LIBRARY

DIPTERA
the bend, the costa fractured at the apex of the subcosta; wings almost
always pictured. (Fruit Flies.) (TRUPANEIDJE) TRYPETIDJE
Subcosta not angularly curved and weakened 51
50. Head broad, flattened above; scutellum and thorax flattened, the
former elongate; large flies . . RHOPALOMERIDlE
Head rather spherical; scutellum usually convex, not elongate; small,
cylindrical flies. (Spiny-legged Flies.) . . SEPSIDJE
51. First segment of the posterior tarsi shortened and incrassate. (Manure
Flies.) . . . BORBORIDJE
First segment of the posterior tarsi normal, usually longer than the
second 52
52. Anal cell absent. 53
Anal cell present . 55
53. PostocellarbristIes divergent. (Shore Flies, Ephydrid Flies.) EPHYD:RlDJE
Postocellars convergent or absent . 54
54. Ocellar triangle large; fifth vein with a distinct curvature near the
middle of the discal cell. (Frit Flies.) . . CHLOROPIDJE
Ocellar triangle small; fifth vein straight or without a sharp curvature.
(Vinegar Flies.) . DROSOPHILIDJE
55. Costa broken at the humeral cross vein . . 56
Costa not broken at the humeral cross vein 58
56. Postocellars divergent, if absent the arista absent. (Leaf-mining Flies.)
AGROMYZIDlE
Postocellars convergent, parallel or absent, arista present . . 57
57. A pair of convergent frontal bristles anteriorly; interfrontals often
present PHYLLOMYZIDlE
Anterior fronta1s not convergent. (Vinegar Flies.) . DROSOPHILIDlE
58. Postocellar bristles convergent . OPOMYZIDJE
Postocellar bristles divergent or absent . . 59
59. Ocellar triangle large and shining, reaching the anterior edge of the
front. (Seashore Flies.) . . CANACEIDlE
Ocellar triangle short . 60
60. Second vein joining the costa just beyond the apex of the first ASTEIIDlE
Second vein joining the costa far beyond the apex of t.he first. 61
61. Costa fractured or weakened at the apex of the auxiliary vein. . 62
Costa not at all weakened PERISCELIDlE
62. Oral vibrissre present. (Leaf-mining Flies.) AGROMYZIDlE
Oral vibrissre absent 63
63. Sternopleural bristle present . OPOMYZIDlE
Sternopleural bristle absent. (Rust Flies.) . PSILIDlE
64. Oral vibrissre present . 65
Oral vibrissre absent 71
65. Mesonotum and scutellum convex, if rather flattened the abdomen
and legs not bristly. . 66
Mesonotum and scutellum flattened; legs and abdomen conspicuously
bristly C