An elongated, often segmented appendage, usually found near the mouth in invertebrate organisms; such as, mollusks, crustaceans, and insects; the functions of which include sensation, locomotion, and feeding.

The number of segments in the maxillary (second pair of jaws under the principal pair) and labial palps respectively.

If the formula had six,four; it would mean six segments in the maxillary palp and four in the labial palp.

Latin: to touch gently, to stroke; to pat; in this unit.