500 PROCEEDINGS OF THE ACADEMY OF [1893. 



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

 of hind tarsi; legs black, tibiae and tarsi with silvery pile, the 

 apical portion of the tarsi ferruginous pepticus. 



MALES. 



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

 beneath, the apical joints, except in crassus and pepticus, ab- 

 normal 8 



Flagellum with the basal joints distinctly 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 

 pubescent; median process of clypeus strong, not bituberculate. 



breviventris. 



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 mandibularis. 



Hind tarsi distinctly spinose 6 



6 — First joint of flagellum shorter than the second; space between 

 the eyes at top narrower than usual; head and thorax densely 



clothed with golden pubescence pncdator. 



First joint of flagellum not shorter than the second. 



Space between the eyes at the top not greater than the leugth 

 of antennal joints 2 and 3 united; longest spur of hind tibue 

 longer than the first hind tarsal joint; abdomen not at all red . 



calcaratus. 



Space between the eyes at the top greater than the length of an- 

 tennal joints 2 and 3 united; longest spur of hind tibue decid- 

 edly shorter than the first joint of hind tarsi; abdominal seg- 

 ments with a transverse band of reddish exornatus. 



7 — Emargination of last ventral plate very narrow; first joint of fla- 

 gellum in leugth about equal to the second; head and thorax 



with golden pubescence harpux. 



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

 flagellum shorter than the second; head and thorax with sil- 

 very pubescence Columbia'. 



8 — Apical joints of the antennae normal 9 



Apical joints of the antenna? abnormal • .... 10 



9 — Apex of femora, tibiae and tarsi, yellow-ferruginous; hind tarsi 

 very feebly spinose crassus. 



