THE DIPTERA OF THE BRISTOL DISTRICT. 
65 
Eristalis rupium (F.) V.R.P. 
horticola (Deg.) Cheddar, Nailsea, and V.R.P. 
Myiatropa florea (L.) Common, Cheddar, Bristol. Generally a very 
variable insect. 
Helophilus trivittatus (F.) Cheddar (Curtis). 
,, pendulus (L.) Occurs everywhere by the water-side. 
,, versicolor (F. ) Rare, Bitton, July, and V.R.P. 
,, lunulatus (Mg\) Shapwick (C. W. Dale, Entomol. Month. 
Mag., vol. XXVIII., 1892) 
transfugus (L.) Rare, Bitton, June. 
These five species resemble Eristalis, but can always be recognized 
by the longitudinal stripes on the thorax. They are fine hoverers. 
Merodon equestris (F.) A local species, Redland, Frampton Cotterell. 
Very common at Wotton-under-Edge in 1903, V.R.P. A very 
variable fly, resembling a small humble-bee. I have bred it from 
larvae in Narcissus bulbs. 
Criorrhina ranunculi (Pz.) Near Bristol (Verrall), and V.R.P. 
,, berberina (F.) Rare, S.M., June, on Bramble blossoms. 
,, oxyacanthm (Mg.) Minehead (Blathwayt), and V.R.P. 
,, floccosa (Mg.) Rare, S.M., May, Stroud (Wainwright). 
Xylota segnis (L.) Common. Males sometimes swarm round Leigh 
Woods pond. 
,, lenta (Mg.) Minehead (Blathwayt), and V.R.P. 
,, sylvarum (L.) Freshford and Leigh Woods, June and July. 
Syritta pipiens (St. F.) Common everywhere. Its early history is 
not known. 
Humerus ornatus (Mg.) Rare, Freshford, July. 
,, strigatus (Fin.) Rare, Leigh Woods, July. 
The larvae of Humerus are said to attack onion-bulbs, just as 
Merodon attacks Narcissus bulbs. The perfect insects have a 
strong resemblance to bees of the genus Halictus. 
Chrysoclamys cuprea (Rond.) Rare, Nailsea, Freshford, Redland in 
July, and V.R.V. 
Arctophila musitans (F.) Batheaston (Blathwayt), and C.J.W. 
Sericomyia borealis (Fin.) V.R.P. A large black fly, with yellow 
bands, and a most beautiful insect, called the ' Singing fly ' from 
a sharp hum it makes when at rest. I have taken it in numbers 
in North Devon, and it should occur on the Somerset Peat-moors, 
as the larvae lives in Peat-bogs. 
Chrysotoxum cautum (Har.) Rare, Sea Mills, June. 
,, arcuatum (L.) Rare, Cheddar, in August. 
,, festivum (L.) Rare, Freshford, July. 
,, bicinctum (L.) S.M., Freshford, Bristol, sometimes 
common 
Microdon mutabilis (L.) Langport Dale. A handsome insect that 
resembles a hive bee. The larvae are slug-like, and were at first 
described as mollusca. The larvae occur in ants' nests. 
