Genus Ambrysus Stål

Ambrysus is distinguished from other members of Ambrysini (Table 1) by the following suite of attributes: deep convexity of the posterior margin of the head; sternum continuously covered by a fine hair pile in both sexes; narrow lateral glabrous band on the abdominal venter in both sexes; and males with variously sized and shaped pseudoparameres of tergum VIII, symmetrical parameres, ventral lobes of the phallosoma with or without teeth, and accessory genitalic process of tergum VI usually present. Ambrysus has been organized into five subgenera (La Rivers 1965, Nieser et al. 1999). Most species are in the nominate subgenus; Melloiella comprises two species in Brazil; Syncollus includes 11 species and recently was reviewed by Reynoso-Velasco et al. (2016); Acyttarus is monotypic and occurs in Death Valley, California (La Rivers 1949, Whiteman & Sites 2008); and Picrops is monotypic (La Rivers 1952), distributed in the Neotropics, and is elevated to genus rank herein (see below).