Marphysa ibaiensis sp. nov. Holotype UMTAnn 2179 (A–I). Light microscopy images and digital drawing A anterior end, lateral view. Arrow shows shallow groove B anterior end, dorsal view C maxillae, dorsal view D mandibles, dorsal view E bidentate hook, chaetiger 97 F parapodium, chaetiger 10 G parapodium, chaetiger 97 H parapodium chaetiger 145 I posterior segments and pygidium, dorsal view. Arrows show the short pair of pygidial cirri. Abbreviations; MI–MV: maxillae I–V, Ac: aciculae, Dc: dorsal cirrus, Vc: ventral cirrus, PCl: prechaetal lobe, Cl: chaetal lobe, PtCl: postchaetal lobe, Sah: subacicular hook, Bf: branchial filament. Scale bars: 2 mm (A, D); 1 mm (B, C, I); 20 µm (E), 0.1 mm (F–H).