\begin{table}%T3
\caption{Nebular abundances for the very high mass CSPN of the
  PHM sample.}
\label{t:abund}
%\centerline
{\small
\begin{tabular}{lrlc}\hline\hline
PN           &He/H     &N/O     &$\log({\rm O/H})+12$ \\ \hline
IC~4593     &0.099    &0.047   &8.50\\
NGC~6826    &0.107    &0.10    &8.46\\
IC~418      &0.086    &0.13    &8.76\\
Hen~2-131   &         &0.38    &8.67\\
Hen~2-108$^{a}$ &$>$0.117   &0.28    &8.40\\
IC~1266$^{b}$     &0.074    &0.09    &8.71\\ \hline
%
type I       &0.137    &0.85    &8.66\\
type II-III  &0.103    &0.26    &8.66\\ \hline
\end{tabular}}

$^{a}$ \citet{TP1977}; $^{b}$ \citet{Phi2003}.
\end{table}