part of continuous with adult apodeme adult ventral external prothorax furcasternum prothoracic sternal apodeme Infolding of the medial ventral prothorax with arms that extend in a dorsal anterior lateral direction to meet the prothoracic pleural apophysis (Ferris, 1950; Gorko et al., 2024). Its opening is surrounded by the furcasternum (Ferris, 1950). SA1 fly_anatomy.ontology FBbt:00004574 prothoracic furca prothoracic furcal arm prothoracic sternal apophysis apophysis