12 
DIPTERA 
2. S. bifasciata, Williston, Biol. Centr. Amer. Dipt. Vol. i, p. 217, pi. 4, 
f. I, la {Plesiatina) (igoo) 
— S . ferriiginea, Wa.\ker == an7iu lata, Meigen. 
— S.flava, Winnertz = annulaia, Meigen. 
3. 5. lauta, Loew, Berl. Ent. Zeitschr.Vol. i3,p. i32 (5) {Plesmstina) (i86g). 
4. 5. mexicana, Giglio-Tos, Boll. Mus. Zool. Anat. Comp. Torino, Vol. 5, 
No 84, pi. 2, f. 7 {Ditomyia) (1890). 
— 5. pallida, Giglio-Tos = aiinulata, Meigen. 
5. S. siigmatica, Philippi, Verh. Zool.-bot. Ges. Wien, Vol. i5, p. 619, 
pi. 23, f. 7 [Centrocnemis) (i865). 
6. S. tristis, Loew, Berl. Ent.Zeitschr. Vol. 1 3, p. i3i (2) (P/^s2as/z«a) (1869). 
— 5. vittata, Walker == anmilata, Meigen. 
7. 5. sonata, Giglio-Tos, Boll. Mus. Anat. Comp. Torino, Vol. 5, No 84, 
pi. 2, f. 6 [Ditomyia) (i8go). 
Mexico. 
East United States. 
Mexico. 
Chile. 
Eastern United States. 
Mexico. 
4. SUBFAM. DIADOCIDIN/E 
Diadocidinae. Wmnertz, Verh. Zool.-bot. Ges. Wien, Vol. i3, p. 656 (i863). 
Characters. — The subfamily is distinguished from all others in having the M-Cu crossvein 
present and at the same time only two branches in the radius. There is but one living genns. Adada, Loew, 
a fossil genus, may also belong here. 
■ I. Genus DIADOCIDIA, Ruthe 
Diadocidia. Ruthe, Isis, Vol. 11, p. 1210 (i83i). 
Macroneura. Macquart, Suites a Buffon, Vol. i, p. 146 (1834). 
? Aclada. Loew, Bernstein Fauna, p. 35 (i85o) (Brief note; no species). 
Characters. — Head rounded, flattened in front; eyes reniform, somewhat approximated on 
the vertex; ocelli three, subequal, arranged in a flattened triangle on the front; palpi slender, four jointed, 
the first joint small, the following two subequal, the fourth filiform, somewhat shorter than the two 
preceding taken together; face hairy; antennae projecting forward, arcuate, slightly laterally compressed, 
2-}-i5 jointed, the apical joint very small, the two basal joints cupuliform. Thorax ovate, arched ; 
scutellum small, semicircular in outline; metathorax somewhat arched. Abdomen seven segmented, 
cylindrical. Legs slender, femora thickened; fore tibiae without, the hind pair with three rows of delicate 
setae. Wings hairy, large, with wide base, folded parallel over and somewhat longer than the abdomen. 
Subcostal vein elongate and ending in the costa, its posterior branch (SC2 = subcostal crossvein) want- 
ing ; Ri ending in the costa distad of the mid length of the wing; the radial sector unbranched and 
ending in the costa before its tip; second anal produced to the wing margin (PI. 3, Fig. I 0). 
Type species : D . ferniginosa, Meigen. 
Geographical distribution of species : 
1. D. boyealis, Coquillett, Proc. Wash. Acad. Sc. Vol. 2, p. 370 (1900). Western North America. 
2. D. ferruginosa, Meigen, Syst. Beschr. Vol. 6, p. 294 (4) [Mycetobia) (i83o). Europe and America. 
ferruginosa, Winnertz, Verh. Zool.-bot. Ges. Wien, Vol. i3, p. 666 (i) {i863) ; 
Schiner, Fauna Austr. Dipt. Vol. 2, p. 426 (1864). 
