Report on the zoological collections made in the Indo-Pacific Ocean ...

:176 COLLECTIONS FKOM MELANESIA.sufficient to say " Mers australes," New Holland, or Australia indealina; with a continent which extends over 30 degrees of latitudeand 40 of longitude, howsoever wide the distribution of the dwellersnor could it be permitted by one who wouldon its shores may be ;study a collection of Port-Jackson specimens, and then take up thecorresponding forms from Port MoUe or Torres Straits (cf. TablesI.-V. of Distribution).Ophiuroidea.— Opldophiax stellatus, described from Singapore, andfound by the ' Challenger ' at lat. 11° 37' N., long. 123° 32' E., hasnow been found at Port Molle, Port Denison, and Torres Straits. IfOpMotlirlx fumaria has been correctly identified, this is apparentlythe first time that a definite locality has been ascribed to it ; 0.martensi has been shown to be very common in the Australianseas ; 0. galatece (from the Nicobars) and 0. punctolimhata (Java)have their distribution extended eastwards ; 0. rotata has been extendedfrom Mindanao to Thursday Island ; and 0. ciliaris, knownfrom the "Indian Ocean," has been seen to appear at Port Jackson.If we might with justice attempt any generalization from suchfacts as these, we should be led to a belief in the significance of thefree-swimming larva as affecting the extent of the distribution ofnot-stalked Echinoderms.With regard generally to the Echinoidea, it may be said that inseven cases we have the area of distribution increased : Diademasetosum, Salmacis bicolor, Temnopleurus toreinnaticus*, T. granulosushave never yet been found on the eastern coast of Australia ;Cliip>easter limnilis and Maretia planidata have been reported fromNew Caledonia, but not from such a locality as Port ]\Iolle or Clairmoutf.Temnopleurus bothryoides, found by the Challenger ' ' in theArafura Sea and Kobi, Japan, is now known from an intermediatelocality. The members of this class bear ample witness to thenow well-known fact that Indian-Ocean and Pacific specimens invadelargely the Australian seas.A question which presented itself to me, but on which I can throwbut little light by way of answer, might perhaps be formulated thusWhat differences are there between the forms of the eastern andnorthern and the western coasts of xVustralia ? tTo the south of the East-Indian islands there lies an area of deepsea almost free from islands, and having sweeping across it, in obedienceto the laws of motion, a current with a south-westerly directionfrom the equator ; this current sweeps, as we know, round the Capeof Good Hope, and there comes into contact with the southern cou-* Mr. Tenison-Woods reports it from " all the coasts of Australia, but rareoutside the tropics."t But M. planulaia was taken at Port Jackson by the Challenger ' ; ' thepresence of this species in the Australian seas is additionally interesting fromthe fad that a form allied thereto, M. anomcda, has been described by Prof.Martin Duncan (Q. J. Geol. Soc. xxxiii. p. 52).I For Echinoderms, as for Fishes (see Giinther, ' Introd. Study of Fishes,'p. 284), the western half of the south coast of Australia is still almost a terraincognita. It is earnestly to be hoped that the investigation of this area maybe soon undertaken.