Fig. 98—LOWER PALAEOZOIC GASTEROPODA.
A—Ophileta subangulata, Tate. Cambrian. South Australia
B—Salterella hardmani, Foord. Cambrian. West Australia
C—Hyolithes communis, Billings. Cambrian. South Australia
D—Scenella tenuistriata, Chapm. Cambrian. Victoria
E—Raphistoma browni, Eth. fil. Ordovician. South Australia
F—Helicotoma johnstoni, Eth. fil. Silurian. Tasmania
The Upper Cambrian of the Mersey River District in Tasmania has afforded some doubtful examples of the genus Ophileta.
In the Upper Cambrian Limestones of the Dolodrook Valley, near Mt. Wellington, Victoria, a minute limpet shaped Gasteropod occurs, named Scenella tenuistriata ([Fig. 98 D]).
Ordovician Gasteropods.—
Ordovician limestones with fossil shells occur in the Leigh’s Creek District in South Australia, and also at Tempe Downs and Petermann and Laurie’s Creeks, W. of Alice Springs. The euomphaloid shell Ophileta gilesi was described from Laurie’s Creek, and Eunema larapinta from the Tempe Downs. A pleurotomarid, Raphistoma browni ([Fig. 98]) occurs near Leigh’s Creek, and at Laurie’s and Petermann Creeks. A Pteropod, Hyolithes leptus, has been described from the Lower Ordovician of Coole Barghurk Creek, near Meredith, Victoria.
Silurian Gasteropods.—
The Silurian Gasteropods are fairly well represented, especially in the upper stage, and are widely distributed throughout the Australian fossiliferous localities. Moreover, some of the species are identical with those found as far off as North America and Europe. In Victoria the shales and sandstones of the lower stage (Melbournian) contain the genera Bellerophon, Cyrtolites and Loxonema. The Pteropoda include Tentaculites, Coleolus, Hyolithes and Conularia (C. sowerbii ([Fig. 99 F]), a species also found in Great Britain). The Victorian limestones and mudstones of the upper stage (Yeringian) are somewhat rich in Gasteropods, such genera occurring as Pleurotomaria, Phanerotrema (with cancellated shell and large slit-band), Murchisonia, Gyrodoma, Bellerophon, Trematonotus (a spiral shell with a large trumpet-shaped mouth and a dorsal row of perforations in place of a slit-band), Euomphalus, Cyclonema, Trochus (Scalaetrochus), Niso (Vetotuba), Loxonema, Platyceras and Capulus. The section Pteropoda contains Tentaculites, Hyolithes and Conularia.