214 DURHAM DIPTERA. 



XXXI. 



75 (102). 0.4 2 open, or just closed at the margin, not stalked. 



76 (97). Eyes bare. 



77 (78). Proboscis bristle-like, far protruding, and doubly 



geniculated, the front part shutting back like a 

 pocket-knife on the second. Siphona, Mg. (396) 



78 (77). Proboscis not bristle-like, nor far protruding, once 



bent, the front part not shutting downwards and 

 backwards. 



79 (84). V.3. bearing bristles at least as far as X.4. 



80 (81). Arista apparently two-jointed, the second joint being 



very small ; mouth bristles extended upwards on 

 the facialia. Roeselia, Dsv. (390) 



81 (80). Arista distinctly three-jointed and bent ; mouth 



bristles not extending upwards ; facial bristles 

 absent. 



82 (83). X.5 2 much nearer to X.4. than to the bend of V.4. ; 



cheeks bristly ; discal abdominal bristles -present 

 on the middle segments. 



Digonoch^eta, Rnd. (392) 



83 (82). X.5 2 about the middle between X.4. and the bend 



of V.4. ; cheeks bare ; discal abdominal bristles 

 generally absent (present in latifrons). 



Thryptocera, Mcq. (393) 



84 (79). V.3. not bearing bristles, or only just at its base. 



85 (86). Arista distinctly three-jointed, the second joint being 



long; abdominal discal bristles absent. 



Craspedothrix, B. & B. (293£) 



86 (85). Arista apparently two-jointed, the second joint being 



very short. 



87 (88). Arista equally thick to the tip, and often as if broken 



over at its base ; V.3. with two or three thorns at 

 its base ; face in profile almost perpendicular. 

 388. Discoch/ETa, B. & B. (1806. muscaria, Fin.) 



88 (87). Arista tapering, thickest at its base, or equally thick 



for half its length, and always straight. 



89 (90). Face in profile retreating; arista equally thick for 



half its length. Degeeria, Mg. (368) 



