[Illustration: =Fig. 100--UPPER PALAEOZOIC GASTEROPODA.= A--Gosseletina australis, Eth. fil. sp. Carboniferous. N.S. Wales B--Yvania konincki, Eth. fil. Carboniferous. N.S. Wales C--Loxonema babbindoonensis, Eth. fil. Carboniferous. N.S. Wales D--Pleurotomaria (Ptychomphalina) morrisiana, McCoy. Carbopermian. N.S. Wales E--Platyschisma oculum, Sow. sp. Carbopermian. N.S. Wales F--Murchisonia carinata, Eth. Carbopermian. Queensland ] In New South Wales the best known genera are _Pleurotomaria_, _Murchisonia_, _Bellerophon_, _Euomphalus_ and _Loxonema_. The two latter genera have also been obtained at Barker Gorge, Western Australia. =Carboniferous Gasteropods.--= Carboniferous Gasteropoda have been found in New South Wales, belonging to the genera _Gosseletina_ (_G. australis_) (Fig. 100 A) and _Yvania_ (_Y. konincki_) (Fig. 100 B), both of which have their countertypes in the Carboniferous of Belgium. _Y. konincki_ is also found in the Carbopermian (Gympie beds) of Rockhampton, Queensland, while _Y. levellii_ is found in the Carbopermian of Western Australia. =Carbopermian Gasteropods.--= The Carbopermian gasteropods of New South Wales are _Pleurotomaria_ (_Mourlonia_), _Keeneia platyschismoides_, _Murchisonia_, _Euomphalus_, _Platyschisma_ (_P. oculum_) (Fig. 100 E), _Loxonema_ and _Macrocheilus_. Examples of the genus _Conularia_ are sometimes found, probably attaining a length, when complete, of 40 centimetres. In Tasmania we find _Conularia tasmanica_, a handsome Pteropod, also of large dimensions. _Platyschisma_, _Pleurotomaria_ (_Mourlonia_), _Bellerophon_ and _Porcellia_ are amongst the Carbopermian Gasteropods of Queensland. In Western Australia _Pleurotomaria_ (_Mourlonia_), _Bellerophon_, _Euomphalus_, _Euphemus_, _Platyceras_, and _Loxonema_ occur in the Carbopermian. =Jurassic Gasteropods.--= Jurassic gasteropods are found sparingly in the limestone of the Geraldton District and other localities in Western Australia. The more important of these are _Pleurotomaria_ (_P. greenoughiensis_), _Turbo_ (_T. australis_) (Fig. 101 A) and _Rissoina_ (_R. australis_) (Fig. 101 B). [Illustration: =Fig. 101--MESOZOIC GASTEROPODA.= A--Turbo australis, Moore. Jurassic. West Australia B--Rissoina australis, Moore. Jurassic. West Australia C--Natica ornatissima, Moore. Cretaceous. Queensland D--Pseudamaura variabilis, Moore sp. Cretaceous. Queensland E--Rostellaria waiparensis, Hector.--Cretaceous. New Zealand ] =Cretaceous Gasteropods.--= The Queensland gasteropod fauna comprises _Cinulia_ a typical Cretaceous genus, _Actaeon_ and _Natica_. These occur in the Lower Cretaceous or Rolling Downs Formation. _Cinulia_ is also found in South Australia at Lake Eyre with _Natica_ (_N. ornatissima_) (Fig. 101 C). _Pseudamaura variabilis_ (Fig. 101 D) is found in New South Wales, Queensland and South Australia; whilst _Anchura wilkinsoni_ occurs in Queensland and South Australia.