E Jones, Ruffin. 1938. ?Report Of Several Species Of Turbellaria Not Hitherto Reported From The United States?. In Sixteenth Annual Meeting Of The Virginia Academy Of Sciences, 48. Sixteenth Annual Meeting Of The Virginia Academy Of Sciences. University of Virginia: Virginia Academy of Sciences.

Ferguson, Frederick F. 1938. ?A Monograph Of The Genus Macrostomum (O. Schmidt 1848)?. In Sixteenth Annual Meeting Of The Virginia Academy Of Sciences, 47. Sixteenth Annual Meeting Of The Virginia Academy Of Sciences. University of Virginia: Virginia Academy of Sciences.

Ferguson, Frederick F, and M A Stirewalt. 1938. ?The Morphology And Taxonomy Of Macrostomum Phillipsi N. Sp.?. Zoologischer Anzeiger 123. Zoologischer Anzeiger: 42-45.

Gieysztor, M. 1938. ?Über Einige Turbellarien Aus Dem Süsswasserpsammon?. Archives D'hydrobiologie Et D'ichthyologie 11. Archives D'hydrobiologie Et D'ichthyologie.

Gieysztor, M. 1938. ?Systematisch-Anatomische Untersuchungen An Turbellarien Polens?. Zoologica Poloniae 2. Zoologica Poloniae: 215-248, 3 plates.