Asexual individuals have a small body, approximately spherical, somewhat expanded dorso-ventrally. The gonozooid has two extensions, one on the oral aperture and a longer one on the atrial aperture. The body is asymmetrical, dorso-ventrally expanded, reaching 7 to 8 mm in this axis. Pharyngeal cavity large. Endostyle short. Gill-septum vertical, slightly arched, with 30 pairs of gill-slits. Alimentary canal U-shaped. Ovary ventral, near the posterior extreme of the endostyle. Testis digitate, on the intestinal coil. Ruby-red pigment concentrated on the oral siphon, in the atrial extension, and in the left wall of the body.