Genus Luidia Forbes, 1839

Type: Luidia fragilissima Forbes, 1839,

a synonym of Asterias ciliaris Philippi, 1837, by monotypy

Diagnosis: Arms 5–11, elongate and gently tapering, lower surface almost flat. Abactinal plates highly paxilliform, the two most lateral series at least forming regular longitudinal rows. Supero-marginal plates much smaller than infero-marginal plates, often difficult to distinguish from similar sized adjacent lateral paxillae (expect in East Pacific subgenus Platasterias). Infero-marginals large and prominent, each bearing several long spines. Interradial areas small, adambulacral plates broad and bandlike, bearing 2–4 large spines. The inner-most (furrow) spine compressed, curved and sabre-like. Tube feet tapering to knob-like tip and lacking terminal suckers. Modified from Clark & Downey (1992).