This new species, described from two6 species of caracaras, differs strikingly from the three other known species of the assessor group of Falcolipeurus . A key to this group is given. Lipeurus polypori Rudow, 1869 (= L. polybori Rudow, 1870) is discussed; this seems an unidentifiable species, probably of the genus Anaticola , whose natural host is not a caracara.