Question

if non labelled diagram of earthworm is given then which special character must be sure to include in it aphylum

Answer 1

because they are biletrally symmetrical and triploblastic.  

Answer 2

A non-labelled diagram of earthworm can be identified with the help of a special character known as clitenium (Clitenium appears like a point of attachment in middle part of their body structure that is in their segmented body )

Besides they have segmented body. The first segment is mouth and last segment has anus.

Hope it helped you.....