Bürger, 1895
Body sturdy, wide and flat, broadly rounded anteriorly, tapering posteriorly to end in a well differentiated caudal fin; length 13-17 mm, width 8.5-11 mm, thickness 1-5 mm; rhynchocoel nearly as long as body; stylet armature a sickle-shaped basis bearing about 7 conical stylets; 22 proboscis nerves; 4-5 pairs of distinct intestinal diverticula, with group of smaller intestinal lobes posteriorly; females with 6-8 pairs of ovaries; males not known.
Distribution: Taken from depths of about 800-1500 m. Found in the North Atlantic (approximately 45ºN, 30ºW), Tropical Atlantic (off the coast of Gabon, West Africa) and the North Pacific off the southern coast of Japan.