The members of phylum Annelida are known as the segmented worms". Their body is metamerically segmented. The excretory units of these invertebrates are coiled tubules, the nephridia.
Example : Nereis, Pheretima and Hirudinaria.
Body Symmetry: Segmented worms have the typical metameric segmentation. Their body consists of segments called somites or metameres and ring like grooves known as annuli. They have bilateral symmetry.
Respiration : Respiration in annelids occurs by the skin. In some, gills are present.
