ABSTRACT A new genus, Onycocaridella, is proposed for a new species of pontoniine shrimp found inhabiting the sponge Mycale sulcata Hentschel at 12 m on Wistari Reef, Heron Island, Queensland, Australia. The new species O. prima is described and illustrated. Two species of the genus Onycocaris, O. stenolepis Holthuis and O. monodoa Fujino and Miyake, are transferred to the new genus. The relationship of Onycocaridella to other genera of spongeassociated pontoniine shrimps (Onycocaris, Periclimenaeus and Typton) is discussed, and a key to the species of Onycocaridella is provided.