Sponges of the genus Clathrina Gray, 1867 from Arraial do Cabo, Brazil Author Klautau, Michelle Centro Federal de Educação Tecnológica de Química, Unidade Rio de Janeiro Rua Senador Furtado 121 - 125, Maracanã, 20270 - 021 Rio de Janeiro (Brazil) mkmt @ centroin. com. br 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 text Zoosystema 2001 23 3 395 410 journal article 10.5281/zenodo.5400552 1638-9387 5400552 Clathrina quadriradiata n. sp. ( Fig. 8 ; Table 8) TYPE MATERIAL . — Holotype , 18.III.1990 , coll. G. Muricy , The Natural History Museum , London ( BMNH 1999.9.16.30). TYPE LOCALITY . — Arraial do Cabo, Rio de Janeiro , Brazil . ETYMOLOGY. — From the Latin Quatuor : four. For the presence of tetractine as main spicule. MATERIAL EXAMINED. — Oasis Coralino. Forno, one specimen . DESCRIPTION The cormus of this species is white in life and in alcohol. It is composed of very thin, regular and tightly anastomosed tubes. Oscula are simple openings located on the top of conical projections, receiving the excurrent-water from several water-collecting tubes. No relevant features were found on the histological sections. The skeleton has no special organisation. It is composed of tetractines ( Fig. 8A ) and a few triactines. Actines are straight and conical, with blunt ends. The apical actine of the tetractines ( Fig. 8B ) is only a little thinner than the facial ones at the base. It is also shorter, conical, sharp and smooth. Only one specimen of this species was collected, and it was from the Oasis Coralino. The habitat of this species is sciaphilous. REMARKS This species resembles C. aspina and C. brasiliensis . However, it has no tripods and tetractines are more abundant than triactines, while in the two other species, triactines are the main spicule. The anastomosis of the tubes is also different, being less regular in C. quadriradiata n. sp.