Solitary zooids: up to 70 mm long (Ritteriella retracta). Number of body muscles varying from 10 to 18, all of them interrupted ventrally. Intermediate muscle and fifth oral sphincter interrupted ventrally. Oral retractor reaching MI. Intestine stretching longitudinally. Blood-forming organ of variable size and form.
Aggregate zooids: up to 39 mm long, excluding projections (Ritteriella retracta 1). Number of muscular fibers (MI-MVI): 60-109.