“…three
cribriform organs in each
interradius. Marginal plates thin; superomarginals not united along the median line of ray [arm] and usually bearing a spine, these forming a series on each side of ray.
Abactinal area covered with membrane containing very small, simple, perforated plates; those on disk bearing usually a single spinelet each; in center of disk a sort of prolongation of the
integument forms a
peduncle, containing an extension of the body cavity, but no intestine.
Actinal interradial areas paved with thin plates, sometimes armed with spinelets.
Adambulacral armature, one to three sharp spinelets. Usually ‘segemented pits and
papillae’ are present. No superambulacral ossicles; tube feet conical, pointed.
Ampullae single.” (Fisher, 1911, p. 24)
