120 AN ACCOUNT OF BRITISH FLIES. 7 
short; tarsi brown; tibie dark ; wey short spurs in hind ones. 
Length, 2} to 3 lin. 
R. maculosa, Zett. 
R. fasciata, Mg. = (2. aiscoidea, Zett. 
M. zonata, Steph. 
_ This is a common species, reddish-yellow in appearance, with 
testaceous ventral surface. The palpi and antennz are testaceous; 
the latter dark at the base. The two veinlets, which form the pre- 
brachial areolet, make a right angle; the posterior one very much 
larger than the fore one ; about three times the length of the fourth 
longitudinal vein before its fork ; the hind branch curved. The anal 
vein extends far beyond fork of fourth longitudinal vein. The abdo- 
men is brownish-black, with four testaceous bands on the fore 
segments ; the extremity of the abdomen is testaceous. The legs 
are long and slender, dark reddish-brown ; tarsi almost black; spurs 
long ; very small on hind tibiz; the fore tibiz much shorter than 
fore metatarsi. Length, 1} to 2 lin. 
There are four other British species of this genus ; viz., ¢runcata, 
Wtz.; maculosa, Mg.; selecta, Wik.; and sericea, Mg. 
Genus.—Dynatosoma, Wtz. = Mycetophila, Mg. 
This genus much resembles Mycetophila. There are two ocelli 
only. Zhe base of the fourth hind areolet is much more distant from 
the base of the wing than ts the base of the second hind areolet. 
et ee _ (M. fuscicornis, Mg. 
D. fuscicornis, Mg. = A. presets, Chace: 
This is the only species of this genus found in Britain. It was 
formerly included in the Mycetophilz, and was described as one by 
Walker ; but it is now raised to a distinct genus by Winnertz. 
The imago is blackish-brown ; thorax tawny in front, with three 
dark-brown spots; palpi yellowish. Antenne yellowish at the base; 
abdomen with a white tomentum beneath; legs yellowish; tarsi 
brownish ; tips of posterior femora dark-brown; fore-tibiz long. 
Wings grayish-brown, with two distinct brown spots, one on the tip 
of the prze-brachial areolet and of the fork of the fourth longitudinal 
vein, the other near the costa; fifth longitudinal vein forked ; sixth 
does not extend to the fork of the fifth. Length 14 to 2 lin. 
Found in the autumn and winter. 
Genus.—Exechia = Mycetophila, Mg. 
The ocelli two, small. Sides of the thorax with bristles. Abdomen 
4 “ ~ = a 
ee 
