In the present paper the north-eastern Atlantic Chalinidae (Porifera, Demospongiae) are systematically revised and redescribed; where necessary lectotype designations are made. Three genera are recognized, viz. Haliclona, Acervochalina and Dendroxea. The latter genus is not represented in the study area. Seventy-two nominal species have been described in Haliclona in the wide sense here employed (including species assigned to other genera here considered junior synonyms of Haliclona:Reniera, Gellius, Adocia, Toxadocia, Orina ). Among these 72 nominal species 12 valid species are recognized. One species new to science is described, viz. Haliclona xena spec. nov.; 4 nominal species of Acervochalina are reduced to 2 valid ones.