DURHAM DIPTERA. 295 



XXXIV. 



49(48). Dorsum short; jowls almost bare; male genitalia 

 with two large oval lamellae, whose margin bears 

 long frizzled bristles which stand up over the back 

 of the abdomen; wings with the usual X-veins. 

 Okenia, Ztt. (cattdata, Ztt., with V.3. and V.4. 

 bent but parallel, and dasyprocta, Lw., with V.3. 

 and V.4. distinctly diverging). 



50 (47). Third antennal joint short, rounded in front ; mouth 



with two distant bristles ; femora thick in the 

 middle; fore and hind femora bent; anal lamellae 

 of the male with short downward directed hair- 

 tufts; third abdominal segment longer than the 

 rest. Bostrichopyga, Beck, (crassipes, Ztt.) 



51 (46). Genitalia of the male without long hair-tufts. 



52 (53). V.4. near the margin bent up to V.3,, and touching 



it at the wing tip. 



Lasioscellus, Beck, {clavatus, Ztt.) 

 So Becker ; but Zetterstedt says "6* ? nervis longitudinalibus 

 3 et 4 summo apice levissime" subconvergentibus. " 



53 (52). V.4. parallel to V.3., or nearly so. 



54 (57). Very long bodied species ; abdomen extending far 



beyond the tip of the hind femora. 



55 (56). Mid and hind femora of the male much thickened 



mid tibiae with four long black bristles ; V.3. and 

 V.4. parallel but much bent downward, and V.3. 

 ending below or beyond the wing tip ; abdomen 

 flat, with lamellae beneath the fourth segment and 

 a short hair tuft at the anus. 



StjEGERia, Rnd. {kunzei, Ztt.) 



56 (55). Legs, including the femora, long and thin; V.3. and 



V.4, almost straight, diverging in the male, parallel 

 in the female; fore femora and fore tibiae with 

 teeth ; male abdomen somewhat thickened at the 

 end, in the female with a shining black sheath, 

 hooked and pointing up ; each side of the mouth 

 with a pair of distant bristles. 



Cosmetopus, Beck, (dentimanus, Ztt.) 



