(Cuvier, 1804)
(Diagnosis corresponding to that of the genus Weelia, since only a single species has been recognized). In both generations, the transverse ribs of the gill bar meet dorsally, narrowing sharply toward the ventral surface, so that they are far apart from one another ventrally.
Solitary zooids: up to 45 mm long (Weelia cylindrica). Test soft and smooth. Body elongate and cylindrical. Eight or 9 body muscles that extend rather far ventrally and are usually separated. MI to MIV converging, contiguous, or fused in the mid-dorsal line. A great variation is also found in the number of muscular fibers.
Aggregate zooids: up to 17 mm long, excluding projections (Weelia cylindrica 1). Body fusiform because of the presence of short anterior and posterior projections. Five body muscles, all of them meeting in the mid-dorsal region. Embryo between MIV and MV.