[Crustacea] In the megalopa the distal 1-3 segmented portion of the maxilliped endopod and the segmented structure attached to the mandible.

[Crustacea] Articulated ramus consisting of one to three articles on the mandible, and up to five articles on the maxilliped. (Palps do not occur on the maxillules or maxillae of isopods.)

[Polychaeta] Elongate or cushion-like sensory or feeding structures on the head.