A new species of Cladorhizidae, from the Aleutian Islands is described and compared with all known species of Cladorhiza worldwide. Cladorhiza corona sp. nov. has a unique growth form with two planes of di¡erently shaped appendages. Appendages are inserted directly at the stalk; a spherical or conical body at the stalk is lacking. It is the only species reported where different spicule types occur in three morphologically
different areas of the sponge. The spiculation of the basal plate is characterized by the occurrence
of short, thick anisoxeas and the lack of anisochelae. Anisochelae are found in the stalk and the basal appendages only. Flattened sigmancistras and (sub-)tylostyles are restricted to the crown. The arrangement of spicules is di¡erent in the basal plate, the stalk with the basal appendages, and in the distal appendages. The dimensions and combination of spicule types separate C. corona sp. nov. from all known members of the
genus.