NORTH AMERICAN HYMENOPTERA, 219 



Petiole of abdomen shorter than the following segment, robust; coxpb black 

 (anterior margin of clypeus with a slight, square production ; base of 



metathorax with a transverse row of short rugje) OCei«leii talis. 



80. — Abdomen black, not banded with reddish; four anterior legs banded with 

 black pedicellatusi. 



Abdomen black, the anterior half of the third segment reddish ; four ante- 

 rior legs yellowish, not banded rufoga.ster. 



MALES. 



Epimerum mesopleuralis armed with a distinct crest or ridge before the middle 



coxse, striated, punctato-striate or striato-punctate ; antennse 12-jointed.2. 



Epimerum mesopleuralis not crested or ridged, at the most with a small pointed 



prominence before the middle coxfe, punctured, rarely striated ; antennge 



13-jointed 31. 



2. — Anterior margin of clypeus produced into a strong, truncated process, not so 



prominently, however, as in the females 3 



Anterior margin of clypeus not strongly produced medially, usually 



rounded 14. 



3. — Flagellum entire, not dentate or emarginate ; sculpture very coarse on head 

 and thorax: first joint of medial tarsi siuuated ; fore tarsi slightly flat- 

 tened 4. 



Flagellum either dentate or emarginate beneath ; sculpture less coarse ; first 

 joint of medial tarsi not sinuous, differing in the diflFerent species; fore 



tarsi distinctly flattened 6. 



4. — Flagellum not broadened basally. being nan-owed from apex, the second 



joint longer than broad ; abdomen coarsely punctured 5. 



Flagellum a little dilated basally. the first joint only narrowed ; the second 

 joint broader than long, as are also several of the succeeding joints: ab- 

 domen with tolerably strong, not coarse, even punctures. 



prod net icollis. 

 5. — Head between the ocelli and occiput covered \fith very large, deep, non-con- 

 fluent punctures, those on the abdomen also strong, but less so than on 

 the head ; abdomen with one, more rarely with two or three terminal 



bands intemiptiis. 



Head between the ocelli and occiput with coarse, confluent punctures, less 

 strong than in iuterruptux, those on the abdomen also finer and closer; 



abdomen with three, rarely with less, terminal bands bell us. 



6. — Ocelli forming a low triangle, tending to a curved line ; pronotum distinctly 



dentate laterally; first four joints of flagellum strongly contracted 



basally and produced a little at apex, the first and fourth most strongly .7. 



Ocelli forming an equilateral triangle ; pronotum rounded at the sides not 



dentate ; first three or four joints of flagellum produced into a huge 



tooth beneath 12. 



7. — First joint of medial tarsi shorter than the three following united, at any 



rate not longer 8. 



Fii-st joint of medial tarsi longer than the three following united 10. 



S.^Occiput and cheeks strongly and sharply margined behind ; pronotum large, 

 very strongly crested anteriorly, the lateral tooth large and shaqi ; cen- 

 tral longitudinal furrow of middle segment not broad ; scajie and first 

 abdominal segment marked with yellowish luoutaiiiis. 



TRANS. AM. ENT. SOC. XXII. JUNE, 1895. 



