A new cave-dwelling species, Roncus yaginumai CURCIC, CURCIC et DIMITRIJEVIC sp. nov., (Neobisiidae: Pseudoscorpiones) is described from southern Montenegro, Yugoslavia. It is illustrated and compared with its phenetically close congener, R. vulcanius BEIER, from south Hercegovina, Bosnia-Hercegovina. Notes are given on the habitat, distribution and teratology of this endemic species.
