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 Grantilla Row, 1909 TYPE SPECIES . — Grantilla quadriradiata Row, 1909 by monotypy. DIAGNOSIS. — Heteropiidae with a syconoid organization. The skeleton of the tubes is inarticulate, composed of subatrial triactines, and subcortical pseudosagittal triactines and tetractines. DESCRIPTION The vast majority of Heteropiidae have only pseudosagittal triactines in the subcortical skeleton. The genus Grantilla has been proposed for the single species G. quadriradiata Row, 1909 , with pseudosagittal tetractines. Other morphological characteristics are quite similar to Sycettusa .