G. C. DAVIS. 197 



26' Metanotiim truncate, sloping from the base 27. 



Metauotuiu not sloping directly from the base 28. 



27. Scutellum strongly elevated, often pyramidal TROGINI. 



Scutellum of the usual form, flat, or a little arched STILPNINI. 



28. Lunulse always present on second and third abdominal segments 29. 



Lunula? wanting, or at least not present on both segments at the same time. 30. 



29. Spiracles of metanotum elongate, linear or oval ICHNEUMONINI. 



Spiracles of metanotum circular PH^OGENOIJINI. 



30. Areolet pentangular, resting above with a broad base 31. 



Areolet quadrangular, triangular or wanting, seldom an irregular jjentagon ..32. 



31. Tarsal claws simple, not pectinate ALOMYINI. 



Tarsal claws strongly pectinate LISTRODROMINI. 



32. Tarsal claws pectinate; clypeus usually narrowed and nearly elliptical. 



CTENOPELMINI. 



Tarsal claws not pectinate, or with only a few strong teeth at base ; in such 



case the cl.vpeus usually extends nearly from eye to eye 33, 



33. Abdomen sessile or subsessile, with plain furrow or sharp caringe on petiole ; 



seldom subpetiolate, but if so, always with prominent carinse. 



TBYPHONINI. 



Abdomen petiolate, the petiole at base without groove or carina, at least the 



latter are never prominent MESOLEPTINI. 



Tribe METOPINI. 



1. Face with a distinct shield ; middle tibiae with a single spur 2. 



Face without a distinct shield ; middle tibiae with two spurs 3. 



2. Head small ; basal segment of abdomen fiat above ; wedge shaped ; ovijjositor 



large, long and geniculate I'liltrarius Davis. 



Head normal; basal segment of abdomen pyramidal or oval above; ovipositor 

 rarely visible Metopiiis Panz. 



3. Eyes distinctly emarginate ; parallel dorsal carinse on first three abdominal 



segments ; scutellum margined l'»»eu<loinetoi>iuN Davis. 



Eyes not emarginate 4. 



4. Face oval, elongate, clypeus wanting; abdomen broadly sessile at base. 



Tylecoiiiiius Holmg. 

 Face transverse ; clypeus more or less distinct ,5. 



5. Tarsal claws not pectinate ; clypeus scarcely separated 6. 



Tarsal claws pectinate 7. 



6. Scutellum depressed : abdominal segments (constricted at base. 



Tliibetoides Davis. 

 Scutellum elevated ; segments of abdomen not constricted . Lietliades Davis. 



7. Abdomen broadly sessile, segments 2-4 constricted at base ; scutellum elevated ; 



cl.ypeus large, protuberant C^atoceiitrus Walsh. 



Abdomen petiolate, clavate ; scutellum broadl.y oval, margined. 



'Spliiiictus Grav. 



CITLTRARIUS n. g. 



Characterized by having the ba.sal segineut of abdomen .short, 

 wedge shaped, upper anterior portion broad, flat, t?lightly concave; 

 the thorax is nearly spherical, produced by the widening of the 



TRANS. AM. ENT. SOC. XXIV. JULY. 1897. 



