420 



— Smallei" species, 5 mm. in length; basal joint of fore tarsi about a 



fourth longer than fore tibise. 20. claripennis. 



27. Large species, considerably more than 9 mm. in length 28 



— Smaller species, at most 8 mm. in length 30 



28. Fore tarsi of male without long hairs ; mesonotum opaque, pale 



green, with deep black vitt^e in both sexes, their surfaces slightly 

 shining; hypopygium stout (PI. XXXIII, Fig. 1) . . . .26. tentans. 



— Fore tarsi of male with long hairs on posterior surface ; mesonotum 



opaque yellowish green, with gray or ferruginous vittae 29 



29. Mesonotum of male with ferruginous vittae; hypopygium as in 



Figure 4, Plate XXXIII ; fore legs of female with long hairs 

 which exceed in length the diameter of the joints which bear 

 them 27. ferrugineovittatus. 



— Mesonotum of both sexes with gray vittse ; apical portion of lateral 



arm of hypopygium as in Figure 17, Plate XXXIV; fore legs of 

 female with the hairs shorter than the diameter of the joints 

 which bear them 28. plumosus. 



30. Males 31 



— Females 43 



31. Fore tarsi with long hairs 32 



— Fore tarsi without long hairs 37 



32. Basal joint of fore tarsi not more than a tenth longer than fore 



tibiae 33 



— Basal joint of fore tarsi more than a tenth longer than fore 



tibiae 34 



33. Basal joint of fore tarsi slightly longer than fore tibiae ; third vein 



ending as far in front of apex of wing as fourth does behind it ; 

 hypopygium as in Figure 3, Plate XXXIII 29. viridis. 



— Basal joint of fore tarsi slightly shorter than fore tibiae ; third vein 



ending distinctly farther from apex of wing than fourth does; 

 hypopygium as in Figure 2, Plate XXXIII. . . .30. pseudoviridis. 



34. Basal joint of fore tarsi at most slightly more than a third longer 



than fore tibife ; hypopygium with superior and inferior processes 

 well developed 36 



— Basal joint of fore tarsi nearly one half longer than fore tibiffi; 



hypopygium with superior and inferior processes very short ... 35 



35. Apices of fore tibiae and of basal joint of fore tarsi narrowly 



browned ; hypopygium as in Figure 18, Plate XXXIV 



31. ahhreviatus. 



— Apices of fore tibiae and of basal joint of fore tarsi conspicuously 



and broadly blackened ; hypopygium as in Figure 6, Plate 

 XXXIII . ." * ." 32. frequens. 



36. Basal joint of fore tarsi slightly more than a third longer than fore 



tibiae (85: 63) ; hypopygium identical with that of ferrugineovit- 

 tatus (PI. XXXIII, Fig. 4) 33. stigmaterus. 



