2)上颚 mandible, or jaw paired appendages of segment4.头节4的一对附肢。 sclerotized, usually articulations with the subgena. HE 化,与颊下区相联。 In herbivorous forms there are both cutting edges(Eu Pt 的切齿叶 incisor lot) and grinding surfaces(后端的白 If molar lobe) on the mandible SAP 区 切区 2