#1
I'm not very sure of this one, same beach, near Etretat (France), at seaside, on seaweeds.
I first thought at Coelopidae, but looks very like
Orygma luctuosum (Sepsidae).
Sept. 22 2007
Size : 7-8 mm.
#4
another fly in seaweed!! Almost in the other post I wrote this genus!!! funny.

it is an unusual Sepsidae, though...