130 E. T. CRESSON. 



Ichneumonides oxypygi. 



Scutellum more or less flat, or convex and then gradually sloping to apex; 

 nietathorax rarely bispinose ICHNEUMON. 



Scutellum strongly elevated or gibbous, abruptly declivous behind; nietatho- 

 rax always bispinose H0PH8MENUS. 



ICHNEUMON, Linn. 



Under this subgenus, there are at present over two hundred species 

 to record, many of which, on future study and observation, will doubt- 

 less prove to be varieties or sexes of other species already described. 

 In the somewhat difficult task of tabulating such a large number of 

 species it has been found more convenient, and in fact necessary, to 

 separate the sexes ; and color, although quite variable at times, has 

 been found more constant and satisfactory for the principal divisions 

 than form or sculpture. 



In the females of many species there will be observed on the 

 posterior coxfc beneath, (generally situate near the tip and seen more 

 readily from a lateral view), a scopa or patch of short, more or less 

 dense, brush-like pubescence ; this, while constant in some species, 

 is variable in others, being sometimes distinct or entirely wanting in 

 specimens of the same species. The sculpture of the thorax has 

 little or no significance, while that of the first and second abdominal 

 segments is of some specific value. The sculpture of the postpetiole, 

 or apex of first segment, which is either rugose, aciculated, punctured 

 or smooth, and the shape and depth of the gastrocceli, or basal foveae 

 or depression on each side of second segment, when present, are gene- 

 rally of considerable importance in separating the species. These 

 characters when found to be constant, have been used to advantage 

 in making up the following tables. 



FEMALES. 

 Abdomen black or blue, without pale bands or spots except sometimes on apex 



of first or last segments Section I. 



Abdomen black, marked with white or yellow spots or bands, and sometimes 



varied with ferruginous Section II. 



Abdomen ferruginous, apex black Section III. 



Abdomen ferruginous or fulvous; the first and base or apex of two or three 



following segments sometimes more or less black Section IV. 



