244 [NoTcmber, 



mtich less extensively darkened at base. Abdomen broad, -with 

 small rounded brownish patches on the first three segments 

 (smallest on the first and largest on the second). Legs, etc., as in 

 the male. 



Length about 5 mm. (females sometimes 6 mm). 



This species appears to be a marsh-laving species which has 

 occurred sparingly at Martham and Ormesby (Norfolk) to Mr. 

 Verrall, in the New Forest (Hants) to Dr. D. Sharp and F. C 

 Adams, and at Walton-on-Naze (Essex) to Col. C. G. Nurse. 

 Mr. H. W. Andrews, however, has taken the species in some 

 numbers in the Thames Marshes (Kent) from May to September. 



2 (1) Thorax with three dark stripes in front, the middle one being narrow 



in front of suture but broadening out and often confluent with side- 

 stripes just behind suture. Arista at most only pubescent. 



3 (6) Scutellum greyish at least on disc. 



4 (5) Darker species with thoracic side-stripes broad. Normally only three 



pairs of postsutural dorsocentrals, Scutellum with dark basal side- 

 patches. Hind femora short-haired posteroventrally 

 .... 24. maculosa Mg. 



J . Frons a little wider than in notata, and the frontal orbits, 

 though narrower than froutalia, are wider than in notata. Arista 

 distinctly pubescent. Thoracic markings not so dark and of a 

 brownish colour ; a broad presutural patch on each side and a 

 narrow central stripe which widens out behind the suture and 

 coalesces with the side-stripes for some considerable distance; a 

 smaller dark patch above the root of each wing. Abdomen viewed 

 from bel)ind with the dark markings on first segment separated by 

 a grey central stripe and leaving the hind margin broadly greyish at 

 sides ; those on the second and third segments usually occup^^ing 

 the full length of each segment, narrow at base but as wide as long 

 on hind margin ; those on third segment smaller ; fourth segment 

 often with a faint brownish middle line. Hypopygium brownish. 

 Middle tibiae with two bristles behind. Hind tibiae occasionally 

 with the usual single anteroventral and anterodorsal bristle dupli- 

 cated. Squamae whitish. Halteres yellow. 



2 . Kesembliug the male, but frons broad. Abdominal dark 

 patches sharply marked and "extending broadly along the hind 

 margin of second and third segments, in that respect more resem- 

 bling e.vsurda and uniseta than the other species of this group, but 

 the arista is more distinctly pubescent than in these two species, and 

 there are normally only three pairs of postsutural dorsocentrals, 

 while in e.vsurda the ground-colour of thorax is more bluish-grey, 

 and in uniseta the thorax more suffused with brown and the stripes 

 less distinct. 



Length 5-6'5 mm. 



This species is more widely distributed than notata. Specimens 

 have been examined from the New Poorest (Hants), Dawlish, 

 Slapton, and Ivybridge (Devon), Porthcawl (Glamorgan), Barmouth 

 (Merioneth), Oxton Bogs (Nottingham), Loch Maree (Ross and 

 Cromarty), I>airg and Tongue (Sutherland), captured by Mr, Verrall, 



J 



