A new species of Boholina, B. ganghwaensis sp. nov. is described, based on specimens collected from burrows of the manicure crab, Cleistostoma dilatatum, in the tidal flat of Ganghwa Island in western Korea. The new species is closely similar to B. purgata and B. parapurgata by having a pointed process on the posterior angles of the second and third pedigerous somites and a similar rostrum in the female, but can be distinguished from its congeners by the following characters: in females by the genital double-somite with small hook-like process on each gonoporal plate, the setation of the distal endopodal segment of mandible, the basis and first endopodal segment of the maxillule incompletely separated, the inner distal spine/outer terminal spine length ratio on P5; and in males by the distal spine present on the posterior surface of the basis of both P5 and the length/width ratio of the endopod of the right P5. This is the first Bololina species recorded from the north-west Pacific.
