Eighty-three specimens of chigger mites were collected from reptilian, avian, and mammalian hosts captured in various localities of Iran. Study of this material has permitted identification of 20 species, of which 19 are new, belonging to 10 genera. The subgenus Ornithogastia Vercammen-Grandjean, 1960, is revived and placed in the genus Guntherana. An extraordinary feature is the discovery of a second species in the genus Womersia (family Leewenhoekiidae, subfamily Apoloniinae). During a stay of 9 months in Iran, one of us (Rohde) assembled a considerable amount of zoological material, from which were isolated 83 specimens of chigger mites. The material was collected from reptiles, birds, and mammals as detailed in Table I. As can be noted from the table, the parasites were relatively selective in their hosts and only two species, Neotrombicula (N.) heterotrichia and Neoschoengastia (N.) elegans were found on both birds and mammals. The material has been deposited in the collection of the Department of Acarology, Division of Environmental Biology, Institute for Public Health Research, University of Teheran (Iran), and the accession numbers are indicated for each species and subspecies as they appear in the text. For proper understanding of our system of classification, we suggest the reader consult Vercammen-Grandjean (1965, 1968) and Wharton et al. (1951). Finally, in addition to those cited in the descriptions, the works of Wharton and Hardcastle (1946), Sasa et al. (1951), Willmann (1952), Kepka (1956), Vercammen-Grandjean (1958, 1965), Brennan (1952), Brennan and Jones (1959), Domrow (1960), Hsu and Wen (1963), Vercammen-Grandjean and Andre (1967), and Vercammen-Grandjean and Kolebinova (1968) were consulted. Received for publication 4 August 1969. * This work was supported by Research Grant AI-03793 from the NIAID, NIH, U. S. Public Health Service. t Research Parasitologist, the G. W. Hooper Foundation, University of California Medical Center, San Francisco, California 94122 (USA). $ Professor of Biological Sciences, Northern Illinois University, DeKalb, Illinois 60115 (USA). ? Department of Acarology, Division of Environmental Biology, Institute of Public Health Research, University of Teheran (Iran). The mite material belonged to two families and was distributed as follows. Trombiculidae Trombiculinae Trombiculini Neotrombicula (Neotrombicula) heterotrichia sp. n. Hexidionis (Pentidionis) agamae Andre, 1929 Eltonella (Eltonella) galerida sp. n. Eltonella (Eltonella) meriones sp. n. Schoengastiini Neoschoengastia (Megaschoengastia) mesghali sp. n. Neoschoengastia (Neoschoengastia) apicosolenidia sp. n. Neoschoengastia (Neoschoengastia) elegans sp. n. Neoschoengastia (Neoschoengastia) galerida sp. n. Neoschoengastia (Neoschoengastia) judysouthworthi sp. n. Neoschoengastia ( Neoschoengastia) kaliophthalma sp. n. Neoschoengastia (Neoschoengastia) picata sp. n. Neoschoengastia (Hypogastia) meshedensis sp. n. Guntherana (Ornithogastia) merops sp. et comb n.* Guntherana (Ornithogastia) oenanthe sp. et comb. n.* Cheladonta brevipalpis ghazvini ssp. n. Cheladonta iraniensis sp. n. Schoutedenichia (Brennanichia) rohdeae sp. n. Gahrliepiinae Walchia (Ripiaspichia) irani sp. n. Leeuwenhoekiidae Leeuwenhoekinae Leeuwenhoekiini Sasacarus (Multisetosa) persicus sp. n. Apoloniinae Womersia irani sp. n. * The subgenus Ornithogastia Vercammen-Grandjean, 1960, placed at that time under the generic name of Pseudoschoengastia, is revived here and placed in the genus Guntherana.