METHOD OF DETERMINING GENERA. 17T 



Three submarginal cells to the wings. 



Abdomen truncated at base . . . Colletes (1). 

 Abdomen ovate. 



Abdomen entire at apex ; maxil- 

 lary palpi as long or longer than 



the maxilltB ANuiiEisrA (4). 



Abdomen entire at apex ; maxil- 

 lary palpi half the length of the 



maxilliE CiLissA (5). 



Abdomen with a vertical incision 



at the apex Halictus (7/ 



Posterior tibia loitJiout hair to convey pollen. 

 Two submarginal cells to the wings . Prosopts (L,. 

 Three submarginal cells to the wings . Sphecodes (3). 



. Apid^ (Normal Bees). 



Toa'QDB AS LONG OR LONGER THAN THE MAXILLA, IN- 

 TLECTED BENEATH, AND COVERED BY THE MAXILLJ? IN 

 REPOSE. 



Without polliniferous organs. 



Two submarginal cells to the wings. 



Abdomen at apex rounded . . . Stelts (17). 

 Abdomen at apex conical .... Ccelioxys (18). 

 Three submarginal cells to the wings. 



Abdomen lanceolate Nomada (14), 



Abdomen subtruncate at base. 



Abdomen obovate, thorax glabrous Epeoltjs (16). 

 Abdomen subcorneal, thorax hir- 

 sute Melecta (15). 



Entire body densely hairy . . . Apathus (25). 



With polliniferous organs. 



Pollen conveyed on the venter. 



Two submarginal cells to the wings of all. 



