—37— 



Metathorax short; clypeus incised in the middle at apex; mesothoracic episterna 



reaching to coxae Subgenus Cecidostiba Thomson. 



Metathorax not short, often with a fold and often also with a slight transverse 



carina; head and thorax usually rigido-pubescent 



Subgenus Ccenacis Foerster. 

 Wings with a small or medium-sized stigmal.club; head often triangular and with 

 prominent eyes; collar often not at all or slightly separated. 

 Head triangular, narrowed towards mouth, face not rigido-pubescent; eyes 

 large, convex, round; presternum large; mesosternal groove distinct; the 

 round spiracles remote from postscutellum. 

 Collar acute. 



Vertex acute in the middle Subgenus ^troxys Westwood. 



Vertex not acute in the middle. 



First funicle joint small Subgenus Cricellius Thomson. 



First funicle joint large Subgenus Holcaeus Thomson. 



Collar not separated Subgenus Stinoplus Thomson. 



Head usually with bulging cheeks; eyes not prominent; sternal groove obsolete; 

 vertex in the middle not acute; metathoracic spiracles usually large, oval; 

 collar not at all or slightly acute; first funicle joint longer than pedicel. 



Collar broad; head with bulging cheeks; left mandible 3-dentate 



Subgenus Habrocytus Thomson. 



Collar narrow in the middle; head narrowing towards mouth; both mandibles 



3-dentate Subgenus Spintherus Thomson. 



Genus ISOCYRTUS. 



Eyes hairy; metathorax long, its apical border with large punctures; abdomen with 



its second segment smooth at base, the third not small. . . 



Subgenus Isocyrtus Walker. 

 Eyes smooth; second abdominal segment with a dense fringe on sides, not large; 

 third small. 

 Vertex broad ; head short, thick, eyes round and prominent; funicle of the ^ 



antennae alternately white Subgenus Polycelis Thomson. 



Vertex not broad, eyes sub-ovate Subgenus Trichomalus Thomson. 



Genus PTEROMALUS. 



Eyes hairy; antennae incrassate; vertex sharp in the middle. 



Wings maculate; U abdomen short, ovate; tibiae with rigid bristles 



Subgenus Halizous Thomson. 



Wings immaculate; abdomen rotund Subgenus Trichoglenus Thomson. 



luooth. 



First funicle joint small Subgenus Meraporus Walker. 



First funicle joint large. 



Metathorax with a large sub-globose neck; flagellum of antennae filiform; G ab- 

 domen ovate-acute; postmarginal vein longer than stigmal. 

 Wings entirely pubescent; head with concave cheeks; neck of metathorax 



smooth Subgenus Catolaceus Thomson. 



Wings with a large clear spot; neck of metathorax punctate 



Subgenus Pteromalus Swederus. 

 Metalhora* usually with a very small neck; postmarginal vein often shorter than 

 stigmal, very rarely longer; 9 abdomen usually rotund. 



Entomologies Americana, Vol. II. 6 May 1886. 



