Both sexes of Monchenkocyclops mehmetadami n. sp. were described from hyporheic freshwater habitat in Turkey. The new species can easily be distinguished from the other four species in the genus by having three setae on the inner margin of the second endopodal segment of the first and second swimming legs and four setae on the inner margin of second endopodal segment of the third and fourth swimming legs. The setation patterns of female and male antennules of the new species are analyzed with reference to the hypothetical 28- segmented antennule of ancestral copepod and the homology of the antennulary segments is determined in both sexes. Paraphyletic status of the genus is briefly discussed.