The genus Lopidea Uhler is revised for America north of Mexico. The relationship of Lopidea to other orthotyline genera is discussed and a hypothesis of spicula evolution is presented. Synapomorphies are provided that identify the genus llnacora Reuter as the sister group of Lopidea.
Forty eight species of Lopidea are recognized as occurring north of Mexico, one, L. bonanza, is described as new. Line drawings for male genitalic structures, a key to adult males and distributional maps for all species are included. The following synonymies within Lopidea are proposed (senior names first): Lopidea arizonae Knight = navajo Knight; balli Knight = chelifer Knight; bullata Knight = paddocki Knight and L. deserta Knight; chandleri Moore = trispicata Knight; confraterna (Gibson) = burkei Knight; davisi Knight = arkansae Knight and L. biselli Knight; falcicula Knight = denmani Knight and Schaffner; garryae Knight mohave Knight; hesperus (Kirkaldy) = amorphae Knight and wisteriae Chandler; instabilis (Reuter) = marginalis (Reuter); major Knight = texana Knight, L. polingorum Knight and L. matamorensis Knight; marginata Uhler = drakei Knight; minor Knight = phlogis Knight, petalostemi Knight and L. johnstoni Knight; nigridia Uhler = nicholi Knight; picta Knight = oregona Hsiao, L. calli Knight, L. knowltoni Knight, L. dawsoni Knight, L. utahensis Knight and L. yampae Knight; staphyleae staphyleae Knight = staphyleae sanguinea Knight; taurina Van Duzee = taurula Knight, L. malvastri Knight, L. nevadensis Knight and L. fuscina Knight; ute Knight = stitti Knight and L. becki Knight.
Neotypes are designated for Capsus confluentus Say and Capsus medius Say. Lectotypes are designated for Capsus robiniae Uhler, Lomatopleura instabile Uhler, Lopidea cuneata Van Duzee and Lopidea marginata Uhler.