12. XYLOMYIA 229 



Squamae (alar) whitish yellow, extending out in a rather narrow lobe which 

 bears at its end rather long whitish yellow pubescence. Hal teres brownish 

 orange. 



? . I cannot clearly distinguish the sexes, but I believe that one sex has the frons 

 slightly narrower than the other, the lower part of the back of the head less 

 puifed out, the palpi yellower, and the abdomen more pointed. 

 Length about 6 mm. 



This species bears a general resemblance to X, marginata but is not 

 really closely allied; the yellow coxse afford an easy distinction, but 

 beyond that the thinner unarmed hind femora show a strong structural 

 character, and I believe the male genitalia of the two species are very 

 distinct. X nigritibialis and its allies (as mentioned by me under JC. 

 marginata) all have serrulate hind femora. It has been bred in consider- 

 able numbers abroad, and numerous specimens which were bred by Leon 

 Dufour exist in the Museum of the Jardin des Plantes in Paris and in Bigot's 

 collection ; the pupa is very similar to that of X. marginata, but has one 

 or two long straggly hairs at the sides of each segment of which no trace 

 exists in X. marginata. 



X. varia at present is only known as British from two specimens in 

 the Stephensian collection in the British Museum, which are probably 

 those upon which Walker founded his description ; one of the specimens 

 is immature and in this specimen the front coxae are discolored and the 

 hind femora are whitish yellow while the antennte seem to be compara- 

 tively short, but in the other specimen (which is larger) the antennae are 

 almost as long as in the specimens I have described. Walker says, " The 

 larva feeds on the wood of the oak." It is very possible that it will be 

 bred in abundance in England when its larva and pupa are searched for, 

 although it is only recorded from Central and Southern Europe. 



Synonymy. — I have seen numerous specimens of X. citrij^es Dufour and have not 

 the slightest doubt about their being the same as X. varia. 



