A new spider species of the genus Pholcus Walckenaer, 1805, Pholcus osaek sp. nov., in the family Pholcidae C.L. Koch, 1850, is described from Korea. This new species belongs to phungiformes-group in the genus. It can be distinguished from its congeners by the shape and structure of genital organs of both males and females. It is found on and between rock walls in mountainous mixed forests. Additionally, the taxonomic status of Pholcus uksuensis Kim & Ye, 2014 is revalidated, re-diagnosed, and redescribed based on specimens collected from the type locality. Considering differences mentioned in the diagnosis through revalidation, P. uksuensis is regarded as a distinct species. Therefore, it should be removed from the synonymy of P. woongil Huber, 2011.

Two spider species of the genus Pholcus Walckenaer, 1805, Pholcus muju sp. nov. and Pholcus yeongheung sp. nov. in the family Pholcidae C. L. Koch, 1850 are newly described from Korea. These two new species belonging to phungiformes-group in the genus can be distinguished from their congeners by the shape and structure of genital organs of both males and females. They are found on rock walls in mountainous mixed forests. This work provides diagnoses, detailed descriptions, and taxonomic photographs for these new species.

This study describes two new species, Desmoscolex (Desmoscolex) delticeps sp. nov. and Desmoscolex (Desmoscolex) obtusiseta sp. nov. Belonging to the subgenus Desmoscolex, they were discovered in subtidal habitats along the coast of Korea. Detailed morphological analyses of the two new species were conducted using differential interference contrast (DIC) microscopy and scanning electron microscopy (SEM). D. (D.) delticeps sp. nov. was collected from subtidal zones near Ulleungdo Island. It is characterized by a broadly triangular head with robust cephalic setae and centrally positioned oval amphidial fovea. Its somatic setae are arranged in 17 main rings. Its conical terminal ring ends in a long, uncovered spinneret. D. (D.) obtusiseta sp. nov. was collected from distant subtidal zones along the western coast. It is characterized by short, blunt cephalic setae situated on peduncles, a flattened anterior head, and an oval amphidial fovea with a central pore. Its somatic setae are arranged in 17 main rings. Its terminal ring tapers ventrally, ending in a short spinneret. This study highlights distinctive cephalic setae morphologies of these species, providing a deeper understanding of nematode diversity in Korean subtidal zones and contributing to the advancement of marine nematode taxonomy.

방아벌레과에 속하는 제주도청동방아벌레(신칭)을 신종으로 보고한다. 본 종은 제주도 고유종으로, 국내 근연종들과 구별이 쉽도록 종 검색 표와 진단형질을 제공한다.

두줄가슴무당벌레붙이속의 붉은두줄가슴무당벌레붙이와 좁은두줄가슴무당벌레붙이 두 종이 한국에서 처음으로 보고된다. 또한, 외부형태 및 생식기의 삽화, 진단특징, 분포도, 그리고 분류키를 제공한다.