Haloclavidae divisible into physa, scapus and scapulus, physa not distinctly marked off from scapus sometimes ampullaceous, sometimes broadly adherent as a flat base. Margin of scapus sometimes forming a collar. A weak diffuse sphincter. Tentacles simple, few, the inner shorter than the outer ones, very regularly but quite atypically arranged with 7 tentacles in the first cycle. The directive tentacle issuing from the compartment corresponding to the single siphonoglyph belongs to the first cycle, the other directive tentacle to the second. Siphonoglyph without conchula. Same number of mesenteries proximally and distally, all mesenteries perfect, and all or the largest ones fertile. Retractors strong, restricted.
Ilyanthus mitchelli Gosse 1853
Definitions and contained taxa are those of Oscar Carlgren
as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series
4, Volume 1, Number 1