522 PROCEEDINGS OF THE ACADEMY OF [1895. 



segment and first abdominal segment not red, the last seg- 

 ment yellow pygidialis. 



16. Clypeus with a bunch of long, curved hairs in each angle ... 17 

 Clypeus with the hair at angles not very long, not curved or 



bunched 18 



17. Spine of ninth joint of flagellum large and distinct; head as 



wide as thorax ; legs black and yellow hamatus. 



Spine of ninth joint of flagellum small, indistinct; head small, 

 narrower than thorax ; legs red and yellow . . . microcephalus. 



18. Wings fuscous, the cloud in the vicinity of the marginal cell 



darker; middle segment with two yellow spots . . denticulatus. 

 Wings, except the usual fuscous cloud in the vicinity of the 

 marginal cell, subhyaline ; middle segment not spotted 

 barbatulus. 



19. Wings entirely yellowish, the marginal cell scarcely darker; 



antennae entirely rufous. Length 11 mm laminiferus. 



Wings slightly yellowish basally, the marginal cell distinctly 

 fuscous; antennae dark above mirandus. 



20. Last ventral segment emarginate or bifid, flagellum rather 



short, the last four joints enlarged, somewhat emarginate 



beneath (wings without a fuscous cloud) insolitus. 



Last ventral segment with a spine or process 21 



21. Posterior surface of middle segment coarsely sculptured ... 22 

 Only the basal enclosure of middle segment coarsely sculptured 27 



22. Eyes very broad, their width equalling more than half their 



length, the space between them at base of clypeus about 

 equal to the length of the latter in the middle; enclosure of 



middle segment irregularly rugose asperatus. 



Eyes as usual, their width scarcely equalling half their 

 length, the space between the eyes at base of clypeus 

 greater than the length of the latter in the middle; enclo- 

 sure of middle segment longitudinally ridged 23 



23. Wings with a strong yellow tinge on basal portion 24 



Wings not, or but slightly, yellow basally 25 



24. Antennae tolerably long, reaching a little beyond the scutel- 



lum; markings bright yellow atrifrons. 



Antennae shorter, not reaching beyond the scutellum; mark- 

 ings whitish albosignatus. 



25. Antennae a little thickened apically, the joints irregular (legs 



black and yellow) cancdiculatus. 



Antennae not thickened apically, the joints more even .... 26 



26. Femora except apex and tibiae in part yellowish; dorsulum 



unspotted atricomis. 



Femora, in greater part, tibiae and tarsi, reddish; dorsulum with 

 a lateral stripe or spot decorus. 



27. Only the base of the enclosure of middle segment with striae. . 28 

 The entire surface of enclosure of middle segment striated. . . 29 



