Digitate and capitate soft corals (Cnidaria: Octocorallia: Alcyoniidae) from Western Australia with reports on new species and new Australian geographical records.

We report on digitate and capitate Octocorallia within the genera Parasphaerasclera McFadden & Ofwegen, 2013, Eleutherobia Pütter, 1900, Sphaerasclera McFadden & Ofwegen, 2013, and Paraminabea Williams & Alderslade, 1999 from tropical Western Australian waters. Three new species (Parasphaerasclera kimberleyensis, Eleutherobia australiensis, Eleutherobia imaharai) are described, with a discussion of their taxonomic placement in the light of a recent treatment of the genus Eleutherobia and related taxa by McFadden & Ofwegen (2013). In addition, range extensions for three species are reported, Parasphaerasclera grayi (Thomson & Dean, 1931) known from Indonesia and the Pacific Ocean, Eleutherobia somaliensis Verseveldt & Bayer, 1988 from Somalia, and Eleutherobia splendens (Thomson & Dean, 1931) recorded from Indonesia and the Philippines.

Deceptive desmas: molecular phylogenetics suggests a new classification and uncovers convergent evolution of lithistid demosponges.

Reconciling the fossil record with molecular phylogenies to enhance the understanding of animal evolution is a challenging task, especially for taxa with a mostly poor fossil record, such as sponges (Porifera). 'Lithistida', a polyphyletic group of recent and fossil sponges, are an exception as they provide the richest fossil record among demosponges. Lithistids, currently encompassing 13 families, 41 genera and >300 recent species, are defined by the common possession of peculiar siliceous spicules (desmas) that characteristically form rigid articulated skeletons.