134 E. T. CRESSON. 



Posterior legs black, their femora ferruginous 141. iiif^olens. 



Posterior legs ferruginous 137. riifiveiitris, var. 



Thorax more or less ferruginous. 



Posterior legs entirely black; head black 143. (lorsalis. 



Posterior legs, except coxse, entirely ferruginous; head ferruginous; sec- 

 ond abdominal segment sometimes black at base. ..144. I^ewisii. 

 Thorax, legs and entire body ferruginous. 



Antennae black, base sometimes ferruginous 145. purpuripcnnis. 



AntcnnsB ferruginous, apical third black, middle joints tinged with 



yellowish 147. conipar. 



Wings hyaline or subhyaline. 

 Thorax entirely black, 



Scutellum black 156. virginicns. 



Scutellum white or yellow. 

 Abdomen with base of segments more or less black. .159. eana<Ieiisis. 

 Abdomen except base of first segment entirely ferruginous. 



Apex of abdomen without pale spot; antennae with short, thick-set 



joints 168. Tuncstas. 



Apex of abdomen with pale spot. 



Antennal jonit 3 longer than 1 and 2 together IGl. f tiscirrons. 



Antennal joint 3 not longer than 1 and 2 together. 



Posterior tibise whitish on basal half. 164. tlltiinuiS. 



Posterior tibiJB ferruginous, black at tips 165. vivax. 



Thorax black, metathorax more or less marked vvith white... 170. W-albuui. 

 Thorax black, meso- and sometimes metathorax more or less ferruginous. 

 Posterior tibiee ferruginous, black at tips. 



Apex of abdomen without pale spot 160. iii!«»tabilis. 



Apex of abdomen with pale spot. 



Posterior coxfe black; gastrocceli deep, fovei form 169. niaitis. 



Posterior coxae ferruginous; gastrocceli very transverse 163. volox. 



Posterior tibise with pale annulus. 



Length of body .40 inch 173. signalipes. 



Length of body .25 — .30 inch 174. aitniilipes. 



Posterior legs, except sometimes the coxae, entirely ferruginous. 

 Antennae with pale annulus. 



Scutellum yellow; abdomen with segments one to four more or less 



black at base; antennae and legs robust 177. seininigcr. 



Scutellum ferruginous; abdomen entirely ferruginous; antenna; and 



legs slender 178. flebilis. 



Antennae pale ferruginous, black at tips, subrobust; abdomen entirely 



ferruginous 180. Iiioinalus. 



Antennae, except first joint, entirely black, slender; spot on i)leura and 



abdomen entirely, ferruginous 179. scqiiax. 



Thorax ferruginous, rnesothorax only black 162. coufirniiitiis* 



Thorax entirely ferruginous, or with black sutures or stains. 



Abdomen with one or more segments banded or margined with black. 

 Antennae long, slender, basal joints of flagellum elongate, cylindrical. 

 Third joint double the length of fourth ; segments three to five of abdo- 

 men narrowly margined at apex with black. ..181. SubriilvilS. 

 Third joint slightly longer than fourth ; broad band at base of segment 

 three of abdomen, and spot on disc of two, black... 182. ccstus. 



