Genus Olindias Müller, 1861

Olindias Müller, 1861b: 318;

type species Olindias sambaquiensis Müller, 1861 by monotypy.

Halicalyx Fewkes, 1882a: 277; type species Halicalyx tenuis Fewkes, 1882 by monotypy.

Olindioides Goto, 1903: 3, type species Olindioides formosa Goto, 1903 by monotypy.

Diagnosis: Olindiidae medusa with 4 radial canals and numerous centripetal canals; numerous tentacles of two kinds: primary ones directed upwards, nematocysts in transverse clasps and often with distal adhesive pads, and secondary ones directed downwards, without adhesive pads, nematocysts in rings. Gonads on papilliform diverticula of radial canals; numerous marginal bulbs which may transform into tentacles, statocysts usually in pairs at base of primary tentacles.

Known hydroid either solitary and lacking tentacles, or forming small stolonal colonies and hydranths with a single filiform tentacle.

Remarks: The grammatical gender of the name is male (Calder, 2010). For descriptions of the hydroid see Weill (1936), Patry et al. (2014), and Toshino et al. (2019). Toshino et al. (2019) provide also a tabular overview on the species of this genus and a phylogenetic tree.