Ans. A-Trichuris trichiura
It is brown being bile-stained.
It has a triple shell, the outermost layer of which is stained brown.
It is barrel-shaped and about 50 micrometres long and 25 micrometres wide in the middle, with a projecting mucus plug at each pole containing an unsegmented ovum.
The plugs are colourless. The egg floats in the saturated salt solution.