SOLUTION

Nephridia are the major excretory organs which help to remove the metabolic waste.
Integumentary nephridia lie scattered on the entire inner or parietal surface of body wall in each segment, except the first two.
There are 200-250 nephridia in each segment.
Integumentary nephridia are V-shaped and lack nephrostomes.
Their terminal duct opens on body surface independently through minute openings, known as nephridiopore. They are thus known as exonephric.