How are the segments of a crayfish different from those of an earthworm?

crayfish have experienced something called tagmosis where some of the segments have merged, thus they have heteronomous metamerism. the difference of the earthworms and crayfish is that earthworms have somewhat called homonomous metamerism - each of the segments looks like every other segment. 

answer; i believe the correct answer is (data); /// good luck