Acoelomate: The animals without any cavity between ectoderm and endoderm. There are mesenchyma tissues (mesodermal in origin) between ec-toderm & endoderm.
Example- Platyhelminthese.
Pseudocoelomate: They have a body cavity between ectoderm and endoderm but it is not lined by the mesoderm.
Example- Aschelminthese
