Brachiopods	Mollusks
B	A
D	C
F	E
G	H
I	K
J

The shells of brachiopods have bilateral symmetry on each shell.  This means that you can draw a line down the middle of each shell and the right and left sides of the line will be mirror images of each other.  The two shells, however, are not identical, meaning that they are not symmetrical between the shells

Bivalve mollusks shells, in contrast, do not have bilateral symmetry.  With the exception of oysters, however, the two shells are identical.

Although the shells are quite similar, the animals inside the shells are very different.  It is because of this that they are in different phyla.