Oozooid elongate, barrel-shaped, with slender muscle bands (<1/2 the width of the interspaces), neural ganglion large, in front of M5. Muscle bands remain narrow in the old nurse. Gastrozooid with main axis up to 8 mm long, with many gill slits (up to 40), alimentary canal U-shaped, anus located dorsally to the esophageal funnel. In both phorozooids and gonozooids, endostyle extending from before M2 or M21/2 to M42/3. Gill-septum slightly arched, beginning at M4 dorsally and ventrally, its posterior bend extending to M51/2. With 12 to 45 pairs of gill-slits. Ovary behind M6. Testis tubular or club-shaped, parallel to the longitudinal axis of the body. Gonozooids up to 9 mm long.