One difference is that some animals are polyp and some are medusa.
The other difference is that some animals have medusa in their life or polp in their life cycle.
Hope these two differences helps :D
They are all in the same family
Break down the table into smaller sections. Memories period by period or if you like by group (like halogens or noble gases).
Just say the elements in order everyday 1-10 then when you get those 11-20 and continued.
