30 DURHAM DIPTERA. 



50 (51). Proboscis projecting far in front, very thin and long, 

 often double-kneed (VI. 27). No vena spuria 

 (V. 21I). Conopid^e, part (XXIX.) 



61 (56). O.6 1 short, not nearly reaching the margin, or absent. 



(V. 12, 22-39). Abdomen often with strong bristles. 



62 (63). Proboscis and palpi rudimentary. (Estridje (XXX.) 



63 (62). Proboscis and palpi distinctly present. 



64 (67). X.5 1 absent, X.5 2 present, that is, only one X-vein on 



V.5., and that beyond X.4. 



65 (66). X.4. placed very near to the base of the wing, 



X.5. far beyond X.4, (V. 14, 15). 



Dolichopodidje, part (XXIV.) 



66 (65). X.4. placed more towards the middle of the wing, 



and nearer to X.5. (V. 12, 36, 37). 

 66a (66b). Proboscis directed straight downwards, pointed, of 



the perpendicular Empis type. Stilpon (SI 2) 

 66b (66a). Proboscis retracted, of the ordinary Muscid type. 



(Pass on to No. 108 of this table). 



67 (64). X.5 1 present, that is, a X-vein on V.5. before, or 



under X.4. • or, no X-veins on V.5. 



68 (69). No X-veins on V.5. Phytomyzims, part (LIV.) 



69 (68). At least X.5 1 present, and generally also X.5 2 . 



70 (75). Squama? distinctly present, though sometimes small. 



Muscid^e calypter^e. 



71 (74). V.4. angled or bent towards V.3. (V. 24-29). 



72 (73). Abdomen with strong bristles on the middle segments, 



in addition to finer hairs, or, if absent, then the 

 arista is bare, or bare on the tip half (III. 49, 50). 



TACHINID2E (XXXI.) 



73 (72). Abdomen with no strong bristles (macrochaetae 



absent) on the middle segments, although often 

 with rather strong hairs. Arista always plumed, 

 or combed, to the tip (III. 51). 



MlJSCIDiE (XXXII.) 



74 (71). V.4. going straigl t, or nearly straight to the hind 



margin (V. 30). Anthomyidje (XXXIII.) 



(Note. — Platystoma (XLI.) has distinct squamse but the wings are clouded and 

 thickly dotted with clear spots). 



