NO. 1206. ICHNEUMON FLIES— ASHMEAD. 85 



vexly swollen at apex, or at ]ea.st not gradually thickened poste- 

 riorly; hind tarsi normal, very rarely thickened. 



Tribe V. Campoplegini. 



5. Spiracles of first abdominal segment placed before the middle; transverse median 



nervure in hind wings broken above the middle, rarely at or below 

 the middle; abdomen in males not ending in two spines, the clasp- 

 ers often large, broad. 



Abdomen petiolate, rarely subsessile; areolet in front wings triangular, or 

 oblique rhomboidal, the second abscissa of the radius most fre- 

 quently strongly curved at its origin and forming with the first 

 abscissa an acute angle (very straight and forming an obtuse angle) ; 

 transverse median nervure in hind wings broken most frequently 

 above the middle, rarely at or below the middle; thorax shining, 

 most frequently impunctate; parapsidal furrows present, but deli- 

 cate; ovipositor exserted Tribe VI. Paniscini. 



Alxlomen sessile or subsessile; areolet in front wings, when present, rather 

 large, rhomboidal, the second abscissa of radius straight, rarel;^ 

 slightly curved at its origin, and forming with the first an obtuse 

 angle; transverse median nervure in hind wings broken far above 

 the middle, very near the apex; thorax usually opaque or i:»unctate, 

 rarely smooth and shining; parapsidal furrows wanting or only 

 slightly and vaguely defined anteriorly; ovipositor usually short, or 



not at all exserted Tribe VII. Banchini. 



Spiracles of first abdominal segment placed at or a little beyond the middle; 

 transverse median nervure in hind wings straight, or broken beloiv 

 the middle; abdomen in males ending in two long spines; abdomen 

 petiolate, polished, the o\'ipositor distinctly exserted, but never 

 very long; areolet in front wings rather large, rhomboidal. 



Tribe VIII. Mesochorini. 



6. ]\Iiddle vein in hind wings wanting or obliterated toward base; basal nervure 



distinctly thickened at apex or Avhere it unites with the costa or 



parastigma Tribe IX. Porizonini. 



Middle vein in hind wings distinct, not obliterated toward the base. 



Hind femora beneath armed with a strong tooth beyond the middle. 



Tribe X. Pristomerini. 

 Hind femora beneath simple, unarmed. 



Head not small; clypeus neither convex nor compressed from the sides; 

 hind tibiae normal, not constricted at the base. 



Tribe XL Cremastini. 



Head usually small; clyj^eus convex and usually compressed from the sides; 



hind tibiai thickened and usually more or less constricted at base. 



Tribe XII. Plectiscini. 



Tribe I. HELLWIGIINI. 



1868. Hellwigioidx, Family 6, F(3rster, Verb. d. naturh. Ver. pr. Rheinl., XXV, 



pp. 141 and 149. 

 1887. Ilehcifjibm, Tribus, Thomson, Opus. Ent., XI, p. 1048. 

 1894. HeUwiffimi, Tribe VI, Ashmead, Proc. Ent. Soc. Wash., Ill, p. 277. 



The essential characters for the ready recognition of this tribe have 

 been brought out prominently in ni}^ table of tribes and need not be 



