294 DIPTERA 
ovate with a subapical slender arista directed somewhat downward, its basal joint very short followed 
by a slightly thickened rudimentary middle joint which may not be evident. Proboscis conical, inflexed, 
two-thirds the height of the head ; palpi vertical, oval, setulose and with apical bristle. Thorax quadrate, 
densely pollinose, not pubescent but setulose and bristly, one humeral, one posthumeral, three 
notopleural, two supraalar, one postalar, five dorsocentral, and four scutellar bristles; pleurz pollinose, 
even the metapleurz bare but the propleurz with a bristle above and one below and the sternopleurz 
with two strong intercoxal bristles. Abdomen pollinose, setulose, consisting of eight segments, with 
two dorsal and several lateral pittings to each segment; hypopygium relatively small. Legs robust, 
coxa setose, the front pair strong; femora stout, setulose and bristly, the hind pair bristly above and in 
front as well as below; all the tibize with three extensor bristles but the hind ones with additional bristles 
in several rows, front tibize with two apical, posterior tibize with one apical bristle, that of the hind legs 
short but strong; tarsal segments becoming depressed distally, hind metatarsi setulose, pulvilli very 
large. Wings rather oblong and narrow, opalescent, the costa evanescent before the fourth vein, its 
first section long, extending beyond the middle of the wing, with strong basal bristle and micro- 
scopically setulose, the second basal cell a little shorter than the first, no anal cell but the outer portion 
of the sixth vein faintly visible as a fold in the wing. 
Type species : C. inusilata, Melander (Pl. 7. Fig. 10). Nubifea, Coquillett, is a true 
Coloboneura as verified by an examination of thetype. The species frequent the dry sands of the seashore, 
over which they run with great agility but do not take readily to the wing although they are able to fly 
well. 
Geographical distribution. 
1. C. argyropalja, Bezzi, Ann. Mus. Hungar. Vol. 2, p. 358, f. 7 (1904). New Guinea. 
2. C. exquisita, Malloch, Ent. News, Philad. Vol. 34, p. 5 (1923). Maryland. 
3. C. hiria, Walker, Ent. Mag. London, Vol. 3, p. 180 [1836] (Tachypesa); Europe, N. Africa. 
Ins. Brit. Vol. r, p. 137, pl. 5, f. 5 [1851] (Chersodromia) ; Becker, 
Zeitschr. Hym. Dipt. Vol. 7, p. 119 [1907] (Chersodromia); Lund- 
beck, Dipt. Danica, Vol, 3, p. 227, f. 125, 126 [1910] (Chersodromia). 
4. C. ornatipes, Bigot, Bull. Soc. Zool. France, Vol. 16. p. 277 [1891] (Cherse- Canary Isl. 
dromyia); Becker, Mitteil. Zool. Mus. Berlin, Vol. 4, p. 44 [1908] 
(Chersodromia). 
5. C. inusitata, Melander, Trans. Amer, Ent. Soc. Vol. 28, p. 230, 344, f. 47-49 Atlantic Coast of 
(1902); Slosson, Ent. News, Philad. Vol. 14, p. 268 (1902). — United States. 
PI. 7, Fig. 1O. 
6. C. nubifera, Coquillett, Dipt. Commander Isl. p. 343 [1899] (Tachydromia); Bering Sea. 
Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 342 [1902] (Tachy- 
dromia); Coquillett, Proc. Ent. Soc. Wash. Vol. 5, p. 265, note 
(1903); Melander, Psyche, Vol. 17, p. 52 (1910). 
8. GENUS CHERSODROMIA, WALKER 
Chersodromia, Walker, Ins. Brit. Vol. r, p. 137 (1851); Rondani. Dipt. Ital. Vol. 1, p. 147 (1856); 
Bigot, Ann. Soc. Ent. France (3), Vol. 5, p. 564 (1857); Schiner, Fauna Dipt Austr. Vol. 1, 
p. 96 (1862); Bigot, Bull. Soc. Zool. France, Vol. 16, p. 277 [1891] (Chersodromyia); Becker, 
Mitteil. Zool. Mus. Berlin, Vol. 2, p. 43 (1902); Coquillett, Proc. Ent. Soc. Wash., Vol. 5, 
p. 247, 261 (1903); Melander, Williston's Man. N. Amer. Dipt. p. 223 (1908); Kertész, Cat. 
Dipt. Vol. 6, p. 144 (1909); Coquillett, Proc. U. S. Nat. Mus. Vol. 37, p. 522 (1910); Lundbeck, 
