Logics for $T$-coalgebras are obtained by giving a
equational presentation of the ``dual'' of $T$. 
In the setting of enriched categories we prove that
endofunctors on finitary (enriched) varieties which
preserve sifted colimits have an equational presentation
in the enriched sense.

We discuss applications of this result to categories
of nominal sets and to varieties enriched over posets.
This is a work in progress, joint with Alexander Kurz