558 The Philippine Journal of Science 1922 
Genus IDIOGNATHUS novum 
I am at a loss to know whether to refer this genus to the 
Joppini or to the Amblytelini. * None of the keys for the separa- 
tion of the tribes of the Joppinz furnishes characters that can 
be interpreted positively for distinguishing these two tribes. In 
general form it resembles much more closely the Heresiarchini, 
especially the genus Nesostenodontus, described above, but the 
strongly bidentate mandibles exclude it from that tribe. In al- 
most every other part it is extremely similar to Nesostenodontus, 
especially in the clypeus, the shape of the head, the scutellum, 
the propodeum, and the venation of the wings. So striking is 
this similarity that I cannot believe that the form of the mandi- 
bles is of real tribal significance in this subfamily. The same 
may be said of the characters employed for the separation of 
the Joppini and Amblytelini. In none of the keys to either of 
the two tribes does it run to anything that is at all related to 
it; in fact one is constantly in doubt, especially with Berthou- 
mieu’s keys,® which alternative to follow. 
Head very similar in shape to that of N esostenodontus gen. 
nov. but shorter and slightly narrower behind the eyes than at 
the eyes; occiput deeply but not nearly semicircularly excavated, 
completely margined; face medially roundly elevated; clypeus 
large, arched at base, separated from face, rounded at apex and 
without apical serrations; eyes broadly reniform ; malar space 
nearly obliterated; mandibles strongly bidentate, dorsal tooth 
somewhat the longer; second joint of maxillary palpus triang- 
ular; antenne nearly as long as body, in female weakly incras- 
sate beyond middle, the incrassate portion flattened below, but 
barely perceptibly compressed, in male filiform, not serrate. 
Thorax scarcely as broad as head; pronotum slightly swollen at 
humeral angles, epomia distinct; notauli sharply defined for 
about a third the length of the mesoscutum; scutellum large, 
nearly flat in female, slightly convex in male; subalar elevation 
on mesopleurum weak; sternauli short, broad but distinct ; lateral 
fovee of postscutellum not crenulate; propodeum obtusely den- 
tate posteriorly ; basal median area confluent with lateral areas, 
which are in turn partially confluent with the spiracular areas, 
none of the longitudinal carine reaching the base of the propo- 
deum; areola broadly hexagonal, nearly round anteriorly ; apical 
carina strong; median longitudinal carine obsolete or wanting 
behind areola; spiracles small oval; wings immaculate; areolet 
* 
*Gen. Ins. fase. 18 (1904). 
