The appendages of the abdomen are called cerci, stylets and gonapophyses.
The gonapophyses are the projections near the extremity of the body that surround the sexual orifices, and vary extremely according to the kind of insect.
The development of the armature has been little studied, and the question whether there may be present gonapophyses homologous with those of the female is open.
The appendages of the eighth and tenth abdominal somites are modified as gonapophyses.
Whether cerci, stylets and gonapophyses are developed from these rudiments has been much debated.