the Dipterous Subfamily Ditomyine. 435 
Centrocnemis insolita (Walker). 
Platyura insolita, Walker, Trans. Linn, Soc. xvii. p. 335 (1856). 
This differs from the two Tasmanian species described 
above in having distinet microtrichia as well as macrotrichia 
on the wing. The type-species (C. stigmatica, Phillippi, also 
from Chile) may agree with C. insolita in this respect, but 
the other South American species in the British Museum 
(C. bifasciata, Williston) has no microtrichia. 
tSymmerus balticus, sp. u., 3. 
Closely allied to S. annulatus, Winn., differing as follows :— 
Size rather smaller (body 6 mm.). Abdomen unbanded, the 
first five segments rather light brown, the next two blackish ; 
hypopygium yellow, its structure similar to that of S. annula- 
tus, but the anal lamellze rather longer and distinctly narrower 
(about 5'5 instead of 4°5 times as long as broad), the ninth 
sternite not clearly visible, but apparently without the two 
long horny points which occur in S. annulatus. Fork of 
media somewhat shorter than in S. annulatus, its base 
scarcely nearer the base of the wing than is the base of 
Roi3. 
Type, a single male in the British Museum (Geological 
Department), from the Baltic amber (Miocene) of East 
Prussia, labelled “‘ No. 13628, Mus. Stantien & Becker. 405. 
Dr. Richard Klebs.” Geol. Dept. no. In. 18679. 
This is the first member of the subfamily which has been 
recorded in the fossil state, though it is probable that 
Mycetobia dejfectiva, Loew MS., mentioned by Meunier 
(Ann. Soc. Sci. Bruxelles, xxviii. 1904, p. 89) as having no 
subcosta, may be a Symmerus, possibly even identical with 
S. balticus. 
Arctoneura (Casa) wakefieldi, sp. n., ?. 
Head; vertex ochreous, a blackish spot behind each 
ocellus ; ocelli almost inastraight line. Frous and face dark 
brown, the frons very small, owing to the antenne being 
inserted close below the narrow “ bridge” of the eyes ; the 
“bridge ”’ is incomplete, the eyes being narrowly separated 
in the middle. Proboscis light brown, palpi darker brown. 
Antenne yellowish, the first thirteen flagellar joints with a 
blackish ring in the middle, the last two joints entirely dark. 
Thorax brownish, mesonotum with three dark reddish-brown 
