Key to the Families of Diptera Associated with Cow Dung

Couplet 19

Either:	Or:
19.   Wing with anal vein A1 attaining wing margin at least as a crease-like fold	19'.   Wing with anal vein A1 never attaining wing margin even as a fold
Go to 20	Go to 21

First published on the Internet in 2000 by J.M. Cumming
Last updated 18 May 2006 by J.M. Cumming and G.D. Murray