NotoproctusNotoproctus is a genus of marine polychaete worms in the family Maldanidae. It is the only member of the subfamily Notoproctinae.DescriptionNotoproctus worms are characterized by the presence of cephalic and pygidial plates, a cephalic plate with a low rim, a wide prostomium that forms a low keel, strongly curved nuchal grooves, notochaetae with long and thick capillaries, neurochaetae shaped as acicular spines or reduced uncini in the first four chaetigers, subsequent chaetigers with a row of rostrate uncini, a pygidium with a flat pygidial plate with a low rim, and an anus dorsal to the plate. They have 10 to 17 chaetigers, and some achaetous segments before the pygidium.ClassificationThis genus contains 9 species:Notoproctus abyssus Notoproctus godeffroyi Notoproctus laevis Notoproctus lineatus Notoproctus oculatus Notoproctus pacificus Notoproctus scutiferus ''Notoproctus sibogae''