They are exceptional in that both their running and striking speeds place them amongst the world's fastest animals ( Crews et al. Spiders of the family Selenopidae Simon, 1897, also known as wall crab spiders or flatties, have a cosmotropical distribution. A key to species is also provided as are new distributional records.
New illustrations are provided, including those of the internal female copulatory organs, many of which are illustrated for the first time. Almost all species are redescribed, barring Cuban endemics and a few species recently described. The males of Selenops bani Alayón-García, 1992 and Selenops marcanoi Alayón-García, 1992 are described for the first time, and the females of Selenops phaselus Muma, 1953 and Selenops geraldinae Corronca, 1996 are described for the first time. The female neotype is designated for Selenops aissus Walckenaer, 1837. Pickard-Cambridge, 1900 (♂), Selenops morosus Banks, 1898 (♂), and Selenops mexicanus Keyserling, 1880 (♀). Lectotypes are designated for the following three species: Selenops marginalis F. = Selenops nigromaculatus Keyserling, 1880 and Selenops salvadoranus Chamberlin, 1925 syn. = Selenops mexicanus Keyserling, 1880 Selenops santibanezi Valdez-Mondragón, 2010 syn. n., Selenops galapagoensis Banks, 1902 syn. = Selenops candidus Muma, 1953 Selenops tehuacanus Muma 1953 syn. Six species names were synonymized: Selenops lunatus Muma, 1953 syn. In total, 21 new species are described, including Selenops arikok sp. No taxonomic changes are currently made to the species from the southwestern United States. In this paper the members of the genus Selenops found in North America, Central America, and on islands of the Caribbean are revised, excluding Cuban endemics. The spider genus Selenops Latreille, 1819 occurs in both the Old World and New World tropics and subtropics and contains nearly half of the species in the family Selenopidae Simon, 1897.