External morphology of H. tianjinensis holotype A dorsal and B ventral view of whole body C dorsal and D ventral view of somites X–XIV E dorsal and F ventral view of somites I–VIII G dorsal and H ventral view of somites XXIV–XXVII and caudal sucker. Abbreviations: an, anus; e, eye; fg, female gomopore; mg, male gomopore; np, nephridiopores. Scale bars: 5 mm (A, B), 2.5 mm (C–H).