(Quoy and Gaimard, 1824)
Solitary zooids: up to 12 mm long, excluding posterior projections (Thalia longicauda). Test smooth. Atrial palps, lateral and mid-ventral projections absent. Posterior projections thin, with very delicate echinae. Body muscles not fused into groups, but running parallel dorsally.
Aggregate zooids: test smooth, oval but pointed posteriorly (Thalia longicauda 1). Number of muscular fibers (MI-MV): 29-38.