface.

Respiratory Pore

The respiratory pore is toward
the front of the mantle edge.


 The tail is the portion of the mollusk
that extends part the end of the shell.


The anus is a small opening
on the mantle edge of the mollusk.

 Pinegreenwoods Montessori
Montessori Zoology