562 STUDIES ON SPONGES, IL-EAPHYRUS HIXONII. A NEW GIGANTIC SPONGE FROM PORT JACKSON. In 1862 Oscax' Schmidt described two sponges (1) as Papillina suberea and nigricans from the Mediterranean. In 1866 Bower-bank (2) described a sponge as Raj)hyrus griffithsii which has also been figured (3.) Oscar Schmidt (4), afterwards colmbined tliis Raphyrus ot Bowerbank with his own Papillina suberea, an arrangement which has been also adopted by Norman. (5) According to this the genera Raphyrus (Bowerbank), and Papillina (O. Schmidt), would appear identical. Among the Australian Sponges there are forms which doubtlessly belong to the genus Papillina (O. Schmidt), whereas others again appear very different from these and coincide with Bowerbank's Raphyrus. All however, contain besides the bulb ac, the pin-shaped spicules, also tr. tr. sp. I assume that these also occur in the European species, but escaped the observation of Bowerbank and O. Schmidt. I think that both these genera should be retained. In Papillina the internal cavities are irregular and large, in Raphyrus tliey are very similar to the cells of a honeycomb, smaller and very regular. The species to be described below, belongs to the latter genus, it is fairly abundant in Port Jackson, Numerous specimens mea-suring 20 X 30 C. m., have been dredged, their shape was bulbous and irregular ; recently a specimen of unusual dimensions was brought up with the dredge. It is the largest Australian Sponge hitherto observed by me. It is named after Captain Hixon, the President of the Marine Board. (1) 0. Schmidt, die Spongien des Adriatischen. Meers 1862. Seite 69. (2) J. Boiverbank. Monograph of the British Sponges. (Ray. Society.) Vol. II., p. 354. (3) ./. Boiterliank. Monograph of the British Sponges. (Ray. Society.) Vol. III., pi. LXIV. (4) 0. Schmidt. Grundziige einer Spongienfaima des Atlantischen Gebietes, 1870. Seite 77. (5) A. M. Norman. Monograph of the British Sponges, by tlie late J. S. Bowerbank. Ray. Society.) Vol. IV, Supplementary, p. 182.