Biologic evolution

It is what of Meretrix meretrix's skin took a picture.
There is Mr. from whom the shellfish dusts two kinds.
I think that everything becomes the same structure to be able to do
nothing but classify it of one of shellfish when they are two how to
classify the picture book just now.
...thought thing.. skins are being taken a picture of the skin of the
shell by me, are Fcrojou, exist in the right and the left, and there
is internal organs between a right, left bags.
I think that being able to do the shell to a right, left bag two is a
shellfish.
However,
It is thought that two that is not the skin (bag)-piece shellfish and
existing are true and the shell without the bag that has it examines
how to do.
The growth of the shell of the type with the bag is examined.