Seven new species of oribatid mites of the genus Galumna are described from litter and soil materials of Sumatra, Indonesia. A new subgenus, Galumna (Atypicogalumna) subgen. n., is proposed; it differs from all galumnid genera and subgenera by the simultaneous presence of porose areas and sacculi on the notogaster (vs. either porose areas or sacculi present). Galumna (Galumna) calva Starý, 1997 is recorded for the first time in the Oriental region, and Galumna (Galumna) sabahna Mahunka, 1995 is recorded for the first time in the Indonesian fauna.

A new genus Sundageophilus is here described for two new species of geophilid centipedes (Chilopoda: Geophilidae) from Sumatra, Indonesia. Both Sundageophilus bidentatus sp. n. and Sundageophilus poriger sp. n. feature a minute body size (less than 1 cm long with 31–35 pairs of legs), a similar structure of the maxillae, elongated forcipules, and few coxal organs. Sundageophilus bidentatus is unique among geophilids because the ultimate article of the forcipule is armed with two conspicuous denticles, one dorsal to the other, instead of a single one or none. The two species of Sundageophilus are the first genuine Geophilidae ever found in Malesia, and among the very few representatives of this family in the entire south-eastern Asia.

A new species of oribatid mite of the genus Pergalumna (Oribatida, Galumnidae) is described from litter and soil materials in Sumatra, Indonesia. Pergalumna paraindistincta sp. n. is morphologically most similar to Pergalumna indistincta Ermilov & Anichkin, 2011, Pergalumna pertrichosa Mahunka, 1995 and Pergalumna sura Balogh, 1997; however, the new species differs from Pergalumna indistincta by the smaller body size, presence of long adanal setae ad1, and large, single median pore in females and males; from Pergalumna pertrichosa by the smaller body size, presence of three pairs of notogastral porose areas, elongated A1 and minute anal setae; from Pergalumna sura by the presence of strong adanal setae ad1, large, single median pore in females and males, and shorter bothridial setae. Furthermore, Pergalumna hawaiiensis hawaiiensis (Jacot, 1934) and Pergalumna panayensis Ermilov & Corpuz-Raros, 2015 are recorded for the first time in the Indonesian fauna. An identification key to the known species of Pergalumna in the Oriental region is given.

Two new species of oribatid mites of the genus Allogalumna (Oribatida, Galumnidae) are described from litter and soil materials of Sumatra, Indonesia. Allogalumna indonesiensis sp. n. is morphologically most similar to Allogalumna borhidii Balogh & Mahunka, 1979, Allogalumna quadrimaculata (Mahunka, 1988), Allogalumna rotundiceps Aoki, 1996 and Allogalumna plowmanae Balogh & Balogh, 1983; however, the new species differs by having densely ciliate bothridial heads, larger body size and absence of a median pore. Allogalumna paranovazealandica sp. n. is morphologically most similar to Allogalumna novazealandica Hammer, 1968; however, the new species differs by the shorter body length and barbed and curving postero-laterad bothridial setae. The genus Allogalumna is recorded for the first time in the Indonesian fauna.