Two new species of Poecilosclerida Crella (Crella) aurantiaca sp. nov. (Crellidae) and Mycale (Aegogropila) denticulata sp. nov. (Mycalidae) are described on the basis of material collected during the XX Italian Expedition (2004–2005) in Antarctica. Crella (Crella) aurantiaca sp. nov. is based on presence of acanthostyles of two size-categories. Mycale (Aegogropila) denticulata sp. nov. is characterized by the presence of palmate anisochelae and styles.