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.

A poorly known spider, Pholcus kwangkyosanensis Kim & Park, 2009 is redescribed with diagnosis, detailed descriptions, and taxonomic photographs of diagnostic characters. P. kwangkyosanensis is similar in appearance to P. kwanaksanensis Namkung & Kim, 1990, in terms of the shape of the genital organ and body, but it can be easily distinguished from the latter by the shape of the cheliceral apophysis, uncus, and procursus in males, as well as the shape of the epigynum and pore plates in females. The specimens of this spider were collected at the type locality (Mt. Gwanggyosan, Suwon), specifically under the bridge on a local stream in an agricultural landscape surrounded by rice fields, upland fields, or horticultural greenhouses.

Currently 41 valid species of the Pholcus phungiformes-group (Araneae: Pholcidae) have been known from Korea. In this study, four new species of this species-group were discovered from Gangwon-do and eastern Chungcheongbuk-do. These new species have common characteristics with Pholcus socheunensis, such as broad and membranous prolateral process and strongly curved pseudoappendix in male palp. The female of Pholcus montanus in the original description is the misidentification of a new species. Brief diagnosis, photographs and a distribution map of the new species and P. socheunensis with discussion on their sympatric distribution are provided.

유령거미속의 4신종, Pholcus chiakensis n. sp. (치악유령거미; 신칭), P. gajiensis n. sp. (가지유령거미; 신칭), P. juwangensis n. sp. (주왕유 령거미; 신칭), P. palgongensis n. sp. (팔공유령거미; 신칭)을 기재한다. 그리고 기지의 17종과 함께 신종들의 검색표를 제공한다.