alternative definition added about 14 years ago by Istvan Miko
A marginal or submarginal, inflected, ridge-like part of the exoskeleton, with one internal and one external side.
Reference: Ronquist, F., and G. Nordlander. 1989. Skeletal morphology of an archaic cynipoid, Ibalia rufipes (Hymenoptera: Ibaliidae). Entomologica Scandinavica, Supplement 33:1-60.
Cross reference:
None provided.