part of adult apodeme adult ventral external metathorax metathoracic sternal apodeme FBbt:00004638 metathoracic furcal arm Infolding of the ventral metathorax. It extends anterolaterally with the two (bilateral) arms forming a V-shape (Johnston and Ellison, 1982). Ferris (1950) says no sternal plate in meso- and meta-thorax. metafurca SA3 fly_anatomy.ontology metathoracic sternal apophysis apophysis