A new species of small cyclopoids from subterranean waters of India is described in a newly established subgenus, Kiefercyclops n.sg., of the genus Haplocyclops Kiefer, 1952. Genital double-somite with ovipores situated in the posterior half, antennula without the lateral seta on the ultimate segment, and caudal rami with the lateral seta inserted in the proximal half are among the most important characters of H. (K.) fiersi n.sp., that warrant its position in the genus Haplocyclops. Also, the new species differs from the other six congeners by several autapomorphic characters, most of them being reductions in armature and/or segmentation of the appendages. In particular, the degree of reductions concerning the segmentation of the swimming legs makes it the most reduced free-living cyclopoid, with both rami of third and fourth legs, as well as the endopod of second leg being one-segmented in both sexes. A key to species of Haplocyclops is given at the end of this paper.