PREFACE. 



preliminary part of the report on the Mollusca in the Proc. 

 Mai. Soc., and further contributions may be forthcoming in 

 the near future. 



Of the 322 genera recorded, the following twenty-one are 

 precinctive to New Zealand : Eudoxochiton, Incisura, Realia, 

 Neojancus, Atagema, Latia, Otoconcha, Gerontm, Thermia, Serpho, 

 Therasia, Phenacohelix, Suteria, Ranfurlya, Schizoglossa, Athora- 

 cophorus, Perrierina, Verticipronus, Pachykellya, Resania, and 

 Pinnoctopus. Whether Phenacohelix is identical with Rhytidopsis, 

 Ancey, from New Caledonia, is still uncertain, as the animal 

 of the latter has not been examined. As far as shell-characters 

 go, there is very little difference between the two. Otoconcha 

 is no doubt very nearly allied to Vitrinopsis, Semper, of the 

 Philippine Islands : externally the animals are similar, and the 

 differences in the jaw, radula, and reproductive organs are 

 very slight. The Tasmanian land - shells I classed in 1893 

 under Gerontia ("' The Nautilus," vol. vii, p. 89) I now consider 

 to belong to a new gemis, most likely allied to Trachycystis of 

 South Africa. 



Of the 322 genera, thirty-seven are precinctive to Australasia 

 (Australia, Tasmania, New Zealand), and of the 1,079 species 

 about 140 occur also in Tasmania and Australia, whereas about 

 sixty species have a more or less wide distribution. The 

 following Pelecypoda are found in European and New Zealand 

 seas : Area reticulata, Mytilus edidis, Lima lima, Cardita calyculata, 

 Venericardia corbis, Thyasira flexuosa, Kellia si(borbiculans, Lascea 

 miliaris, and Corbula gibba. According to Sir Charles Eliot's 

 publication, the New Zealand Nudibranchs are composed of 

 three elements 1. Tropical : Chromodoris, Doriopsis. 2. Forms 

 characteristic of colder seas : Doris, Acanthodoris, Goniodoris, 

 Rostaiiga. 3. Peculiar to Australasia : Alloiodoris and Atagenta. 



The following of our marine species have a wide austral 

 distribution : Nacella fuegiemis - - Tierra del Fuego, Falkland, 

 Kerguelen ; Monodonta nigerrima west coast of South America ; 

 Argobucdnum argns St. Paul and Amsterdam Islands, South 

 Africa, Tristan da Cunha, and Chile ; Siphonaria lateralis - 

 Kerguelen, Falkland, Magellan, and Patagonia ; Mytilus edulis 

 and M. magellanicus are circumaustral ; Modiolarca pitsilla - 

 Tierra del Fuego; M. trapezina-- Patagonia, Tierra del Fuego, 



