192 THE CANADIAN ENTOMOLOGIST. 



20. Scopal hairs long and curved < 21. 



Scopal hairs short and straight 22. 



Abdomen covered with pale hairs except at apex 23. 



Abdomen only partly covered with pale hairs. 

 First abdominal segment with pale hairs. 



Posterior legs black or nearly saccata. 



First and second abdominal segments with some pale hairs; 

 scopa pale. 

 Clypeus rather sparsely punctured, especially in the 



middle hemileuca. 



Clypeus rather densely purictured clypeoporaria. 



22. Scopa thinly pubescent advarians. 



Scopa densely pubescent IVashijigtoui. 



23. Clypeal punctures fine and dense. 



Nearly all scopal hairs white. 



Pubescence on abdomen abundant ; anal fimbria white, tinted 



with brown .... moesta. 



Only the lower half of the scopa with pale or 



white hairs . . , albililrta =perarmata. 



Clypeal punctures large and sparse. 



Dorsulum with sparse pubescence ; first two segments of abdomen 



no more pubescent than the remaining segments Harveyi. 



Dorsulum with abundant pubescence ; first two segments of 

 abdomen distinctly more pubescent than the remaining 

 segments asmi. 



24. Fovea about one-half as wide as the distance between the eye and 



lateral ocellus 26. 



Fovea distinctly broader than one-half the distance between the eye 

 and lateral ocellus. 



Process of labrum -ordinary, truncate or rounded 25. 



Process of labrum various, as long as broad at base, quadrate, 



finger-shaped, emarginate or pointed 27. 



35. Clypeus with a distinct median impunctate space or the punctures 

 sparse. 

 A clearly defined median impunctate space on the 



clypeus medionitens. 



No clearly defined median impunctate space on the 



clypeus sejiiipolita. 



