Concretions of the Wenlock Series Herefordshire Konservat-Lagerstätte of the Welsh Borderland have yielded one of the few recorded Silurian radiolarian faunas world-wide and the only one known from the Silurian of Britain. The low diversity radiolarian fauna consists of new forms of Inaniguttidae (Inanihella sagena sp. nov. and Inanihella sp.), Haplentactiniidae (Haplentactinia armista sp. nov.) and a previously reported form of Secuicollactidae (Secuicollacta hexatinia (Won et al., 2002)). The fauna has affinities with Silurian radiolarian assemblages of the Urals, the Canadian Arctic and Alaska. Stratigraphically the Herefordshire fauna appears transitional between established Silurian radiolarian biozones.