Genus Lithoptilum gen. nov. urn:lsid:zoobank.org:act: 1FBC7165-1EF8-4D82-871C-37092D96F992 3.3.1 Diagnosis The peduncle is an enlarged distinct bulbous structure; in in-situ colonies the peduncle is loosely attached to the surface of a hard substratum. In a collected specimen, the base of the peduncle is a widened and folded structure with a terminal knob. In phylogenetic trees of sea pens, members of this genus form a monophyletic clade sister to Anthoptilum spp., Anthoptilum grandiflorum and Anthoptilum murrayi. 3.3. 2 Type Species Anthoptilum lithophilum Williams & Alderslade, 2011, is designated as the type species. 3.3.3 Nominal Species There are currently 5 species 2 that should be included in Lithoptilum gen. nov. — Lithoptilum decipiens (Thomas & Henderson, 1906), comb. nov, Lithoptilum gowlettholmesae (Williams &Alderslade, 2011), comb. nov., Lithoptilum lithophilum (Williams & Alderslade, 2011), comb. nov., Lithoptilum gnome (Kushida et al, 2024), comb. nov., and Lithoptilum francei (Williams & Alderslade, 2011), comb. nov. 3.4 Etymology The name of the new genus is derived from a combination of the Greek words “litho” meaning stone and “ptil” meaning a feather. The name is a reflection of the habitat utilization by these sea pens. Gender of this taxon name is neutral.

Published as part of Ganguly, Upasana & France, Scott C., 2024, Expanded distribution and a new genus for rock-inhabiting sea pens (Cnidaria, Anthozoa, Octocorallia, Pennatuloidea), pp. 123-139 in Zootaxa 5507 (1) on pages 130-133, DOI: 10.11646/zootaxa.5507.1.5, http://zenodo.org/record/13747860