700 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Key to Genera. 



Females. 



1. Veins of front wings, beyond first recurrent vein, not obsoles- 



cent, but distinct like other veins 2 



Veins of front wings, beyond first recurrent vein, obsolescent 



Halictus p. 700 



2. Labrum flat, ciliate; rima on fifth abdominal segment absent 



Sphecodes p. 708 

 Labrum produced at apex, laterally compressed, pectinate; 

 rima present Halictus p. 700 



Males. 



1. Abdominal segments without apical pubescent fasciae 2 



Abdominal segments with apical pubescent fasciae 



Halictus p. 700 



2. Head and thorax black 3 



Head and thorax not black Halictus p. 700 



3. Clypeus black, rather densely pubescent Sphecodes p. 708 



Clypeus with a yellowish mark anteriorly, or black and thinly 



pubescent Halictus p. 700 



Halictus Latreille. 

 Key to Species. 



Females. 



1. Veins of fore wing beyond first recurrent vein distinct like 



other veins; labrum. produced at apex and laterally com- 

 pressed, pectinate; rima present on fifth abdominal seg- 

 ment 2 



Veins of fore wing beyond first recurrent vein, or some of 

 them, obsolescent 5 



2. Bright golden green; segments of abdomen with basal pubes- 



cent fasciae or without fasciae 3 



Black or dull greenish; segments of abdomen with apical 

 pubescent fasciae 8 



3. Propodeum not truncate along posterior margin or subquad- 



rately truncate 4 



Propodeum circularly truncate along posterior margin 10 



4. Hind spur of hind tibia finely serrate; hind knee-plate present 12 

 Hind spur of hind tibia with four to six teeth; hind knee- 

 plate absent; second abdominal segment shining, sparsely 

 punctate, hardly ciliate viridissimus 



5. Fore wings with second cubital vein absent or obsolescent.. 6 

 Fore wings with second cubital vein neither absent nor ob- 

 solescent; propodeum rounded posteriorly, without a 

 distinct posterior face; clypeus produced, mesonotum and 

 propodeum smooth and lusterless coriaceus 



