The excretory organs of earthworm occur as segmentally arranged coiled tubules called nephridia. They are of three types: (i) septal nephridia, present on both the sides of intersegmental septa of segment 15 to the last that open into intestine, (ii) integumentary nephridia, attached to the lining of the body wall of segment 3 to the last that open on the body surface and (iii) pharyngeal nephridia, present as three paired tufts in the 4^th, 5^th, and 6^th segments. Nephridia regulate the volume and composition of body fluids. A nephridium starts out like a funnel that collects excess fluid from the coelomic chamber. The funnel connects with a tubular part of the nephridium which delivers the wastes through a pore to the surface in the body wall into the digestive tube.