AbstractEnghoff, H. (Zoological Museum, University of Copenhagen, DK‐2100 Copenhagen Ø, Denmark.)Taxonomic problems in parthenogenetic animals. Zool. Scr. 5 (3–4): 103–104, 1976.—The species concept in parthenogenetic animals is discussed. In addition to the absence of interbreeding inthelytoky(constant obligatory parthenogenesis), polyphyly of thelytokous forms is emphasized as a complicating factor. It is concluded that a holomorphological but not a biological species concept may be applied to certain thelytokous forms. Practical consequences of the absence of males in thelytokous forms are also touched on, as is degenerative variability of atavistic males and female copulatory organs. Finally, it is recommended that the subspecies category should never be applied to thelytok