236 WILLIAM J. FOX. 



6. — The sulcus oi\ metanotum very wide; scutellum scarcely impressed; py- 



gidium with a coppery lustre Miandibiilaris. 



The sulcus on metanotum not wide; scutellum distinctly impressed; jiy- 



gidium silvery breviveiilris. 



7. — Abdomen black 8. 



Abdomen in part red; head and thorax clothed with dense silvery pubes- 

 cence fulviveiitris. 



8. — Abdomen dorsally with four silvery bands; front silvery 9. 



Abdomen dorsally with but three silvery bands; longer spur of hind tibiae 

 in length about equal to the first joint of the hind tarsi; front golden. 



crasstis. 

 9. — Longer spur of hind tibiae longer than the first joint of the hind tarsi ; 



apex of femora, tibise and tarsi, yellowish ferruginous coluiiibiie. 



Longer spur of hind tibiae, in length, about equal to the first joint of hind 

 tarsi ; legs black, tibife and tarsi with silvery pile, the apical portion of 

 the tarsi ferruginous pepticus. 



3IALES. 



1. — Flagellum with the basal joints not or scarcely rounded out beneath, the 



apical joints, except in crassus and pepticus, abnormal 8. 



Flagellum with the basal joints strongly rounded out beneath, the apical 



joints normal 2. 



2. — Anterior margin of clypeus, in the middle, not produced into a tooth or 



lobe, at the most simply thickened 4. 



Anterior margin of clypeus in the middle produced into a tooth or lobe. ..3. 



3. — Metanotum slightly sulcate ; thorax densely pubescent ; median process of 



clypeus not prominent, strongly impressed, having the appearance of 



being bituberculate validus. 



Metanotum distinctly and rather strongly sulcate ; thorax sparsely pubes- 

 cent; median process of clypeus strong, not bituberculate. 



breviveiitris. 



4. — Last dorsal abdominal segment tufted laterally with dark hair 7. 



Last dorsal abdominal segment not tufted with dark hair 5. 



5. — Hind tarsi not at all spinose; lateral teeth of clypeus large and distinct. 



niaiKiibularis. 



Hind tarsi distinctly spinose 6. 



6. — First joint of the flagellum shorter than the second ; head and thorax 

 densely clothed with golden pubescence; space between the eyes at top 



narrower than usual prtetlator. 



First joint of the flagellum longer than the second ; front and clypeus sil- 

 very ; thorax sparsely clothed with grayish pubescence.. ..calcaratiis. 

 7. — Emargination of last ventral plate very narrow; first joint of flagellum in 

 length about equal to the second ; head and thorax with golden pubes- 

 cence barpax. 



Emargination of last ventral plate broad and round; first joint of flagellum 

 shorter than the second ; head and thorax with .silvery pubescence. 



coliiinbise. 



8. — Apical joints of the antennae normal 9. 



Apical joints of the antennae abnormal 10. 



