NORTH AMERICAN HYMENOPTERA. 223 



on apical two-thirds, greenish basally. where it is narrowly streaked with 

 yellow ; hind tibife at base and a line externally, yellow. Size small 



8 mm.) teiiiii»«. 



Medial femora yellow at apex only. Size larger 39. 



39. — No tooth or prominence at base of outer margin of fore femora, the latter 



with an internal spine only 40. 



A tooth or prominence at the base of outer margin of fore femora ; markings 

 yellow; medial legs with trochanters and greater part of femora black ; 

 metanotum marked with yellow ; markings segments 1-3 separated, 

 those on segment 1 sometimes meeting ; dorsulum compactly'punctured . 41. 

 40. — In shape the fore femora are triangular, being almost as broad at base as they 

 are long: first joint of medial tarsi not much longer than the remaining 

 joints united ; markings white ; medial legs entirely, coxse excepted, 

 scutellum and postscutellum whitish ; marks on abdomen all touching 



within pallidum. 



In shape the fore femora somewhat oblong, flattened, fully three times 

 broader than long ; first joint of medial tarsi about one-third longer than 

 remaining joints united; markings yellow; greater part of medial 

 femora black: marks on scutellum and postscutellum; marks on seg- 

 ments 1-3 separated cribreilirer. 



41. — Anterior femora at the base of outer margin with a strong production, which 

 is somewhat bifurcate at apex ; space between hind ocelli much less ttian 

 that between them and the nearest eye-margin : tibial shield basally 

 yellow, posteriorly greenish, and streaked and dotted with yellow. 



pleura] is. 

 Anterior femora at base of outei- margm with a sharp tooth ; space between 

 hind ocelli but little less than that between them and the nearest eye- 

 margin ; tibial shield in greater part deep black, basally greenish and 



with broken streaks of yellow largior. 



42. — Flagellum short, stout, not much more than twice the length of the scape-43. 

 Flagellum long, slender, at least half as long again as twice the length of 



the scape 45. 



43. — Mesosternum clothed with a dense, white pubescence ; mesopleurse in addi- 

 tion to the punctuation, with a delicate striation ; medial tarsi rather 

 strongly flattened (hind tarsi blackish ; tibial shield brownish yellow at 



base and irregularly mottled with darker) teuuiglossus. 



Mesosternum naked; mesopleurse not striated; medial tarsi not flattened; 

 tibial shield brownish, with several yellow, longitudinal stripes medi- 

 ally 44. 



44. — Mesopleura; sparsely and rather subtilely punctured ; fore femora beneath 

 yellow and greater part of tibiae of that color ; metanotum black. 



tiiiuidiis. 

 Mesopleurse rather closely and strongly punctured ; fore femora entirely and 



greater part of tibiae, black ; metanotum yellow iiicerSus (?). 



45. — Mesopleurse and scutellum coarsely striated ; wings on apical half subfus- 



cous (no yellow on thorax; tibial shield greenish, dotted with whitish or 



yellowish, and broadly bordered anteriorly with black)- . • -Tirgaf us. 



Mesopleurpe (episternum excepted in one case) iiot coarsely striated, at the 



most striato-punctate above 46. 



TRANS. AM. ENT. SOC. XXII. JUNE. 1895. 



