Cormus formed of irregular and loosely anastomosed tubes.

Cells with yellow granules are present in the mesohyl, as are embryos, which are always found near choanocytes.

The cells with yellow granules are distributed homogeneously, throughout the mesohyl.

Diactines are abundant on the external tubes; they are curved or straight, vary in size and have sharp tips, one of which is club-shaped.

They project through the surface in some parts of the cormus only, and the club-shaped portion of the spicule lies inside the tube.