24 ; DIPTERA 
35. H. sydneyensis, Schiner, Novara Reise, Dipt. p. 203 (1868); Bezzi, Ann. N. S. Wales. 
Mus. Hungar, Vol. 2, p. 327 (1904). 
36. H. tenuibes, Brunetti, Rec. Indian Mus. Vol. 9, p. p. 13 (1913); Feu India. 
Brit. Ind. Dipt. Vol. r, p. 338, pl. 4, f. 7, 8 (1920) : 
37. H.* tenuis. Meunier, Ann. Sc. Nat. (Zool.), Vol. 7. P. 91, 109, pl. 7, Baltic Amber. 
f. 6, 7 (1908). 
38. H. tibialis, Bezzi, Ann. Mus. Hungar, Vol. 10, p. 455 [1913] (Nocsa) ; Formosa. 
Suppl. Ent. Berlin, Vol. 3, p. 67 [1914] (Noesa). ; 
39. H. typicus, Wheeler & Melander, Biol. Centr.-Amer. Dipt. Vol. 1, p. 373 Mexico. 
(1901); Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 246 (1902); 
Bezzi, Nova Acta Akad. Naturf. Halle, Vol. 91, p. 305 (1909). 
40. H, vagans, Loew, Jenaische Zeitschr. Ges. Naturw. Jens, Vol. 43, p. 417 Persia. 
(1874). 
41. H. xanthopodus, nov. sp. (1). Costa Rica. 
4. GENUS EUHYBOS, COQUILLETT 
Euhybos, Coquillett, Proc. U. S. Nat. Mus. Vol. 18, p. 399, 437 (1896) ; Melander, Trans. Amer. Soc. 
Vol. 28, p. 248 (1902); Coquillett, Proc, Ent. Soc. Wash. Vol. 5, p. 250, 259, 264 (1903); Proc. 
U. S. Nat. Mus. Vol. 37, p. 541 (1910); Bezzi, Ann. Mus. Hungar, Vol. 1o, p. 456 (1912). 
Characters. — Hunchbacked, shining black, pilose species with strong, spinose hind femora, 
contiguous eyes, long ovipositor and reduced mouthparts. Head globular, largely composed of the 
eyes, the occiput broadly conical and hairy but not bristly,ocellar prominence on the summit of the head, 
no front, face or cheeks, due to the large eyes, rarely, however, a small narrowly triangular subantennal 
space representing the face, sometimes continued as a line to the oral margin, antennal incision of the 
eyes small, uppermost facets enlarged, a horizontal line extending through the middle of the eyes; 
antennze three-jointed but the basal joints connate, the second joint with a circle of small hairs, the third 
joint elongate oval or subulate, two to three times as long as broad, the terminal arista very slender, 
thread-like, bare and averaging twice the antennal length; proboscis not half as long as the head, extend- 
ing forward, when closed the two valves of the labella come together as a thin vertical lamella, palpi 
minute, scarcely projecting, each with a preapical hair. Thorax greatly convex, humeri prominent, 
prothorax quadrate when viewed from above, more or less densely and long pilose, typically no bristles, 
except two notopleural and a pair of apical scutellars; pleure bare, the mesopleurz and sternopleure 
shining, otherwise the pleure lightly coated with pollen. Abdomen elongate, cylindrical, devoid of 
bristles but with long loose pale hairs toward base; pygidium terminal, rather large, ovoid in outline, 
comprising an upper and a lower opposing convex valve, each of which terminates in a complicated 
manner, between these a small elliptical plate on the left side and a delicate process on the right, an - 
upcurved terminal filament, which is flattened, ribbon-like, hairy, and usually is long and attenuated 
(1) Hybos xanthopodus, nov. sp. — Female. Length 4 mm. Third antennal joint three times as long as 
wide, arista one and three-quarters times antennal length; upper facets large. Mesonotum very thinly dusted, a 
patch of white dust near notopleural suture, dorsocentral bristle minute, scutellar pair small; pleure white-dusted. 
Abdominal hairs sparse and yellow. Coxe and legs yellow, hind tibiz ani tarsi and tips of anterior tarsi with 
brownish tinge, a flexor yellow seta at basal one-third of anterior tibiz, middle tibiae with two long extensor setae 
on proximal part, hind femora relatively slender, three fine fulvous setz» toward knee on lower anterior side, flexor 
denticles black, hind edge ciliate with sixteen delicate yellow sete, no denticles on metatarsal sole.  Halteres, 
calypteres and root of wing yellow; wings hyaline, stigma faint, not filling marginal cell, veins black, first vein 
ending in middle of stigma, sections of fifth vein 2 : r. 
Two specimens, La Suiza de Turrialba, Costa Rica, April, November, 1922, Pablo Schild, col'ector. 
