Deep Water Polymastiidae (Porifera, Polymastiida) from the South West Pacific Author Ekins, Merrick Queensland Museum, PO Box 3300, South Brisbane 4101, Brisbane, Queensland, Australia & School of Biological Sciences, University of Queensland, St Lucia, Queensland, 4072 Australia & Griffith Institute for Drug Discovery, Griffith University, Brisbane 4111, Queensland, Australia Author Erpenbeck, Dirk GeoBio-Center, Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany & Dept. of Earth and Environmental Sciences Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany Author Wörheide, Gert 0000-0002-6380-7421 GeoBio-Center, Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany & Dept. of Earth and Environmental Sciences Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany & SNSB - Bayerische Staatssammlung f ¸ r Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 M ¸ nchen, Germany woerheide @ lmu. de; https: // orcid. org / 0000 - 0002 - 6380 - 7421 woerheide@lmu.de Author Hooper, John N. A. Queensland Museum, PO Box 3300, South Brisbane 4101, Brisbane, Queensland, Australia & Griffith Institute for Drug Discovery, Griffith University, Brisbane 4111, Queensland, Australia text Zootaxa 2023 2023-11-08 5369 1 57 88 https://www.mapress.com/zt/article/download/zootaxa.5369.1.3/52229 journal article 10.11646/zootaxa.5369.1.3 1175-5326 10146837 F906AFDC-DA4E-4ADB-9835-BC4B7692F1FD Polymastia Bowerbank, 1862 Diagnosis: Polymastiidae of encrusting, massive, globular, hemispherical or discoid body shape, always bearing papillae with oscula at the summits. Main choanosomal skeleton composed of tracts of principal monactines radiating from the sponge base or forming a reticulation.Auxiliary choanosomal skeleton comprises smaller monactines, freescattered or grouped in little bundles. Cortical skeleton constituted at least by a superficial palisade of small smooth tylostyles or subtylostyles and an internal layer of larger monactines lying obliquely to the surface and may include middle layers. A fringe of extra-long monactines may be present at the edge of the body ( Plotkin et al. 2018 ).