SYSTEMATIC  ACCOUNT.                                         107

Echidnocephalus Lamb.    1914.    Trans. Linn. Soc, 16, 351.    This genus was described as

being near Liomyza, and is accordingly to be referred to the Asteinse.
Hypselothyrea de Meijere.    1906.    Ann. Mus. Nat. Hung., 4, 193.    This genus is to be

referred to the Asteinse.
Liomyza Meigen.    1838.    Syst. Beschr., 7, 394.    I am not familiar with this genus, but

it appears to fit best in the Asteinse.    It is surely not a drosophiline, as that group

is here defined.
Microperiscelis Oldenberg.    1914.    Arch. Naturgesch., 80, A, 2.    Near Periscelis, and

therefore probably to be placed in the Agromyzinse.
Monocera van der Wulp.    1898.    Termes. Fuzetek., 21, 425.    De Meijere (1914, Tijd.

Ent., 57, 238) refers this genus to the LauxanUnse.
Paratissa CoquiUett.    1900.    Canad. Ent., 32, 36.    This genus evidently belongs in the

Ephydrinse, where it is now usually placed.
Periscelis Loew.    1858.    Berlin, ent. Zeit., 113, 2.    Oldenberg has pointed out that this

genus is scarcely to be considered as a Drosophiline.    American specimens that I

have examined seem to me to fit best in the Agromyzinse.
Sigaloessa Loew.    1865.    Berl. ent. Zeit., 120.    Close to Asteia, and therefore to be placed

in the Asteinse.
Stenomicra Coquillett.    1900.    Proc. U. S. Nat. Mus., 22, 262.    The type seems to me

to be a geomyzine, close to Mumetopia.
Uranucha Czerny.     1903.    Wien.  ent.  Zeit.,  22.    Described as being near Liomyza.

Is to be considered an asteine.

XI. GEOLOGICAL HISTORY.

According to Handlirsch (1906-1908), Diptera first appear in the
Liassic; Cyclorrhapha not until the Lower Oligocene. In the latter
period the Muscidse acalyptratse are already numerous, and are repre¬
sented by nine subfamilies, all with species described as belonging to
existing genera. The Lauxaniinse, Ephydrinse, Chloropinse, and
Drosophilinse are among these subfamilies. The drosophiline, which
is the only fossil member of the group known to me from the literature,
is a form from Baltic amber recorded by Loew (1850) as "Drosophila
sp." Loew did not describe the species, and it is to be noted that later
(Loew, 1864) he referred to the subfamily as one "whose existence in
amber is tolerably well established," as distinguished from others
''now known certainly to occur in amber."