The present paper dricribes two new species of Dactylogyrus, collected fromProcypris merus Lin. in the Bo' ai, Xiyang Jiang (of the Zhu Jiang River system).Syntype-specimens are deposited in the Department of Biology, South China NormalUniversity.1. Dactylogyrus cystovagina sp.nov.(Fig. 1)Body 0.494--0.585×0.173--0.205mm. Marginal hooklets 0.021--0.039mm intotal length. Central large anchors of D.wunderi type;total length 0.059--0. 070mm,basal portion 0.044--0.047mm, point 0.023--0.027mm, inner root 0. 034--0.036×0. 010--0.011mm, outer root 0.005--0. 008mm. Connective plate 0.009--0.010×0. 043--0.057mm in size. Supplementary plate V-shaped,0.003×0.010--0.017mmm size.Copulatory organ is 0.047--0.057mm in total length. Copulatory tube curved andstrong in shape, 0.039--0.042mm in total length. Supporting apparatus is halberdli-ke, 0.047--0.057mm.Vagina is peach--like, 0.023--0.029×0.016--0.020mm in size. Description is based on 3 specimens.Remarks: This worm is similar both to D. vastator and D. minutus, but it differsthe latter in the maseures of cuticular structures of the anchors, tube and supportingapparatus. The new species is near to D. clasterocirrus in the central large anchorsand copulatory tube, but differs from the structure of the supporting apparatus andshape of the supplementary plate.2. Dactylogyrus boaiensis sp. nov. (Fig. 2)Worm of medium size, being 0.091--0.130mm wide, 0.442--0.546mm long.Marginal hooklets 0.021--0.042mm in total length. Central large anchors of D.wunderi type;total length 0.048--0.057mm, basal portion 0.042--0.043mm, point0.013--0.017mm, inner root 0.016--0.022mm, outer root 0.005mm. Connectiveplate 0.005--0.008×0.039--0.044mm. Supplementary plate T-shaped, 0.008--0.026mm in size.Copulatory organ is 0.044--0.055mm in length; Copulatory tube S-shaped, 0.036--0.052mm in length. Supporting apparatus is lotuslike, 0.029--0.039mm.Vagina resembles a magnolia in bloom, 0.023--0.034×0.008--0.010 mm in size.Description is based on 4 specimens.Remarks: The new species is distinguished from the other species of the genus byits characteristic structure of the vagina and shape of the male genitalia.