Halcampoididae Appellof 1896

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.