Sept., 1914-1 Ellis: New Bees of Genus Halictus. 219 



the disc of the first segment which is often quite impunctate. These 

 species may be separated from one another by the following key : 



a. Punctures of the mesonotum very fine and widely scattered in the broad 



area on either side of the median groove. 



b. Hind legs and tarsi of the other legs light brown ; abdomen dark brown, 



the margins of the segments testaceous; clypeus short, extending 



very little below the eyes ; tegulse and stigma testaceous ; margin of 



the basal area of the metathorax not elevated near the middle. 



H. exiguus Smith. 



bb. Legs dark brown or black, tarsi sometimes lighter; abdomen piceous, 



the broad margins of the segments not testaceous. 



c. Clypeus somewhat produced, about one-half its length extending 



below the eyes ; tegulas almost colorless testaceous ; stigma light 



yellowish brown; tarsi rufo-testaceous H. tropicior n. sp. 



cc. At least two thirds of the clypeus produced below the eyes ; stigma 



and tegulce dark brown H. exigiiiformis n. sp. 



aa. Punctures of the mesonotum quite close and coarse (i. e., as compared with 

 other small bees). 

 d. Head and thorax blue-green ; stigma and tegulse very dark brown. 



e. Posterior margin of the basal area of the metathorax not elevated ; 

 facial quadrangle longer than broad ; abdomen shiny black. 



H. deccptor Ellis. 

 ee. Basal area of the metathorax narrow, the outer margin very 

 slightly elevated on either side of middle; facial quadrangle as 

 broad as long ; clypeus rather narrow, produced almost its 

 entire length below the eyes ; abdomen black with dark me- 

 tallic green reflections H. hypochlorus n. sp. 



dd. Mesonotum bright golden green, head and remainder of the thorax 

 olive green ; stigma and tegulae yellowish testaceous ; posterior 

 margin of the basal area of the metathorax very slightly elevated 

 on either side of the middle ; facial quadrangle a little broader 

 than long, clypeus produced for about half its length below the 

 eyes ; abdomen dark brown with faint olive green reflections. 



H. chrysonotus n. sp. 



Halictus tropicior new species. 



Female s mm. or a little more. Head and thorax dark metallic green, 

 abdomen dark brown, the broad margins of the segments shading to somewhat 

 lighter brown near the edge. Facial quadrangle almost as broad as long, nar- 

 rower below, very closely punctured except on the clypeus and the supra- 

 clypeal area, clypeus blackish and shiny with a few coarse punctures, supra- 

 clypeal area very dark green with some slight coppery reflections, faintly lineo- 

 late and with a few rather fine punctures ; flagellum, especially the under side, 

 yellowish near the tip ; mesonotum shiny, the punctures very fine and scat- 

 tered, more crowded about the parapsidial groove ; disc of the metathorax 



