1019.; 57 



4 (3) Species not entirely pale green. 



5 (8) Face Avithout distinct black spots, 



(7) Elytra without a brown line next the costa, usually with a wide 

 irregular brown baud across the middle. Insect lives on sallow. 



cereus Germ. 



7 (6) Elytra with a brown line next the costa, without a dark bund. 



Insect lives on elm , ubni Scott. 



8 (5) Face with one or more black spots. 



9 (12) Hind femora with a black or dark-brown streak on the upperside 



which does not reach the base. 



10 (11) Narrower and more pointed in front; elytra with two wide ill-defined 



fuscous bands distinctus Scott. 



11 (10) Wider and less pointed in front ; elytra without fuscous bands. 



impiirtcs Boh. 



12 (9) Hind femora entirely pale. 



13 (IG) Face without a black spot at the summit. 



l-I (15) Elytra brown from the base to beyond the half-length, afterwards 

 whitish-hyaline with a brown cloud on the dorsum reaching about 

 half-way across the elytron, a black or dark-brown stripe on the 

 basal half of the costa decoratus Edw. 



15 (14) Elytra variously coloured, but not as in decoratus . , . .nassatus Germ. 



16 (13) Face with a black spot on the summit. 



17 (18) Elytra : cells 1st R and 2nd M qidte hyaline fuscinervis Boli. 



18 (17) Elytra: the cells last-named not hyaline populi Edw. 



19 (2) Crown rounded or scarcely angular in front, face somewhat convex. 



20 (2oj Elytra hyaline with a brownish-yellow tinge, the veins dark brown 



or black. 



21 (24) Upper pair of facial spots roundish, free. Clypeus without a distinct 



keel. Black lines on the inner- and undersides of hind tibiae, 

 when present, continuous. 



22 (23) Upper division of the side of prosternum with a wide black band 



reaching from side to side, the lower division unmarked or rarely 

 with a black point. Insect lives on Hubus rubi Boh. 



23 (22) Upper division of the side of prosternum with a large roundish or 



oblong black spot, the lower division often with a roundish black 

 spot about half the size of the one on the upper division. Insect 

 lives on Salices scutellatns Boh. 



24 (21) Upper pair of facial spots somewhat comma-shaped, their inner sides 



more or less 'connected with the unpaired sj)ot. Clypeus with » 

 longitudinal keel. The black lines on the inner- and undersides of 

 the hind tibiae widely interrupted in the middle. Insect lives o» 

 nettle tibialis Scott. 



25 (20) Elytra lacteo-hyaline nanus H.-S. 



26 (1) Crown linear tiliae Germ. 



Four sections of the genus are indicated by our species, exemplified 

 by virescens Fab., 7'iibi 1^Q\\., nanus H.-S., and tiliae Germ, respectively. 

 Tlie members of tbe ruhi group may be regarded as elementary or 



