12. XYLOMYIA 221 



similar to those of X. maculata but has very much longer antennge ; unfortunately 

 it has lost both wings, but it must be very closely allied to Xylomyia or even 

 congeneric as Osten Sacken suggested in 1886; the hind femora are not thickened 

 and have no serration beneath. 



Table of Species. 



1 (2) Thorax black with conspicuous yellow spots, 1 maculata. 



2 (1) Thorax black without any conspicuous yellow markings. 



3 (4) Coxse blackish, 2 marginata. 



4 (3) Cox0e all orange. 3 varia. 



1, X, maculata Meigen, Thorax black with conspicuous yellow spots. 

 Abdomen with yellow cross-bands. 



A very handsome exotic-looking black and yellow fly. 



(^, Ground colour rather shining black. Eyes separated at the vertex by about 

 one-seventh the width of the head and almost equally so down to the mouth, 

 as the widening which begins just above the antennae is very slight ; this sjmce 

 is dull black except on the shining part just outside and in front of the ocellar 

 space, but the vertex, the ocellar space itself, and a considerable part of the 

 frons after the shining portion is rather densely 

 covered with glistening greyish yellow adpressed 

 pubescence which leaves only a dull black unequal 

 cross-band a little above the antennas on which 

 there is neither dust nor pubescence, and the portion 

 anterior to that just above and all round the antennae, 

 including the narrow strip of face below the antennae, 

 is densely covered with greyish dust ; the face is very 

 short and only forms a strip just below the antennas 

 because a wide quadrate clypeus extends far uj^wards 

 from the mouth and leaves only a very narrow grey fj^. i^t .-Xyioviyia 

 Ime down each eyemargm, the clypeus itself being maculata S- x 32. 

 also densely covered with greyish dust ; jowls and 



back of the head so shallow as to be almost absent, but behind the eyes 

 from their lowest part to nearly one-third up there are some fairly long 

 pale greyish hairs, and on the rest of the back of the head there is a line 

 of short dense inconspicuous black bristles ; quite behind the vertex there is 

 a patch of minute pale pubescence on the back of the head. Proboscis large 

 and entirely exserted, being apparently composed of the large pale orange 

 sucker-flaps which look like a lower pair of palpi; palpi large and rather 

 club-shaped, bright orange. Eyes bare ; facets all equal. Antennas (fig. 157) 

 slightly longer than the head when seen from above, more or less extensively 

 dull orange on the inner side, but blackish on the outside and upper side 

 and on the base and tip ; basal joint short, being barely so long as broad, 

 second joint slightly shorter but more equally transverse, and these two 

 joints bear tiny black bristles except on their inner side ; third joint (tlagellum) 

 with seven annulations before the conical end one, first annulation nearly as 

 long as broad, but the next six only about half as long and very gradually 

 diminishing in size, eighth annulation microscopically hairy, quite twice as 

 long as its base is broad, conical, and sending from its point a short sharp 

 apical bristle. 



Thorax shining black, Avith several conspicuous orange spots ; each end of 

 the suture has an orange spot which usually extends rather narrowly along 

 the suture and is widened at its inner end into another (though smaller) spot of 

 irregular shape, but the middle third of the suture remains black ; humeral 

 knobs and adjoining front of thorax pale orange, or sometimes with an 

 adjacent orange spot out on the disc; postalar calli with a large irregular 



