312 LEPTID^ 



is a sliort pale brownish ciliation. Halteres brown, with the large knobs 

 blackish brown, 



? . Resembling the male in venation but otherwise very distinct. Frons and 

 face light to rather dark brownish grey, nearly half the width of the head at 

 the narrowest part which is at the slight suture crossing the frons a 

 little above the antennte ; frons with rather sparse short black setose 

 pubescence all over except on each side of the ocellar triangle, near the 

 occipital bristles, and close to the antennae ; face bare on the epistoma but 

 with rather sparse short black pubescence on the broad side-cheeks ; side- 

 cheeks slightly produced from the eyes in profile ; jowls and back of the head 

 rather broadly inflated and bearing rather short setose black pubescence, but 

 the actual postocular margin bare until above the middle of the head, after 

 which the bristles become longer on the top fifth and some of them come close 

 to the eyes ; actual back of the head bare. Proboscis and palpi blackish ; 

 proboscis slightly the longer and with short sparse pubescence beneath ; 

 palpi with black setose pubescence. Eyes rather small ; facets all equal in 

 size. Antennfe similar to those of the male, but the two basal joints and the 

 base of the third joint faintly ochreous. 



Thorax brownish or brownish black with a slight gloss and usually (but 

 not always) with indications of three or five darker brown rather broad 

 stripes ; humeri rather ochreous. Pubescence all evenly and moderately 

 subsetose, but without any special bristles though with longer pubescence 

 on the posthumeral district and on the margin of the scutellum. 



Abdomen pointed, rather shining chocolate brown or almost black, with 

 moderate black pubescence. Ovipositor ap]mrently composed of several 

 joints which end in a pair of elongate lamellre. 



Legs brownish black or blackish, very similar to those of the male but the 

 hind legs show no special ciliation except antero-ventrally on the femora ; 

 spur on the hind tibiae short ; " touch-hairs " shorter than in the male. 



Wings as in the male, though they may be more smoky blackish brown ; 

 veinlets from the upper corner of the discal cell varying almost as in the 

 male. Halteres rather paler. 



Length about 4 mm. 



This species may be distinguished from Ft. aira in the male by the 

 basal joints of the antennte bearing only very short bristles, and in both 

 sexes by the pubescent side-cheeks and less hairy thorax, abdomen, and 

 legs, and by the more rounded third joint of the antennae. To distinguish 

 it from allied European species attention must in addition be given to the 

 thorax and abdomen being by no means bare, while the thorax is dull in 

 both sexes and not striped in the male, but the European species are still 

 very little known and not satisfactorily differentiated. It varies consider- 

 ably in size and to a certain extent in darkness of coloration, and a pair 

 from Glanville's Wootton in the late ]\Ir C. W. Dale's collection have very 

 blackish wings, the thorax of the male deep velvety black, and the abdomen 

 and legs quite black, while in the female the thorax and abdomen are 

 blackish grey with scarcely any trace of stripes on the thorax. The 

 specimens I have figured prove the valuelessness in this genus of any 

 characters derived from the presence, length, or absence of a stem to 

 the two upper veinlets from the discal cell. 



P. dbscvra is uncommon in Britain and is only now beginning to bo 

 well understood. I caught it in the New Forest and in the Isle of Wight 

 (Bonchurch) in June 1885, and Dr Sharp and Mr C. G. Lamb found it in 

 abundance near the village of Bank in the New Forest in June 1901 and 

 1902, and it occurred sparingly in that spot in 1905. I have also taken 

 single specimens at Bettws-y-Coed and Ulleswater; Dr J. H. Wood has 

 taken it near Tarrington in Herefordshire, and Colonel Yerbury at 



