July, 1910.] 



149 



ON THE BRITISH SPECIES OF PHORA. 



BY JOHN H. WOOD, M.B. 



(Continued from Vol. xlv, p. 244). 



Section D. 



1 (44) First costal division much longer than the second and third together (at 



least half as long again, often twice as long or even more). 



2 (25) Costal fringe short. 



3 (4) Middle and hind tihise tvith douhle rows of cilia, one on each side the 



seam. 

 $ ? . Thorax and halteres yellow, mesopleurse bare ; venter and 1st segment 

 of male abdomen wholly yellow, the rest of the dorsum black or suffused 

 on the last segment or two with yellow, female abdomen black only on 

 dorsrun of 3rd and 4th segments; frons yellow, dusky towards vertex, 

 rather longer than broad, its bristles large, inner bristle of the lower row 

 nuich below level of outer one, but well away from eye margin ; one pair 

 only of very minute supra-antennal bristles; antenna? and palpi clear 

 yellow, the former large and oval and with a very short arista (about as 

 long as the frons), the latter small and with very short and stubby 

 bristles ; wings pale yellowish ; costa about f wing length, 1 fully 

 double 2 + 3 ( <? ) rather less ( ? ), angle at fork rather small, 1st thin 

 vein recurved at margin ; legs yellow ; tibial cilia on inner side of seam 

 very large and conspicuous, on outer smaller and confined to upper half 

 of limb ; hind metatarsi somewhat thickened ( $ ) much thickened ( ? ) ; 

 hypopygiiun more or less concealed within the last segment, but usually 

 leaving visible the short rounded flap into which the lower edge on each 

 side is ciit ; anal organ very large, yellow, but more dusky at its base, and 

 with the usual pair of terminal bristles remarkably large ; ovipositor very 

 large, the 1st joint always exserted and often the whole organ, 2nd joint 

 encircled at the end with 6 strong bristles 1^ — 2 mm. fasciata, Fall. 



4 (3) Cilia on one side of the seam only — the inner. 



5 (14) Mesopleurse bristly. 



6 (7) Halteres yellow. Arista very short — not longer than the frons. 



J . Thorax yellow, pleural bristles small and few ; abdomen black ; frons 

 grey, as long as broad, frontal bristles as in fasciata ; the upper pair of 

 supra-antennal bristles small, the imder very minute ; antennas red, not 

 large, and of the usual roundish form : palpi pale yellow, large and armed 

 as in fasciata ; wings and veins yellow ; costa about f wing length, 1 about 

 half as long again as 2 + 3, angle at fork acute, 1st thin vein nearly 

 straight at its origin from the fork and not recurved at the margin (this 

 straightness at the start is the invariable condition of the first thin vein, 

 at least in those species in this section which do not much exceed 1 mm. in 

 measurement) ; legs yellow, hind femora dusky at tip, the hairs on basal 

 half of its ander-side well developed; hind tibias strongly arched and 

 strongly ciliated ; hypopygivun concealed, anal organ clear yellow, very 



