Prochristianella spinulifera n. sp (Cestoda : Trypanorhyncha) from Australian dasyatid and rhinobatid rays

Prochristianella spinulifera n. sp. (Cestoda: Trypanorhyncha: Eutetrarhynch idae) is described from the spiral valves of the rays Rhinobatos typus (Rhi nobatidae) and Himantura fai (Dasyatidae) from Heron Island, Queensland, Au stralia. The new species is distinguished from all congeners by the deltoid microtriches covering the anterior 80% of the scolex and the presence of a dorsoventrally elongate genital atrium. The species occurred in the anteri ormost section of the spiral valve of R. typus. The orientation of the arma ture of this and other congeners is such that principal rows of hooks begin on the bothridial surface of the tentacle and end on the antibothridial su rface.