O E. T. CRESSON. 



20. Second segment of abdomen black, ornamented with silvery, golden or cupre- 



ous pubescent markings 21. 



Second segment black, with two or four smooth or punctured aud shining or 



opaque spots 35. 



Second segment black, with a narrow, smooth, polished yellow band at 



apex 74. 



Second segment black, with two smooth, polished yellow stripes 75. 



21. Head unusually large, quadrate or subquadrate, as large or lai'ger than the 



thorax and broader; space behind eyes very long, posterior angles of 



head more or less acutely carinate 22. 



Head not unusually large, not as large as thorax and not or rarely broadei'...39. 



22. Head toothed beneath 24. 



Head not toothed beneath 23. 



23. Head black, with pale pubescent stripe behind each eye; antennte and legs 



black ; second segment of abdomen above with a median pale golden 

 stripe, continued on first segment, but abbreviated posteriorly, and a 

 transverse spot of same color on each side behind middle; two entire 

 silvery pubescent stripes on thorax: form robust. .23. harpy ia Gerst. 

 Head golden pubescent; antennae, first segment of abdomen and legs ferru- 

 ginous; first and second segments broadly pale golden on apical mid- 

 dle, continued narrowly on lateral margin ; two abbreviated silvery 

 stripes on thorax ; form not robust 24. vera Cress. 



24. Second segment of abdomen above with a discal spot of cupreous, golden or 



silvery pubescence 25. 



Second segment with a pale ochraceous spot on apical middle, continued in a 

 slender stripe to apex of abdomen ; first segment with a discal ochra- 

 ceous spot 28. 



25. Head entirely black above 26. 



Head black, with two silvery or golden pubescent spots or lines behind the 



eyes 27. 



26. Discal spot on second segment of abdomen above rounded and cupreous ; meta- 



thorax with two pale golden pubescent stripes, extending a short dis- 

 tance on mesothorax ; cheeks beneath with a long acute tooth on each 

 side 25. cephalotes Swed. 



Discal spot on second segment rounded aud golden cupreous; two spots on 

 mesothorax, two on metathorax at base, and two indistinct spots on 

 vertex, pale golden pui)escent; head beneath posteriorly with au acute 

 tooth, the posterior margin above acutely carinate. 



26. speciilaris Gerst. 



Discal spot on second segment much smaller, oblong-ovate aud golden ; thorax 

 above entirely black ; head beneath with two long, widely separated, 

 subacute teeth, and a small tooth on cheeks beneath ; posterior angles 

 of cheeks produced into a sharply compressed tooth. 



27. spinieeps Cress. 



27. Discal spot on second segment longitudinally ovate and cupreous; sides of 



third segment and spot behind each eye, silvery pubescent; head be- 

 neath with two median approximate teeth, and a shorter tooth on 

 cheeks beneath; clypeus-with a long narrow, median, flattened pro- 

 jection, bidentate at tip; posterior angles of head, when viewed from 

 above, acute 28. centroiiiaciilata Cress. 



