514 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 93 



39. Mesopraescutum with bristles distributed over its entire surface, as in 



fig. 19, e hagenowii (Ratzeburg) (p. 554) 



Mesopraescutum with bristles at lateral margins only. 



cassidis, new species (p. 555) 



40. Body elongate, slender; head rounded, with antennae inserted approximately 



in center of frons, well above level of ventral margins of compound eyes, 

 as in fig. 16, a; postocellar line only slightly, if at all, longer than 



ocellocular line 41 



Antennae inserted at or near level of ventral margins of compound eyes, and 

 much below center of frons; postocellar line at least one and one-half 

 times as long as ocellocular 43 



41. Body iridescent blue semiauraticeps (Girault) (p. 556) 



Body dull brown, or brown and yellow 42 



42. Ocelli in a nearly straight line; apex of scape reaching level of anterior 



ocellus, first funicle segment twice as long as broad. 



longicorpus (Girauit) (p. 557) 

 Ocelli forming a low triangle, apex of scape exceeding level of vertex ; 

 first funicle segment three times as long as broad. 



Oklahoma (Girault) (p. ■" 57 I 



43. Mesoscutellum bearing five pairs of bristles, three of which are located along 



posterior margin of this sclerite; mesopraescutum bearing several rows of 



Silver-colored bristles at each lateral margin argyrus, new species (p. 558) 



Mesoscutellum almost always bearing only two pairs of bristles, sometimes 

 with three or four pairs 44 



44. Mesoscutellum with four pairs of bristles: mesopraescutum with three rows 



of bristles at each lateral margin ; length of malar space two-thirds as great 

 as height of compound eye, antennae inserted slightly ventrad of level of 



ventral margins of compound eyes phegus, new species (p. 559) 



Mesoscutellum with two or three pairs of bristles 45 



45. Length of malar space slightly greater than height of compound eye ; antennae 



inserted slightly ventrad of level of vetral margins of compound eyes, apex 

 of scape reaching level of vertex; abdomen elongate, slender, twice as long 

 as thorax and propodeum combined ; marginal vein twice as long as stig- 



mal gigas, new species (p. 5G0) 



Length of malar space less than height of compound eye 46 



40. Color black with faint green or blue-green iridescent reflections ; body elongate, 

 narrow; gaster one and three-fourths to twice as long as thorax and pro- 

 podeum combined; antennae inserted slightly ventrad of level of ventral 

 margins of compound eyes; length of malar space four-fifths as great as 



height of compound eye holbeini Girault (p. 561) 



Not having that combination of characters 17 



47. Mesopraescutum with bristles distributed over entire surface, as in fig. 19, e; 



or, at least, with more than two rows of bristles at each lateral margin__ 43 

 Mesopraescutum with one or two rows of bristles at each lateral margin__ 56 



48. Bristles of mesopraescutum distributed over entire surface in a rather hap- 



hazard manner; some bristles contiguous with mesal furrow, as in fig. 



19, e 49 



Mesopraescutal bristles not present on meson; three to five rows of bristles 

 present at each lateral margin, but none contiguous with mesal furrow, 

 as in fig. 10, b, d 52 



49. Metatibiae almost entirely dark brown or black— modestus Howard (p. 562) 

 Metatibiae entirely light yellow or white 50 



