"Tretaspis moeldenensis sp. nov. from 'Bala limestone' of Carmarthenshire is described. Almost identical forms previously referred to T. kiaeri Stoermer and T. aff. kiaeri occur in the Calymene beds of northern England. The trilobite previously described as T. cf. kiaeri from the Phillipsinella parabola zone of the Ashgill series of north Wales is discussed and thought to be another new species."