492 Mr. G. Meade- Waldo's revision of the species oj 



23. (20) Tegulae normal. 



24. (67) Postscutellum \\ith lateral tubercles. 



25. (32) Tergite 2 with a longitudinal carina. 



26. (29) Clypeus with three conspicuous longitudinal carinae; the 



median one not reaching the apex, 



27. (28) Tergite 2 viewed from above as broad as long; pronotum. 



tegulae, scutellum, postscutellum, median segment and 

 tergite 1 (except yellow apical fascia) ferruginous. 



gambiensis, sp. n. 



28. (27) Tergite 2 viewed from above longer than broad, pronotum 



onlj' partly, tegulae, scutellum partly and tergite 1 

 laterally ferruginous silverlocki, sp. n. 



29. (26) Clypeus without longitudinal carinae. 



30. (31) Robust species; black, pronotum totally ferruginous, 



tergites 1 and 2 with lateral, ovate ferruginous marks, 



stiraspis. Cam, 



31. (30) Slender species; black, pronotum (except anterior margin 



medially) tergites 1 ajid 2 except yellow apical fasciae, 

 black, . , , sjostedti. Cam, $ ( = yngvei. Cam, ^). 



32. (25) Tergite 2 without a longitudinal carina, 



33. (44) Clypeus ($) distinctly punctate striate, clypeus {^) less 



distinctly sculptured, 



34. (39) Clypeus (o and $) pale; yellow or ferruginous, no black 



markings, 



35. (36) Abdominal segment 1 very short and broad; black yellow 



and ferruginous, a robust insect; all the tergites wath 

 yellow apical fasciae. Total length 9 mm, 



pakasae, sp, n, 



36. (35) Abdominal segment 1 more slender, a distinct constriction 



between segments 1 and 2, 



37. (38) Tergites 1 and 2 with narrow yellow apical fasciae ; terminal 



segments ferniginous whiteanus. Cam, 



38. (37) No yellow markings; tergites 4-6 entirely black, 



dimorphus, sp, n. $, 



tergites 4-6 orange dimorphus, sp. n, var. 



(0. senex. Cam,, comes in here.) 



39. (34) Clypeus ($) black, basally yellow ; clypeus {^) yellow. 



40. (41 ) Scape, flagellum basally and tegulae ferruginous ; terminal 



abdominal segments ferruginous. . silaensis, Sauss. 



41. (40) Scape beneath yellow; tegulae whitish yellow with centre 



black; terminal segments of abdomen black, \\ith 

 yellow apical fasciae, and fascia on tergite 1 enlarged 

 laterally. 



42. (43) Median segment black, no yellow markings on surface of 



