Genera in the family include:
Species of Halcampidae mostly have elongated columns which are sometimes differentiated into different regions. The base is usually rounded but in some species it is flattened. There is no sphincter. There are up to forty tentacles, all of equal length. There are up to twenty pairs of perfect mesenteries (internal partitions) with strong retractors. There are one or two siphonoglyphs (ciliated grooves).