138 THE UNIVERSITY SCIENCE BULLETIN. 



A. Vertex rather angularly produced continued. 



DD." Pronotum cinereous, without distinct black lines. 

 E. Face usually entirely dark. 



F. Vertex without median transverse bars. 

 G. Elytra with large, black median 

 spot, face entirely black. 



areolatus. 



GG. Elytra without black median spot, 

 face sometimes with light spot on 

 apex of front. imputans. 



FF. Vertex with median transverse bars. 



visendus. 

 EE. Face dark above, light below. 



F. Face fuscous above, shading out below, 

 no sharp line of demarcation; species 

 nearly unicolorous above, inflatus. 

 FF. Face black above, light below, line of 

 demarcation sharp. Species marked 

 with fuscous. reflexus. 



CC. Elytra shorter, two outer apical veinlets short, at nearly 

 right angles to the costa, third veinlet running distinctly 

 to the posterior margin. 



D. Size larger, over 3 mm. ; female segment distinctly 

 emarginate, plates of male produced with almost 

 parallel margins. sayi. 



DD. Size smaller, 3 mm. or less; female segment pro- 

 duced or truncate, plate of male short, rapidly 

 narrowing to acute apices. misellus. 



BB. Pronotum longer, hardly twice broader than long, elytra long, 

 with appendix, costal veinlets never reflexed. 



C. Front with numerous black arcs; central anteapical cell 



distinctly constricted. signatifrons. 



CC. Front without black arcs ; central anteapical cell not dis- 

 tinctly constricted. 

 D. Elytra distinctly green. 



E. Form slender; length 3 mm. or less. 



F. Vertex unlined; female segment black- 

 tipped, medially notched, valve of male 

 large and obtuse. minimus. 



FF. Vertex with two oblique lines; fe- 

 male segment unicolorous and broadly 

 rounded, male valve smaller and acute. 



parvulus. 

 EE. Form stouter; length 3.25 mm. or more. 



F. Vertex acutely angled, usually longer 



than broad. debilis. 



FF. Vertex obtusely angled, as wide as long. 



collinus. 



DD. Elytra not distinctly green, hyaline yellowish, or 

 with nervures fuscous margined. 

 E. Male valve enlarged, inflated, covering all 

 but tips of plates; female segment slightly 

 angularly excavated. affinis. 



