A revision of the supraspecific classification of the subclass Calcaronea (Porifera, class Calcarea) Author Borojevic, Radovan Departamento de Histologia e Embriologia, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Caixa Postal 68021, 21941 - 970 Rio de Janeiro (Brazil) radovan @ iq. ufrj. br radovan@iq.ufrj.br Author Boury-Esnault, Nicole Author Vacelet, Jean Centre d’Océanologie de Marseille (CNRS-Université de la Méditerranée, UMR 6540 DIMAR), Station marine d’Endoume, F- 13007 Marseille (France) esnault @ com. univ-mrs. fr jvacelet @ com. univ-mrs. fr text Zoosystema 2000 22 2 203 263 journal article 10.5281/zenodo.5392175 1638-9387 5392175 Genus Leucyssa Haeckel, 1872 TYPE SPECIES . — Leucyssa spongilla Haeckel, 1872 by monotypy. DIAGNOSIS. — Trichogypsiidae (?) with a skeleton composed only of smooth diactines. DESCRIPTION The external shape of this sponge, which has a pedunculate cormus with a large clathrate body of anastomosed tubes, is quite different from both the Baeriida and Leucosoleniida , and is rather common among the Clathrinida . However, Eilhardia also has quite an unusual shape, and it is possible that our knowledge of only a very small number of sponges in the Baeriida gives the impression of a great divergence of the observed forms. We place this sponge among the Baeriida , following Haeckel’s (1872) description of the rather irregular alveolar choanosome supported by a dense skeleton of small diactines, scattered without order.