FORMOSAN AGROMYZIDAE. 
327 
penultimate section; and the size of the specimens averages barely 
over 2 mm. 
Type: Chip-Chip, February. 
Paratypes : Chip-Chip ; Tainan ; and Takao, various dates. Fifty-two 
specimens. 
Some of the examples show considerable variation in the situation 
of the inner cross vein and rarely it is very slightly beyond the middle 
of the discal cell. I consider, however, that there is only one species in the 
series before me, as in some species of this group there is considerable 
variation. 
20. Agromyza anguliceps n. sp. 
Female: Glossy black. Center stripe of frons opaque black; apex of 
proboscis yellowish. Pleuræ and ventral surface of abdomen subopaque 
black. Legs glossy black. Wings clear, veins black: Squamæ grayish, fringe 
brown. Halteres black the stalks brown. 
Frons slightly over one third the width of head ; orbits distinct, nar¬ 
row, each equal to less than one fourth the width of central stripe, 4 pairs 
of orbitals present, which are not strong and decrease slightly in length 
anteriorly, the anterior pair strongly incurved ; a few very short hairs on 
the orbits in addition to the bristles ; triangle distinct., highly glossy, narrow, 
extending to beyond middle of frons ; antennæ inserted well below middle 
of profile, small, third joint rounded; arista bare, swollen at base, the 
apical portion very thin, entire length about equal to two thirds that of 
frons ; face concave ; frons declevitous ; cheek about equal to one eighth 
the height of eye, very distinctly produced at anterior angle, its anterior 
extremity being in vertical line with the anterior margin of third antennal 
joint, marginal hairs weak, vibrissa well differentiated. Mesonotum with 
2 pairs of dorso-centrals ; disc with numerous short, hairlike setulæ. Ab¬ 
domen ovate ; ovipositor stout ; surface of abdomen and ovipositor with 
numerous hairs. Legs slender; the mid tibial bristles weak but distinct. 
Inner cross vein at beyond end of first vein and at one third from end of 
discal cell ; last section of fourth vein about 6 times as long as penultimate 
section ; veins 3 and 4 slightly divergent ; last section of fifth vein two 
thirds as long as penultimate section; auxiliary vein complete. 
Length: 2 mm. 
Type : Tainan, February. 
n This species belongs to the group in which the male has the vibirssal 
angle distinctly produced, and the vibrissæ in the form of fasciculi. 
