ii6 
DIPTERA 
Characters. — Head oval, flattened in front, placed very low on the thorax, so that in profile 
it makes a continuous curve with the thorax ; front broad, the anterior margin produced into a triangle 
the apex of which reaching the base of the antennae; eyes oval, ocelli two in number, placed close to the 
eye margin; palpi incurved, four jointed, the first joint small, the fourth as long or longer than the 
third, usually slender, rarely oval (PI. I , Fig. I 0); antennae arcuate, 2 + 14 jointed, the basal joints 
differentiated, setose at the apex, the flagellar joints cylindrical, compressed, pubescent (PI. I , Fig. 6). 
Thorax oval, highly arched, produced over the head, pubescent, the lateral margin and over the base of 
the wing with longer hairs, posterior margin setose; scutellum usually semicircular, its margin setose; 
metanotum highly arched. Abdomen of the male six segmented, anal segment usually small, forceps 
small (PI. 7, Fig. i 7); that of the female seven segmented, more or less compressed, constricted at 
the base, ovipositor with two lamella. Legs stout, the femora compressed; tibiae with spurs, fore tibiae 
with small setae on the outer side, middle tibiae with two ranges of stout setie on the extensor surface, 
and one range on the inner side; hind tibiae with two or three ranges of long stout setae on the extensor 
surface; plantae of the hind tarsi ciliate with fine setulae. Wings somewhat longer than the abdomen, 
oval, its base more or less rounded, the microscopic setulae arranged in longitudinal rows. Costa not 
produced beyond the tip of the radial sector and does not reach the tip of the wing; subcosta very 
short, incomplete, curved toward but not reaching the costa ; media forks under or proximad of the 
base of the radial sector, its petiole very short; fork of the cubitus proximad, under or sometimes even 
slightly distad of the fork of the media, its branches usually parallel on the apical half, rarely slightly 
convergent or divergent; first anal vein incomplete, the second usually stout, and incomplete (PI. 61 
Fig. 23, 24, abnormal). 
The flies of this genus are frequentl}' found in woods and shrubbery wherever fungi grow, at all 
seasons except in midwinter. The larvae, which live in fungi and in rotten wood, possess transverse 
rows of microscopic ambulacral setulae upon the margins of the segments of the venter ; differing in 
this respect from the larvae of Phrouia, Exechia, Rkymosia, and the like. The parallel branched cubitus, the 
two ocelli, and the stout tibial lateral setae will separate this genus from its nearest relatives. 
Type species : M. agarici, Meigen (i8o3). 
Europe. 
Tasmania. 
North Europe. 
Geographical distribution of species : 
1. M. abdominalis, Staeger, in Krojer, Naturhist. Tidsskr. Vol. 3, p. 246 North Europe. 
(10) (1840). 
abdominalis, Zetterstedt, Dipt. Scand. Vol. 11, p. 4197 (18) (i852). 
2. M. adumbrata, Mik, Wien. Ent. Zeit. Vol. 3, p. 81 (2) (1884). 
3. M. aeqiialis, Walker, Ins. Saund. Dipt. Vol. i, p. 415 (iS56). 
aeqiialis, Skuse, Proc. Linn. Soc N. S. Wales (2), Vol. 3, p. I2i3 (167) 
(1888). 
4. M. agarici, Meigen, Illiger's Mag. Vol. 2, p. 263 (i8o3). 
agarici, Olivier, Encyl. Method. Vol. 8, p. 77 (10) (1811). 
? agarici. Da Villers, Linn. Ent. p. igi (1789). 
agarici seticoriiis,, Degeer, Mem. pour serv. a I'hist. d. Ins. Vol. 6, p. 367 
(i5). pi. 22, f. 6-i3 {Tipula) (1776). 
grisea, ZettersteJt, Dipt. Scand. Vol. 11, p. 4208 (26) (i852). 
^5. M. aUerna, Meigen, Syst. Beschr. Vol. 7, p. 46 (63) (i838) (Perhaps Europe. 
Rhymosia). 
■'6. M. amabilis, Dufour, Ann. Sc. Nat. (2), Vol. 12, p. 23 (2), pi. i, f. 19 Europe. 
[Dynatosoma?) 1839. 
7. M. amoena, Heer (fossil), Ins. tert. Oeningen, Vol. 2, p. 2o3, pi. i5. Central Europe. 
f. 14 (1849). 
8. M. amoena, VVinnertz, Verb. Zool.-bot. Ges. Wien, Vol. i3, p. 936 Central Europe. 
(I9)(i863). 
