Fig. 1.

In-aquaria observations of the cidaroid, Eucidaris sp., consuming and processing crinoid skeletal elements. (A) Oral side of Eucidaris sp.; arrow indicates a stalk segment of the isocrinid, N. decorus, held in the Aristotle lantern. (B) A dissected section of Eucidaris sp., aboral side down; arrow indicates a multiple-element piece of a comatulid arm at the periproct, in the distal-most part of the hindgut. (C) Multiple-element comatulid arm segment that had passed through the gut of Eucidaris sp. (D) Multiple-element comatulid arm segment that had passed through the gut of Eucidaris sp. (Scale bars: 1 mm.)