LAWSON: KANSAS CICADELLID^E. 139 



A. Vertex rather angularly produced concluded. 



EE. Male valve normal, less than half the length 

 of the plates ; female segment produced, more 

 or less notched. 

 F. Yellow species; male plates not longer 



than broad. oculatus. 



FF. Greenish species, marked with fuscous; 

 male plates longer than broad. 



sylvestris. 



AA. Vertex short, disc convex or sloping, more or less rounding to front, 

 without well-defined margin. 

 B. Black species with white points on vertex, costa yellow. 



flavicosta. 

 BB. Lighter species, marked with black. 



C. Clavus reticulated between outer claval vein and suture. 

 D. Species small, not exceeding 3.5 mm. 



E. Vertex acutely produced in the middle ; elytra 

 longer than abdomen; male plates convexly 

 pointed. weedi. 



EE. Vertex more obtusely rounding. 



F. Markings dull, elytra usually, longer 

 than abdomen. Male plates convexly 

 narrowed; over 3 mm. obtectus. 

 FF. Markings bright, elytra not exceeding 

 abdomen. Male plates concavely nar- 

 rowed; 2.75 mm. long, compactus. 

 DD. Species larger, 4.5 mm. or over. inimicus. 



CC. Clavus not reticulated between outer claval vein and 

 suture. 



D. Species large, about 5 mm. long. osborni. 



DD. Species smaller, length 4 mm. or less. 



E. Vertex with two large black spots. 



punctatus. 

 EE. Vertex with four smaller black spots. 



F. Broader robust species ; face with black 



arcs. nigrifrons. 



FF. More slender species; face with light 



arcs. sonorus. 



Deltocephalus bilineatus G. & B. 



Deltocephalus bilineatus G. & B., Hemip. Colo., p. 85, 1895. 

 Deltocephalus bilineatus Bak., Psyche, viii, p. 115, 1897. 

 Deltocephalus bilineatus O. & B., Proc. la. Acad. Sci., iv, p. 200, 1897. 

 Deltocephalus bilineatus Van D., Cat. Hemip. N. A., p. 640, 1917. 



Form: Rather long and narrow. Length, 3.5 to 4 mm. Vertex as long 

 as wide, subacute at apex. Pronotum a little over twice as broad as 

 long, anterior margin strongly convex, posterior slightly concave, lateral 

 margins short, humeral margins long. Elytra long and narrow, exceed- 

 ing abdomen, two outer apical veinlets strongly reflexed. 



Color: Ashy or yellowish-white, marked with brown or black. Vertex, 

 pronotum and scutellum with two broad longitudinal bands, a similar 

 oblique pair laterally on pronotum and elytra, just inside the outer claval 



