April, 1902.] North American Species of Athysanus. 245 



segment produced into long, blunt tipped, slightly divergent teeth, between 

 these teeth the margin is produced into two small, rounding lobes separated 

 by a slight notch. Male valve very large, triangular, the apex slightly pro- 

 duced, plates much enlarged, broad at base where they are convex, extending 

 beyond the valve about half its length without narrowing, their truncate tips 

 standing nearly perpendicular to the plane of the valve and together with the 

 short pygofers forming an enclosed cavity. 



Habitat : Colorado. 



SUBGENUS COMMELLUS NOV. 



Head as wide as the pronotum ; vertex angled before, flat or 

 nearly so, angled with front and with a definite margin, not in the 

 form of a conical point ; front broad, nearly flat in both diameters, 

 margins straight and narrowing directly to the clypeus. Elytra 

 in two forms, slightly shorter than the abdomen and inclined to 

 be flaring, or long and parallel-margined ; venation irregular, 

 often obscured by longitudinal stripes. Sometimes the inner fork 

 of first sector not forking again or onlj' at extreme apex, forming 

 a small, triangular cell ;. sometimes forking as usual and the second 

 cross nervure present. 



Type of the subgenus /I. comma \'an Duzee, no European rep- 

 resentative known. 



Key to the Subgenus. 



A. Ocelli and frontal suture distant from the e3e-suture, several times the 

 width of the ocelli ; spots on anterior margin of vertex extending 

 down equally onto front and visible from below. 

 B. Two pair of spots common to vertex and front ; stripes on pro- 

 notum black. Elytra with the venation obscured by brown 

 stripes ; but one anteapical cell. 

 C. Four separate stripes on each elytron ; anteapical cells 



wanting or a single minute one, comma Van D. 



CC. Eight separate oblique stripes on each elytron ; one large 

 anteapical cell, colou O. and B. 



BB. A single pair of spots common to vertex and front. Pronotal 

 stripes irregular, brownish ; venation distinct, nervures light, 

 two or three anteapical cells, sexvittatiis Van D. 



AA. Front above the antennae approximating the eye. Ocelli scarcely 

 their own width from the eye-sutures (not the color line). Spots on 

 vertex back of the margin, not visible from below. 

 B. Vertex margin sharp ; a pair of longitudinal, red stripes across 

 vertex, pronotum and scutellum. Venation obscured by 

 oblique, red stripes, texanus Osb. and Ball. 



BB. Vertex with the margin blunt ; no red stripes ; venation distinct 

 two cross nervures between sectors, a divided central anteapi- 

 cal cell. 

 C. Straw-colored, spots on vertex small, in a row between the 

 ocelli. Front and clypeus without apparent suture, 



osborni Van D. 

 CC. Greenish yellow, spots on vertex large, the apical pair in 

 front of the others ; front inflated, with a distinct suture 

 below, si)iiplari!is nov. nom. 



