398 M. W. R. de V. GRAHAM 



weakly convex, frenum marked off by a rather distinct impressed line 



ROHATINA Boucek (p. 700) 

 Propodeal nucha represented merely by a lunate, transversely-aciculate to 

 smooth strip. Genae not distinctly produced ventrad of anterior margin 

 of clypeus, the latter with a median tooth or tubercle and usually an 

 angular projection on either side of it. Thorax arched dorsally ; scutellum 

 convex, its frenum not very distinctly marked off 



STENOMALINA Ghesquiere (p. 600) 



83 (81) Oral fossa greatly enlarged (Text-figs. 337, 338), so that genae are very short, 



breadth of oral fossa 5 to 30 times the malar space ..... 84 



Oral fossa not greatly enlarged, its breadth at most about 3-5 times the 



malar space ........... 86 



84 (83) Mandibles (Text-fig. 338) small, separated from the gena by a large hemi- 



spherical pit, which appears to be membranous 



PTEROMALUS Swederus (p. 488) 

 and HABROCYTUS Thomson (p. 494) 

 Mandibles (Text-fig. 337) large, the base of each mandible forming a flat or 

 convex lamina, whose rounded edge fits closely to the edge of the gena or is 

 separated from it only by a narrow lunate space ..... 85 



85 (84) Anterior margin of clypeus broadly and shallowly emarginate. Antennae 



with funicular segments quadrate . HABROCYTUS Thomson (p. 473) 



- Anterior margin of clypeus moderately deeply incised. Antennae with 



funicular segments, except sometimes the sixth, somewhat longer than 

 broad PS YCHOPHAG US Mayr (p. 473) 



86 (83) Anterior margin of clypeus (Text-figs. 307, 361) deeply and rather narrowly 



incised medially, sometimes bidentate ....... 87 



- Anterior margin of clypeus more broadly and shallowly emarginate (Text- 



figs- 394. 435. 450, 457. 4 6 4. 49°, 523-527. 529, 5 6 6, 5°8, 655) ... 94 



87 (86) Pronotum as wide or virtually as wide as the mesoscutum. Genae, just 



above bases of mandible, with a sharp edge. Head and thorax usually 



with whitish hairs. Mesepisternum sometimes wholly reticulate . . 155 



- Either pronotum distinctly less wide than the mesoscutum ; or else genae 



without a sharp edge, and vertex and dorsum of thorax, excluding the 

 propodeum, with dark hairs. Mesepisternum with a partly to entirely 

 smooth area below the base of the hind wing ..... 88 



88 (87) Propodeum (cf. Text-fig. 360) with a reticulate nucha which occupies about 



one third of the median length of the sclerite, and is not sharply defined in 

 front. Basal cell of fore wing bare, or pilose only just at its apex ; wing 

 sometimes with a trace of two fuscous clouds SPILOMALUS Graham (p. 479) 



- Either the propodeal nucha is represented merely by a narrow, weakly- 



sculptured transverse strip ; or the basal cell of the fore wing is pilose over 



at least its distal half ......... 89 



89 (88) Propodeum (cf . Text-fig. 349) with a moderately large reticulate nucha ; plicae 



nearly complete ; costula usually indicated. Basal cell of fore wing with 

 its distal half or more pilose . . ERYTHROMALUS Graham (p. 468) 



Propodeal nucha represented only by a transverse ridge, or a lunate nearly 

 smooth or weakly transversely-aciculate strip ; plicae sometimes very 

 incomplete ; costula often absent. Basal cell of fore wing most often 

 bare, extensively pilose only in some Caenacis ..... 9° 



90 (89) Clypeus reticulate. Marginal vein of fore wing slightly shorter than, or at 



most as long as, the stigmal vein. Hind tibia with two spurs. Pronotal 

 collar not margined .... CAENOCREPIS Thomson (p. 429) 



