Infrabasal circlet of five identical plates; visible in lateral view of cup.
It is different from Arachnocrinus in the conical rather than rounded cup, five infrabasals, rather than single fused conical infrabasal circlet, the presence of an anal plate in the cup, in the axillary primibrachials and secundibrachials contacting the radial facet, completely different arm construction and in the rounded rather than square outline of the stem facet, with a wide axial canal with no additional canals.
Five infrabasals similar in size and shape are visible on the side of the cup, 1-2 mm high.
Infrabasals presumably five and equal in size; infrabasal circlet low, approximately 18% of aboral cup height; infrabasal concavity absent.
OSU 50489a **: crown height, 21.0; aboral cup height, 2.6; proximal aboral cup width, 2.0; distal aboral cup, 4.5*; anal sac height, 13.5; infrabasal plate height, 0.5; basal plate height, 1.4; basal plate width, 1.2; radial plate height, 1.4; radial plate width, 2.0.