326 
PANAMA DERMAPTERA 
The genus is monotypic. Genotype. — Gerax phantasma new 
species. 
Generic features are given in the key. These are: the ocular 
antennal characters, the general pronotal structure, character of 
hairy covering, simple male forceps and highlj^ specialized male 
metaperameres. In addition, we would oljserve that the caudal 
metatarsus is supplied ventrad with hairs, but no chaetiform 
spines, agreeing in this character with Eugerax, it is distinctly 
longer than the combined length of the second and third tarsal 
joints; the second tarsal joint is exceptionally elongate, fully twice 
as long as its greatest width and over half as long as the short 
third joint. As in Eugerax, the limbs are elongate and slender. 
The genus shows an unmistakably Diplatyine general facies. 
Gerax phantasma new species (Plate XXVI, figs. 10 and 11.) 
This minute insect is pale and immaculate; its slender form, 
large eyes, minute pronotum, ample tegmina and minute, simple 
forceps, give it a distinctive appearance. 
Type . — cf ; Trinidad River, Panama. March 17, 1912. (A. 
Busck.) [U. S. National Museum.] 
The most important characters are given in the key and generic diagnosis. 
In addition, the following features are noted. Form very slender. Head with 
brief lateral margins of cheeks rounding broadly into the transverse caudal 
margin, this entire margin with a fringe of well spaced l^ristles; medio-longi- 
tudinal occijiital suture distinct only toward caudal margin of head. Antennal 
joints not moniliform; first joint about equal to combined length of second and 
third joints, succeeding joints increasing in length distad.^® Pronotum very 
small, smooth except for a single bristle at each latero-cephalic angle; prozona 
convex; metazona decidedly ascending laterad, feebly ascending caudad; 
lateral margins feebly diverging caudad, caudal margin strongly convex. 
Tegmina with surface smooth; evenly convex from sutural to costal margin 
beyond shoulders, narrowing only in distal third, where the costal margin is 
broadly convex to the rather sharply rounded angle at the sutural margin. 
Wings supplied with a few minute, scattered hairs; costal margin w'eakly con- 
vex to very brief, transverse, distal truncation. Ultimate dorsal abdominal 
segment much as in Bar ygerax esau, but with distal margin only feebly produced 
in a minute convexity above the dorsal ridge of each arm of the forceps. 
Pygidium minute, delicate, declivent, with straight lateral margins w'eakly 
converging to the broad, transverse, disto-ventral margin. Forceps moder- 
ately stout, more slender than in B. esau, straight and evenly tapering to 
the immediate, chitinous, aciculate, incurved apex; ventro-internal margins 
Nine and eleven joints remain, the antenna with the greatest number hav- 
ing apparently lost only one or two distal joints. 
