Oligoneuriopsis villosus sp. nov., larvae, abdomen and gills A abdomen outline, male B abdomen outline, female C proximal portion of abdomen under SEM in lateral view D gill IV under SEM in dorsal view E gill IV under SEM in ventral view F gill plate I in dorsal view G gill plate I in ventral view H gill plate IV in dorsal view I gill plate IV in ventral view J gill plate VII in dorsal view K gill plate VII in ventral view. Scale bars: 1 mm (A, B); 0.5 mm (C); 0.2 mm (D–K). Same scale bar for F–K.