North American Hymenoptera. 239 



as the ramidulusj Fabr. which has also opake whig-spots, 

 but is black on the tip of the abdomen. The hilineatus^ 

 Nob. may be distinguished from this species by having 

 many raised lines on the metathorax and by being desti- 

 tute of the opake wing-spots. The sexes are similar in 

 coloFj and both have the opake wing-spots^ which is not 

 the case in Mr. Winthem's specimens of ramiduliis. 



2. O. glahratus. Honey-yellow; a glabrous spot in 

 the large cubital cellule. 



Inhabits Indiana. 



Body dull honey-yellow : head bright yellow : an- 

 tenncB^ mouth and stemmata honey-yellow : eyes black- 

 ish : wingSj first cubital cellule beyond its middle with a 

 longitudinally oval glabrous space, but destitute of any 

 opake spot : metathorax transversely wrinkled near the 

 petiole of the abdomen . 



Length about four fifths of an inch. 



Much like purgatus, Nob.^ with a similar glabrous 

 spot in the cubital cellule, but this spot is destitute of 

 any appearance of the opake coriaceous spots which dis- 

 tinguish that species. 



3. O. mundus. Black; antennae, posterior tibiae and 

 tarsi yellow. 



Inhabits Indiana. 



■t 



^ Body black : head with the front, nasus and ante- 

 rior orbits greenish-yellow : anteniKB fulvous yellow ; 

 three or four basal joints above black; the first joint 

 beneath greenish-yellow : trunk w ith rather dense, short 

 hairs: wings purple-black : abdomen much compressed; 

 basal joint cylindrical ; second segment as long as the 

 first, or a little longer, compressed towards the tip : ante- 

 rior pair of feet yellowish before : intermediate pair 

 with a line before and base of the tibiae yellowish : pos~ 



