ON A NEW GENUS AND SPECIES OF LABROID FISH FROM PORT JACKSON. By E. Pierson Ramsay, F.R.S.E., &c., and J. Douglas-Ogilby. (Notes from the Aitstralian Museum.) EuPETRiCHTHYS, gen. nov. Branchiostegals six : pseudobranchise present. , Body elongate and compressed. Gill-membranes attached to the isthmus. Pre-opercle entire. Jaws with a pair of curved canines anteriorly, and a lateral row of conical teeth : posterior canine present. Dorsal fin with nine spines and twelve rays : anal with three spines and eleven rays; ventral tins with an elongated ray. Scales cycloid, large : opercle and cheek scaly. Lateral line continuous. From the above diagnosis it is evident that the true position of this fish belongs to that group of Lahridce to which Dr. Gunther (Brit. Mus. Cat. iv. p. 66) has given the name Jididina, and a glance along the different sections of that group shews that its place is among those having " nine dorsal spines, the lateral line not interrupted, and the cheeks and opercles scaly." Its close aflinity to Labrichthys — that most numerously represented genus of Labroids on our shores — is at once apparent, but in such a genus where the fin formula remains constant throughout the whole series of about thirty * species, any departure from the normal number must necessarily carry with it a greater weight than among fishes which enjoy a greater latitude in this respect. This difierence therefore coupled with the elongate ventrals and general form have induced us to raise this new species to generic rank under the above name, placing it in the system between the genera Labrichthys and Lahroides. * The examination of a more extended series of specimens will probably reduce this number somewhat.