Internal characters of H. tianjinensis A dorsal view of reproductive system B ventral view of dissected anterior sucker C ventral view of jaw. Abbreviations: a, atrium; ag, albumen gland; co, common oviduct; e, epididymis; eb, ejaculatory bulb; g, ganglion; j, jaw; o, ovisac; p, prostate; ps, penis sheath; s, sulcus; te, testisac; to, tooth; v, vagina; vd, vas deferens.