CLASSIFICATION OF THE BEES. 83 



Table of Genera. 



Marginal cell at apex more or less remote from the costa, or broadly, obliquely 

 tru ncate .">. 



Marginal cell towards apex acuminate, attaining the costa. 



Abdomen usually rather long; second joint of hind tarsi normal, inserted in 



the middle, of the first 2. 



Abdomen sliort. subglobose, black, shining, with white fascia' at apex : second 

 joint of hind tarsi angulate beneath, not inserted in the middle of the 

 first; clypeus in % yellow, the hind femora incrassated ; antenna- in 

 both sexes filiform, longer than the head; tongue short; maxillary 

 palpi 6-jointed, labial palpi 4-jointed Macropis Panzer. 



2. Body, and more particularly the thorax, distinctly pubescent, the abdomen 



with white fascia? 3. 



Body sparsely pubescent, the thorax rarely densely pubescent, the abdomen 

 always glabrous, shining, not fasciate, although the anal segment is 

 distinctly ciliate at apex. 

 Transverse median nervure interstitial, or very nearly. 



Anal lobe in hind wings not longer than the suhmedian cell ; head and 

 thorax sparsely pubescent ; abdomen in 9 black, not at all fasciate; 

 clypeus in % black, the antennae longer than the thorax, the flagellar 



joints nodose beneath II ;i I i< I oi<l< -> Nyl. 



Anal lobe in hind wings distinctly longer than the suhmedian cell; head 

 and thorax rather densely pubescent; abdomen in 9 rufous or brown- 

 ish, or at least reddish at apex of the segments: clypeusin £, yellow. the 

 anteunse not longer than the thorax, normal. . Paraiitfrena Robt. 

 Transverse median nervure not interstitial, joining the median vein before 

 the basal nervure; antennae in % not longer than the thorax, the 

 flagellum simple; maxillary palpi 6-jointed, the joints subequal ; labial 

 palpi 4-jointed, the first joint the longest, about as long as joints 2-3 

 united, the third longer than joints 2-4. 



Diifourea Lepel. = HemihaJictus Ckll. 



3. Suhmedian cell usually shorter than the mediau, or never longer, the trans- 



verse median nervure joining the median vein before the origin of the 



basal nervure or interstitial with it 4. 



Suhmedian cell a little longer than the median, the transverse median nervure 

 joining the median vein beyond the origin of the basal nervure. 

 Thorax above with fulvous or ferruginous hairs; maxillary palpi 6-jointed; 

 labial palpi 4-jointed Biareolina Dufour. — Callandrena Ckll. 



4. Thorax above usually with a whitish or griseous pubescence, very rarely with 



a slight ocbraceous tinge. 



Labial palpi deformed, the basal joint long and quite different from the 

 last; face in 9 with blackish hairs; antennae in % longer than the 

 thorax, the apical joint attenuate from the middle. Rliopliites Spin. 



Labial palpi normal, all the joints being similar and nearly equal ; face in 9 

 with white hairs; antenna' in % as long as the thorax, the last joint 

 acuminate at apex only RliopIiitoidesSchenck = HesperapisCk]]. 



5. Marginal cell at apex more or less acuminate or narrowly rounded, not or 



rarely truncate, although sometimes appendiculate ; mandibles den- 

 tate 11. 



TRANS. AM. ENT. SOC. XXVI. JUNE. 1H99. 



