April, 1902.] North American Species of Athysanus. 
2 45 
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 only at extreme apex, forming 
a small, triangular cell ; sometimes forking as usual and the second 
cross nervure present. 
Type of the subgenus A. comma Van Du/.ee, no European rep- 
resentative known. 
Key to the Sitbgenus. 
A. Ocelli and frontal suture distant from the eye-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, colon 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, sexvittatus 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, 
osborn i Van D. 
CC. Greenish yellow, spots on vertex large, the apical pair in 
front of the others ; front inflated, with a distinct suture 
below, simp/arins nov. nom. 
