THE CANADIAN ENTOMOLOGIST. 245 



7. Vein III S wanting Dialicius. 



Vein III. present 8. 



8. Apex oflabrum produced, laterally compressed, pectinate; mandibles 



dentate ; cheek narrow Chloralictus. 



Apex of labrum broadly rounded, flat, ciliate \ mandibles simple ; 

 cheeks and face broad ; scopa, and rima of segment 5, 

 obsolete Paralictus. 



Males. 

 Segments with apical pubescent fasciae; black or dull 



greenish Halictus. 



Segments without apical pubescent fasciae 1. 



r. Head and thorax dull greenish or bluish 6. 



Head and thorax bright golden green 4. 



Head and thorax black 2. 



2. Clypeus black, rather densely whitish pubescent; cell III, usually 



about X A as long as 1 1 1 + ; abdomen often more or less 



red Sphecodes. 



Clypeus anteriorly with a yellowish mark, or black and thinly 

 pubescent 3. 



3. Joint 4 a little shorter than 2 + 3 ; cheek broad ; metathorax rather 



smooth; segments 2-4 with basal pubescent fascise . Lasioglossum. 



Joint 4 longer than 2 + 3, or only a little longer than 3 ; those with 



basal pubescent fasciae always have the metathorax strongly 



rugose Evylaens. 



4. Abdomen black, with yellow bands .Agapostemon. 



Abdomen like the head and thorax 5. 



5. Ventral segments 1-3 rigid, bright green, the others dark, retracted ; 



tibife green ; tarsi pale Augochlora. 



Ventral segments dark, except sometimes the middle ones, not rigid 

 or retracted ; tibiae pale at least at base and apex . . . Oxystoglossa. 



6. Joint 4 hardly longer than 3 ; vein III S absent Dialictus. 



Joint 4 = 2 + 3, or nearly; vein III. present 7. 



7. Clypeus convex Chloralictus. 



Clypeus flat Paralictus 



Halictus, Latr. 

 Females. 



Dull greenish ; hind spur with 4 or 5 teeth .fasciatus. 



Black, sometimes inclining to ferruginous ; 1, 



