1893.] NATURAL SCIENCES OF PHILADELPHIA. 503 



7 — Mandibles very broad and flat, with an exceedingly narrow notch; 



abdomen black obscurus. 



Mandibles of the normal form, with a broad notch 8 



8 — Metanotum not at all furrowed; abdomen varying from red and 

 black to entirely ferruginous; size also variable. . rufofasciatus. 



Metanotum nunc or less furrowed 9 



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



joints 2 and 3 united; elypeus not dentate obductus. 



Space between eyes at top a little less than the length of second 

 and third antennal joints united; elypeus armed with a large 

 prong on each side mergus. 



MALES. 



1 — Wings yellow, with the apical portion dark 2 



Wings not yellow, hyaline or subhyaline 3 



2 — Third joint of antenna? nearly one-third longer than the fourth; 

 metanotum distinctly punctured; tibiae and tarsi black .... 



aurulentus. 



Third joint of antenna? but little longer than the fourth; metano- 

 tum not punctured; apex of femora, tibia? and tarsi yellow fer- 

 ruginous distinctus. 



3 — Abdomen and legs more or less red; third joint of antenna? in 

 length about equal to the fourth; metanotum slightly furrowed; 



femora, 'except base, reddish rufofasciatus. 



Abdomen and legs black.- 4 



4 — Space between eyes at top much less than the length of antennal 



joints 2-4 united 5 



Space between eyes at top about equal to the length of antennal 



joints 2-4 united; apical margins of the wings fuscous. . parvus. 



o — Notch on outer edge of mandibles very narrow; body not densely 



silvery sericeous obscurus. 



Notch on outer edge of mandibles as usual; body rather densely 

 clothed with silvery sericeous pile sericatus. 



13. — T. aurulentus Fab. 



Larra aui itlenta Fab., Syst. Piez. p. 220. 

 Lyrops aurulenta Say, Bost. Journ. I, p. 371. 

 1 Tachytes aurulentus Lep., Hvui. Ill, p. 247. 

 Tachytes aurulentus 8m., Catal. Brit. Mus. IV, p. 306. 

 Litis coxalis Patton, Ent. News, III, p. 90. 9 $ . 



New Jersey (July and August) to Florida, westward to Texas 

 and Missouri. 



14. — Tachytes contractus Fox. 



T. contractus Fox, 1. c. p. 245, £ • 



Georgia. 



3 T. minimus has been excluded from this table as it is a species of Tacbysphex. 



