Choanotaenia atopa (Cestoda: Dilepididae) is described (host: domestic cat from the vicinity of Manhattan, Kansas); its natural host is presumed to be a rodent. Choanotaenia atopa is morphologically similar to cestodes of 6 species, all from rodents, formerly placed in the genus Rodentotaenia Matevosian, 1953, and subsequently removed to the genera Choanotaenia Railliet, 1986, or Monopylidium Fuhrmann, 1899. The systematic position of those cestodes is discussed; Monopylidium and Rodentotaenia are treated as synonyms of Choanotaenia. Choanotaenia atopa is distinguished by size and form of rostellar hooks, regularly alternating genital pores, and other characters in genital organs.