36 



[February, 



9 (10) Front of head above the antennae viewed from the side with many 

 long hairs (not merely with a few remote ones) ; propodeum quite 

 conspicuously pilose cousobrhms. 



10 (9) Front of head with a few remote long hairs ; propodeum bare or with 



a few hairs laterally «... .(/ibbus, unf/uicularis, and tveamaeli. 



11 (8) I'ecten undeveloped, the front tarsi with only short spines, and the 



outer margin of the 2nd joint without a long spine about the middle. 



12 (13) Upper side of the quadrangular 3rd cubital cell about as long as that 



of the second, or often longer spissiis. 



13 (12) Third cubital cell often triangular or subtriangular, or if distinctly 



quadrangular its upper side is much shorter than that of the second. 



minutulus, 



14 (1) Abdomen wholly black or black with white spots. 



15 {22) Pecten of front tarsi either undeveloped, the spines being short, or 



else imperfect, the 2nd joint never with an elongate spine about the 

 middle of its outer margin, but at most with one on the apical angle 



16 (21) Legs black, apical dorsal segment with man}' bristly black hairs. 



17 (18) rronotum with its emargination arcuate or strongly rounded in the 



middle, not distinctly angulate; tomentum of 2nd and 3rd ab- 

 dominal segments not forming a gre}' basal band. (Spines on 

 the legs less developed than in either of the following.) 



cardiii. 



18 (17) Pronotal emargination angulate; in fresh specimens there is a distinct 



grey basal band on the 2ud and 3rd abdominal segments. 



19 (20) Fourth joint of hind tarsi nearly as long as the fifth (excluding the 



pul villus and claws) or at least from | to f as long, .niycrrimus. 



20 (19) Fuurtli joint of liiud tarsi short, not nearly § the length of the fifth. 



approximatus. 



21 (16) Legs red, apical dorsal segment much less hairy. (Face and pro- 



notuni with white markings.) cinctellus. 



22 (15) Pecten of front tarsi perfect, a long spine on the outer margin of the 



second joint, as well as one at the apical angle. 



23 (26) Propodeum and basal abdominal segment not conspicuously hairy, but 



merely tomentose. 

 21 (25) Front wings subinfuscate on the apical portion, the infuscation in- 

 cluding the marginal, 2nd cubital, and outer discoidal cells. (Pecten 

 rather feeble.) sericens. 



25 (24) Front wings with narrow dark apical band, not occupying the whole 



space up to the 3rd transverse cubitus and outer discoidal cell. 

 (Pecten very long.) plumbetis. 



26 (23 Propodeum and basal abdominal segment with conspicuous long hairs. 



(Pecten very long.) ru/ipes. 



The three black males of the nigerrimus group ma}' be easily 

 distinguished, as follows : — 



1 (2) Apical ventral segment of the abdomen broad, widely rounded at the 



apex, nearly flat, and with a feeble median carina . . carihii. 



2 (1) Apical ventral segment narrow, being very strongly compressed from 



the sides into a strou.'' median carina. 



