The original collection of Spirifer tornacensis de KÖNINCK, 1883b is composed of the seven specimens of the type series plus two specimens added by de KONINCK in 1887. Lithographs of five specimens were published in 1883b, and again in 1887 together with those of two more specimens. In spite of intensive search, one of the specimens of the type series, unfortunately chosen as lectotype, has not been found in the collection bought from de KONINCK in 1878 by the Musée royal d'Histoire naturelle in Brussels. Therefore, a neotype has been designated in accordance with the ICZN rules. The long overdue re-examination of the original specimens and their new description resulted in the assignment of the specimens of the type series to a new genus, Atylephorus . One of the two hypotypes of 1887 belongs to this genus, but the other is here assigned to Unispirifer CAMPBELL, 1957. Atylephorus tornacensis is considered herein to be a geographically (Tournaisis in western Belgium) and stratigraphically (late Tournaisian) restricted species. It follows that all forms under the species name outside the type area are not likely to belong to it.