LAWSON: KANSAS CICADELLID^. 187 



slightly produced, front narrow, slightly constricted at an- 

 tennal socket, then angularly widened to the ocelli; surface 

 smooth polished, nearly flat above. Elytra subhyaline, the 

 second cross nervure present (sometimes obscure) and the 

 central anteapical cell slightly constricted. Usually with a 

 number of supernumerary veinlets along the clavus and costa." 

 Three of the four species keyed below have been collected in 

 Kansas. 



KEY TO SPECIES.* 

 A. Species with fuscous markings or at least with fuscous nervures. 

 B. A dark saddle on elytra between the cross nervures. 



mgy^idorsum. 

 BB. Without a definite dark band. 



C. Size of nigridorsum, vertex depressed, with four spots on 

 anterior margin, connected by a line posteriorly, with a 

 broad band below vertex. straminea. 



CC. Smaller than nigridorsiitn, vertex flat, sometimes with 

 a narrow line above and below margin. 



colorade72sis. 

 A A. Species fulvous-yellow with light spots. vitellina. 



Mesamia nigridorsum Ball. 



Mesamia nigridorsum Ball, Proc. Dav. Acad. Sci., xii, p. 60, pi. 3, fig. 6; pi. 4, fig. 6, 

 1907. 



Paramesus twiningi Van D., Trans. Am. Ent. Soc, xxi, p. 290, 1894. 

 Paramesus jucundtis G. & B., Heniip. Colo., p. 84, 189.5. 

 Eutettix nigridorsum DeL., Tenn. St. Bd. Ent., Bui. 17, p. 68, 1916. 

 Mesamia nigridorsum Van D., Cat. Hemip. N. A., p. 628, 1917. 



Form: Length, 3.75 to 5 mm. Vertex one-third longer on middle than 

 next the eye, not quite twice as broad as long, disc depressed, anterior 

 margin elevated and acutely angled with front. Pronotum scarcely twice 

 as broad as long, lateral margins somewhat shorter than the humeral. 

 Elytra long, flaring, with characteristic venation, two cross nervures 

 between the sectors, several cross veins along clavus and claval suture 

 and with six or seven reflexed costal veins. 



Colar: Vertex white apically, back of which is an irregular black line 

 connected anteriorly with two large quadrangular spots, disc brown. 

 Pronotum brown anteriorly back of which is a light line containing two 

 dark spots on either side, rest of pronotum brownish, irrorate with 

 fuscous. Scutellum brown with one white spot on each margin and one 

 apically. Elytra milky-white, nervures brown, a dark brown saddle across 

 posterior two-thirds of clavus, apex and costal veinlets black. Face 

 brownish, black above, arcs pale. 



External genitalia: Female, last ventral segment long, posterior mar- 

 gin broadly and deeply emarginate and with a median lobe which is 

 slightly notched apically; pygofers stout, exceeded by ovipositor, sparsely 

 spined apically. Male, valve very small, posteriorly broadly rounded-* 



* Adapted from key by Doctor Ball, Proc. Dav. Acad. Sci., xii, p. 60, 1907. 



