New combinations, notes, synonymy and redescriptions of some Neotropical Halictidae bees described by Vachal (1911), are given, and a new genus Vachalias is proposed to accommodate Haliclus cosmetor Vachal, 1911. The following species of Halictus: engys Vachal, 1911, liaspis Vachal, 1911 and rohdei Vachal, 1911 are transfered to Augochlora (Augochlora) Smith, 1853; H. levinasis Vachal, 1911 is a synonym of Augochlorella striala (Pmvzmcher, 1888); H. xanthogastris Vachal, 1911 belongs to Habralictus, H. myrrhites Vachal, 1911 to Pereirapis and H. psoraspis Vachal, 1911 to Ceraialiclus. Some notes are made on the specimens of Pereirapis simotes Vachal, 1911. Haliclus psorops Vachal, 1911 is included as a synonym in Ceratalictus clonius (Brèthes, 1909) and also Oxystoglossa theia Schrottky, 1910 and Oxystoglossa thalia pauloensis Schrottky, 1910. Halictus selloi Vachal, 1911 belongs to Augochloropsis (Augochloropsis). The lectotypes are designated for the following species: Halictus simotes and H. cosmetor.
Neotropical Halictidae: new genus; new combinations and synonymy