76 Descriptions of neto species of Hyrmnoptercp'. 
a black spot, their tibiae dusky at tip and their tarsi yel- 
low; abdomen black at tip and on the superior edge of 
the second segment, which is at least as long as the first 
segment. 
Length ? nearly three-fifths of an inch. 
3. 0. geminatus. Yellowish; vertex with a black spot; 
larger central cellule of the wings obtuse at tip. 
Inhab. Indiana. 
^od'y dull yellowish; head y^Wow, vertex hldioX^; an- 
tennse somewhat shorter than the body, tinged with 
brown, the first joint yellow; wings hyaline, with fus- 
cous nervures and honey-yellow somewhat dilated carpal 
spot; larger central cellule obtuse at tip, the nervure of 
the tip double; smaller central cellule very obtusely 
rounded at the superior basal angle; pleura and pectus 
pale yellowish ; abdomen, second segment obviously 
shorter than the first, and not longer than the third. 
Length about two-fifths of an inch. 
This species closely resembles 0. bilineatus, Nob. but 
is much smaller, and the arrangement of the wing-ner- 
vures prove it to be a different species. 
4. 0. emarginalus. Black ; antennae fuscous ; feet 
lioney-yellow. 
Inhab, Indiana. 
Body black, sericaous with short hair ; head convex 
beneath the antennae, at the base of which the head is 
much more prominent than immediately above the an- 
tennas where the head is indented; antennae short, above 
dark fuscous, beneath paler, first joint rather large; palpi 
whiter thorax immaculate; metathorax wdth four longi- 
tudinal slightly raised lines; wings hyaline with fuscous 
nervures and carpal spot; larger central cellule obtuse or 
