1. They have no distinct heads.
2. Exoskeletons are absent.
3. They have no jointed appendages.
4. Excretion occurs through nephridia.
5. Respiration occurs through skin or parapodia, e.g. earthworm, Aphrodite.
1. Body is divided into head, thorax and abdomen.
2. Body is covered by chitinous exoskeletons.
3. They have jointed appendages.
4. Excretion occurs through coxal gland on malpighian tubules.
5. Respiration occurs through tracheae or book lungs, e.g. prawn, cockroach.