354 The Philippine Journal of Science 1920 
previous description of the species which lacked this: Forceps 
slender, moderately long, slightly clavate distad, not as long as 
height of anal valve; anal valve large, with a caudal projection 
about as long as height of anal valve. 
The East African species of this genus (M. nyasae Newstead)? 
is remarkably similar in male and female genital characters but 
differs in minor wing venational features. 
This genus appears certainly to be related to the Pauropsylli- 
nz instead of to the Carsidarinz. 
Genus TRIGONON novum 
Head much deflexed, short, without genal processes; vertex 
triangular, converging in front to a narrow point at front 
ocellus; genz extending laterad somewhat beyond vertex. An- 
tenn very long and slender, as long as body to tip of folded 
wings or longer. Eyes very large, hemispherical. Thorax 
strongly arched, hirsute. Forewings more or less transparent, 
rounded at apex, veins setiferous; pterostigma present. 
Type of the genus, Heteropsylla longicornis Crawford. 
The most distinctive features of this genus are the triangular 
vertex and excessively long antennz. Two species are included, 
both from the South Pacific. 
Trigonon pacificum sp. nov. Plate 1, fig. 6. 
Related to T. longicornis Crawf., a South Pacific species, but 
much larger. 
Length of body (female), 4.4 millimeters; length from head to 
tip of folded wing, 5.7. General color brown, with a pale stripe 
down center of thoracic dorsum and two black stripes on each 
side of mid line. 
Head short, broad, sparsely hirsute; vertex strongly concave, 
posterior ocelli elevated; frons visible around front ocellus and 
beneath it to labrum; gene large, nearly meeting over frons at 
one point just beneath front ocellus, not produced into conical 
processes or lobes, except for a very small tubercle on each gena 
opposite the labrum. Antenne very long and slender, as long as 
body to tip of folded wings. 
Thorax rather broad, stout, sparsely hirsute. Legs short; 
hind tibie stout, with a small spur at base and several spines at 
apex. Forewing fumate or slightly browned but transparent, 
narrowly rounded at apex, veins with short setze, costa thick 
*Ent. News 25 (1914) 62-65. 
