438 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
directed mesad ; a complex cuplike fold projecting above dorsal margin 
at middle. 
Described from a single male specimen taken by the writer in 
Caura Valley, Northern Range, Trinidad, B. W. I. (April 5, 1941), 
in forest, resting on fungus. Type, U.S.N.M. No. 56687. This species 
is well distinguished by the proportions of the apical cells of M in 
the tegmina, by the structure of the genitalia, and by the very pale 
color. 
DERBE SEMIFUSCA, new species 
PLATE 9, Figures 129-135 
Male: Length, 6.5 mm.; tegmen, 15.0 mm. 
Vertex short, subquadrate, somewhat produced before eyes; frons 
longer than broad (2.5 to 1), lateral margins slightly diverging dis- 
tally, median carina absent; frontoclypeal suture deeply impressed ; 
clypeus tricarinate, median carina obsolete at base; antennae with 
second segment subcylindrical, slightly expanding toward apex, ter- 
minal joint inserted apically on second. Pronotum short in middle, 
longer laterally anterior margin straight, posterior deeply emarginate; 
mesonotum inflated, upturned at scutellum. 'Tegmina with posterior 
sector of M with seven branches reaching margin, the cells posterior 
to the fifth, sixth, and seventh of these branches each six times as 
long as wide. 
Head and body fuscous, clypeus at apex and on sides and mesonotum 
very dark, pronotum abruptly testaceous in posterior half, tegulae 
pale, abdomen dark testaceous dorsally, paler ventrally; tegmina with 
veins fuscous, all, with the exception of the apical veins of M and 
Cu,, bordered with a broad hyaline band, middle portion of cells 
fuscous, apical cells of R and M, hyaline, a small dark patch on each 
of the apical branches of these veins near margin, remainder of apical 
cells fuscous; wings fuscous, veins fuscous bordered hyaline except 
near apical margin. 
Pygofer with lateral margin sinuate, medioventral process large, 
nearly two-thirds as long as ventral posterior plate of pygofer, nar- 
rowly triangular, rounded at apex. Aedeagus in dorsal view sub- 
ovate with three spinose processes arising two-thirds from base near 
left side, directed anteriorly, a long curved spine arising at same 
level and crossing obliquely forward to project beyond right margin, 
a broad lamina arising apically, directed forward and narrowing to 
a ribbonlike blade directed obliquely upward; at the basal end of this 
lamina a flattened spine directed anteriorly. Genital styles long, 
narrow, incurved at apex in a pincerlike manner, dorsal margin 
sinuate, a complex cuplike fold on dorsal margin at basal third. 
Described from one male collected by F. W. Urich, Trinidad, B. W. I. 
(1916), taken from the collection of the former Imperial Depart- 
