  We consider evolutionary equations of the form $u_t=F(u, w)$ where
$w=D_x^{-1}D_yu$ is the nonlocality, and the right hand side $F$ is polynomial
in the derivatives of $u$ and $w$. The recent paper \cite{FMN} provides a
complete list of integrable third order equations of this kind. Here we extend
the classification to fifth order equations. Besides the known examples of
Kadomtsev-Petviashvili (KP), Veselov-Novikov (VN) and Harry Dym (HD) equations,
as well as fifth order analogues and modifications thereof, our list contains a
number of equations which are apparently new. We conjecture that our examples
exhaust the list of scalar polynomial integrable equations with the nonlocality
$w$. The classification procedure consists of two steps. First, we classify
quasilinear systems which may (potentially) occur as dispersionless limits of
integrable scalar evolutionary equations. After that we reconstruct dispersive
terms based on the requirement of the inheritance of hydrodynamic reductions of
the dispersionless limit by the full dispersive equation.
