THE PHORIDAE OF FORMOSA. 
541 
Formosa, when the fauna of the adjacent continental area has been 
more fully explored. 
Key to the Species of Aphiochaeta known to occur in Formosa. 
1. Scutellum with four marginal bristles. „„ _ „„ „„ _ _ 2. 
— Scutellum with only two marginal bristles. „„ „„ „„ 4. 
2. Costal vein less than two-fifths as long as the wing. A. insulana n. sp. 
— Costal vein extending at least to the middle of the wing. „„ _ „„ 3. 
3. Mesopleura bristly above, with one or two bristles larger than the others ; 
abdomen yellowish above. _ „„ „„ „„ A. ochracea n. sp. 
— Mesopleura entirely bare ; abdomen marked with black above. 
A. trivialis n. sp. 
4. Costal vein very short ; about one-third as long as the wing. 
A. pygmaea Zett. 
— Costal vein half as long as the wing or longer.™ „ „„ _ ... 5. 
5. Mesopleura bristly above, with one bristle very much enlarged. 6. 
— Mesopleura entirely bare.„_ ÍJ „„ „„ „„ „„ „„ ™ 8. 
6. Halteres black ; wing veins dark brown. _ . „„ „„ „„ „„ „„ _ 7. 
— Halteres yellow, wing veins weakly colored, yellowish. A. flaviclava n. sp. 
7. Head and thorax honey yellow ; costa extending well beyond the middle 
of the wing.. . „„ . „„ _ „„ „„ „„ A. atriclava n. sp. 
— Head and thorax black ; costa just attaining the middle of the wing. 
A. aemula n. sp. 
8. Front much shortened ; twice as broad as high. „ .... A. latifrons n. sp. 
— Front of the usual quadrate form. . . |J „„ 9. 
9. Halteres black ; mesonotum yellowish brown. „„ ™ „„ „„ „„ 12. 
- Halteres yellow or brown ; mesonotum as dark or darker than the hal¬ 
teres. ™ __ ™ ™ ™ „„ ™ ™ „„ ™ 10. 
10. Tip of first vein closer to the tip of the second than to the humeral 
cross-vein ; small black species, with clear delicate wings. A. nana n. sp. 
- Tip of first vein farther from the tip of the second than from the hume¬ 
ral cross-vein. _ „„ „„ .... „„ _ „„ „„ 11. 
11. Middle row of frontal bristles forming a straight transverse row; thorax 
piceous ; hind legs very slender. „„ ™ m ™ A. recta n. sp. 
— Middle row of frontal bristles strongly curved upward at the sides ; thorax 
yellowish brown; legs moderately stout.™ _ .... ™ _ A. curva n. sp. 
12. Costal vein extending far beyond the middle of the wing ; fourth vein 
curved forward at both base and apex ; wings distinctly infuscated. 
A. chipensis n. sp. 
— Costal vein extending scarcely beyond the middle of the wing. .... _ 13. 
13. Two proclinate frontal bristles, the lower pair represented only by short 
hairs ; hind tibiæ obsoletely setulose. _ ™ % A. meracula n. sp. 
- Four proclinate frontal bristles ; hind tibiæ very strongly setulose. 
A. Sauteri n. sp. 
