Specimens of Lagenochitina Eisenack 1931 from the Arenig of Spitsbergen show structures considered to be homologous with the prosome and operculum. These occur together in the same specimen. The fact that both a prosome and an operculum can exist toget her, raises doubt as to the validity of grouping the chitinozoans into Prosomatifera and Operculifera.