CLASSIFICATION OF THE BEES. ' * 



is more transverse, the temples not so broad, the stigma in front 

 wings poorly developed, but narrower and longer, while the abdo- 

 men above is more depressed, most frequently distinctly fasciate or 

 with white hair bands, the basal segment sharply truncate or broadly 

 concave at base, so as to fit close to the metathorax when elevated. 

 The absence of pulvilli between the claws is, however, the only 

 reliable character that will separate them. 



To this group or subfamily belong the genuine leaf-cutting bees, 

 so called from the habit the female has of cutting small, almost cir- 

 cular pieces out of the tender leaves of various trees and plants, 

 wherewith to line its cells. The cells themselves are cylindrical, 

 tubular, or, in outline, not unlike a small open-mouthed vial, com- 

 posed of numerous layers of pieces of leaves, wrapped into shape, 

 layer upon layer, as a cigarmaker wraps his cigar ; these cells are 

 arranged in rows, end to end, one upon each other, in burrows or 

 tunnels made in the ground or in decaying wood. 



The genera are not numerous and may be recognized by the use 

 of the following table : 



Table of Genera. 



Second cubital cell receiving both recurrent nervures. 



Mandibles strong, broad, dilated at apex and 3-, 4- or 5-dentate 2. 



Mandibles narrower, simple, bi- or tri-dentate, never broad or dilated at apex. 



Mandibles simple or bideutate at apex ; 9 with a prominent lamina beneath 



the insertion of antennae ; pygidium in % simple or trilobed ; maxillary 



palpi 6-joiuted ; labial palpi 4-jointed. 



9 with the inner spur of hind tibise lunulate and finely serrated within ; 



apical abdominal segments in % trilobed; mandibles simple. 



Ctenoplefta Smith. 

 9 with the inner spurs of hind tibise normal ; apical abdominal segment 

 in % unarmed, the antennas long, the apical two joints compressed, 

 spatulate; mandibles in % simple, in 9 bidentate. 



Steganomus Ritsema = Cyathoeera Smith. 



Mandibles tridentate or subtridentate ; 9 with a prominent lamina or ridge 



beneath the insertion of the antennae ; pygidium in % terminating in 



a tooth or strong spine, the antennas normal ; maxillary and labial 



palpi 4-jointed LiturgUS Latr. 



•> First cubital cell not longer than the second, of an equal length or nearly ; 



maxillary palpi 4-jointed Megachile Latr. (sens lat). 



First cubital cell distinctly longer than the second • 3. 



3. Marginal cell appendiculate at apex, or at least with a stump of a vein 4. 



Marginal cell not appendiculate at apex. 

 Labial palpi 4-jointed, the two basal joints elongate. 3 4-jointed, subclavate ; 

 maxillary palpi 2-jointed, minute; antenna- long, joints it 11 very long 

 and slender, 12-13 abruptly clavate Tliaumalosoiiia Smith. 



TRANS. AM. EST. SOC. XXVI. JUNE ' 1H "- 



