38 DIPTERA 
| 8. GENUS ACARTERUS, LokeEw 
Acarterus, Loew, Oefv. Vet. Akad. Fórh. Vol. 15, p. 340 (1858); Dipterenf. Südafr. p. 262 (1860); 
Bigot, Ann. Soc. Ent. France (6), Vol. 9, p. 118 (1889); Bezzi, Ann. Mus. Hungar, Vol. 2, 
p. 321 (1904). 
Characters. — Third antennal joint conical, longer than the apical arista, which is stiff, 
straight and bare, its microscopic hairs visible only by very strong magnification; proboscis longer 
than the head, horizontally porrect, slender and sharply pointed, the palpi linear; eyes completely 
contiguous on the vertex. Body wholly black, subshining, the thorax apparently not greatly convex, - 
abdomen conical. Legs simple, the hind femora neither thickened nor spinose below. underside of the 
hind tibie and tarsi with short whitish pile. First vein very long ending near the second, which 
scarcely bows into the costa, stigma long and brown, basal cells of nearly equal extent, discal cell but 
little shorter than the second posterior, emitting two simple posterior veins, third and fourth veins 
slightly convergent. 
Type species : A. uuicolor, Loew (Pl. 5, Fig. 42), the original species. The genus Acar- 
terus, founded on a South African fly that possessed only negative characters, has been associated with 
Parahybos by Bezzi. At first, the position of the arista, terminal in Acarterus and subapical in ParaAybos, 
was thought a sufficient distinguishing trait to maintain the two as valid genera. But Bezzi has recently 
found a series of East Indian species, evidently closely related, in which the location of the arista 
varies. However, Loew's figures of Acarterus show the pedicel of the second and third veins much 
abbreviated, the first vein unusually long. the arista decidedly shorter than the third antennal joint and 
the thorax not greatly convex. The South African species can therefore not be congeneric with the 
Oriental species placed in Acarterus and Parahybos, and the latter accordingly have here all been removed 
to Parahybos, leaving Acarterus a monotypic genus. 
Geographical distribution. 
t. A. unicolor, Loew, Oefv. Vet. Akad. Fórh. Vol. 15, p. 340(1858); Dipterenf. Cape of Good Hope. 
Südafr. p. 262 (1860). — PI. 5, Fig. 42. 
9. GENUS SYNECHES, WALKER 
Syneches, Walker, Ins. Saunders. Dipt. Vol. r, p. 165 (1852); Bigot, Ann. Soc. Ent. France (6), Vol. 9, 
Pp. 118 (1889); Schwarz, Proc. Ent. Soc. Wash. Vol. 2, p. 146 [1891] (habits); Coquillett, Proc. 
U. S. Nat. Mus. Vol. 18, p. 39o, 436 (1895); Williston, Man. N. Amer. Dipt. p. 74 (1896); 
Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 251(1902); Coquillett, Proc. Ent. Soc. Wash. Vol. 5, 
P. 258 (1903); Bezzi, Ann. Mus. Hungar, Vol. 2, p. 329 (1904), Vol. 3, p. 425 (1905); Melander, 
Williston's Man. N. Amer. Dipt. 3 ed. p. 224 (1908); Bezzi, Nova Acta Akad. Naturf. Halle, 
Vol. gt, p. 3or, 313 (1909); Kertész, Cat. Dipt. Vol. 6, p. 9 (1909); Mc Atee, Ent. News, 
Philad. Vol. 20, p. 359 [1909] (habits); Coquillett, Proc. U. S. Nat. Mus. Vol. 38, p. 610 (1910)4 
Bezzi, Ann. Mus. Hungar. Vol. 1o, p. 456 (1912); Brunetti, Fauna Brit. Ind. Dipt. Vol. t, p. 327 
(1920). 
Pterospilus, Rondani, Dipt. Ital. Vol. r, p. 152 (1856); Schiner, Fauna Dipt. Austr. Vol. 1, p. 77, 
(1862); Bigot, Ann. Soc. Ent. France (6), Vol. 9, p. 115 (1889) (Plerosbylus); Coquillett, Proc. 
Ent. Soc, Wash. Vol. 5, p. 256 (1903); Proc. U. S. Nat. Mus. Vol. 37, p. 598 (1910). 
