Some silicified Ordovician fossils from South Wales

A preliminary description is given of a silicified fauna from the Upper Llanvirn or Lower Llandeilo of South Wales. The material consists mostly of trilobites, ostracods, and bryozoans. One new genus and two new species of ostracods are named, and the ontogeny of Tallinnella complicata (Salter) is described. Because of the silicified and fragmentary nature of the material, most of the numerous bryozoan species have not been named formally.