CICADELLINAE: PART 2. NEW WORLD CICADELLINI 5 
UCAL University of California, Berkeley (Dr. Jerry Powell). 
ZIL Zoological Institute, University of Lund, Sweden (Dr. C. H. Lindroth). 
ZIMH Zoologisches Institut und Museum, Hamburg (Dr. Wilhelm Wagner, Dr. 
Herbert Weidner). 
Additional acknowledgment of assistance received is made in appropriate 
places in the text below. 
Morphology 
The total length of the specimens, in the descriptions below, is measured from 
the apex of the crown of the head to the apices of the forewings at rest. The me- 
dian length of the crown is measured from the apex of the crown to the posterior 
margin of the crown. The interocular width is the least width between the com- 
pound eyes. The ocelli may be in line with the anterior eye angles, in dorsal view, 
or before a line drawn between the anterior angles, or behind such a line. An 
ocellus may be located equidistant from the adjacent anterior eye angle and the 
median line of the crown, or closer to the eye angle than to the median line, or 
closer to the latter. The contour of the surface of the crown is a useful character. 
It may be entirely convex, or may bear a longitudinal or a transverse (best seen in 
lateral and slightly dorsal view) concavity. The crown is rarely concave. The oc- 
currence of setae on the crown is often useful as a character. The texture of the 
crown may be glabrous, smooth, granular, punctate, pitted, rugulose, or rugose 
(observations made with stereoscopic microscope at no more than X 64). The oc- 
currence of elongate pits or depressions on the crown has been found to be a 
useful character for separating certain groups of genera in the key. The lateral 
clypeal sutures extend up onto the crown to or near the ocelli in most of the 
Cicadellinae, and this is a useful character at subfamily level. But they fail to ex- 
tend onto the crown in most species of Mesogonia, a genus that is sufficiently close 
to Juliaca to warrant retaining it in Cicadellini. The presence or absence of an 
angle or carina at the transition from crown to face is useful in classifying genera. 
In a few genera of Cicadellini, the antennal ledges are protuberant, in dorsal 
view, but never to the extent found usually in the Proconiini. The anterior 
margin of an antennal ledge, in lateral view, may be vertical or oblique; in either 
case it may be convex or rectilinear. The arcuate impressions of the dilator mus- 
cles of the cibarium, in a vertical row on each side of the clypeus, may be distinct 
or not. The surface texture of the portion of the clypeus between the muscle im- 
pressions is often useful. A transclypeal suture separates the clypeus from the 
clypellus, but it is frequently obscure medially. The clypellar profile is often a 
continuation of the curvature of the clypeus, but frequently its lower portion is 
more nearly horizontal, more nearly parallel to the venter. 
The thorax has several useful characters: its greatest width compared with the 
transocular width of the head, the shape of the lateral margins in dorsal view 
(parallel, convergent anteriorly, divergent anteriorly), the sculpturing and 
pubescence of the disk, the shape of the posterior margin, and the texture of the 
scutellum. The dorsopleural carina of the prothorax is usually complete (extend- 
ing to the eye margin) in Western Hemisphere Cicadellini, but it may be absent 
(e.g. Draeculacephala) or incomplete (not attaining the eye margin). As in some 
