1.Elongated and meta- merically segmented body.
2.Appendages borne on body segments.
3.Setae are present.
4.The body wall dermo- muscular.
5.The body cavity is a coelom.
6.Respiratory pigment is haemoglobin.
1.Body segmented. Differentiated into cephalic, thoracic and abdominal regions.
2.Appendages may be segmented or jointed.
3.Setae are absent.
4.The body wall is not dermomuscular.
5.The body cavity is haemocoel.
6.Respiratory pigment is absent.