Siliceous sponges in the upper Devonian of the Rade of Brest (France).

Three organisms occurring as impressions in silico-pyritic nodules of the F amennian Schistes noirs de Porsguen in the Rade de Brest, Finistere, France , previously presented as plant remains, are re-interpreted as siliceous sp onges. A. new genus and species of hexactinellid is described as Porsguenos pongia lejalnicolae. Two other forms, less well preserved, are left in open nomenclature: one is clearly an anthaspidellid, the other is tentatively r eferred to the astylospongiids. These species comprise the largest elements of the benthic assemblage of the Schistes de Porsguen.