CICADELLINAE: PART 2. NEW WORLD CICADELLINI 495 
golden, with posterior margin and often (not in type) with a median line ex- 
tending anteriorly to midlength and giving off a branch to each side parallel 
to anterior margin, black; scutellum golden, apex black; forewing black on 
approximately middle one-third, membranous at base and at apex, the apical 
membrane including all of apical cells and a variable portion of anteapical 
cells; face entirely black, thoracic pleura black except for portion of proepi- 
meron and mesepisternum which are yellow; legs partly yellow and partly 
black. 
Holotype male, Monsén Valley, 10 XI 1954, Tingo Maria, Peru (E. I. 
Schlinger and E. S. Ross) and a series of six topotypic males, November 10, 
1954; November 29, 1954; October 26, 1954, and December 9, 1954 (same 
collectors) (CAS). 
M. semilucida, n. sp., one of the largest species in the genus, is very similar 
externally to M. attenuata (Osborn) from which the male differs in its shorter 
and broader pygofer, its shorter aedeagus and shorter styles, and to M. 
ferrugatula (Breddin) from which the male may be most readily separated by 
the strongly biundulate dorsal margin of its aedeagus. 
Mesogonia bicornuta, NEW SPECIES 
Ficure 406, PAGE 496 
Length of male 8.1-8.6 mm. Head with median length of crown slightly 
more than one-half interocular width and from slightly less to slightly more 
than one-third transocular width, without a distinct carina at transition from 
crown to face, ocelli located on a line between anterior eye angles and either 
equidistant from median line of crown and adjacent anterior eye angle or 
slightly closer to latter (type), surface of crown sloping gradually towards an- 
terior margin, not concave, lateral clypeal sutures barely extending onto 
crown; antennal ledges not carinate dorsally; face weakly pubescent beneath, 
transclypeal suture distinct. Thorax with pronotum narrower than head, 
dorsopleural carina extending anteriorly to eye margin; forewing coriaceous 
except apically, veins indistinct. Other external anatomical characters as in 
M. retrorsa, n. sp. 
Male pygofer not strongly produced, apical margin broadly rounded, with a 
few anteapical macrosetae, with an apical bifid process on each side; plates 
extending almost as far posteriorly as pygofer apex, without a dorsal lobe in 
lateral view, each tapered in apical half in ventral view, with uniseriate 
macrosetae in apical two-thirds and with a number of short lateral 
microsetae; style extending posteriorly beyond apex of connective, without 
preapical lobe, subacute at apex; connective elongate-triangular, keeled; 
aedeagus biundulate in lateral view, slightly expanded at apex and with apical 
margin rounded; paraphyses stalked, rami short and slightly asymmetrical. 
Female unknown. 
Crown, pronotum and scutellum, dull yellow, partly suffused with orange, 
the pronotum with a large sordid green area covering most of surface except 
anterior margin; forewings black, fading to tan over clavus, commissural 
