Family Adeonidae Busk, 1884

Remarks

This family consists of approximately 10 genera and 106 species (Bock & Gordon 2013). Most genera form erect colonies with flat, dichotomous branches (e.g., Adeonella and Adeonellopsis) or are cribrate in form (e.g., Adeona), although some genera form encrusting colonies (e.g., Reptadeonella Busk, 1884). Adeonella and Adeonellopsis differ in the type of frontal shield: Adeonella has a lepralioid shield in which a spiramen leads into the space above the sinus, and a distinct primary orifice, while Adeonellopsis is thought to have an umbonuloid frontal shield and the spiramen leads into the space above the frontal membrane (Cook 1973; Lidgard 1996; Berning et al. 2014). Adeonella and Adeonellopsis are also different in the arrangement of the spiramen and frontal/suboral avicularia; Adeonella generally has a monoporous spiramen and frontal avicularia in various positions, whereas Adeonellopsis has a monoporous or multiporous spiramen, with a suboral avicularium situated distal to the spiramen, directed distally or distolaterally.