The genus Halectinosoma Vervoort, 1962 is first reported from Korean waters by the discovery of H. perforatum Itô, 1981. This species, previously recorded only from Japan, is collected from the sandy beach on the south coast of Korea, and is well distinguished from other congeners by the combination of following morphological characteristics: the elongate caudal ramus; the remarkably bilobated exopod of female P5; the small innermost seta on the distal margin of female P5 exopod; the presence of three setae on the distal exopodal segment in P4; and the presence of scale-like spinules on the ventral surfaces of urosomite. We herein provide detailed description and illustrations of this species.

• Jong Guk Kim(Department of Marine Life Science, College of Natural Sciences, Chosun University)
• Tae Won Jung(National Science Museum)
• Seong Myeong Yoon(Department of Biology, College of Natural Sciences, Chosun University) Corresponding author