148 



AN ACCOUNT OF BRITISH FIIES. 



Genus Mycetobia, Mg. 

 Body rather short. Head round, flat above. Eyes reniform. Pro- 

 boscis and palpi short ; the latter is 4-jointed, first joint small, second 

 long, third small and fourth long. Antennae 17-joihted, end joint 

 very small. Abdomen composed of seven segments. Legs stout ; tibire; 

 without spines, very short spurs. Wings broad, small hairs ; brachial 

 and cubital (third) forming a sessile fork 3 fourth longitudinal vein 

 forked near the tip of the wing, and emerging from the pobrachial 

 transverse veinlet ; fifth forked, forming the prse- and pobrachials ; 

 sixth and seventh incomplete. Areolets thirteen, viz., the humeral, 

 radical, sub-costal, x?i^\2\,pr(ebrachial united to the pobrachial, cubital, 

 sub-apical, anal, sub-anal, sub-axillary, axillary and three externo- 

 medials. 



Fig. 32. — Mycetobia pallipcs. a = posterior tibia and spurs ; b = Iast tarsal joint 

 and ungues ; c = wing; d = palpus. 



The larvas feed on fungi and rotten wood. Macquart reared them 

 from larv^ found in the detritus of elm wood. The only species of 

 this genus inhabits woods, and may be taken at rest on tree stems, 

 especially decayed ones, and those covered by lichens. 



M. pallipes, Mg. 



Black. Abdomen brown. Head and antennae black ; palpi 

 yellow. Legs yellowish, tarsi brown. Wings limpid, black veins. 

 Spurs yellow. Inhabits decayed tree trunks. 



Genus Ditomyia, ^Vtz. = i Mycetobia, Mg. 

 ( Symnierus, Wlk. 



Body slender. Head roundish, small. Proboscis and palpi short ; 

 first joint small, oval ; second long, third and fourth small. Antennae 

 I '/-jointed, slender, compressed; first joint cyathiform ; second 

 transverse, the rest ovate-cylindrical ; the seventeenth small. Eyes 

 roundish ; ocelli three, central one small. Thorax oval. Abdomen 

 seven segments, long, compressed, widened at the tip in the ? , 

 linear in thcc?. Legs long; posterior tibicC longer than tarsi ; tibiae 

 armed by short spines and fairly long spurs. Wings hairy, fairly 



