1893.] NATURAL SCIENCES OF PHILADELPHIA. 507 



Metathorax, above, strongly reticulated; usually the last segment 



only red apicalis. 



15 — Greater part of abdomen black 16 



Greater part of abdomen red or equally red and black 18 



16 — Metanotum reticulated. 



Vertex and dorsulum coarsely punctured; tarsi black . . acntus. 

 Vertex and dorsulum very linely punctured; tarsi reddish on 



apical half nigrior. 



Metanotum smooth or finely granulated, opaque 17 



17 — With dense sericeous pile; wings subhyaline punctifrons. 



Without sericeous pile, deep black; wings dark fuscous . aethiops. 



18 — Tibia?, tarsi and femora, in part, red posterus. 



Tibia? and femora black 19 



19 — Metanotum strongly reticulated asperatus. 



Metanotum longitudinally striated sculptilis. 



Metanotum granulated or coriaceous 20 



20 — Abdomen not at all compressed, depressed throughout .... 21 



Abdomen compressed apically rnontanus. 



21 — Pygidium in length, but little, if anything, greater than twice its 



width at the base. Length 6 mm pauxillus. 



Pygidium in length, greater than twice its width at base; meta- 

 thorax above finely granulated consimilis. 



MALES. 



1 — Space between the eyes at top about equal to the length of anten- 



nal joints 2 and 3 united 2 



Space between the eyes at top greater than the length of antennal 



joints 2 and 3 united 3 



2 — Abdomen black; apex of femora, tibia? and tarsi entirely, reddish 



yellow minimus. 



Abdomen on basal half red; femora and tibia? not reddish. cequalis. 

 3 — Abdomen entirely black, except extreme apex in some few 



species 4 



Abdomen red or black and red 10 



4 — Metathorax above smooth or indistinctly sculptured 5 



Metathorax above coarsely sculptured 6 



5 — Lateral angles of produced portion of anterior margin of clypeus 

 obtuse; metathorax above without a longitudinal, impressed 



line; clothed with sericeous pile punctifrons. 



Lateral angles of produced portion of anterior margin of clypeus 

 acute; metathorax above with a distinct,longitudinal, impressed 



line; deep black, without sericeous pile aethiops. 



6 — Space between the eyes at top decidedly less than the length of 

 antennal joints 2-4 united, but little greater than the length of 



joints 2 and 3 mundus. 



Space between the eyes at top as great or greater than the 

 length of antennal joints 2-4 united 7 



