ART. 16 NORTH AMERICAN ICHNEUMON-FLIES CUSHMAN 23 



or less distinct median carina, medially impressed or flattened 

 immediately before front ocellus; malar space rather lon*^; clypeus 

 truncate, convex with a rather broad reflexed margin ; labrum ex- 

 posed; upper tooth of mandible larger and longer than lower; 

 antennae of moderate length, rather stout, in female slightly thicker 

 and flattened below toward apex, first three flagellar joints long, 

 fourth abruptly shorter, in male tapering, flagellar joints gradually 

 shorter from base toward apex. Thorax stout, strongly sculptured ; 

 upper margin of pronotum swollen on each side of middle; notauli 

 usually distinct anteriorly, sometimes obsolete; scutellum flat or 

 weakly convex without distinct lateral carinae, lateral areas coarsely 

 striate; prepectal carina and sternauli complete, the latter foveolate; 

 propodeum short, precipitate behind, basal carina distinct, apophyses 

 rounded, spiracles large, oval; hind legs long, stout; stigma narrow, 

 radius before middle; areolet quadrate in position open behind, 

 cubitus nearly straight beyond recurrent; nervulus nearly or quite 

 interstitial; postnervu-lus broken at or slightly above the middle; 

 norvellus broken near the bottom. Abdomen in female broad fusi- 

 form, in male very small and apically more or less distinctly com- 

 pressed; postpetiole, especially in female, broad, spiracles far beyond 

 middle of segment; sheath much shorter than abdomen; ovipositor 

 stout, compressed, subsagittate and serrate both above and below 

 at apex. 



Seven North American species are known, distinguishable by the 

 following key: 



1. Hind coxae red or red and yellow 2 



Hind coxae "black and yellow or black, red, and yellow 5 



2. Notauli obsolete ; first tergite pale with a black spot on postpetiole. 



texanus (Aslimead). 

 Notauli distinct ; first tergite red with or without yellow apical band 3 



3. Anterior and posterior orbits broadly yellow, thorax profusely marked with 



yellow, mesopleurum largely yellow audax (Cressou). 



Orbits at most narrowly yellow ; thorax with only small yellow spots, meso- 

 pleurum very largely or entirely black 4 



4. Orbits narrowly yellow ; metapleurum immaculate ; second tergite red at apex. 



saundersi (Cresson). 



Orbits immaculate; metapleurum marked with yellow, second tergite yellow 



at apex ?armatus (Provancher). 



5. Abdomen black and white 6 



Abdomen red abdominalis, new species. 



6. Mesosternum with only a small yellow spot on each side near sternauli ; 



diameter of ocelli in male little more than half ocell-ocular line. 



candidus (Cresson) 

 Mesosternum in female with a large yellow spot on each side of middle, the 

 two forming a jew's-harp-shaped figure, in male largely yellow; diameter 

 of ocelli in the male fully three-fourths ocell-ocular line fortis (Cresson). 



