310 The Philippine Journal of Science 1921 
Key to the Philippine species of Diodontus Curtis. 
1. Abdomen black or with reddish spots only on second tergite......... 2. 
Abdomen reddish except sometimes the petiole 4. 
2. Scutellum yellow; no tubercles on frons near the top of the eyes; 
four anterior femora yellow.............------- D. xanthognathus (Rohwer). 
Scutellum black; a prominent tubercle on frons near the top of the 
eyes; four anterior femora black except the apices 3. 
3. Posterior surface of propodeum rugulose; pronotum and metanotum 
marked with yellow. D. tuberculifrons sp. nov. 
Posterior surface of propodeum coarsely reticulate; pronotum and 
metanotum black D. maurus sp. nov. 
4. Parapsidal furrows strong, extending to scutellum; petiole black. 
D. scutatus sp. nov. 
Parapsidal furrows weak, wanting posteriorly. 5. 
5. Thorax except tubercles black 6. 
Thorax largely yellow. q. 
6. Petiole concolorous with gaster; area outside lateral ocelli depressed. 
D. philippinensis sp. nov- 
Petiole black; area around ocelli not depressed.... D. basilanensis sp. nov. 
7. Frons, near the top of the eye, with a low tubercle; scutum with large 
punctures . D. bakeri sp. nov: 
Frons without tubercles; scutum practically impunctate.............--- 8. 
8. Face with a transverse ridge just below antennz; large species. 
D, ajax sp. nov. 
Face without a transverse ridge. , 9. 
9. Apical margin of clypeus slightly produced and emarginate so as to 
appear bidentate; scutum mostly yellow; first recurrent and first 
intercubitus interstitial D. luzonensis sp. nov. 
Apical margin of clypeus truncate, not bidentate; scutum largely black; 
first recurrent interstitial hoe EUs 
10. Frons shining, with a few aciculations; first recurrent in the first cu- 
bital; flagellum much thickened apically...........- D. luteopictus sp. nov- 
Frons subopaque, coriaceous; first recurrent in the second cubital; 
flagellum not much thickened apically..............- D. multipictus sp. nov. 
A. Parapsidal furrows complete to scutellum. 
Diodontus scutatus sp. nov. 
In the complete parapsidal furrows and the venation of the 
anterior wings, this species differs from the typical members 
of this genus. 
Female.—Length, 7 millimeters. Clypeus flat, shining, sparse- 
ly punctured basally, the apical margin straight, with three 
small median teeth and a small lateral tooth; face opaque, 
finely granular; a median, free-edged, truncate process above 
the middle of the face connecting with the lower margin 
of the very prominent ventral portion of the frontal carina; 
frons, vertex, and posterior orbits smooth, shining; no tuber- 
cles on the frons; a broad, shallow U-shaped depression 
partially surrounding the ocellar area; ocelli in an equilateral 
