‘Lithistids’ Incertae Sedis

Abstract

Five poorly known genera of lithistid sponges (Demospongiae, ‘lithistids’), based on deciduous material and thus devoid of loose spicules, remain of uncertain status, but most probably they are synonyms of other well-known genera. These include lithistids with tetr- aclone desmas (Collectella Schmidt, 1880b; Collinella Schmidt, 1879), or with rhizoclone desmas (Arabescula Carter, 1873c; Plakidium Lendenfeld, 1907; and Poritella Schmidt, 1879). The status of these genera might be decided when well-preserved material with all spicules in place is found