- Hydroperla parallela Frison, 1936: 261.
Holotype; male; 959741fe-af65-44fc-b020-e4ff80ec3f9b; deposited at: Illinois Natural History Survey (INHS); United States: Oregon: Corvallis, Willamette river
- Perlodes americana (Klapálek, 1912) in Alexander, 1936: 24.
- Perlodes (Perlodes) americana (Klapálek, 1912) in Claassen, 1940: 110, 111.
- Arcynopteryx americana Klapálek, 1912 in Hanson, 1942: 394.
- Arcynopteryx americana Klapálek, 1912 (subjective synonym of Dictyopteryx compacta McLachlan, 1872) in Brinck, 1949: 60. Classification
- Skwala paralella (Frison, 1936) in Illies, 1966: 378.
- Skwala americana (Klapálek, 1912) in Flannagan & Cobb, 1983: 676.
- Hydroperla parallela Frison, 1936 (synonym of Arcynopteryx americana Klapálek, 1912) in Zwick, 1989
- Skwala americana (Klapálek, 1912) in Zwick, 1989: 181.
- Skwala americana (Klapálek, 1912) in Mangum, 1999: 131.
- Skwala americana (Klapálek, 1912) in Kondratieff & Baumann, 2002: 397.
- Skwala americana (Klapálek, 1912) in Stewart & Oswood, 2006: 11, 191, 285. Key
- Skwala americana (Klapálek, 1912) in Cary & Jacobi, 2008: 143.
- Skwala americana (Klapálek, 1912) in Newell, Baumann & Stanford, 2008: 179.
- Skwala americana (Klapálek, 1912) in Heinold, 2010: 152.
- Skwala americana (Klapálek, 1912) in Zuellig, Heinold, Kondratieff & Ruiter, 2012: 57.
- Skwala americana (Klapálek, 1912) in Dosdall & Giberson, 2014: 225.