The present report is not concerned with a large number of new species. Of these there are only thirteen. They are distributed among the same number of genera, of which three are new. Incidentally also a new genus, Parawaldeckia, is instituted for a species previously called Nannonyx thomsoni, from New Zealand, and not as yet recorded in Australian waters. The new genus Ochlesis is worthy of note, since by the character of its maxillipeds it forms a link between the Gammaridea and the Hyperiidea. For this reason it appears to justify the institution of a new family, the Ochlesidae. In all, forty-four species have been identified among the specimens of the "Thetis" collection. In the genera Eusiroides, Eurystheus and Icilius, it is possible that future stringency of specific determination may reduce the number of species here noted. Some reductions in regard to other genera are suggested in the report itself. Thus, the genus Vijaya, Walker, 1904, is made a synonym of Haswell's Amaryllis, and Walker's Gallea tecticauda, of the same date, loses its significant specific name by identification with Haswell's earlier Cyproidea ornata. Etc.