introdduction of Mollusca with classes

Mollusca(soft body animals)

            The animals with soft body enclosed in shell produced by them are called Mollusca.There are four classes of the Mollusca. They are

1)    Aplachophora or solenogasters

These are mollusca which are without head,mantle,foot ,shell and nephridia.

  (A=not+plax=plate+pherein=bearing)

2) Polyplacophora        

                        These are mollusca which are provided with shell formed by longitudinal series of eight calcareous pieces.

          ( poly=many+plax=plate+pherein=bearing)

3) Monoplacophora                                   

                   These are mollusca which are provided with shell formed by single piece of calcareous piece.

(Mono=single+plax=plate+pherein=bearing)

4)    Gastropoda  

                         These are mollusca provided with foot on visceral mass.

(Gaster=belly+podos=foot)

5)scaphopoda 

   Theseare mollusca provided with boat shaped  foot.

   ( scapha=boat+podos=food)

6)Pelecypoda

 These are mollusca which are provided by shells with two 
  lateral valves,swinging together mid darsoventrally.(Pelekys=hatchet+podos=foot)

7)Cephalopoda

These are mollusca which are provided with reduced shell embeeded in mantle

(kephal=head+poda=foot)