Cyamidia Lambert & Thiéry, 1914

Mooi, Rich, Kroh, Andreas & Srivastava, Dinesh K., 2014, Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida), Zootaxa 3857 (4), pp. 501-526 : 511

Genus Cyamidia Lambert & Thiéry, 1914

Type species. Echinocyamus nummuliticus nummuliticus Duncan & Sladen, 1884, p. 132 , by original designation (Lambert & Thiéry 1914: 288).

Emended diagnosis. Small fibulariids with an antero-posteriorly elongated periproct, and an apparent ringlike flange around the peristome made of slightly exaggerated bars just distal to the buccal pores.

Remarks. This genus differs from the type genus Fibularia in having low ambulacral plates at the ambitus, an elongate periproct, and the interambulacra much narrower than the ambulacra, notably at the ambitus. Cyamidia nummulitica nummulitica tends also to have a lower overall test height to test length, but the applicability of this feature to all members of the genus Cyamidia will require full assessment of all the taxa ascribed to it by Duncan & Sladen (1884).