(6) Scaphander sulcatinus Adams, 1862 nomen inquirendum

Remarks: As mentioned above, the descriptions by Adams (1862) of Scaphander were brief and elusive and were not accompanied by any illustrations. To our knowledge, the names S. dilatatus, S. elongatus, and S. sulcatinus have not been used after the original descriptions, unless in direct quotations of the work by Adams (1862) (e.g. Pilsbry 1893, Habe 1955). We therefore suggest these names to be considered as nomina inquirendae, i.e. names attributed to species of doubtful identity requiring further investigation.