- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
The new gastropod species Matherella? acuticostata is described. It is the only gastropod occurring with a brachiopod fauna in siltstones of Ordovician age (Arenig) near Trefor on Anglesey, northwest Wales.