1901.] 267 



22 (21) Maxillary palpi of ? normal, head of $ closely punctured in front, its 



maxillary palpi less developed 0. Uthophilus, sp. nov. 



23 (20) Wings for most part fuscous, shining, but without distinct blue irides- 



cence,* c? clypeus and thorax entirely black (? unknown)... 



0. aci/anus, sp. nov. 



24 (11) Abdomen black above, not yellow-banded, rarely with the apices of some 



segments narrowly and inconspicuously testaceous. Thorax never 

 marked with yellow. 



25 (26) Dorsal and posterior faces of post-scutellum sharply defined by a serru- 



late ridge, easily seen from in front. 

 25a (256) Costae of second ventral segment more or less obsolete... 



O. nigripennis, Holmg. 

 256 (25a) Costae long and well-developed 0. eplpseustes, sp. nov. 



26 (25) Postscutellum without serrulated ridge. 



27 (38) Wings dark, with conspicuous blue or jjurple iridescence. 



28 (31) Intermediate tibiae without a true calcar, only with short spines at the 



apex. (Propodeum smooth, basal abdominal segment evenly curved 

 backwards from near the petiole) Nesodynerus, gen. nov. 



29 (30) Second ventral segment simply flat beneath behind the costae... 



N. rudolpki, D. T. 



30 (29) Second ventral segment with a shallow but evident triangular depression 



behind the costs N. optaiilis, sp. nov. 



31 (28) Intermediate tibiae with a calcar (propodeum often rough, basal abdo- 



minal segment very strongly curved in lateral view, so as to be vertical 

 or subvertical in front). 



32 (37) Propodeum rugose or rugosely punctate, second ventral segment with the 



whole series of costse well developed, the depression wide and shallow. 



33 (36) Second dorsal segment of abdomen with shallow but distinct punctura- 



tion. 

 33« (336) Mesothoras densely subrugosely punctured, the punctures of different 



sizes, but both kinds conspicuous 0. erro, Perk. 



336 (33«) Mcsothorax not densely subrugosely punctured, the smaller punctures 



excessively minute when present. 



34 (35) Mesothorax not very dull, scutellum very distinctly, generally rather 



deeply, though remotely punctured O. montanus, Sm. 



35 (34) Mesothorax very dull, scutellum with sparse and very feeble punctures... 



O. illudens, sp. nov. 



36 (33) Second dorsal segment hardly visibly punctured O. iopteryx, Perk. 



37 (32) Propodeum smooth, second ventral segment rather strongly and abruptly 



raised at the sides from the apices of the costae, which are subobsolete, 

 or entirely effaced about the middle of the series... O. unions, Perk. 



38 (27) Wings shining fuscous, without conspicuous blue or purple iridescence. 



39 (39a) Intermediate tibiae without a calcar, second ventral segment without a 



depression, its basal portion very large and tumid, mucli longer than 

 the costse Nesodynerus ohlitus, Perk, (an gen. nov. ?) . 



* In all cases the colour of the wings is described from examplea in which these parts are 

 unfolded. 



