132 Mr. R C. L. Perkins' 



2. (1) Postscutelluiiiwithoutatran.sver.se elevated ridge; second 



discoidal cell at the apex generally much less than twice 

 as high as the third at its base. 



3. (14) Costa?, of second ventral segment wanting, or much effaced 



and indistinct ; or extremely short, the middle ones not 

 so long as the transverse basal portion of the segment, 

 which is before them. 



4. (9) Second ventral segment greatly raised Ijehind the transverse 



sulcature, very much higlier than its basal portion. 



5. (6) (J. Mandibles and apex of clypeus red; propodeum smooth 



and shining with a few punctures in front ; abdomen 



deep-black, shining 0. cypris, sp. nov. 



G. (5) (J. Mandibles and apex of clypeus not red; propodeum 

 dull, 07- with the concavity densely and largely punctate. 



7. (8) Posterior concavity of the propodeum coarsely and closely 



punctured ; mesothorax shining between the punctures. 



0. eidrettts, sp. nov. 



8. (7) Posterior concavity of propodeum dull, with at most some 



feeble and indefinite punctures ; mesothorax not shining. 



0. heterochromvs, P. 



9. (4) Second ventral segment little, or not at all, raised behind the 



costpp, or transverse sulcature. 



10. (11) Front of head and mesothorax very dull, with the 



puncturation nearly effaced, hardly visible. 



0. egens, P. (? var. = 0. infmistvsy P.). 



11. (10) Me.sothorax dull with distinct punctures, or shining and 



coarsely punctured. 



12. (13) Mesothorax dull, finely punctured, abdomen often red- 



marked above or beneath 0. ciianoj)teryx, P. 



13. (12) Mesothorax coarsely and clo.sely punctured, shining between 



the punctures ; abdomen entirely black. 



0. holomehts, sp. nov. 



14. (3) Costaj of second ventral segment ahvays distinct, and 



never very short, the middle ones about as long or 

 sometimes longer than the basal portion of the segment. 



15. (26) First and second abdominal segments above red, or one or 



botli spotted with red at the .sides, the red colour some- 

 times dull and not obvious at a glance, the spots of 

 second segment sometimes confined to the deflexed sides 

 and hardly visible in dor.sal view. 



IG. (17) First and s?cond abdominal segments nearly wholly red. 

 A\'ings with only a slight blue iridescence. 



0. frater, D. T. 



17. (16) First and second segments only spotted with red ; if 



