12. XYLOMYIA 225 



moderately inflated with a narrow light grey eyemargin, and bearing rather long 



pendulous whitish pubescence ; back of the head on its upper third very 



shallow and with short depressed greyish white pubescence against the eyes 



and behind the vertex. Proboscis orange, large, exserted, 



with the sucker-tiaps resembling pendulous palpi and 



bearing a little pale yellow pubescence ; palpi pale orange, 



very long, thin, lying between the sides of the face almost 



up to the antennae, and bearing rather abundant short 



pale yellow pubescence. Eyes large, bare ; facets all equal. 



Antennae (fig. 158) dull black, but the second joint partly ^^^ \b^ —Xiiionmia 



ferruginous ; the tAvo basal joints short and transverse, mar'ginaia S- x^so. 



about equal in length, and bearing tiny pale pubescence • 



third joint practically bare, about three times as long as the two basal joints 



together, so that the whole antennae are about as long as (or slightly longer 



than) the head ; third joint a little thicker than the others about its base and 



slightly tapering, though still thick and blunt at its tip, where a minute 



sharp apical style can sometimes be traced ; the third joint has eight 



indistinct annulations, of which the basal one is the longest, though the last 



one is about twice as long as the penultimate one. 



Thorax black, very crowdedly and coarsely pimctate so that it is but little 

 shining, and the ground colour is somewhat obscured by the depressed 

 glistening pale pubescence ; humeri with the extreme lower corner reddish 

 (extensively pale yellow in a Bohemian specimen), and a fairly wide 

 orange stripe runs along the upper margin of the mesopleurae from beneath 

 the humeri to the wing-base, but sometimes this stripe becomes thin and dies 

 out in a point at the hind corner of the mesoiDleui-a though even then a 

 reddish spot remains just in front of the wing-base ; lower front corner of 

 hypopleurce obscurely reddish ; pubescence all over the disc of the thorax 

 almost adpressed glistening greyish white, but giving an impression of being 

 arranged m broad black and grey stripes because of the differing directions in 

 which the hairs slope, and especially showing (when viewed from above) a 

 broad black middle stripe ; pleurae shining black, but roughened and bearing 

 very short depressed shimmering greyish white pubescence which becomes 

 conspicuous and almost silvery on the sternopleurae and hindmargin of the 

 mesopleurae, and rather longer and denser but inconspicuous on the meta- 

 pleurae. Scutellum shining reddish orange with the extreme side corners 

 black ; pubescence very short and greyish white ; metanotum black, obscured 

 by greyish dust. 



Abdomen black, moderately shining and all rather roughly punctate, with 

 an arched reddish orange spot extending all across the base and with the 

 hindmargins of the second to fifth segments narrowly orange all across the 

 disc but not extended over the sides ; the basal four segments have almost 

 parallel sides, but the fifth slightly contracts and the sixth distinctly does so, 

 while the seventh segment is shorter and droops over the genitalia : all the 

 segments have an inconspicuous transverse depression across the disc just 

 after the middle of each segment ; pubescence on the disc black but incon- 

 spicuous, being very short and dense, but away from the middle of the disc 

 there are some short adpressed greyish white hairs, which become longer and 

 more conspicuous towards the sides and on the sidemargins, and longer still 

 and more erect about the basal corners, while the third to sixth segments 

 have pale hindmarginal fringes. Belly moderately shining black with the 

 basal pale spot shining through from above, and the second to fifth segments 

 with narrow yellow hindmargins and with their sides luteous ; pubescence 

 yellowish, very slight. Genitalia forming a large knob beneath the sixth and 

 seventh dorsal segments, the end part forming a large arched plate which is 

 shining black down its middle but shining chestnut at the sides ; at the upper 

 basal corners there is a pair of long almost thread-like orange lamellae which 

 have long pale fringes, and similar fringes extend from these along the hind- 

 margin of the seventh segment ; beneath the large plate there is a pair of 

 short stout orange lamellae against the hind corners of the sixth segment, 

 while the large curved middle part is rather blackish chestnut. 



Legs mainly orange ; coxae and trochanters shining black, but the trochanters 

 with chestnut reflections ; front coxae long and stout, trochanters moderate in 



