72 Descriptions of new species of Hymenoptera. 
tral cellule small, quadrangular, longitudinal, somewhat 
oblique, not distinctly narrowed at either end; posterior 
tarsi at their tips dusky; abdomen depressed; venter 
with a dusky spot near the tip. 
Length $ nearly three-tenths of an inch. 
8. I. malacus. Body black; antennse annulate w^ith 
white, beginning at the tenth joint and terminating at the 
eighteenth; joints very distinct; ivings blackish; small 
cellule with one bulla, larger anal cellule with three bul- 
lae and two short processes; metathorax with elevated 
lines; abdomen with an impressed line each side. 
Length more than half an inch* 
9. I. pectoralis. Black; abdomen rufous: antcnnsp 
blackish, whitish near the middle. 
Inhab. Indiana. 
Body black; orbits and all beneath the antennae, yel- 
low; antennae blackish, 13, 14, 15, 16 joints white; tho- 
rax with a w^hite line before the wings, interrupted be- 
fore; scuteldinA transverse line beneath it, yellow; wings 
hyaline, central cellule pentangular, transverse; pleura 
black; pectus black, with a large yellow spot between 
the intermediate and posterior feet; feet yellow; poste- 
rior thighs tinged with rufous; posterior tibiae rufous at 
tip; abdomen rufous, with black incisures. 
Length over one-fifth of an inch. 
10. I. bifasciatus. Ferruginous; wings dusky, bifas- 
ciate. 
Inhab. Indiana. 
Body ferruginous; antennse somewhat tinged with 
whitish beyond the middle and fuscous at tip; thorax 
circumscribing incisure black; ivings dusky with a hya- 
