ON MOLLUSCA FROM THE MONTE BELLO ISLANDS. 6G5 37. Report on Mollusca collected at the Monte Bello Islands. Bj ToM Iredale *. [Received March 18, 1914 : Read June 9, 1914.] (Text-figure 1.) Index. Page Geographical relationships 665 List ot Shells collected 666 Systematic :— Euliina montagueana , sp. n 672 Suhularia montebelluetisis, sp. n 673 ScajpheUa hedleyi, noui. no v., for S. reticulata 674 The small collection brought back by Mr. P. D. Montague is still of much interest on account of the geographical position of the group. Hedley, in the Proc. Linn. Soc. N.S.W. vol. xxviii. pp. 876-883 (1903), introduced divisional names to indicate the different faunal elements recognisable in the Marine Fauna of Australia. He determined four primary divisions, to which he gave the names Adelaidean, Peronian, Solanderian, and Dampierian Regions. The limits of the Adelaidean Region were noted as pi'obably being Wilson's Promontory in Victoria and Geraldton in West Australia, embracing the whole southern coast of Australia and round the south-west corner. The Peronian Region designated the East Coast from Wilson's Promontory north to Moreton Bay in South Queensland. The Solanderian Region was given to the remainder of the Queensland coast northwards to Torres Straits ; whilst the Dampierian Region extended westwards from Torres Straits to Houtmann's Abrolhos, scarcely north of Geraldton, West Australia. Yerco (Trans. Roy. Soc. South Austr. vol. xxxvi. pp. 202-205, 1912) has now given a list of common Geraldton and Houtmann's Abrolhos niai'ine molluscs, which have been clearly shown to belong to the Adelaidean Region, as out of a total of 150 species, 71 per cent, were also found in South Australia. This suggests that the limit of the Adelaidean must be placed noi^th of Houtmann's Abrolhos, and I can now show that few Adelaidean forms extend as far north as the Monte Bello Group. Hedley recently catalogued the Queensland Marine Molluscan Fauna (Proc. Austr. Assoc. Adv. Sci. Brisbane, 1909, pp. 343-371 & 809-810), when he mentioned over 1800 species. Yery numerous additions have since been made. No list of West Australian Marine Mollusca is known to me, but it would be of great advantage to zoogeogr^aphers were such, when prepared, shown under Hedley 's regional names. * Communicated hy Prof. ,T, Stanley Gaedinee, M.A., F.R.S., F.Z.S.