Diagrams of basal sclerites of labium, as explained for Figure 33-3. a, Systropha curvicornis (Scopoli) (Halictidae); b, Lonchopria herbsti Vachal (Colletidae); c, Colletes inaequalis Say (Colletidae); d, Caupolicana hirsuta Spinola (Colletidae); e, Euryglossa subsericea Cockerell (Colletidae); f, Amphylaeus morosus (Smith) (Colletidae); g, Ctenocolletes albomarginatus Michener (Stenotritidae). (For abbreviations, see legend, Fig. 33-3.) From Michener, 1985a. (source: Michener, 2007)