mamelon
From ZooTerms (Dictionary of Invertebrate Zoology)
mamelon (noun; French mamelon, protuberance): 1. (Echinodermata: Echinoidea) Terminal knob on the boss that articulates with the spine on the test.
2. (NEMATA: Secernentea) Two or three ventral, serrated projections on the ventral surface of the male of the genus Syphacia; function unknown.
