buttress
From ZooTerms (Dictionary of Invertebrate Zoology)
buttress (noun; Old French bouterez, to thrust): 1. (Arthropoda: Insecta) In Culicidae pupae, a sclerotized, thickened basolateral part of the paddle; external buttress; external thickening; nervure.
2. (Mollusca: Bivalvia) A radiating ridge on the interior that reinforces the hinge process.
