308 LEPTID.5^ 



Thorax almost as in the male, but in an entirely abraded specimen 

 a broad brown middle stripe extends though rather vaguely well forward 

 and two broad side stripes occur which are widely interrupted at the suture 

 and a small brown patch exists on each side almost above the wing-base. 



Abdomen without any distinct blackish bands across the base of the 

 segments. Ovipositor with long telescopic joints which have dull orange 

 hindmargins, and ending in a pair of very small ovate lamellae. 



Legs with the coxre and trochanters less darkened. 



Wings, etc., as in the male, but the veins near the base sometimes strongly 

 orange. 



Length about 5-5 mm. 



This species may be known by its almost entirely pale legs, its small 

 size, and its conspicuous stigma. It is very difficult to obtain in perfect 

 condition because its golden pile is very easily rubbed off or bleached. 

 Continental specimens seem to be slightly larger, and in perfect specimens 

 the ground colour of the abdomen seems to be deeper black, while some- 

 times the antennae are rather ferruginous, the hind coxse entirely luteous, 

 and the golden scales on the front and hind femora fairly numerous 

 though indistinct on the yellow ground colour. A continental female 

 has all the ground colour of the thorax and abdomen concealed by dense 

 whitish yellow pile except on the last three segments of the abdomen 

 (which seem to form part of the ovipositor). The European G. splendidtt 

 has much blacker femora, and the eye-facets of the male more distinctly 

 unequal. 



C. aureus is hardly so common as C. cristafus, but still may occur 

 anywhere in rather marshy localities, as I have records from Cornwall 

 (Penzance) to Sutherland (Inchnadamph). My dates range from June 

 20 to August 3. It is recorded from Denmark to Italy. 



7. PTIOLINA. 



Ptiolina (Stffiger) Zetterstedt, Dipt. Scand., i., 21 and 226 (1842). 



Small dark colored flies, which differ very much in the 



sexes. 



Head rather large ; epistoma small and bare, socketed between the broad side- 

 cheeks ; side-cheeks occupying more than two-thirds the space between the eyes, and 

 either pubescent or bare. Eyes bare, touching for a considerable space and leaving 

 only a small triangular bare frons just above the antennae and a small vertical 

 triangle at the toj:) in the male, but widely separated in the female ; facets consider- 

 ably enlarged on the larger upper part and sometimes very sharply separated from 

 the small facets on the smaller lower part, or sometimes the distinction rather 

 gradual. Antennaj (figs. 200, 201) with the two basal joints short; third joint com- 

 paratively large and long, short ovate, and bearing an almost apical stout bristle-like 

 style which is hardly longer than the third joint. 



Thorax and scutellum simple, equally pilose without any distinctive bristles. 



Abdomen simple, with seven distinct segments which gradually decrease in length 

 and breadth from the second to the seventh, the seventh being rather short in 

 proportion to the others ; all equally and moderately pilose. Genitalia of the male 

 rather knobbed, being rather short and blunt. 



Legs simple, evenly i)ilose or almost bare ; front tibial without any spur, middle 

 tibiai with two obvious nearly equal sjjurs, hind tibiit with one small spur ; front 

 tarsi as long as the tibiae and with a few '' touch-hairs " on the underside of the basal 

 joint, which is almost as long as the other four johits together ; middle tarsi rather 

 shorter than the tibiie ; hind tarsi about as long as the thin straight tibia?. 



