222 WILLIAM J. FOX. 



30. — Head finely ]ninctured above, shining, not or indistinctly striated ; pronotum 

 declining strongly to the sides, not as wide as the occipital margin of 

 head, widely, though not very strongly, furrowed ; middle femora be- 

 neath and greater pai-t of middle tibite, black ; no spots on scutellum. 



siugularis. 



Head strongly striato-punctate above, subopacfae ; pronotum declining but 



little toward the sides, as wide as the occipital margin of head, deeply 



furrowed ; greater part of medial femora and their tibia; entirely, yellow ; 



scutellum with yellow spots trapezoideus. 



3L — Abdomen not petiolate, more or less sessile 32. 



Abdomen petiolate, the petiole more or less nodose at apex 64. 



32. — Abdomen always spotted or marked with yellowish 33. 



Abdomen not spotted, entirely black 53. 



33. — Fore tibite bearing a ^arge vari-shajjed shield 34. 



Fore tihife without a shield, simple 48. 



34. — AntennfE more or less dilated, the joints more or less prolonged beneath; 



fifth joint of fore tarsi with a peculiar appendage 35. 



Antennfe simple , fifth joint of fore tarsi without an appendage 42. 



35. — First joint of flagellum broadened to meet the second, longer than the pedi- 

 cellum, the four terminal joints as long as or longer than the four pre- 

 ceding joints united, none of the joints with a long, acute appendix on 



outer margin .36. 



First joint of flagellum not broadened to meet the second, not longer, though 

 broader, than the pedicellum, the four terminal joints together about as 

 long as the three preceding ones united, joints 2 6 with a large appendix 

 on outer margin, that on joint 2 narrowest and most curved, that on 

 joint 6 broadest and not curved (tibial shield brownish, yellow basally, 

 covered with pale dots, which are at extreme base and apex, linear; scu- 

 tellum and raetauotum black ; first abdominal segment banded ; medial 

 legs, coxte excepted, entirely yellow, the first joint of their tarsi about 

 twice as long as the remaining tarsal joints united) argiis. 



36. — First joint of flagellum with a bunch of pale, curled hair beneath 38. 



First joint of flagellum not hirsute beneath 37. 



37. — Tibial shield very large, fully two-thirds as long as the thorax, its under 

 margin (the fore leg is supposed to be stretched out its entire length) 

 with a medial lobe, or, iu other words, is twice siuuated, black at base, 

 streaked with paler, the apical two-thirds yellowish, with three large 

 black streaks ; flagellum broadest by far at the base, gradually narrowed 

 to the apex ; first joint of medial tibiae distinctly more than one-third 

 times longer than the remaining joints united ; medial femora with a 



yellow streak before and behind liitipe!^ (= coloradensis) , 



Tibial shield comparatively small, not more than one-third as long as the 

 thorax, its outer margin without a medial lobe, being once sinuated, the 

 greater portion entirely black, toward the base, however, yellowish, 

 streaked with darker; flagellum not much broadened, but widest me- 

 dially and narrowed basally and apically ; first joint of medial tibiae 

 somewhat less than one-third times longer than the united remaining 

 joints ; medial femora entirely black inediu.*). 



38. — -Medial femora streaked with yellow anteriorly and posteriorly (scape entirely 

 black behind ; scutellum and metauotum black ; tibial shield brownish 



