Phascolopsis gouldii can reach thirty centimetres long and is a smooth slender cylindrical shape.
The trunk is covered by a thick integument and is largely composed of bands of longitudinal muscles which can be seen through the cuticle.
[2] This peanut worm is found in shallow coastal waters on the eastern seaboard of the United States from Connecticut to Florida,[2] and Canada.
[3] Particular locations where it has been found include Cobscook Bay, the Gulf of Maine, Minister's Island, Indian Point, Newfoundland and the St Lawrence estuary.
It is a deposit and filter feeder, collecting detritus with its tentacles for insertion into its mouth or for consumption after retraction of the introvert.