World Register of Marine Species (WoRMS)
Schuchert, P.; Choong, H.; Galea, H.; Hoeksema, B.; Lindsay, D.; Manko, M.; Pica, D. (2026). World Hydrozoa Database. Halecium sessile Norman, 1867. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=117605 on 2026-08-30
Norman, A M. (1867). Report of the committee appointed for the purpose of exploring the coasts of the Hebrides by means of the Dredge. Part II. On the Crustacea, Echinodermata, Polyzoa, Actinozoa, and Hydrozoa. Reports of the Meetings of the British Association for the Advancement of Science. 36: 193-206.