THE DIPTERA OF THE BRISTOL DISTRICT. 
53 
larvae of Merodon, the resulting decay in the bulb affording the 
food of the larvae. I should be inclined to think that in the case 
of the potato, there is some disease (fungoid ?) which causes the 
tuber to decay, and so prepares it for Epidapus. 
Zygoneura sciarina (Mg.) Bristol. June. 
Mycetophila punctata (Mg.) S. M. July. 
lineola (Mg.) S.M. April. 
nigritula (Wlk.) V.R.P. 
Rhymosia fenestralis (Mg.) C.J.W. 
fasciata (Mg.) C.J.W. 
Exechia fungorum (Dg.) S.M. February. 
lateralis (Mg.) C.J.W. 
Allodia crassicornis (Stan.) S.M. February. Have often found 
these hibernating in caves, &c. 
Sciophila fasciata (Zett. ) V.R.P. 
Platyura marginata (Mg. ) V.R.P. 
Ceroplates tipuloides (F.) S.M. July. 
Macrocera ceyitralis (Mg.) S.M. June. These beautiful little gnats 
may be known by their immensely long thread-like 
antennae ; they are sometimes quite common. 
lutea (Mg.) C.J.W. and V.R.P. 
vittata (Mg.) V.R.P. 
angulata (Mg.) V.R.P. 
,, stigma (Curt.) V.R.P. 
Plesiastina annulata (Mg.) V.R.P. 
Bibionid^e — Medium sized, black, hairy flies, seen in spring, 
sometimes in immense numbers. The males dance up and down 
in the air. The larvae live in decaying vegetation. 
Scatopse notata (L.) S.M. April. C.J.W. Bred from a wasp's nest. 
, , scutellata ( Lw. ) V. R. P. 
flavicollis (Mg.) V.R.P. 
Scatopse is a genus of small, shining, mostly black, flies ; the fe- 
males are sometimes found congregated in numbers under bark. 
Dilophus febrilis (L.) S.M. Very common. Bred from larvae living 
in cow-dung. 
,, albipennis (Mg.) S.M. May. 
,, femoratus (Mg.) S.M. June. 
These are small, black, hairy flies ; the larvae are said to be some- 
times very injurious to hops. These three are all the British species. 
Bibio marci (L.) St. Mark's fly. Common everywhere in April. 
,, pomonce (F '.) V.R.P. 
,, hortulanus (L.) V.R.P. 
,, johannis (L.) St. John's fly. (S.M.) Common in May. 
,, clavipes (Mg.) Throughout the district. 
,, nigrwentris (Hal.) V.R.P. 
,, leucopterus (Mg.) S.M. and V.R.P. 
