Catalogue of Geadephaga (Coleoptera, Adephaga) of America, north of Mexico Author Bousquet, Yves Agriculture and Agri-Food Canada, Central Experimental Farm, Ottawa, Ontario, Canada bousquety1@yahoo.com text ZooKeys 2012 2012-11-28 245 1 1722 http://dx.doi.org/10.3897/zookeys.245.3416 journal article http://dx.doi.org/10.3897/zookeys.245.3416 1313-2970-245-1 FFFF52503A0AFF882450FFB66D45FF8E 578462 Genus Amerizus Chaudoir, 1868 Amerizus Chaudoir, 1868b: 216. Type species: Trechus spectabilis Mannerheim, 1852 by monotypy. Etymology. From the Greek a (without) and merizo (to divide, split), probably alluding to the apparent undivided outer lobe of the maxilla (" maxillae tenues, elongatae, mala externa ... haud biarticulata ") of adults [masculine]. Diversity. About 50 species in North America (five species) and Asia (about 45 species) placed in two subgenera: Tiruka Andrewes for most Asian species and Amerizus for the Nearctic species and one Asian species. Taxonomic Note. Toledano (2011) noted that Amerizus is closely related to the genus Caecidium Ueno (two species in Japan). Lindroth (1980: 203) pointed out that Bembidion (Gnatholymnaeum) blackburni (Sharp) from Hawaii is structurally similar to the species of this genus and indeed listed the species within the subgenus Amerizus . However, Liebherr (2008: 36) argued against such association. Both Caecidium and Bembidion blackburni were not sequenced by Maddison (2012).