original description
Beneden, P.J. van. (1844). Sur les genres Eleutherie et Synhydre. <em>Bulletins de l'Académie Royale des Sciences et Belles-Lettres de Bruxelles.</em> 11: 305-314., available online at https://www.biodiversitylibrary.org/page/15742170
page(s): 314 [details]
context source (Hexacorallia)
Fautin, Daphne G. (2013). Hexacorallians of the World. (look up in IMIS) [details]
basis of record
van der Land, J.; Vervoort, W.; Cairns, S.D.; Schuchert, P. (2001). Hydrozoa, <B><I>in</I></B>: Costello, M.J. <i>et al.</i> (Ed.) (2001). <i>European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels,</i> 50: pp. 112-120 (look up in IMIS) [details]
additional source
NODC. (1997). NODC Taxonomic codes. [details]
additional source
Schuchert, P. (2008). The European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Filifera part 3. <em>Revue suisse de Zoologie.</em> 115: 221-302.
page(s): 223 [details] 
additional source
Bouillon, J.; Boero, F. (2000). Synopsis of the families and genera of the Hydromedusae of the world, with a list of the worldwide species. <i>Thalassia Salent. 24</i>: 47-296 (look up in IMIS) [details]
Present
Inaccurate
Introduced: alien
Containing type locality
From editor or global species database
Hydractinia echinata (Fleming, 1818)
Hydractinia echinata Fleming, 1823 and Pagurus bernhardus
Image from typetaxon
Van Beneden (1844, pl. 6)
Image from typetaxon
Hydractinia aculeata, whole colony on hermit crab
Unreviewed