Pseudopolydesmus serratus (Say, 1821). North America, USA, North Carolina, Wake Co.

Retrorsia leonardi Shelley, 2003 (Zootaxa, 296:1-12). NA, USA, Wash., Cowlitz Co., Germany Creek. Photo courtesy of W. P. Leonard.

Retrorsia n. sp. NA, USA, Wash., Cowlitz Co., Germany Cr. Photo courtesy of W. P. Leonard.

Scytonotus granulatus (Say, 1821). N. Amer., USA, Illinois. Photo by G. Montgomery.

Scytonotus bergrothi Chamberlin, 1911. North America, USA, Washington, King Co., Snoqualmie River. Photo courtesy of W. P. Leonard.

Unidentified Polydesmidae. Asia, China, unnamed cave in Sichuan Prov. Photo courtesy of J. Krejca.

Brachydesmus superus Latzel, 1884. Native to Europe; introduced to North America, Atlantic Ocean islands, and Australia. Reproduced from Tasmanian multipedes site (http://www.qvmag.tas.gov.au/zoology/multipedes/mulintro.html) with permission of R. Mesibov.

Scytonotus bergrothi Chamberlin, 1911. North America, USA, Washington, King Co., Snoqualmie River. Photo courtesy of W. P. Leonard.

Unidentified Polydesmidae. Asia, Vietnam, Cat Tien National Park. Photo courtesy of Nguyen Duc Anh.

Pseudopolydesmus sp. North America, USA, Ohio, Highlands Co., Hillsboro. Photo courtesy of D. Anderson.

Polydesmus sp., lateral view. North America, Oregon. Native to Europe but introduced to US; feeding on crop roots of potatoes and strawberries. Photo by T. Valente, Oregon Department of Agriculture.

Polydesmus sp., ventral view showing both leg pairs on metazonite. North America, Oregon. Native to Europe but introduced to US; feeding on crop roots of potatoes and strawberries. Photo by T. Valente, Oregon Department of Agriculture.