= 
118 AN ACCOUNT OF BRITISH FLIES. 
the tip of the pre-brachial areolet and another near the costa. 
Length, 1} to 2 lin. 
_ MM. lunata, Mg. 
The metamorphosis of the species has been well followed by 
Heeger, but in his paper are many curious and erroneous state- 
"ments, as seen in the following quotations: ‘‘ The stigmata are nine, 
on nine consecutive segments of the body, except the two first ;” 
and another more important point, viz., ‘‘The locomotive swellings 
and their bristles are described on the éack of the larva,” etc., etc. 
- The eggs are + lin. long, cylindrical and white. The /a7ve are 
stout white maggots, with a dark-brown corneous head. The eggs 
may be laid by the @ singly or in patches (twenty to thirty) on the — 
same fungus. The larve hatch after eight or ten days, and com- 
mence to burrow into the under side of the pileus. They shed their 
skin three times, and transform near the outer margin. Haliday 
says: “The larvee spins for its transformation a long pouch of silk 
(white), with a flat circular lid.” The pupal state lasts nine to 
twelve days, the fly generally coming out in the morning. The 
perfect insects and pupz hibernate, and appear in the spring. Bremi 
obtained it from Agaricus citrinus, and Haliday also records the 
larvee as living gregariously in the hollow stalks of Agarics, 
M. arcuata, Zett. 
M. bi _F. -{ 
tmaculata M. pictula; Meg. 
This is a somewhat rare species in England. It is brownish- 
black and covered with pale yellowish hairs. Head blackish-brown. 
Palpi yellowish. Antennz blackish-brown ; yellowish at the base. 
Thorax with a yellowish stripe on each side, which is largest and 
broadest in front. Abdomen blackish-brown; ¢ genitalia brown ; 
? with blackish-brown lamelle. Wings with a brown spot, which 
passes from the costa to the pre-brachial areolet, and at three- 
quarters of length with a gray band, which is brown in front. Tips 
of wings gray. The veinlets of the pre-brachial areolet form an 
obtuse angle. The fifth longitudinal vein forked beyond the fork of 
the fourth longitudinal vein. Halteres brownish-yellow. Legs tes- 
taceous ; tarsi brown. Length, 13 to 2 lin. ‘This is a large species, 
with alar expansion of 4-5 lin. 
