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

172 COLLECTIONS FROM MELANESIA.It will be seen, then, that of the Echinids 19 were found south ofthe tropical line, and 11, or 57"5 per cent., were not found eitherby the 'Alert' or 'Australian Museum' collectors within the tropics.Of the Opliiurids 9 were found south of the line, and only one alsowithin it, so that of this class 88'8 per cent, were found only to thesouth of the tropics.When we turn to the lists of the Alert ' ' collections in the ' Australian' seas and in the western part of the Indian Ocean, we find avery different story.Ech'mids.—Of the 28 species collected within the tropical seas ofAustralia, four only, or 14-2 per cent., were found also at PortJackson, while no less than 23, or 72 per cent., were found also inthe tropical parts of the western Indian Ocean.Table III.—List of Echinoidea collected by the ' Alert ' (to whichis added a statement of such as are found also north of theequator, but within the tropics).^ (u .-< =^ § S O o ^1-3Cidaris metulariaPhyllacauthus annulifera ..baculosaDiadema setosumAstropyga radiataSalmacis alexandribicolorsulcataTemnopleurus toreumaticusgranulosusbotliryoidesEchinus angulosusdarnleyensisToxopncustes pileolusTripneustes angulosusStroiigylocentrotus erythrogrammusEchinometra lucunterFibularia volvaOlypeaster humilisscutil'ormisLaganum depressumdecagonaleEchiuoneuB cyclostomusMaretia planulataLovenia elongataBreynia aust ralasiceEchinocardium australeBrissus uuicolorMetalia sternalis