Diagnosis.—One or several, vertical or oblique penetrations, irregularly cylindrical, surrounded on the outer substrate urface by an asymmetrical depression with a set of stellate grooves increasingly distinct towards the margin of the trace.

Description.—Holotype: Substrate: An incomplete left valveof the oyster R. suborbiculatum (preserved length ca. 6 cm) with ventral and ventro-posterior margins broken. The colour pattern (longitudinal brown flames) is preserved near the umbo. Entobian perforations near the posterior margin and on the centre of the shell. The holotype is located near the ventro-anterior margin (Fig. 5A).