98 DIPTERA . 
However, the illustration of the head drawn by Mrs. Meunier suggests a dichoptic insect. Loew's 
species of Gloma with slender antennz, likewise from the Baltic amber, possibly belong here. 
Geographical distribution, 
1. T. * ? acuticornis, Loew, Bernsteinfauna, p. 41 [1850] (Gloma) ; Giebel, Ins. Baltic Amber. 
Vorwelt, p. 208 [1856] (Gloma). 
2. T. fumosa, Hutton, Trans. New. Zeal. Inst. Vol. 33, p. 31 [1901] (Clinocera); New Zealand. 
Bezzi, Ann. Mus. Hungar. Vol. 2, p. 321, note [1904] (Heleodromia) ; 
Kertész, Cat. Dipt. Vol. 6, p. 123 [1909] (Heleodromia); Engel, 
Deutsche, Ent. Zeitschr. 1918, p. 47 [1918] (Hydrodromia). — PI. 6, 
Fig. 53. 
3. T. * ? gracilis, Meunier, Ann. Sc. Nat. (Zool.) Vol. 7, p. 92, 113, pl. 8, Baltic Amber. 
f. 10, Vol. 9, p. 2-4 [1908] (Brachystoma). 
4. T. * ? palpata, Loew, Bernsteinfauna, p. 41 [1850] (Gloma); Giebel, Ins. Baltic Amber. 
Voorwelt, p. 208 [1856] (Gloma). 
6. GeENUs OREOGETON, SCHINER 
Oreogeton, Schiner, Wien. Ent. Monatschr. Vol. 4, p. 53 (1860); Fauna Dipt. Austr. Vol. t, p. 112 
(1862); Bigot, Ann. Soc. Ent. France (6), Vol. 9, p. 116 (1889); Melander, Trans. Amer. Ent. 
Soc. Vol. 28, p. 275 (1902); Coquillett, Proc. Ent. Soc. Wash. Vol. 5, p. 254, 262 (1903); Bezzi, 
Ann. Mus. Hungar. Vol. 3, p. 45r (1905); Melander, Williston, Man. N. Amer. Dipt. p. 225 
(1908); Kertész, Cat. Dipt. Vol. 6, p. 8o (1909); Coquillett, Proc. U. S. Nat. Mus. Vol. 37, 
p- 580 (1910). 
Characters. — Rather large black or yellow more or less pollinose species somewhat resembling 
L«ptis in appearance. Head small, eyes of the male contiguous on the front but widely separated below, - 
facets nearly uniform, bare; antennze inserted below the middle of the head, the face small and quadrate, 
receding below as the pollinose broad epistome; basal joints of the antenne short and setose, third joint 
conical, terminated by a thick arista longer than the third joint and tipped with a short hair; proboscis 
very short and fleshy, directed forward, palpi long, clavate, hairy, porrect; occipital hairs abundant, not 
differentiated into bristles above; ocellar triangle of the male alittle elevated. Thorax bristly, dorso- 
centrals numerous, several humerals, posthumerals, notopleurals, supra-alars and scutellars, the acros- 
tichals biseriate; pleurze pollinose, metapleurz setose. Abdomen hairy and bristly, twice as long as the 
thorax, rather slender and cylindrical, pygidium not large, bilateral, lateral valves oblong, pointed at the 
upper apex and bearing a dorsal tooth, dorsal valves small and cerciform; abdomen of the female 
somewhat depressed, tapering at the apex. Legs slender, setose, in the male the middle pair sometimes 
ornate with bunches of bristles, the tibiz* bearing sets of apical as well as intermediate bristles, pulvilli 
large. Wings large, veins strong, the first, second and sometimes the third veins bearing setule on the 
upper surface and the second setulose on the lower side, the setule of the first vein dense, costa conti- 
nuing around the entire wing but weakened on the hind margin, auxiliary vein distinct, ending in the 
costa, third vein forked, the upper branch short and oblique, basal cells shorter than the apically blunt 
discal cell, anal crossvein abruptly reflexed, continuous with the underside of the anal cell, anal vein - 
obsolete, anal angle of the wing strongly rectangular, alula distinct; calypteres large, margined and 
densely fringed. 
Type species : O. £asalis, Loew (PI. b, Fig. BO). There is a tendency in the genus for the base 
of the abdomen to be pellucid and for the females to be yellowish in color. In neuration and body-color 
