104 ENTOMOLOGICAL SOCIETY 



throughout aud widening posteriorly ; in some species, however, narrow 

 ing uniformly from the base to apex, which is somewhat compressed ; 

 ovipositor capable of being almost entirely redrawn into the abdomen, 

 and generally of small size occasionally exserted, however, and large 

 and powerful. The males have attached to the terminal ventral plate of 

 the abdomen two curved appendages, forming a sort of pincers, which is 

 supposed to be of service in copulation. Legs medium, posterior 

 femora thickened ; tarsi longer than tibiae, which are armed with two 

 spurs at tip. 



Metopius rileyi, n. sp. <j? Black ; spot beneath the antennae, scape 

 beneath, line on inner orbit, line below base of wings, apex of scutelluin 

 and line behind, two spots at side of meta-thorax apex of all the abdo 

 minal segments, exterior of anterior tibiae and apex of posterior femora, 

 lemon yellow ; base and apex of antennae and legs fusco-ferruginous, 

 posterior femora almost black, trochanters reddish ; antennae one-third 

 length of body, thickened toward apex ; wings fuliginous, distinctly 

 darker on anterior half, hind apical portion hyaline ; thorax and abdo 

 men coarsely punctured ; abdomen narrowing uniformly from base to 

 apex and compressed at apex, oviposits extremely large and with large 

 basal portion or support when retracted almost entirely filling the ab 

 domen. Length 8-10 mm. 



Described from five specimens all females collected in 

 Kansas and South Dakota. 



The following table will assist in the determination of the 

 North American species of this genus : 



TABLE OF SPECIES. 



i. General color black 2 



General color yellow and ferruginous .pulchellus Cr. 



2. Abdomen entirely black hageni Cr. 



Abdomen more or less marked with white or yellow 3 



3. Wings hyaline or yellowish hyaline 4 



Wings more or less fuliginous 6 



4. Abdomen mostly yellowish white or ferruginous ; scutellum basal ly 



black 5 



Abdomen mostly black ; scutellum entirely yellow. scitulus Cr. 



5. Abdomen sulphur yellow ; segments more or less black basally 



montanus Cr. 



Abdomen with base of segments 1-3 and middle of 4 ferruginous 



comptus Cr. 



Abdomen pale yellow ; base of segments 1-3 black ; remaining seg 

 ments each with two black spots at base beUns Cr. 



6. Costal margin distinctly darker 7 



Costal margin not distinctly darker 12 



