132 KANSAS ACADEMY OF SCIENCE. 



i. First basal cell hyaline; first antennal joint thickened (San Domingo). 



Feazabi, n.sp. 

 First basal cell largely inf uscated 5 



5. Second basal cell inf uscated on the proximal third or beyond 6 



Second basal cell hyaline 8 



6. Prevailing color of body black; palpi blackish 7 



Prevailing color of body brownish yellow; jjalpi reddish fulvasteb O. S. 



7. Abdomen wholly black pebtinax, n. sp. 



Sides of first and second abdominal segments red noctifeb O. S. 



8. First antennal joint distinctly thickened pachtceea, n. sp. 



First joint not distinctly thickened 9 



9. A hyaline spot in the discal cell discalis Will. 



No hyaline spot in the discal cell 10 



10. Abdomen with four continuous black stripes sequax, n. sp. 



Abdomen not striped 11 



11. The black facial callosities small, not converging inferiorly peoolivds 0. S. 



The black facial callosities large, converging inferiorly; dorsum of thorax dis- 

 tinctly vittate suBDus O. S. 



Chbysops excitans Walker. 



I have numerous specimens of this species from Washington, where it seems to 

 be common, with others from Anticosti. The latter have no reddish yellow on the 

 sides of the third abdominal segment, as is the case with the Western ones. 



Cheysops mitis O. S. 



A specimen from Montana agrees very well with the description of this species, 

 except in size (9 mm.). 



Cheysops fugax Osten Sacken. 



Specimens that I refer to this species I have from Anticosti, Massachusetts, and 

 North Park, Colorado. Some of these specimens have the thoracic poUinose mark- 

 ings and the pubescent triangles of the abdomen well indicated, so that the presence 

 of the small hyaline spot at the base of the fifth posterior cell — a slight character — 

 is about all that can be relied upon to distinguish it from C. mitis. The Colorado 

 specimen has the four posterior femora largely reddish at the base. 



Cheysops jestuans v. d. W^ulp. — Western Kansas. 



Cheysops oallidus Osten Sacken. 



A single female specimen from Washington Territory, I am unable to satisfac- 

 torily distinguish from this Eastern species. The distal part of the costa is less 

 distinctly clouded, and the cross-band less dark, especially posteriorly. The third 

 and fourth abdominal segments are less dark, leaving only a pair of basal triangles. 



Cheysops pebtinax, n.sp. 



Female: Length 9-11 mm. Front gray, the large transverse callosity shining 

 black. Face light yellow, the large callosities black, broadly coalescent above the oral 

 margin, and separated from the shining black cheeks. Antenniv black, slender, first 

 two joints reddish at base, and together about two-thirds as long as the third joint. 

 Dorsum of thorax black, with two broad, median, anterior, greenisli-gray stripes, 

 limited by three slender brown ones. Abdomen shining black, in well-preserved 

 specimens, with small median triangles of whitish pubescence, and with similar 



