1. They are triploblastic animals. That is, the body has cell layers called ectoderm, endoderm and mesoderm.
2. The body is bilaterally symmetrical and flattened like a leaf or ribbon.
3. They are Asilomates. Between different organs are parenchyma or collenchyma cells.
4. Body skin is soft, without cilia or cuticles.
5. The mouth has suckers or hooks or proglottids.
6. The excretory system is made up of flame cells.
7. The nervous system is ladder-like and consists of ganglia and digitorum plexus.
8. Their epidermis is composed of syncytes.
9. Circulatory system and respiratory system are absent.
10. Alimentary system is incomplete, branched and consists of mouth, pharynx and intestine. There is no anus.
11. They self-destruct. The life cycle consists of larvae such as radia, cercoria, sporocysts, cysticercus etc.
[Key words to remember characteristics: triploblastic, flattened, parenchyma, autophagic, sucker, hook, flame cell, syncytial]