AMERICAN HYMENOPTERA. 141 



Posterior legs black, their tibi£B with white line or spot laterally towards 



base; seutclhim wliite; scape entirely black 139. deviiictor. 



Posterior legs black, their femora and tibiae ferruginous; scutellum black. 



Abdomen brown-ferruginous 137. rufiveutriM, var. 



Abdomen and legs entirely ferruginous. 



Thorax black, mesothorax, scutellum and disc of metathorax ferruc;i- 



nous US. criidus. 



Thorax entirely ferruginous 146. ciipitu.s. 



Antenure with pale annulus. 



Head and thorax black ; abdomen narrow, subcylindrical, segments not 



constricted at base 141. injSoIeil»i. 



Head and thorax ferruginous, metathorax and pleura sometimes blackish ; 



abdominal segments constricted at base 149. trogiroriiiis. 



Wings hyaline or subhyaline, sometimes pale ferruginous. 

 Antennae without pale annulus. 

 Abdomen ferruginous, basal margin of segments more or less black. 

 Head and thorax black. 

 Posterior legs black, their tibiae yellow, black at tips. 



First abdominal segment entirely black 151. niiiniOHUS. 



First abdominal segment black, yellow at apex 104. crcpcfUS. 



Posterior legs ferruginous; mesothorax more or less dull ferruginous. 

 First and base of second segments of abdomen black; metathorax 



entirely black 152. (la!«cns. 



First and second segments of abdomen entirely ferruginous; meta- 

 thorax more or less marked with ferruginous 150. diflicilis. 



Head and thorax ferruginous, pleura generally black beneath. 



Gastrocoeli deep, fovei form; postpetiole acieulated 185. loilgiilus. 



Gastrocoeli linear; postpetiole smooth and polished. ..186. volcns, var. 

 Abdomen ferruginous, first segment only black. 

 Scutellum black. 



Sides of face white 158. Saiiudersi. 



Face entirely yellow Ambly. fraternus. 



Scutellum pale at apex; face entirely whitish 157. vultus. 



Scutellum entirely white or yellow. 

 Posterior femora black. 

 All the coxae black. 



Posterior trochanters white 154. TillllleiltllS. 



Posterior trochanters black Ambly. nubivagus. 



Four anterior coxae white 153. jillapMiiM. 



Posterior femora ferruginous 155. nuuciiis. 



Abdomen entirely ferruginous. 



Posterior femora black; thorax black Ambly. nubivagus, var. 



Posterior femora ferruginous; thorax mostly ferruginous. 

 Head black and yellow. 



Mesothorax black 176. libeilS. 



Mesothorax ferruginous 199. ulili^i. 



Head ferruginous, face yellow 191. !>i€*il>iliM. 



Head entirely ferruginous 195. rilbivuudUH. 



Antennae with pale annulus. 



Posterior coxae black, or black and white. 

 Gastrocojli foveiform, transverse or oblique, distinct. 

 Abdomen immaculate, first segment except apex black 166. Tafer. 



