Two new species Dromiciocoptes marmosops sp. n. and Dromiciocoptes caenolestes sp. n., of the subfamily Dromiciocoptinae (Acari: Myocoptidae), are described from Marmosops parvidens Tate (Didelphimorphia: Didelphidae) from Peru and Caenolestes fuliginosus (Tomes) (Pauctituberculata: Caenolestidae) from Ecuador, respectively. Dromiciocoptes has been included in a monobasic subfamily in the Myocoptidae on the basis of female and nymph legs III and IV of being modified for clasping the hair of the host. Observations on the actual structure of these appendages, however, indicate that the mode of hair clasping is fundamentally different than in other myocoptids. The structure of the male legs IV of Dromiciocoptinae and Myocoptinae are also different. Additional diagnostic characters of the subfamily Dromiciocoptinae in both sexes are the enlarged propodonotal and hysteronotal shields; indistinct openings of the opisthonotal glands; reduced pretarsi II; retrorse spurs on coxal fields I–IV; absence of setae vi, c3, famulus e, and one pair of genital papillae; presence of setae sIII; and a pair of antiaxial projections on femora I and II. Synapomorphies uniting these two subfamilies include body shape, separate apodemes I, apical position of tarsus I solenidia ω1 and ω3, scales on the ventral surface of the female opisthosoma (in only some myocoptines), and bilobed male opisthosoma. None of these states are unique among the parasitic Psoroptidia, indicating that the monophyly of the family is weakly supported.