Excretory structure is absent in
Asterias (Echinodermata) has no specific excretory structures but tube feet help in it partly.
Apis (Terrestrial arthropods) - Malpighian tubules.
Ascaris (Aschelminthes) - Excretory tube removes body wastes from the body cavity through the excretory pore.
Fasciola (Platyhelminthes) - Flame cells.