The pedipalps have only six segments: the metatarsus is missing. In adult males, the tarsus of each palp is modified to carry an elaborate and often species-specific structure used for mating (variously called a palpal bulb, palpal organ or copulatory bulb). The basal segments of the pedipalps, the coxae, next to the mouth, are modified to assist with feeding, and are termed maxillae, although they are not homologous with the maxillae of mandibulate arthropods. In mesothele and mygalomorph spiders, the maxillae are only slightly modified; in araneomorph spiders, the anterior edge is often saw-like and is used in cutting up prey.