138 



E. T. CRESSON. 



Posterior coxae black. 

 Apical segments of abdomen black, immaculate. 

 Scutellurn black. 



Face yellow; abdomen robust, opaque 66. siinilaris. 



Face black; abdomen rather slender and smooth beyond second seg- 

 ment; wings fuscous 07. petlalis. 



Scutellurn yellow Ambly. luctus. 



Apical segment of abdomen fulvous; face yellow 64. sipiciilis. 



Apical segment of abdomen white; face black with sides narrowly pale; 

 scutellurn white posteriorly 69. lielvipes. 



Section II. — Abdomen black spotted or banded with white beyond first segment and 



before apex. 



Second segment only with two white spots 70. bioculatus. 



Second and third segments each with a spot on each side, and narrow apical 



margins of third and following segments, white 77. ConsignatilS. 



All the segments narrowly margined at apex with white. 



Metathorax and pleura black, with pale markings; posterior femora black; 



antennae without pale annulus 7S. albomarginatiis. 



Metathorax and pleura ferruginous, with pale markings; posterior femora 

 ferruginous; antennae with pale annulus 79. ISlandii. 



Section III. — Abdomen black and yellow, sometimes varied with ferruginous. 



Apex of abdomen black, with a white spot on last segment 74. texanus. 



Apex of abdomen black, immaculate. 



Antennse with pale annulus 75. suadiis. 



Anteunse without pale annulus. 

 Third segment with indistinct yellowish band at base; wings fuliginous; 



metathorax entirely black 58. Bronteiis, var. 



Third segment with broad yellow band shading into fulvous at apex; 



wings hyaline; metathorax white at tip SO. Dakota. 



Second and third segments entirely yellow 81. pictif'roilS. 



Second and third segments yellow tinged with fulvous, third segment with 



large blackish mark at base 82. bipiinctatus. 



Second and third segments yellow, varied at base and apex, and some- 

 times centrally, with ferruginous or fuscous 84. Tersabilis. 



Second and third segments yellow, more or less black at apex. 



Abdomen shining, postpetiole smooth and polished, gastrocoeli linear; 



metathorax entirely black 83. Wilsoni. 



Abdomen opaque, postpetiole aciculated, gastrocceli transverse ; meta- 

 thorax generally more or less yellow 85. COIlies. 



Second and third segments yellow, more or less black at base. 

 Gastrocceli deep. 



Size medium, .60 inch 86. trizoiiatns. 



Size small, .35 inch 91. parvus. 



Gastrocosli shallow, subobsolete 92. vcscns. 



Second and third segments yellow, narrowly black at apex, fourth segment 



ferruginous, postpetiole fulvous 100. salvns. 



Second to fourth segments more or less yellow, sometimes also postj)etiole. 

 Base of segments 2 — 4 yellow, apex black, first segment entirely black. 

 Gastrocceli deep, the yellow band on fourth segment interrupted 

 medially; size rather large 85. coiues, var. 



