|Class 9 Biology Diversity In Living Organisms||Annelida|
The organisms belonging to this group are bilaterally symmetrical and triploblastic.
These organisms have a true body cavity so that the true organs are enveloped within the body structure.
The differentiation occurs in a segmental fashion, with the segments lined up one after
the other from head to tail.
An organism of this group lives in variety of habitats like fresh water, marine water and land.
Examples of organisms belonging to this group are Earthworms and leeches are familiar examples