Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones Author Gusmão, Luciana C. Author Rodríguez, Estefanía text Zoological Journal of the Linnean Society 2021 2021-02-18 193 1392 1415 https://doi.org/10.1093/zoolinnean/zlaa176 journal article 3130 10.1093/zoolinnean/zlaa176 f0ab84e8-4ff4-46a8-a567-a9acd016305c 0024-4082 5752621 D000BAA9-51C4-46FE-AC9B-BB361B601FA2 FAMILY HALCAMPOIDIDAE APPELLÖF, 1896 Diagnosis (after Carlgren, 1949 ; additions in bold and modifications in italics). Enthemonae with elongate body with proximal end physa-shaped, rarely flat. Column sometimes without regional differentiation, sometimes divisible into physa, scapus and scapulus. No sphincter. Tentacles few up to 40, the inner not shorter than the outer ones. Often with a single siphonoglyph, rarely with two indistinct ones. Perfect pairs of mesenteries variable in number up to 20. Retractors of perfect mesenteries strong, diffuse to restricted, more or less reniform. Parietal muscles distinct. Cnidom: gracile spirocysts, basitrichs, holotrichs, b- mastigophores and p- mastigophores A . Type genus: Halcampoides Danielssen, 1890 I n c l u d e d g e n e r a: A c t h e l m i s L ü t k e n, 1 8 7 5 (?), Calamactinia Carlgren, 1949 (?), Calamactis Carlgren, 1951 (?), Halcampella Andres, 1883 (?), Pentactinia Carlgren, 1900 (?), Scytophorus Hertwig, 1882 and Siphonactinopsis Carlgren, 1921 (?). Remarks: Rodríguez et al . (2012) synonymized Halcampoididae with Halcampidae based on the position of an unidentified species of Halcampoides ( type genus of Halcampoididae ) as the sister-group to an unidentified species of Halcampa Gosse, 1858 ( type genus of Halcampidae ). Based on the results of our phylogenetic analyses, we consider Halcampidae and Halcampoididae as separate families ( Studer, 1879 ). Thus, we resurrect family Halcampoididae and reclassify it as an actinostoloidean, given its position in our phylogenetic analysis. We include H. purpureus and S. striatus Hertwig, 1882 until a complete revision of remaining former halcampoidid genera.