Solitary zooids: up to 7 mm long, excluding posterior projections (Thalia orientalis). Test soft, with eight longitudinal rows of minute echinae on the surface. Posterior projections very long, lateral projections absent, mid-ventral projections strongly developed. All test projections echinate. Atrial palps bifurcate. MI to MII barely contiguous, MII to MIII and MIV to MV strongly fused dorsally. Number of muscular fibers, including the intermediate muscle: 30-36.
Aggregate zooids: (Thalia orientalis 1) similar to Thalia democratica.