A Moiiogrnph of Egyptian Diplera. 27 



62 (71) Cu'2 heiit at right angles, the iiiferior 



angle of Cu cell drawn ont to a jxtint 

 extending well beyond M3; wings with 

 a s{)ot or cloud at apex. 



63 (64) Prsc. présent Chaefod. zonatus, Saunu 



64 (63) Prsc. absent. 



65 (66) Wings with a very dark stigma and Se. 



and Costa darkened; thorax dark with 

 very conspicuously contrasted yellow 

 hnmeri and scutelliim Dac. annulatus, Beck. 



66 (65) Stigma iivOt very dark; thorax i)aler. 



67 (68) Thorax with 3 dark longitudinal lines; 



médium sized species (6 mm.) Dac. oieae, (.mil. 



6S (67) Thorax without stripes. 



60 (70) Large s]>ecies (9 nnn.); humeri, prealai' 



ealli and seutellum pale vellow Dac. longistyius, Wied. 



70 (6U) Sniall .species (4.3 mm.); prealar ealli 



and seutellum reddish brown, almost 



unicolorous with thorax Dac. semisphaereus, ijEct 



71 (62) Cu2 at most bent at an obtuse angle; 



inferior angle of Cu eell not elongated ; 

 wings entirely hyaline. 



72 (73) Thoraeic pubescence bright yellowish- 



brown; large species (6.3 mm.) wings 



tinged yellowish at base Terei. virens, Lw. 



73 (72) Thoraeic pubescence very pale greyish 



or yellowish ; wings not yellowish at 

 base; smaller species (from 4.8 to 3.5 

 mm.). 



74 (75) Wings milky white ; thoraeic pubes- 



cence very pale and abmidant; upper 



