A well-characterized new species of Cyathura (Stygocyathura) is described from the underflow of a wadi in Oman where a large population is present. Sixteen species have been attributed to this entirely stygobiont subgenus; they are either from the Caribbean - Gulf of Mexico region, or from the western Pacific, whereas a single species has been recorded from the realm of the Indian Ocean: C. (S.) milloti Chappuis, Delamare & Paulian from Réunion Island. The new species could be remotely related to C. (S.) milloti.