| abstract | A new species of oribatid mites, Metrioppia krivolutskyi sp. n. is described from Mongolia. The new species is somewhat similar to M. zlotoni Krivolutsky, 1971 and M. helvetica Grandjean, 1931. However, the new species is readily distinguishable from above mentioned species by the relatively short interlamellar setae, the presence of well-developed insertions of 9 pairs of notogastral setae (setae p1, p2 and p3 are distinctly developed), the relatively short and blunt rostral teeth and the thinner and shorter lamellar, which do not reach the rostral tip. The known species of oribatid mite, Ceratoppia bipilis (Hermann, 1804) is registered for the first time in the fauna of Mongolia and redescribed. The features of the Mongolian specimens are almost consistent with those of European and Asian materials, but there are some differences. In the Mongolian specimens, the lamellae is a little longer, insertion of notogastral seta h1 is rather well developed, anterior margin of notogaster is rounded and the humeral projection is relatively poorly developed. |