In connection with the study of the pollination of flowers by insects, for several years and in several journals I have published notes on the local Halictinæ, with descriptions of new species and the missing sexes of some which were only known in one sex. This paper is intended to bring my results together in a brief form.

The so-called genus Halictus of authors seems to be altogether too heterogenous. I restore Lasioglossum and propose two other new genera. I think that the several genera must stand or fall together. The venation shows that Agapostemon and Augochlora are more closely related to Halictus, as here limited, than are Lasioglossum, Evylaeus and Chloralictus.