A large collection of kinorhynch specimens from coastal and subtidal localities around the Korean Peninsula and in the East China Sea was examined, and the material included several species of undescribed or poorly known species of Echinoderes Claparède, 1863. The present paper is part of a series dealing with echinoderid species from this material, and inludes descriptions of four new species of Echinoderes, E. aspinosus sp. nov., E. cernunnos sp. nov., E. microaperturus sp. nov. and E. obtuspinosus sp. nov., and redescriprion of the poorly known Echinoderes tchefouensis Lou, 1934.

Two new harpacticoid species belonging to the genera Microarthridion Lang, 1944 (Tachidiidae) and Nitocra Boeck, 1864 (Ameiridae) are recorded from underground caves in the karst area of Ninh Binh Province, North Vietnam. Microarthridion thanhi n. sp. is distinguished from congeneric species by the number of setae on the antennary exopod, the structure of leg 5 in both sexes, and the finger-like process modified from an outer distal pinnate seta of the third endopodal segment of leg 2 in the male. Nitocra vietnamensis n. sp. has the character combination of six setae on the ellipsoidal exopod of leg 5 in both sexes, the first endopodal segment of leg 1 shorter than the whole exopod, the seta/spine armature of an inner seta of P2-P4 enp-1 and four elements on P2 enp-3, and the reduction of the proximal endite to a seta on the maxillary syncoxa.

Collections of brackish and freshwater ostracods on Jeju Island, South Korea, yielded 26 species, including two new species belonging to the genera Cyclocypris and Cypretta, and nine new records for the Korean fauna: Bradleytriebella tuberculata (Hartmann, 1964), Strandesia flavescens Klie, 1932, Potamocypris variegata (Brady & Norman, 1889), Heterocypris salina (Brady, 1868), Stenocypris hirutai Smith and Kamiya, 2006, Ishizakiella miurensis (Hanai, 1957), Terrestricythere ivanovae Schornikov, 1969, Limnocythere sp. and Tanycypris alfonsi Nagler, Geist and Matzke-Karasz, 2014. Tanycypris alfonsi is also known from Germany, where it is considered to be an alien species. The Limnocythere species belongs to the stationis group, which consists of another eight species, and is probably undescribed. A lack of males hinders its description, but its presence in Korea is significant; including the record herein, seven of the group inhabit North-East Asia, indicating the group may have originated in this region. http://zoobank.org/urn:lsid:zoobank.org:pub:74FA8742-D301-4EC0-B058-021EE1CDFCB0

A new species of Nitokra and Ameira parvula (Claus) belonging to the family Ameiridae are recorded from brackish waters in South Korea. Nitokra koreanus n. sp. most resembles N. spinipes and N. pietschmanni, however, it is characteristic in having the character combination of ellipsoidal P5 exopod and very short P1 enp 1. Ameira parvula is reported for the first time from the Northwestern Pacific. Description of the new species and the taxonomic accounts of both species are presented.

Preliminary surveys of brackish and freshwater habitats in the southeast and east of South Korea produced a total of fifteenspecies. Ten of these species are new records for Korea, and one additional species, belonging to the genus Tanycypris, isnewly described herein. Twenty-seven species of nonmarine ostracods are now reported from Korea, but this is probablyonly a small proportion of the actual number of species inhabiting the peninsula. The presence of Dolerocypris ikeyaiSmith & Kamiya, 2006, Cryptocandona brehmi (Klie, 1934), Cryptocandona tsukagoshii Smith, 2011, Physocypria nip-ponica Okubo, 1990 and Vestalenula cylindrica (Straub, 1952) on the Korean Peninsula demonstrates that these species are also distributed on the continent, and are not endemic to Japan.