Diagnosis. Traces of varying, usually shallow depth, on skeletons of Hypermorphocrinus and occa sionally other crinoids. Ovoid in outline (less com monly oval and round), bilaterally symmetrical, rimmed by marginal groove or two grooves, with a rel atively deeper subcentral depression and as a rule, paired tubercles between it and the posterior margin. Sometime skeleton was perforated.

Attachment; substrate calcareous; tracemaker invertebrate?