Considerable confusion surrounds the nomenclature and taxonomic status of the tongue sole, Paraplagusia dollfusi Chabanaud, 1931 (Cynoglossidae, Cynoglossinae), described from a single specimen captured in the Gulf of Suez, Red Sea, and Cynoglossus (Trulla) dollfusi Chabanaud, a name used by Gruvel and Chabanaud in 1937 for another specimen of tongue sole taken in the Suez Canal, Red Sea. Since publication, subsequent authors have considered there to be either one or two nominal species represented by these names, and authors have disagreed as to what genus (Paraplagusia, Cynoglossus, or both) nominal species associated with these names should be assigned. Both specimens have been reported as lost since at least the 1970s rendering it impossible to directly examine them to help resolve issues concerning their identities. We retrace historical literature involving these names and comment on reasons for the confusion experienced by previous authors. Our results, supported by irrefutable evidence gleaned from three different papers authored by Paul Chabanaud between 1931 and 1947, support the conclusion that only one valid nominal species is involved with these two names and the appropriate name for this taxon is Cynoglossus dollfusi (Chabanaud, 1931). Although never explicitly stated, nor indicated by use of appropriate punctuation in the descriptive account of the tongue sole specimen in the 1937 publication, we demonstrate that Gruvel and Chabanaud did not propose a new name when using the trinomial, Cynoglossus (Trulla) dollfusi, for this specimen. Rather, based on evidence uncovered in our investigation, as well as that appearing in a previously overlooked publication by Chabanaud in 1947, Cynoglossus (Trulla) dollfusi represents a new combination proposed by Gruvel and Chabanaud to reflect transfer of the nominal species, dollfusi, from Paraplagusia to Cynoglossus. Evidence is also provided to support the hypothesis, as has been suggested by previous authors, that appropriate generic assignment of Chabanaud's nominal species, dollfusi, is Cynoglossus, and not Paraplagusia.