- Test wheel-shaped, depressed above and below.
- Apical disc large, pentagonal, a little less than half test diameter in length, extending slightly into posterior interambulacrum. Plates not bound to corona, always missing; presumed monocyclic.
- Ambulacra straight; plating polygeminate (5-6 elelments to a plate), compounded in phymosomatid style. Pore-pairs undifferentiated; biserially arranged aborally to the ambitus, in arcs subambitally and expanded into short phyllodes adorally.
- A single primary tubercle to each compound plate plus a smaller perradial secondary on ambital and adapical plates. Smaller secondaries and granules fill remainder of perradius.
- Interambulacral plates wider than tall; with a single primary tubercle, positioned centrally plus smaller secondary tubercles flanking, one interradially and usually several adradially, which diminish adorally and adapically. A well developed naked interradial zone present aborally, expanding towards the apex.
- Tubercles imperforate and crenulate.
- Peristome small, circular, sunken, with small, but clearly defined buccal notches with thickened lip; no tag.
- No sphaeridial pits; no basicoronal interambulacral plate.
- Spines unknown.
- Lantern unknown.
||Agassiz, L. & Desor, P. J. E. 1846-1847. Catalogue raisonné des familles, des genres, et des espèces de la classe des échinodermes. Annales des Sciences Naturelles, Troisième Série, Zoologie : 6 (1846): 305-374, pls. 15-16; 7 (1847): 129-168; 8 (1847): 5-35, 355-380.