original description
Chamberlin, R. V. (1943). On some genera and species of American millipeds. Bulletin of the University of Utah, Biological series, 8(2): 1-20
page(s): 12 [details]
additional source
Shelley, R. M.; Smith, J. M. (2016). Parajulid milliped studies XII: Initial assessment of <em>Ptyoiulus</em> Cook 1895 and neotype designations for <em>Julus impressus</em> Say 1821 and <em>J. montanus</em> Cope 1869 (Diplopoda: Julida). <em>Insecta Mundi.</em> (0522): 1-21., available online at https://digitalcommons.unl.edu/insectamundi/1027/
page(s): 9 [details] Available for editors 
additional source
Hoffman, R. L. (1999). Checklist of the millipedes of North and Middle America. <em>Virginia Museum of Natural History, special publication.</em> 8: 1-584., available online at https://www.biodiversitylibrary.org/page/63590410
page(s): 162 [details]
From editor or global species database
Taxonomic remark Placed as a junior subjective synonym of Ptyoiulus impressus (Say 1821) by Shelley & Smith (2016) on page 9. [details]